Background Dietary fat is important for energy provision and immune function of lactating sows and their progeny.However,knowledge on the impact of fat on mammary transcription of lipogenic genes,de novo fat synthesis...Background Dietary fat is important for energy provision and immune function of lactating sows and their progeny.However,knowledge on the impact of fat on mammary transcription of lipogenic genes,de novo fat synthesis,and milk fatty acid(FA)output is sparse in sows.This study aimed to evaluate impacts of dietary fat levels and FA composition on these traits in sows.Forty second-parity sows(Danish Landrace×Yorkshire)were assigned to 1 of 5 dietary treatments from d 108 of gestation until weaning(d 28 of lactation):low-fat control diet(3%added animal fat);or 1 of 4 high-fat diets with 8%added fat:coconut oil(CO),fish oil(FO),sunflower oil(SO),or 4%octanoic acid plus 4%FO(OFO).Three approaches were taken to estimate de novo milk fat synthesis from glucose and body fat.Results Daily intake of FA was lowest in low-fat sows within fat levels(P<0.01)and in OFO and FO sows within highfat diets(P<0.01).Daily milk outputs of fat,FA,energy,and FA-derived carbon reflected to a large extent the intake of those.On average,estimates for de novo fat synthesis were 82 or 194 g/d from glucose according to method 1 or 2 and 255 g de novo+mobilized FA/d according to method 3.The low-fat diet increased mammary FAS expression(P<0.05)and de novo fat synthesis(method 1;P=0.13)within fat levels.The OFO diet increased de novo fat synthesis(method 1;P<0.05)and numerically upregulated mammary FAS expression compared to the other high-fat diets.Across diets,a daily intake of 440 g digestible FA minimized milk fat originating from glucose and mobilized body fat.Conclusions Sows fed diets with low-fat or octanoic acid,through upregulating FAS expression,increased mammary de novo fat synthesis whereas the milk FA output remained low in sows fed the low-fat diet or high-fat OFO or FO diets,indicating that dietary FA intake,dietary fat level,and body fat mobilization in concert determine de novo fat synthesis,amount and profiles of FA in milk.展开更多
This experiment was conducted to investigate the effects of heat stress(HS) on the feed intake, milk production and composition and metabolic alterations in the mammary gland of dairy cows. Twenty Holstein cows were r...This experiment was conducted to investigate the effects of heat stress(HS) on the feed intake, milk production and composition and metabolic alterations in the mammary gland of dairy cows. Twenty Holstein cows were randomly assigned to one of two treatments according to a completely randomized design. Half of the cows were allocated to the HS group in August(summer season), and the other half were assigned to the HS-free group in November(autumn season). HS reduced(P<0.01) dry matter intake(DMI), milk yield, milk protein and milk urea nitrogen(MUN) of cows compared with HSfree control, but increased(P<0.01) milk somatic cell counts(SCC). We determined the HS-induced metabolic alterations and the relevant mechanisms in dairy cows using liquid chromatography mass spectrometry combined with multivariate analyses. Thirty-four metabolites were identified as potential biomarkers for the diagnosis of HS in dairy cows. Ten of these metabolites, glucose, lactate, pyruvate, lactose, β-hydroxybutyrate, citric acid, α-ketoglutarate, urea, creatine, and orotic acid, had high sensitivity and specificity for HS diagnoses, and seven metabolites were also identified as potential biomarkers of HS in plasma, milk, and liver. These substances are involved in glycolysis, lactose, ketone, tricarboxylic acid(TCA), amino acid and nucleotide metabolism, indicating that HS mainly affects lactose, energy and nucleotide metabolism in the mammary gland of lactating dairy cows. This study suggested that HS might affect milk production and composition by affecting the feed intake and substance metabolisms in the mammary gland tissue of lactating dairy cows.展开更多
The cow stock of smallholder farmers with less than 100 cows still accounted for nearly 50% of total cows in China. Since the milk scandal occurred in 2008, raw milk safety has become focus for the sound development o...The cow stock of smallholder farmers with less than 100 cows still accounted for nearly 50% of total cows in China. Since the milk scandal occurred in 2008, raw milk safety has become focus for the sound development of the Chinese dairy industry. Adoption of on-farm milk safety measures by smallholders is a key for ensuring milk safety, and these measures are largely voluntary in nature. The recent survey conducted in northern China reveals that an overall adoption rate of various milk safety measures by smallholders is close to 48% with wide variations across the dairy farmers. We employ the Poisson regression model to study the determinants of farmers' adoption of voluntary milk safety measures. Compared with backyard dairy farmers, dairy complex and scaled dairy farms adopted more milk safety measures. Moreover, the empirical result indicates that farmers' adoption of raw milk safety measures is positively affected by farm size. These findings suggest that the changing dairy production structure towards larger farms and away from backyard dairy farming prompts smallholder dairy farmers to adopt more raw milk safety measures. This lends some support to the role of recent policy initiatives towards larger farms and away from backyard dairy farming on increasing the farmers' milk safety practices and reducing on-farm incidence of milk safety.展开更多
Improved utilization of rice(Oryza sativa L.)straw and Chinese milk vetch(Astragalus sinicus L.,vetch)has positive effects on rice production.So far,few studies have investigated the productivity of vetch under differ...Improved utilization of rice(Oryza sativa L.)straw and Chinese milk vetch(Astragalus sinicus L.,vetch)has positive effects on rice production.So far,few studies have investigated the productivity of vetch under different residue management practices in double-rice cropping system.The effects of rice straw on the growth and nutrient accumulation of vetch across seven years(2011–2017)and the subsequent effects of rice straw and vetch on two succeeding rice crops in a vetch–rice–rice cropping system,with the vetch established by relay cropping,were examined.The seven-year double-rice experiment consisted of the following treatments:(1)100%chemical fertilizer(F-F100);(2)only vetch without chemical fertilizer(M-Con);(3)80%chemical fertilizer plus vetch plus a low-cutting height(low-retained stubble)with the removal of straw(M-F80);(4)80%chemical fertilizer plus vetch plus a low-cutting height with the retention of straw(M-F80-LR);(5)80%chemical fertilizer plus vetch plus a high-cutting height(high-retained stubble)with the retention of straw(M-F80-HR);and(6)no fertilizer(F-Con).The yields of the two rice crops after vetch were not affected by either the cutting height of stubble with retention of straw or by the management of straw(retention vs.removal)with low-cutting height of stubble.The yields of the two rice crops after vetch were significantly higher for M-F80-HR than for M-F80-LR,but the relative contributions of the high-cutting height and straw retention to the higher rice yield could not be determined in this study.The yield stability of the double-rice grain in M-F80-HR was also increased,as determined by a sustainable yield index.Significant increases in vetch biomass and nutrient uptake were observed in the fertilized treatments during the rice season compared with the unfertilized treatments.In M-F80-HR plots,improvements in the growing environment of the vetch by conserving soil water content were associated with the highest vetch biomass,nutrient uptake,and yield stability of vetch biomass.These increased nutrient inputs partially replaced the demand for chemical fertilizer and stimulated the rice yields.It can be concluded that retaining higher-cutting stubble residues with straw retention could be the best straw management practice for increasing the vetch biomass and nutrient use efficiency,thereby allowing utilization of high-cutting height with retention of straw and vetch to improve the stability of rice productivity in a double-rice cropping system.展开更多
Background:Previously,phosphoinositide-3-kinase regulatory subunit 1(PIK3R1)and dual specificity phosphatase 1(DUSP1)were identified as promising candidate genes for milk production traits due to their being different...Background:Previously,phosphoinositide-3-kinase regulatory subunit 1(PIK3R1)and dual specificity phosphatase 1(DUSP1)were identified as promising candidate genes for milk production traits due to their being differentially expressed between the dry period and the peak of lactation in livers of dairy cows.Hence,in this study,the single nucleotide polymorphisms(SNPs)of PIK3R1 and DUSP1 genes were identified and their genetic associations with milk yield,fat yield,fat percentage,protein yield,and protein percentage,were investigated using 1067 Chinese Holstein cows from 40 sire families.Results:By re-sequencing the entire coding region and 2000 bp of the 5′and 3′flanking regions of the two genes,one SNP in the 5′untranslated region(UTR),three in the 3′UTR,and two in the 3′flanking region of PIK3R1 were identified,and one in the 5′flanking region,one in the 3′UTR,and two in the 3′flanking region of DUSP1 were found.Subsequent single-locus association analyses showed that five SNPs in PIK3 R1,rs42590258,rs210389799,rs208819656,rs41255622,rs133655926,and rs211408208,and four SNPs in DUSP1,rs207593520,rs208460068,rs209154772,and rs210000760,were significantly associated with milk,fat and protein yields in the first or second lactation(P values≤0.0001 and 0.0461).In addition,by the Haploview 4.2 software,the six and four SNPs in PIK3R1 and DUSP1 respectively formed one haplotype block,and the haplotype-based association analyses showed significant associations between their haplotype combinations and the milk traits in both two lactations(P values≤0.0001 and 0.0364).One SNP,rs207593520(T/G),was predicted to alter the transcription factor binding sites(TFBSs)in the 5′flanking region of DUSP1.Further,the dual-luciferase assay showed that the transcription activity of allele T in rs207593520 was significantly higher than that of allele G,suggesting the activation of transcriptional activity of DUSP1 gene by allele T of rs207593520.Thus,the rs207593520 SNP was highlighted as a potential causal mutation that should be further verified.Conclusions:We demonstrated novel and significant genetic effects of the PIK3R1 and DUSP1 genes on milk production traits in dairy cows,and our findings provide information for use in dairy cattle breeding.展开更多
Milk is synthesized by mammary epithelial cel s of lactating mammals. The synthetic capacity of the mammary gland depends largely on the number and efficiency of functional mammary epithelial cel s. Structural develop...Milk is synthesized by mammary epithelial cel s of lactating mammals. The synthetic capacity of the mammary gland depends largely on the number and efficiency of functional mammary epithelial cel s. Structural development of the mammary gland occurs during fetal growth, prepubertal and post-pubertal periods, pregnancy, and lactation under the control of various hormones(particularly estrogen, growth hormone, insulin-like growth factor-I, progesterone, placental lactogen, and prolactin) in a species- and stage-dependent manner. Milk is essential for the growth, development, and health of neonates. Amino acids(AA), present in both free and peptide-bound forms, are the most abundant organic nutrients in the milk of farm animals. Uptake of AA from the arterial blood of the lactating dam is the ultimate source of proteins(primarily β-casein and α-lactalbumin) and bioactive nitrogenous metabolites in milk. Results of recent studies indicate extensive catabolism of branched-chain AA(leucine, isoleucine and valine) and arginine to synthesize glutamate,glutamine, alanine, aspartate, asparagine, proline, and polyamines. The formation of polypeptides from AA is regulated not only by hormones(e.g., prolactin, insulin and glucocorticoids) and the rate of blood flow across the lactating mammary gland, but also by concentrations of AA, lipids, glucose, vitamins and minerals in the maternal plasma, as well as the activation of the mechanistic(mammalian) target rapamycin signaling by certain AA(e.g.,arginine, branched-chain AA, and glutamine). Knowledge of AA utilization(including metabolism) by mammary epithelial cells will enhance our fundamental understanding of lactation biology and has important implications for improving the efficiency of livestock production worldwide.展开更多
Age at first calving (AFC) affects the profitability of dairy enterprises. This study examined the relationships between AFC and subsequent fertility, milk production and survival up to third calving in UK Holstein-Fr...Age at first calving (AFC) affects the profitability of dairy enterprises. This study examined the relationships between AFC and subsequent fertility, milk production and survival up to third calving in UK Holstein-Friesian heifers;Study 1 comprised 134 consecutively born heifers from the same herd (AFC 764 ± 8 days) and Study 2 contained 445 heifers born on 17 farms (AFC 796 ± 6 days). Growth rates and fertility during rearing were monitored and animals were subsequently divided into four AFC groups for analysis: <23 months, 23 - 25 months, 26 - 30 months and >30 months. The actual AFC reflected both growth rate and heifer fertility, with later calving heifers already lighter by 6 months of age. The proportion conceiving to first service was highest (93% and 84% for Studies 1 and 2, respectively) for the youngest AFC group. Fertility in the first lactation was best in cows calving at 23 - 25 months and worst in the oldest AFC group. Milk production parameters in the first and second lactations were broadly similar between AFC groups but significantly more heifers with an AFC < 26 months calved for a third time. These younger calving animals therefore achieved more days in milk over 5 years, with >44% of their days alive spent in milk production compared with only 18% - 40% in cows calving at ≥26 months. Hence cows with an AFC < 26 months produced the most milk in their first 5 years of life. These results indicate that an AFC of 0.75 kg/d up to 15 months and good heifer fertility and resulted in the best subsequent performance.展开更多
A cross-sectional study was carried out to assess hygienic production and postharvest handling practices of raw camel milk in Degahbour district. The survey studies were based on a total of 120 (2 production systems *...A cross-sectional study was carried out to assess hygienic production and postharvest handling practices of raw camel milk in Degahbour district. The survey studies were based on a total of 120 (2 production systems * 2 rural kebele * 30 households) milk producers, which were selected from Degahbur district using stratified sampling technique. Data from the selected producers were collected using questionnaire survey and field observation. The results showed that the majority of the sampled household heads in pastoral (93.3%) and agro-pastoral (76.6%) production systems were illiterate. Moreover, none of the respondents in the study area had training on hygienic milk production and postharvest handling practices. The study result also indicated that none of the respondents in the study area washed the udder of milking camel before milking. Moreover, only 6.6% of pastoralists and 25% of agro-pastoralists wash their hands before milking. Equipment made of wooden materials are mainly used for milking, whereas, plastic jerry-cans were most commonly used for storage. About 45% of the pastoralists and 81.6% of the agro-pastoralists were cleaning milk vessels regularly;however, majority of the respondents both production systems were using water from non-tap sources for hygienic practices. Bosciaminimifolia, Acacia ethaica and Blanitesgalabra were the most commonly used plant species for smoking in the study area. Therefore, hygienic production and postharvest handling practices should be followed to improve the quality and suitability of camel milk for its intended use in the study area.展开更多
Background:Phosphorus(P) supplementation is costly and can result in excess P excretion.This study investigated the effects of reducing dietary P on milk production and P excretion in dairy cows over a full lactation....Background:Phosphorus(P) supplementation is costly and can result in excess P excretion.This study investigated the effects of reducing dietary P on milk production and P excretion in dairy cows over a full lactation.Method:Forty-five multiparous Holstein dairy cows were divided into 15 blocks according to expected calving date and previous milk yield,and assigned randomly to one of the three dietary treatments:0.37,0.47,and 0.57%P(DM basis);these P levels represent the NRC recommendations,Chinese recommendations,and the amount of dietary P commonly fed by Chinese dairy farmers,respectively.Average daily feed intake was calculated from monthly data on feed offered and refused.Milk yields of individual cows were recorded weekly,and milk samples were taken for analysis of protein,fat,solids-not-fat,lactose,and somatic cell count.Blood samples were collected on days-6,-3,0,3,6 relative to calving,and then monthly throughout lactation,and analyzed for P and Ca concentrations.Spot samples of feces and urine were collected for 3 consecutive d during weeks 12,24,and 36,and P concentrations were analyzed.Reproduction and health data were recorded.Results:Dietary P did not affect dry matter intake or milk yield(P> 0.10).Milk fat content was slightly higher in cows fed 0.37%P than in cows fed 0.47%P(P = 0.05).Serum concentrations of P and Ca did not reflect dietary P content(P> 0.10).Fecal and urinary P both declined linearly(P< 0.05) as dietary P decreased from 0.57 to0.37%.Fecal P content was 25%less when dietary P was 0.37%compared to 0.57%.Health events and reproductive performance were not associated with dietary P content(P> 0.05).Conclusions:Lowering dietary P from 0.57 to 0.37%did not negatively affect milk production,but did significantly reduce P excretion into environment.展开更多
In this study, polymorphisms of the DGAT1 andSTAT5A genes were detected in 528 individuals from Xinong Saanen and Guanzhong goat breeds by PCR-RFLP, PCR-SSCP and DNA sequencing methods. Three allelic variants were ide...In this study, polymorphisms of the DGAT1 andSTAT5A genes were detected in 528 individuals from Xinong Saanen and Guanzhong goat breeds by PCR-RFLP, PCR-SSCP and DNA sequencing methods. Three allelic variants were identified: DQ380250: g.407_408insC, AJ237937: g.6798C>T and g.6852C>T in both breeds. At g.407_408insC locus, the frequencies of C1 allele were 0.79–0.85, and frequencies of C2 allele were 0.21–0.15. At g.6852C>T locus, frequencies of C3 allele were 0.70–0.72, and frequencies of T3 allele were 0.30–0.28. Compared with goats with C1C1 and C3C3, those with C1C2 and C3T3 genotypes had significant effects on milk yield and fat percentage (P<0.05), respectively. The result showed that does with C1C1C3T3 and C1C2C3T3 had higher milk yield than those with C1C2C3C3 (P < 0.05). In addition, the combined effect of C1C2C3C3 on milk fat percentage was the highest in comparison with other combination genotypes (P<0.05).展开更多
Our previous studies demonstrated that the region around markers BMS470 and BMS1242 on BTA6 showed a linkage to 305-d milk yield and composition traits in the Chinese Holstein population. We herein focused on such nar...Our previous studies demonstrated that the region around markers BMS470 and BMS1242 on BTA6 showed a linkage to 305-d milk yield and composition traits in the Chinese Holstein population. We herein focused on such narrow region to fine map milk production QTLs with 15 SNPs across 25 Mb with each SNP in 1 Mb within most regions in a Chinese Holstein population with daughter design. 1 449 Holstein cows and 11 sires were genotyped for such SNPs by using TaqMan probe and RFLP assays. Multipoint linkage analysis across family revealed a QTL affecting milk yield between PPARGC1A C4075T and SLC34A2 T1713C. Meanwhile, within family analysis found three milk yield QTLs (two in CR T60984131G-CEP135 C501T and one in PDLIM5 A106C-OPN T3907, a fat yield QTLin UGDH T1670C-CR T60984131G region, and two protein yield QTLs in TBC1D1 G501C-UGDH T1670C and PPARGC1A C4075T-SLC34A2 T1713C, respectively. Associations between aforementioned significant SNP markers and milk production traits were further implemented. We found significant associations of PPARGC1A C4075T, SLC34A2 T1713C with milk yield (P<0.05, P<0.01, P<0.01), UGDH T1670C, and CR T60984131G with fat yield (P<0.01, P<0.01), and PPARGC1A C4075T, SLC34A2 T1713C, UGDH T1670C and OPN T3907 with protein yield (P<0.01, P<0.01, P<0.01, P<0.01). Our findings implied that QTLs affecting milk production traits on BTA6 were pleictropism or multigenic effect and PPARGC1A and OPN may be the causal mutations behind milk production QTLs on BTA6 in the Chinese Holstein population.展开更多
Background: Populations of Gontougo (C?te d’Ivoire) commonly used Euphorbia hirta (Euphorbiaceae) leaves as galactagogue to boost milk production in lactating women. Our study was carried to verify this traditional b...Background: Populations of Gontougo (C?te d’Ivoire) commonly used Euphorbia hirta (Euphorbiaceae) leaves as galactagogue to boost milk production in lactating women. Our study was carried to verify this traditional belief via evaluations of milk production, serum prolactin levels, body weight and mammary lobuloalveolar proliferation induced by the aqueous leaf extract of this medicinal plant in Wistar rats. Methods: 6 groups of 6 virgin rats and 6 groups of 6 lactating rats were used. Each lactating rat was isolated with its six pups. These groups of animals were treated orally with distilled water, Metoclopramide (Metocl 5 mg/kg) and E. hirta aqueous leaf extract (EHae 100, 200, 400 and 600 mg/kg) daily during 17 days of lactation. The indirect method which assimilates the weight gain of untreated pups to the quantity of milk produced by lactating rats was used. At the end of the treatment, histological sections of the abdominal mammary glands of lactating rats were observed. Results: EHae administration induced an increase of milk production in lactating rats. This action of EHae was stronger at the dose of 200 mg/kg. Milk production of the treated rats at a dose of 200 mg/kg was 118.14 ± 1 g. The quantity of milk produced by the control female rats was 83.83 ± 0.88 g. Compared with the control, EHae 200 mg/kg significantly increased milk production (40.92%) (P Conclusion: EHae showed a galactagogue activity illustrated by increases of milk production, PRL secretions and the development of the lobuloalveolar system of the mammary glands in treated female rats. This galactagogue property could partly justify the traditional use of this plant to boost milk production in lactating women.展开更多
Background:Economically important milk production traits including milk volume,milk fat and protein yield vary considerably across dairy goats in New Zealand.A significant portion of the variation is attributable to g...Background:Economically important milk production traits including milk volume,milk fat and protein yield vary considerably across dairy goats in New Zealand.A significant portion of the variation is attributable to genetic variation.Discovery of genetic markers linked to milk production traits can be utilised to drive selection of highperformance animals.A previously reported genome wide association study across dairy goats in New Zealand identified a quantitative trait locus(QTL)located on chromosome 19.The most significantly associated single nucleotide polymorphism(SNP)marker for this locus is located at position 26,610,610(SNP marker rs268292132).This locus is associated with multiple milk production traits including fat,protein and volume.The predicted effect of selection for the beneficial haplotype would result in an average production increase of 2.2 kg fat,1.9 kg protein and 73.6 kg milk yield.An outstanding question was whether selection for the beneficial allele would co-select for any negative pleiotropic effects.An adverse relationship between milk production and udder health traits has been reported at this locus.Therefore,a genome wide association study was undertaken looking for loci associated with udder traits.Results:The QTL and production associated marker rs268292132 was identified in this study to also be associated with several goat udder traits including udder depth(UD),fore udder attachment(FUA)and rear udder attachment(RUA).Our study replicates the negative relationship between production and udder traits with the high production allele at position 19:26,610,610(SNP marker rs268292132)associated with an adverse change in UD,FUA and RUA.Conclusions:Our study has confirmed the negative relationship between udder traits and production traits in the NZ goat population.We have found that the frequency of the high production allele is relatively high in the NZ goat population,indicating that its effect on udder conformation is not significantly detrimental on animal health.It will however be important to monitor udder conformation as the chromosome 19 locus is progressively implemented for marker assisted selection.It will also be of interest to determine if the gene underlying the production QTL has a direct effect on mammary gland morphology or whether the changes observed are a consequence of the increased milk volume.展开更多
Goats are one of the oldest domesticated animal species widely distributed in the world playing an important role in the food production system in Sub-Saharan African Region (SSAR). Due to their multiple uses (milk pr...Goats are one of the oldest domesticated animal species widely distributed in the world playing an important role in the food production system in Sub-Saharan African Region (SSAR). Due to their multiple uses (milk production, meat, fiber and hides) and adaptation aptitudes to ecological conditions, goats produce and contribute positively to farmers’ socio-economy status in various production systems. This review aimed at giving a summary overview on the goat’s production systems characteristics, the genetic diversity and the candidate genes affecting reproductive and milk production performances in goat breeds in SSAR. It has been observed that traditional livestock production system with communal grazing system is the most used in goat keeping in SSAR. The geographical locations play an important role in the relationships between goat’s distributions in the region. At the same time, goats might have been differentiated and isolated one to others due to the wide geographic range, the diversify climate and the topography in the region. Among the six worldwide known haplogroups of goat (A, B, C, D, G and F), haplogroup A is the most representative in SSAR. However, haplogroup G and B can be found in some goat populations in some countries in east (Kenya and Ethiopia) and south parts of Africa. This review reveals that little is known on the candidate genes associated with prolificacy and milk production traits in indigenous goat breeds in the region. That observation suggests the importance of assessing candidate genes associated with economic traits in the populations of goat in SSAR.展开更多
The aim of the study was to determine the effect of supplementing an oat winter pasture with a total mixed ration (TMR) on lactation performance of dairy cows. Nine multiparous Holstein cows were used in a 3 × 3 ...The aim of the study was to determine the effect of supplementing an oat winter pasture with a total mixed ration (TMR) on lactation performance of dairy cows. Nine multiparous Holstein cows were used in a 3 × 3 Latin square design with three TMR: pasture ratios at 79:21 (T1), 58:42 (T2) and 33:67 (T3) on a dry matter (DM) basis. The response to the 100% TMR diet (TMR-100) was tested using an extra period of 14 days inmediately after finishing the Latin square schedule using the nine experimental cows. Total DM intake resulted higher in TMR-100 (28.2 (kg/cow·day) and decreased by 2.64 kg/cow·day in T1, 5.02 kg in T2 and 6.68 kg in T3. Yields of milk (31.2 kg/cow·day) and fat corrected milk (26.8 kg/cow·day) was similar between T1, T2 and T3. Milk yield resulted higher in TMR-100 (32.1 kg/cow·day) compared to T2 (30.7 kg/cow·day). Milk fat concentration (g/100 g) was higher in T2 (3.13) and T3 (3.20) compared to T1 (2.96) and TMR-100 (2.85) and milk fat yield did not differ. Milk protein content resulted higher in TMR-100 and T2 averaging 3.37 g/100 g compared to T1 (3.32 g/100 g). The lowest milk protein concentration was observed in T3 (3.29 g/100 g) that resulted only different to T2. Milk protein yield did not differ between T1, T2 and T3 averaging 1.03 kg/cow·day. A lower protein yield was detected in T2 (1.03) and T3 (1.00) when compared to TMR-100 (1.07). Efficiency of milk production (kg milk/kg DM intake) resulted higher in T3 (1.42) compared to T1 (1.25). Treatments that included pasture yielded a higher efficiency of milk production when compared to TMR-100 (1.13). Plasma urea concentration resulted lower in TMR-100 (33.8 mg/dl) with no significant differences for this parameter between the other treatments. Glucose plasma levels did not differ between T1, T2 and T3 but plasma non-esterified fatty acids (NEFA) gradually increased as the proportion of pasture was enhanced according to the lower energy intake. Plasma insulin levels were higher in TMR-100 and T2 whereas concentration of somatomedins (IGF-1) remained unaffected. Grouth hormone (GH) levels and the GH/insulin ratio were highly variable and not affected by treatments. Concentration of vaccenic and conjugated linoleic acids gradually increased with the inclusion of pasture in the diet. Supplementing a winter oat pasture with TMR may be a suitable strategy to maintain milk production with a high conversion efficiency but part of the produced milk could be sustained at the expense of endogenous energy mobilization. The conditions of replacing pasture for TMR in high yielding dairy cows should be defined taking into account the depressing effect of pasture on total DM and energy intake when fresh forage is included in high proportion in the diet.展开更多
A cross-sectional study was carried out to assess handling and hygienic production practices of goat milk in Degahbur district of Jarar zone, Somali Regional State, Ethiopia. A total of 120 households were purposively...A cross-sectional study was carried out to assess handling and hygienic production practices of goat milk in Degahbur district of Jarar zone, Somali Regional State, Ethiopia. A total of 120 households were purposively selected for this study using a stratified sampling technique. The data were collected through the questionnaire, field observations, key informants interview and focus group discussions. The study showed that majority of the sampled households were illiterate. The goats were kept in an open kraal made of thorny acacia trees on an earthen floor that had no roof. The goats were milked inside these open kraals, and were sometimes contaminated with muck and animal dung mainly the rainy season which could raise the possibility of milk contamination & spoilage. Moreover, traditional hand milking was the only milking method and majority of the respondents didn’t wash their hands and the udder of the animal before milking, indicating low community awareness and knowledge of sanitary milk production procedures. Plastic equipment which is difficult to clean and can increase milk contamination and spoilage was used. About 43.3% of the pastoralists and 76.67% of the agro-pastoralists were cleaning milk vessels regularly. The most often used plant species for smoking milk handling equipment in the study area to extend shelf life and add flavor & aroma were Acacia ethaica, Blanites galabra, and Solanum Carense. The main constraints to hygienic goat milk in the area were identified to be poor barn hygiene, poor production procedures, disease, source of washing water and lack of extension services. In general, it can be concluded that handling and hygienic production practices of goat milk used in the study area were unsanitary, which may have been primarily caused by the community’s lack of awareness & understanding as well as a lack of supporting infrastructures. Therefore, the concerned bodies should place a high priority on the improvement of hygienic practices by carrying out various relevant development interventions, such as raising milk producers’ awareness, improving the health of goats, and providing the necessities for milk handling.展开更多
Background:Transformation of feed energy ingested by ruminants into milk is accompanied by energy losses via fecal and urine excretions,fermentation gases and heat.Heat production may differ among dairy cows despite c...Background:Transformation of feed energy ingested by ruminants into milk is accompanied by energy losses via fecal and urine excretions,fermentation gases and heat.Heat production may differ among dairy cows despite comparable milk yield and body weight.Therefore,heat production can be considered an indicator of metabolic efficiency and directly measured in respiration chambers.The latter is an accurate but time-consuming technique.In contrast,milk Fourier transform mid-infrared(FTIR)spectroscopy is an inexpensive high-throughput method and used to estimate different physiological traits in cows.Thus,this study aimed to develop a heat production prediction model using heat production measurements in respiration chambers,milk FTIR spectra and milk yield measurements from dairy cows.Methods:Heat production was computed based on the animal’s consumed oxygen,and produced carbon dioxide and methane in respiration chambers.Heat production data included 16824-h-observations from 64 German Holstein and 20 dual-purpose Simmental cows.Animals were milked twice daily at 07:00 and 16:30 h in the respiration chambers.Milk yield was determined to predict heat production using a linear regression.Milk samples were collected from each milking and FTIR spectra were obtained with MilkoScan FT 6000.The average or milk yield-weighted average of the absorption spectra from the morning and afternoon milking were calculated to obtain a computed spectrum.A total of 288 wavenumbers per spectrum and the corresponding milk yield were used to develop the heat production model using partial least squares(PLS)regression.Results:Measured heat production of studied animals ranged between 712 and 1470 kJ/kg BW0.75.The coefficient of determination for the linear regression between milk yield and heat production was 0.46,whereas it was 0.23 for the FTIR spectra-based PLS model.The PLS prediction model using weighted average spectra and milk yield resulted in a cross-validation variance of 57%and a root mean square error of prediction of 86.5 kJ/kg BW0.75.The ratio of performance to deviation(RPD)was 1.56.Conclusion:The PLS model using weighted average FTIR spectra and milk yield has higher potential to predict heat production of dairy cows than models applying FTIR spectra or milk yield only.展开更多
The experiment was conducted on 10 small-holder dairy farmers under the administration of Dairy Promotion Organization of Thailand (DPO) in the Northeast region of Thailand. The aim of the research was to investigate ...The experiment was conducted on 10 small-holder dairy farmers under the administration of Dairy Promotion Organization of Thailand (DPO) in the Northeast region of Thailand. The aim of the research was to investigate the effect of legume (Phaseolus calcaratus, PC) as roughage mixed with Ruzi grass for dairy cows. Fours cows per farm were assigned into 2 groups including Ruzi grass (control) and PC mixed with ruzi grass (at the ratio 50:50), were given ad libitum as a roughage sources. All cows were offered a concentrate with ratio to milk yield of 1:2. The results revealed that roughage source did not affect on ruminal pH and temperature, ammonia nitrogen, blood urea nitrogen, and milk urea nitrogen concentrations. Total volatile fatty acid, acetic acid, propionic acid, and butyric acid proportions, and acetic acid to propionic acid ratio were not significantly different among treatments. Dry matter intake and digestibility of nutrient including dry matter, organic matter, crude protein, neutral detergent fiber and acid detergent fiber were not significantly different among treatments. Moreover, amount of digested dry mater was similar among treatments. However, cows received PC mixed with Ruzi grass tended to be higher on dry matter, organic matter, and crude protein digestibility and dry matter digestible nutrient intake than control group. Milk yield, and 3.5% fat corrected milk were significantly higher (P < 0.05) in cow fed with PC mixed Ruzi grass than those the control group. Milk compositions and feed cost were similar among treatments;in contrast, the income and profit from milk selling were greater in cows fed with PC mixed with Ruzi grass than the control. High quality roughage such as PC mixed with Ruzi grass could be advantages for dairy farming in the Northeast of Thailand.展开更多
The purpose of the study is to measure the "growth drag" according to the characteristic of Chinese land resource.Romer model (2001) holds that every country is inevitably affected by the "growth drag&q...The purpose of the study is to measure the "growth drag" according to the characteristic of Chinese land resource.Romer model (2001) holds that every country is inevitably affected by the "growth drag" due to the limitation of land resource.So it's of profound strategic significance to measure the "growth drag" according to the character of Chinese land resource.Modified two-level CES production function was employed,and this paper modified the hypothesis of the model.The result indicates that the limitation of Chinese land resource casts shadow over the economic development of China,and the growth rate is 0.4618% lower than that without the limitation of land resource.Through implementing the land resource protection policy along with the technology improvement and the substitute effect of other factors to the land resource,China will keep a steady and balanced economic growth.展开更多
基金Financially supported by the Danish Council for Independent Research,Technology and Production Sciences (Copenhagen K,Denmark)。
文摘Background Dietary fat is important for energy provision and immune function of lactating sows and their progeny.However,knowledge on the impact of fat on mammary transcription of lipogenic genes,de novo fat synthesis,and milk fatty acid(FA)output is sparse in sows.This study aimed to evaluate impacts of dietary fat levels and FA composition on these traits in sows.Forty second-parity sows(Danish Landrace×Yorkshire)were assigned to 1 of 5 dietary treatments from d 108 of gestation until weaning(d 28 of lactation):low-fat control diet(3%added animal fat);or 1 of 4 high-fat diets with 8%added fat:coconut oil(CO),fish oil(FO),sunflower oil(SO),or 4%octanoic acid plus 4%FO(OFO).Three approaches were taken to estimate de novo milk fat synthesis from glucose and body fat.Results Daily intake of FA was lowest in low-fat sows within fat levels(P<0.01)and in OFO and FO sows within highfat diets(P<0.01).Daily milk outputs of fat,FA,energy,and FA-derived carbon reflected to a large extent the intake of those.On average,estimates for de novo fat synthesis were 82 or 194 g/d from glucose according to method 1 or 2 and 255 g de novo+mobilized FA/d according to method 3.The low-fat diet increased mammary FAS expression(P<0.05)and de novo fat synthesis(method 1;P=0.13)within fat levels.The OFO diet increased de novo fat synthesis(method 1;P<0.05)and numerically upregulated mammary FAS expression compared to the other high-fat diets.Across diets,a daily intake of 440 g digestible FA minimized milk fat originating from glucose and mobilized body fat.Conclusions Sows fed diets with low-fat or octanoic acid,through upregulating FAS expression,increased mammary de novo fat synthesis whereas the milk FA output remained low in sows fed the low-fat diet or high-fat OFO or FO diets,indicating that dietary FA intake,dietary fat level,and body fat mobilization in concert determine de novo fat synthesis,amount and profiles of FA in milk.
基金supported financially by the National Key Research and Development Program of China (2016YFD0500503)the Shanghai Science and Technology Promotion Project for Agriculture (Shanghai Agriculture Science Promotion Project (2019) No. 1-2)
文摘This experiment was conducted to investigate the effects of heat stress(HS) on the feed intake, milk production and composition and metabolic alterations in the mammary gland of dairy cows. Twenty Holstein cows were randomly assigned to one of two treatments according to a completely randomized design. Half of the cows were allocated to the HS group in August(summer season), and the other half were assigned to the HS-free group in November(autumn season). HS reduced(P<0.01) dry matter intake(DMI), milk yield, milk protein and milk urea nitrogen(MUN) of cows compared with HSfree control, but increased(P<0.01) milk somatic cell counts(SCC). We determined the HS-induced metabolic alterations and the relevant mechanisms in dairy cows using liquid chromatography mass spectrometry combined with multivariate analyses. Thirty-four metabolites were identified as potential biomarkers for the diagnosis of HS in dairy cows. Ten of these metabolites, glucose, lactate, pyruvate, lactose, β-hydroxybutyrate, citric acid, α-ketoglutarate, urea, creatine, and orotic acid, had high sensitivity and specificity for HS diagnoses, and seven metabolites were also identified as potential biomarkers of HS in plasma, milk, and liver. These substances are involved in glycolysis, lactose, ketone, tricarboxylic acid(TCA), amino acid and nucleotide metabolism, indicating that HS mainly affects lactose, energy and nucleotide metabolism in the mammary gland of lactating dairy cows. This study suggested that HS might affect milk production and composition by affecting the feed intake and substance metabolisms in the mammary gland tissue of lactating dairy cows.
基金supported by the National Natural Science Foundation of China (71361140369)
文摘The cow stock of smallholder farmers with less than 100 cows still accounted for nearly 50% of total cows in China. Since the milk scandal occurred in 2008, raw milk safety has become focus for the sound development of the Chinese dairy industry. Adoption of on-farm milk safety measures by smallholders is a key for ensuring milk safety, and these measures are largely voluntary in nature. The recent survey conducted in northern China reveals that an overall adoption rate of various milk safety measures by smallholders is close to 48% with wide variations across the dairy farmers. We employ the Poisson regression model to study the determinants of farmers' adoption of voluntary milk safety measures. Compared with backyard dairy farmers, dairy complex and scaled dairy farms adopted more milk safety measures. Moreover, the empirical result indicates that farmers' adoption of raw milk safety measures is positively affected by farm size. These findings suggest that the changing dairy production structure towards larger farms and away from backyard dairy farming prompts smallholder dairy farmers to adopt more raw milk safety measures. This lends some support to the role of recent policy initiatives towards larger farms and away from backyard dairy farming on increasing the farmers' milk safety practices and reducing on-farm incidence of milk safety.
基金supported by the earmarked fund of China Agriculture Research System(CARS-22)the Key R&D Projects in Hunan Province,China(2017NK2051)+1 种基金the National Key R&D Program of China(2017YFD0301504 and 2018YFD03006)the Hunan Agricultural Science and Technology Innovation Fund Project,China(2018zd06)。
文摘Improved utilization of rice(Oryza sativa L.)straw and Chinese milk vetch(Astragalus sinicus L.,vetch)has positive effects on rice production.So far,few studies have investigated the productivity of vetch under different residue management practices in double-rice cropping system.The effects of rice straw on the growth and nutrient accumulation of vetch across seven years(2011–2017)and the subsequent effects of rice straw and vetch on two succeeding rice crops in a vetch–rice–rice cropping system,with the vetch established by relay cropping,were examined.The seven-year double-rice experiment consisted of the following treatments:(1)100%chemical fertilizer(F-F100);(2)only vetch without chemical fertilizer(M-Con);(3)80%chemical fertilizer plus vetch plus a low-cutting height(low-retained stubble)with the removal of straw(M-F80);(4)80%chemical fertilizer plus vetch plus a low-cutting height with the retention of straw(M-F80-LR);(5)80%chemical fertilizer plus vetch plus a high-cutting height(high-retained stubble)with the retention of straw(M-F80-HR);and(6)no fertilizer(F-Con).The yields of the two rice crops after vetch were not affected by either the cutting height of stubble with retention of straw or by the management of straw(retention vs.removal)with low-cutting height of stubble.The yields of the two rice crops after vetch were significantly higher for M-F80-HR than for M-F80-LR,but the relative contributions of the high-cutting height and straw retention to the higher rice yield could not be determined in this study.The yield stability of the double-rice grain in M-F80-HR was also increased,as determined by a sustainable yield index.Significant increases in vetch biomass and nutrient uptake were observed in the fertilized treatments during the rice season compared with the unfertilized treatments.In M-F80-HR plots,improvements in the growing environment of the vetch by conserving soil water content were associated with the highest vetch biomass,nutrient uptake,and yield stability of vetch biomass.These increased nutrient inputs partially replaced the demand for chemical fertilizer and stimulated the rice yields.It can be concluded that retaining higher-cutting stubble residues with straw retention could be the best straw management practice for increasing the vetch biomass and nutrient use efficiency,thereby allowing utilization of high-cutting height with retention of straw and vetch to improve the stability of rice productivity in a double-rice cropping system.
基金financially supported by the National Natural Science Foundation of China(31872330,31802041)Beijing Dairy Industry Innovation Team(BAIC06–2018/2019)+3 种基金Beijing Science and Technology Program(D171100002417001)National Science and Technology Programs of China(2013AA102504)earmarked fund for Modern Agro-industry Technology Research System(CARS-36)the Program for Changjiang Scholar and Innovation Research Team in University(IRT_15R62).
文摘Background:Previously,phosphoinositide-3-kinase regulatory subunit 1(PIK3R1)and dual specificity phosphatase 1(DUSP1)were identified as promising candidate genes for milk production traits due to their being differentially expressed between the dry period and the peak of lactation in livers of dairy cows.Hence,in this study,the single nucleotide polymorphisms(SNPs)of PIK3R1 and DUSP1 genes were identified and their genetic associations with milk yield,fat yield,fat percentage,protein yield,and protein percentage,were investigated using 1067 Chinese Holstein cows from 40 sire families.Results:By re-sequencing the entire coding region and 2000 bp of the 5′and 3′flanking regions of the two genes,one SNP in the 5′untranslated region(UTR),three in the 3′UTR,and two in the 3′flanking region of PIK3R1 were identified,and one in the 5′flanking region,one in the 3′UTR,and two in the 3′flanking region of DUSP1 were found.Subsequent single-locus association analyses showed that five SNPs in PIK3 R1,rs42590258,rs210389799,rs208819656,rs41255622,rs133655926,and rs211408208,and four SNPs in DUSP1,rs207593520,rs208460068,rs209154772,and rs210000760,were significantly associated with milk,fat and protein yields in the first or second lactation(P values≤0.0001 and 0.0461).In addition,by the Haploview 4.2 software,the six and four SNPs in PIK3R1 and DUSP1 respectively formed one haplotype block,and the haplotype-based association analyses showed significant associations between their haplotype combinations and the milk traits in both two lactations(P values≤0.0001 and 0.0364).One SNP,rs207593520(T/G),was predicted to alter the transcription factor binding sites(TFBSs)in the 5′flanking region of DUSP1.Further,the dual-luciferase assay showed that the transcription activity of allele T in rs207593520 was significantly higher than that of allele G,suggesting the activation of transcriptional activity of DUSP1 gene by allele T of rs207593520.Thus,the rs207593520 SNP was highlighted as a potential causal mutation that should be further verified.Conclusions:We demonstrated novel and significant genetic effects of the PIK3R1 and DUSP1 genes on milk production traits in dairy cows,and our findings provide information for use in dairy cattle breeding.
基金supported by Texas A&M Agri Life Research (H-8200)The Agriculture and Food Research Initiative Competitive Grant from the Animal Growth & Nutrient Utilization Program of the USDA National Institute of Food and Agriculture (2014-67015-21770)+4 种基金National Basic Research Program of China (2012CB126305)National Natural Science Foundation of China (31572412 and 31272450)the 111 Project (B16044)Natural Science Foundation of Hubei Province (2013CFA097 and 2013CFB325)Hubei Hundred Talent program
文摘Milk is synthesized by mammary epithelial cel s of lactating mammals. The synthetic capacity of the mammary gland depends largely on the number and efficiency of functional mammary epithelial cel s. Structural development of the mammary gland occurs during fetal growth, prepubertal and post-pubertal periods, pregnancy, and lactation under the control of various hormones(particularly estrogen, growth hormone, insulin-like growth factor-I, progesterone, placental lactogen, and prolactin) in a species- and stage-dependent manner. Milk is essential for the growth, development, and health of neonates. Amino acids(AA), present in both free and peptide-bound forms, are the most abundant organic nutrients in the milk of farm animals. Uptake of AA from the arterial blood of the lactating dam is the ultimate source of proteins(primarily β-casein and α-lactalbumin) and bioactive nitrogenous metabolites in milk. Results of recent studies indicate extensive catabolism of branched-chain AA(leucine, isoleucine and valine) and arginine to synthesize glutamate,glutamine, alanine, aspartate, asparagine, proline, and polyamines. The formation of polypeptides from AA is regulated not only by hormones(e.g., prolactin, insulin and glucocorticoids) and the rate of blood flow across the lactating mammary gland, but also by concentrations of AA, lipids, glucose, vitamins and minerals in the maternal plasma, as well as the activation of the mechanistic(mammalian) target rapamycin signaling by certain AA(e.g.,arginine, branched-chain AA, and glutamine). Knowledge of AA utilization(including metabolism) by mammary epithelial cells will enhance our fundamental understanding of lactation biology and has important implications for improving the efficiency of livestock production worldwide.
文摘Age at first calving (AFC) affects the profitability of dairy enterprises. This study examined the relationships between AFC and subsequent fertility, milk production and survival up to third calving in UK Holstein-Friesian heifers;Study 1 comprised 134 consecutively born heifers from the same herd (AFC 764 ± 8 days) and Study 2 contained 445 heifers born on 17 farms (AFC 796 ± 6 days). Growth rates and fertility during rearing were monitored and animals were subsequently divided into four AFC groups for analysis: <23 months, 23 - 25 months, 26 - 30 months and >30 months. The actual AFC reflected both growth rate and heifer fertility, with later calving heifers already lighter by 6 months of age. The proportion conceiving to first service was highest (93% and 84% for Studies 1 and 2, respectively) for the youngest AFC group. Fertility in the first lactation was best in cows calving at 23 - 25 months and worst in the oldest AFC group. Milk production parameters in the first and second lactations were broadly similar between AFC groups but significantly more heifers with an AFC < 26 months calved for a third time. These younger calving animals therefore achieved more days in milk over 5 years, with >44% of their days alive spent in milk production compared with only 18% - 40% in cows calving at ≥26 months. Hence cows with an AFC < 26 months produced the most milk in their first 5 years of life. These results indicate that an AFC of 0.75 kg/d up to 15 months and good heifer fertility and resulted in the best subsequent performance.
文摘A cross-sectional study was carried out to assess hygienic production and postharvest handling practices of raw camel milk in Degahbour district. The survey studies were based on a total of 120 (2 production systems * 2 rural kebele * 30 households) milk producers, which were selected from Degahbur district using stratified sampling technique. Data from the selected producers were collected using questionnaire survey and field observation. The results showed that the majority of the sampled household heads in pastoral (93.3%) and agro-pastoral (76.6%) production systems were illiterate. Moreover, none of the respondents in the study area had training on hygienic milk production and postharvest handling practices. The study result also indicated that none of the respondents in the study area washed the udder of milking camel before milking. Moreover, only 6.6% of pastoralists and 25% of agro-pastoralists wash their hands before milking. Equipment made of wooden materials are mainly used for milking, whereas, plastic jerry-cans were most commonly used for storage. About 45% of the pastoralists and 81.6% of the agro-pastoralists were cleaning milk vessels regularly;however, majority of the respondents both production systems were using water from non-tap sources for hygienic practices. Bosciaminimifolia, Acacia ethaica and Blanitesgalabra were the most commonly used plant species for smoking in the study area. Therefore, hygienic production and postharvest handling practices should be followed to improve the quality and suitability of camel milk for its intended use in the study area.
基金supported by the earmarked fund for China Agriculture Research System(CARS-37)the National Key Technologies R&D Program of China(2012BAD12B02)the Special Fund for Agro-scientific Research in the Public Interest(No.201303143)
文摘Background:Phosphorus(P) supplementation is costly and can result in excess P excretion.This study investigated the effects of reducing dietary P on milk production and P excretion in dairy cows over a full lactation.Method:Forty-five multiparous Holstein dairy cows were divided into 15 blocks according to expected calving date and previous milk yield,and assigned randomly to one of the three dietary treatments:0.37,0.47,and 0.57%P(DM basis);these P levels represent the NRC recommendations,Chinese recommendations,and the amount of dietary P commonly fed by Chinese dairy farmers,respectively.Average daily feed intake was calculated from monthly data on feed offered and refused.Milk yields of individual cows were recorded weekly,and milk samples were taken for analysis of protein,fat,solids-not-fat,lactose,and somatic cell count.Blood samples were collected on days-6,-3,0,3,6 relative to calving,and then monthly throughout lactation,and analyzed for P and Ca concentrations.Spot samples of feces and urine were collected for 3 consecutive d during weeks 12,24,and 36,and P concentrations were analyzed.Reproduction and health data were recorded.Results:Dietary P did not affect dry matter intake or milk yield(P> 0.10).Milk fat content was slightly higher in cows fed 0.37%P than in cows fed 0.47%P(P = 0.05).Serum concentrations of P and Ca did not reflect dietary P content(P> 0.10).Fecal and urinary P both declined linearly(P< 0.05) as dietary P decreased from 0.57 to0.37%.Fecal P content was 25%less when dietary P was 0.37%compared to 0.57%.Health events and reproductive performance were not associated with dietary P content(P> 0.05).Conclusions:Lowering dietary P from 0.57 to 0.37%did not negatively affect milk production,but did significantly reduce P excretion into environment.
文摘In this study, polymorphisms of the DGAT1 andSTAT5A genes were detected in 528 individuals from Xinong Saanen and Guanzhong goat breeds by PCR-RFLP, PCR-SSCP and DNA sequencing methods. Three allelic variants were identified: DQ380250: g.407_408insC, AJ237937: g.6798C>T and g.6852C>T in both breeds. At g.407_408insC locus, the frequencies of C1 allele were 0.79–0.85, and frequencies of C2 allele were 0.21–0.15. At g.6852C>T locus, frequencies of C3 allele were 0.70–0.72, and frequencies of T3 allele were 0.30–0.28. Compared with goats with C1C1 and C3C3, those with C1C2 and C3T3 genotypes had significant effects on milk yield and fat percentage (P<0.05), respectively. The result showed that does with C1C1C3T3 and C1C2C3T3 had higher milk yield than those with C1C2C3C3 (P < 0.05). In addition, the combined effect of C1C2C3C3 on milk fat percentage was the highest in comparison with other combination genotypes (P<0.05).
基金supported by the National 948 Project of China (2006-G48)the National Key Technologies R&D Program of China (2006BAD04A01)+1 种基金the Key Development of New Transgenic Breeds Program of China (2009ZX08009-156B)the National Natural Science Foundation of China (31072016)
文摘Our previous studies demonstrated that the region around markers BMS470 and BMS1242 on BTA6 showed a linkage to 305-d milk yield and composition traits in the Chinese Holstein population. We herein focused on such narrow region to fine map milk production QTLs with 15 SNPs across 25 Mb with each SNP in 1 Mb within most regions in a Chinese Holstein population with daughter design. 1 449 Holstein cows and 11 sires were genotyped for such SNPs by using TaqMan probe and RFLP assays. Multipoint linkage analysis across family revealed a QTL affecting milk yield between PPARGC1A C4075T and SLC34A2 T1713C. Meanwhile, within family analysis found three milk yield QTLs (two in CR T60984131G-CEP135 C501T and one in PDLIM5 A106C-OPN T3907, a fat yield QTLin UGDH T1670C-CR T60984131G region, and two protein yield QTLs in TBC1D1 G501C-UGDH T1670C and PPARGC1A C4075T-SLC34A2 T1713C, respectively. Associations between aforementioned significant SNP markers and milk production traits were further implemented. We found significant associations of PPARGC1A C4075T, SLC34A2 T1713C with milk yield (P<0.05, P<0.01, P<0.01), UGDH T1670C, and CR T60984131G with fat yield (P<0.01, P<0.01), and PPARGC1A C4075T, SLC34A2 T1713C, UGDH T1670C and OPN T3907 with protein yield (P<0.01, P<0.01, P<0.01, P<0.01). Our findings implied that QTLs affecting milk production traits on BTA6 were pleictropism or multigenic effect and PPARGC1A and OPN may be the causal mutations behind milk production QTLs on BTA6 in the Chinese Holstein population.
文摘Background: Populations of Gontougo (C?te d’Ivoire) commonly used Euphorbia hirta (Euphorbiaceae) leaves as galactagogue to boost milk production in lactating women. Our study was carried to verify this traditional belief via evaluations of milk production, serum prolactin levels, body weight and mammary lobuloalveolar proliferation induced by the aqueous leaf extract of this medicinal plant in Wistar rats. Methods: 6 groups of 6 virgin rats and 6 groups of 6 lactating rats were used. Each lactating rat was isolated with its six pups. These groups of animals were treated orally with distilled water, Metoclopramide (Metocl 5 mg/kg) and E. hirta aqueous leaf extract (EHae 100, 200, 400 and 600 mg/kg) daily during 17 days of lactation. The indirect method which assimilates the weight gain of untreated pups to the quantity of milk produced by lactating rats was used. At the end of the treatment, histological sections of the abdominal mammary glands of lactating rats were observed. Results: EHae administration induced an increase of milk production in lactating rats. This action of EHae was stronger at the dose of 200 mg/kg. Milk production of the treated rats at a dose of 200 mg/kg was 118.14 ± 1 g. The quantity of milk produced by the control female rats was 83.83 ± 0.88 g. Compared with the control, EHae 200 mg/kg significantly increased milk production (40.92%) (P Conclusion: EHae showed a galactagogue activity illustrated by increases of milk production, PRL secretions and the development of the lobuloalveolar system of the mammary glands in treated female rats. This galactagogue property could partly justify the traditional use of this plant to boost milk production in lactating women.
基金co-funded by the Dairy Goat Co-operative,Ministry of Business,Innovation&Employment(3709153)the Ministry for Primary Industries Sustainable Food and Fibre Futures Fund(5000835)。
文摘Background:Economically important milk production traits including milk volume,milk fat and protein yield vary considerably across dairy goats in New Zealand.A significant portion of the variation is attributable to genetic variation.Discovery of genetic markers linked to milk production traits can be utilised to drive selection of highperformance animals.A previously reported genome wide association study across dairy goats in New Zealand identified a quantitative trait locus(QTL)located on chromosome 19.The most significantly associated single nucleotide polymorphism(SNP)marker for this locus is located at position 26,610,610(SNP marker rs268292132).This locus is associated with multiple milk production traits including fat,protein and volume.The predicted effect of selection for the beneficial haplotype would result in an average production increase of 2.2 kg fat,1.9 kg protein and 73.6 kg milk yield.An outstanding question was whether selection for the beneficial allele would co-select for any negative pleiotropic effects.An adverse relationship between milk production and udder health traits has been reported at this locus.Therefore,a genome wide association study was undertaken looking for loci associated with udder traits.Results:The QTL and production associated marker rs268292132 was identified in this study to also be associated with several goat udder traits including udder depth(UD),fore udder attachment(FUA)and rear udder attachment(RUA).Our study replicates the negative relationship between production and udder traits with the high production allele at position 19:26,610,610(SNP marker rs268292132)associated with an adverse change in UD,FUA and RUA.Conclusions:Our study has confirmed the negative relationship between udder traits and production traits in the NZ goat population.We have found that the frequency of the high production allele is relatively high in the NZ goat population,indicating that its effect on udder conformation is not significantly detrimental on animal health.It will however be important to monitor udder conformation as the chromosome 19 locus is progressively implemented for marker assisted selection.It will also be of interest to determine if the gene underlying the production QTL has a direct effect on mammary gland morphology or whether the changes observed are a consequence of the increased milk volume.
文摘Goats are one of the oldest domesticated animal species widely distributed in the world playing an important role in the food production system in Sub-Saharan African Region (SSAR). Due to their multiple uses (milk production, meat, fiber and hides) and adaptation aptitudes to ecological conditions, goats produce and contribute positively to farmers’ socio-economy status in various production systems. This review aimed at giving a summary overview on the goat’s production systems characteristics, the genetic diversity and the candidate genes affecting reproductive and milk production performances in goat breeds in SSAR. It has been observed that traditional livestock production system with communal grazing system is the most used in goat keeping in SSAR. The geographical locations play an important role in the relationships between goat’s distributions in the region. At the same time, goats might have been differentiated and isolated one to others due to the wide geographic range, the diversify climate and the topography in the region. Among the six worldwide known haplogroups of goat (A, B, C, D, G and F), haplogroup A is the most representative in SSAR. However, haplogroup G and B can be found in some goat populations in some countries in east (Kenya and Ethiopia) and south parts of Africa. This review reveals that little is known on the candidate genes associated with prolificacy and milk production traits in indigenous goat breeds in the region. That observation suggests the importance of assessing candidate genes associated with economic traits in the populations of goat in SSAR.
文摘The aim of the study was to determine the effect of supplementing an oat winter pasture with a total mixed ration (TMR) on lactation performance of dairy cows. Nine multiparous Holstein cows were used in a 3 × 3 Latin square design with three TMR: pasture ratios at 79:21 (T1), 58:42 (T2) and 33:67 (T3) on a dry matter (DM) basis. The response to the 100% TMR diet (TMR-100) was tested using an extra period of 14 days inmediately after finishing the Latin square schedule using the nine experimental cows. Total DM intake resulted higher in TMR-100 (28.2 (kg/cow·day) and decreased by 2.64 kg/cow·day in T1, 5.02 kg in T2 and 6.68 kg in T3. Yields of milk (31.2 kg/cow·day) and fat corrected milk (26.8 kg/cow·day) was similar between T1, T2 and T3. Milk yield resulted higher in TMR-100 (32.1 kg/cow·day) compared to T2 (30.7 kg/cow·day). Milk fat concentration (g/100 g) was higher in T2 (3.13) and T3 (3.20) compared to T1 (2.96) and TMR-100 (2.85) and milk fat yield did not differ. Milk protein content resulted higher in TMR-100 and T2 averaging 3.37 g/100 g compared to T1 (3.32 g/100 g). The lowest milk protein concentration was observed in T3 (3.29 g/100 g) that resulted only different to T2. Milk protein yield did not differ between T1, T2 and T3 averaging 1.03 kg/cow·day. A lower protein yield was detected in T2 (1.03) and T3 (1.00) when compared to TMR-100 (1.07). Efficiency of milk production (kg milk/kg DM intake) resulted higher in T3 (1.42) compared to T1 (1.25). Treatments that included pasture yielded a higher efficiency of milk production when compared to TMR-100 (1.13). Plasma urea concentration resulted lower in TMR-100 (33.8 mg/dl) with no significant differences for this parameter between the other treatments. Glucose plasma levels did not differ between T1, T2 and T3 but plasma non-esterified fatty acids (NEFA) gradually increased as the proportion of pasture was enhanced according to the lower energy intake. Plasma insulin levels were higher in TMR-100 and T2 whereas concentration of somatomedins (IGF-1) remained unaffected. Grouth hormone (GH) levels and the GH/insulin ratio were highly variable and not affected by treatments. Concentration of vaccenic and conjugated linoleic acids gradually increased with the inclusion of pasture in the diet. Supplementing a winter oat pasture with TMR may be a suitable strategy to maintain milk production with a high conversion efficiency but part of the produced milk could be sustained at the expense of endogenous energy mobilization. The conditions of replacing pasture for TMR in high yielding dairy cows should be defined taking into account the depressing effect of pasture on total DM and energy intake when fresh forage is included in high proportion in the diet.
文摘A cross-sectional study was carried out to assess handling and hygienic production practices of goat milk in Degahbur district of Jarar zone, Somali Regional State, Ethiopia. A total of 120 households were purposively selected for this study using a stratified sampling technique. The data were collected through the questionnaire, field observations, key informants interview and focus group discussions. The study showed that majority of the sampled households were illiterate. The goats were kept in an open kraal made of thorny acacia trees on an earthen floor that had no roof. The goats were milked inside these open kraals, and were sometimes contaminated with muck and animal dung mainly the rainy season which could raise the possibility of milk contamination & spoilage. Moreover, traditional hand milking was the only milking method and majority of the respondents didn’t wash their hands and the udder of the animal before milking, indicating low community awareness and knowledge of sanitary milk production procedures. Plastic equipment which is difficult to clean and can increase milk contamination and spoilage was used. About 43.3% of the pastoralists and 76.67% of the agro-pastoralists were cleaning milk vessels regularly. The most often used plant species for smoking milk handling equipment in the study area to extend shelf life and add flavor & aroma were Acacia ethaica, Blanites galabra, and Solanum Carense. The main constraints to hygienic goat milk in the area were identified to be poor barn hygiene, poor production procedures, disease, source of washing water and lack of extension services. In general, it can be concluded that handling and hygienic production practices of goat milk used in the study area were unsanitary, which may have been primarily caused by the community’s lack of awareness & understanding as well as a lack of supporting infrastructures. Therefore, the concerned bodies should place a high priority on the improvement of hygienic practices by carrying out various relevant development interventions, such as raising milk producers’ awareness, improving the health of goats, and providing the necessities for milk handling.
基金One part of Experiment 1(Supplementary Table 1)was executed within JPI FACCE program and another part in the optiKuh project,both financially supported by the German Federal Ministry of Food and Agriculture(BMBL)through the Federal Office for Agriculture and Food(BLE),grant number 2814ERA04A and 2817201313,respectivelyExperiment 2 was performed within ERA-GAS program and financially supported by the BMBL through the BLE,grant number 2817ERA09C+2 种基金Experiment 3 was financially supported by the BMBL through the Landwirtschaftliche Rentenbank(LR),grant number 28RZ3P077Experiment 4 received funding from the core budget of the FBNThe authors acknowledge financial support for publication fom the Open Access Fond of the FBN and declare that the aforementioned funding parties had no role in the design of the study or in data collection,analysis,interpretation and writing of the manuscript.
文摘Background:Transformation of feed energy ingested by ruminants into milk is accompanied by energy losses via fecal and urine excretions,fermentation gases and heat.Heat production may differ among dairy cows despite comparable milk yield and body weight.Therefore,heat production can be considered an indicator of metabolic efficiency and directly measured in respiration chambers.The latter is an accurate but time-consuming technique.In contrast,milk Fourier transform mid-infrared(FTIR)spectroscopy is an inexpensive high-throughput method and used to estimate different physiological traits in cows.Thus,this study aimed to develop a heat production prediction model using heat production measurements in respiration chambers,milk FTIR spectra and milk yield measurements from dairy cows.Methods:Heat production was computed based on the animal’s consumed oxygen,and produced carbon dioxide and methane in respiration chambers.Heat production data included 16824-h-observations from 64 German Holstein and 20 dual-purpose Simmental cows.Animals were milked twice daily at 07:00 and 16:30 h in the respiration chambers.Milk yield was determined to predict heat production using a linear regression.Milk samples were collected from each milking and FTIR spectra were obtained with MilkoScan FT 6000.The average or milk yield-weighted average of the absorption spectra from the morning and afternoon milking were calculated to obtain a computed spectrum.A total of 288 wavenumbers per spectrum and the corresponding milk yield were used to develop the heat production model using partial least squares(PLS)regression.Results:Measured heat production of studied animals ranged between 712 and 1470 kJ/kg BW0.75.The coefficient of determination for the linear regression between milk yield and heat production was 0.46,whereas it was 0.23 for the FTIR spectra-based PLS model.The PLS prediction model using weighted average spectra and milk yield resulted in a cross-validation variance of 57%and a root mean square error of prediction of 86.5 kJ/kg BW0.75.The ratio of performance to deviation(RPD)was 1.56.Conclusion:The PLS model using weighted average FTIR spectra and milk yield has higher potential to predict heat production of dairy cows than models applying FTIR spectra or milk yield only.
文摘The experiment was conducted on 10 small-holder dairy farmers under the administration of Dairy Promotion Organization of Thailand (DPO) in the Northeast region of Thailand. The aim of the research was to investigate the effect of legume (Phaseolus calcaratus, PC) as roughage mixed with Ruzi grass for dairy cows. Fours cows per farm were assigned into 2 groups including Ruzi grass (control) and PC mixed with ruzi grass (at the ratio 50:50), were given ad libitum as a roughage sources. All cows were offered a concentrate with ratio to milk yield of 1:2. The results revealed that roughage source did not affect on ruminal pH and temperature, ammonia nitrogen, blood urea nitrogen, and milk urea nitrogen concentrations. Total volatile fatty acid, acetic acid, propionic acid, and butyric acid proportions, and acetic acid to propionic acid ratio were not significantly different among treatments. Dry matter intake and digestibility of nutrient including dry matter, organic matter, crude protein, neutral detergent fiber and acid detergent fiber were not significantly different among treatments. Moreover, amount of digested dry mater was similar among treatments. However, cows received PC mixed with Ruzi grass tended to be higher on dry matter, organic matter, and crude protein digestibility and dry matter digestible nutrient intake than control group. Milk yield, and 3.5% fat corrected milk were significantly higher (P < 0.05) in cow fed with PC mixed Ruzi grass than those the control group. Milk compositions and feed cost were similar among treatments;in contrast, the income and profit from milk selling were greater in cows fed with PC mixed with Ruzi grass than the control. High quality roughage such as PC mixed with Ruzi grass could be advantages for dairy farming in the Northeast of Thailand.
基金founded by the Excellent Young Teachers Program of Shanghai Municipal Education Commission (Grant No. B8101090039)the Project for Doctoral Research Fund of Shanghai Ocean University (Grant No.A2400080314)
文摘The purpose of the study is to measure the "growth drag" according to the characteristic of Chinese land resource.Romer model (2001) holds that every country is inevitably affected by the "growth drag" due to the limitation of land resource.So it's of profound strategic significance to measure the "growth drag" according to the character of Chinese land resource.Modified two-level CES production function was employed,and this paper modified the hypothesis of the model.The result indicates that the limitation of Chinese land resource casts shadow over the economic development of China,and the growth rate is 0.4618% lower than that without the limitation of land resource.Through implementing the land resource protection policy along with the technology improvement and the substitute effect of other factors to the land resource,China will keep a steady and balanced economic growth.
