The genetic polymorphism of SLA-DQA gene was investigated by PCR-RFLP. The effects of SLA.DQA gene on birth weight and 30-day-old weight were analyzed in 250 individuals of FI hybrid pig （ Heilongjiang wild boar x Be...The genetic polymorphism of SLA-DQA gene was investigated by PCR-RFLP. The effects of SLA.DQA gene on birth weight and 30-day-old weight were analyzed in 250 individuals of FI hybrid pig （ Heilongjiang wild boar x Beijing Black sow）. The analysis revealed four poly- morphic loci in the SLA-DQA gene, but only the Pvu II locus in exon 2 of SLA-DQA gene （ BB genotype） greatly increased the 30-day-old weight of piglets.展开更多
Since determining the weight of pigs during large-scale breeding and production is challenging,using non-contact estimation methods is vital.This study proposed a novel pig weight prediction method based on a mod-ifie...Since determining the weight of pigs during large-scale breeding and production is challenging,using non-contact estimation methods is vital.This study proposed a novel pig weight prediction method based on a mod-ified mask region-convolutional neural network(mask R-CNN).The modified approach used ResNeSt as the backbone feature extraction network to enhance the image feature extraction ability.The feature pyramid net-work(FPN)was added to the backbone feature extraction network for multi-scale feature fusion.The channel at-tention mechanism(CAM)and spatial attention mechanism(SAM)were introduced in the region proposal network(RPN)for the adaptive integration of local features and their global dependencies to capture global in-formation,ultimately improving image segmentation accuracy.The modified network obtained a precision rate(P),recall rate(R),and mean average precision(MAP)of 90.33%,89.85%,and 95.21%,respectively,effectively segmenting the pig regions in the images.Five image features,namely the back area,body length,body width,average depth,and eccentricity,were investigated.The pig depth images were used to build five regression algo-rithms(ordinary least squares(OLS),AdaBoost,CatBoost,XGBoost,and random forest(RF))for weight value pre-diction.AdaBoost achieved the best prediction result with a coefficient of determination(R^(2))of 0.987,a mean absolute error(MAE)of 2.96 kg,a mean square error(MSE)of 12.87 kg^(2),and a mean absolute percentage error(MAPE)of 8.45%.The results demonstrated that the machine learning models effectively predicted the weight values of the pigs,providing technical support for intelligent pig farm management.展开更多
According to the relevant statistical data in National Agricultural cost-benefit Data Compilation(2001- 2013),we use the modified entropy weight- TOPSIS model to research the cost-benefit status of scale pig breeding ...According to the relevant statistical data in National Agricultural cost-benefit Data Compilation(2001- 2013),we use the modified entropy weight- TOPSIS model to research the cost-benefit status of scale pig breeding in Shandong Province from the perspective of comparing it with that of the entire country and 9 other main pig producing areas. The results show that compared with the national average,the cost-benefit ratio of small scale pig breeding in Shandong Province is lower,while the cost-benefit ratio of medium scale and large scale pig breeding is significantly improved; the cost-benefit ratio of small scale pig breeding in Shandong Province is basically the same as that in 9 other main pig producing areas,while the cost-benefit ratio of medium scale and large scale pig breeding is higher; the output value of main products and the purchase price of piglet are two major bottlenecks restricting the cost-benefit improvement of scale pig breeding in Shandong Province.展开更多
Porcine carcass traits and organ weights have important economic roles in the swine industry. A total of 576 animals from a Large White×Minzhu intercross population were genotyped using the Illumina PorcineSNP60K...Porcine carcass traits and organ weights have important economic roles in the swine industry. A total of 576 animals from a Large White×Minzhu intercross population were genotyped using the Illumina PorcineSNP60K Beadchip and were phenotyped for 10 traits, speciifcally, backfat thickness （6-7 libs）, carcass length, carcass weight, foot weight, head weight, heart weight, leaf fat weight, liver weight, lung weight and slaughter body weight. The genome-wide association study （GWAS） was assessed by Genome Wide Rapid Association using the mixed model and regression-genomic control approach. A total of 31 single nucleotide polymorphisms （SNPs） （with the most signiifcant SNP being MARC0033464, P value=6.80×10-13） were located in a 9.76-Mb （31.24-41.00 Mb） region on SSC7 and were found to be signiifcantly associated with one or more carcass traits and organ weights. High percentage of phenotypic variance explanation was observed for each trait ranging from 31.21 to 67.42%. Linkage analysis revealed one haplotype block of 495 kb, in which the most signiifcant SNP being MARC0033464 was contained, on SSC7 at complete linkage disequilibrium. Annotation of the pig reference genome suggested 6 genes （GRM4, HMGA1, NUDT3, RPS10, SPDEF and PACSIN1） in this candidate linkage disequilibrium （LD） interval. Functional analysis indicated that the HMGA1 gene presents the prime biological candidate for carcass traits and organ weights in pig, with potential application in breeding programs.展开更多
Porcine reproductive traits are characterized by low heritability, making improvement by traditional selective breeding rather difficult. Molecular breeding offers powerful approaches to overcome previous limitations ...Porcine reproductive traits are characterized by low heritability, making improvement by traditional selective breeding rather difficult. Molecular breeding offers powerful approaches to overcome previous limitations and is expected to generate economic benefits via progress in pig breeding. Cytochrome P450 family 19 subfamilyA polypeptide 1 （CYP19A1） gene is a key enzyme of estradiol biosynthesis that plays an important role in the establishment of gestation and maintenance of pregnancy. In this study, the sequence and structure characteristics of the porcine CYP19A1 gene was analyzed and expression patterns of CYP19A 1 in different tissues of adult female pigs were detected. Fourteen single-nucleotide poly- morphisms （SNPs） in the exons and introns of porcine CYP19A1 were identified and genotyped using the Sequenom MassARRAY platform, after which the allele frequency of each SNP was analyzed..The association between CYP19A1 SNPs and litter size and piglet birth weight was assessed in a crossbred pig population （n=375）. The expression pattern of CYPf9A1 revealed that it was highly expressed in the ovary, spleen, and uterus and lowly expressed in the other tissues. Moreover, one SNP, rs341891833, was significantly associated with piglet birth weight during the multiparity period （P〈0.01）. We concluded that CYP19A1 could be used as a candidate molecular marker in breeding aimed at rapid improvement of the reproductive characteristics of pigs.展开更多
Background: The aim of this study was to determine how maternal undernutrition during pregnancy and offspring birth-weight can affect the postnatal development of offspring under farm conditions, which may lead to con...Background: The aim of this study was to determine how maternal undernutrition during pregnancy and offspring birth-weight can affect the postnatal development of offspring under farm conditions, which may lead to consequences in its meat and carcass quality. The current study involved a total of 80 litters from Iberian sows fed a diet fulfilling daily requirements(n = 47; control) or providing 70% daily requirements(n = 33; underfed) from d 38 to d 90 of gestation when fetal tissue development begins. After birth, piglets born live were classified as low birthweight(LBW; < 1 kg) and normal birth-weight(NBW; ≥1 kg). During the growing phase, 240 control and 230 underfed pigs(50% males and females) distributed by BW category and sex were studied until the slaughter.Results: At birth and weaning, there were significant differences in all morphological measures and weight between NBW and LBW piglets as expected(P < 0.0005), but few effects of the gestational feed restriction. During the growing phase, NBW pigs continued with higher weight than LBW pigs on all the days of evaluation(P < 0.05),even though control-LBW-females and LBW-males showed a catch-up growth. However, underfed pigs showed slower growth and higher feed conversion ratio than control pigs(P < 0.0001) at 215 days old. Moreover, the average daily weight gain(ADWG) for the overall period was greater for NBW, male and control pigs than for their LBW, female and underfed pigs(P < 0.0001, P< 0.0005 and P< 0.05, respectively) and NBW pigs were slaughtered at a younger age than LBW pigs(P < 0.0001). After slaughtering, control pigs also had higher carcass yield and backfat depth than underfed pigs(P < 0.0005) and the maternal nutritional effect caused main changes in the polar lipid fraction of liver and loin. The fatty acid composition of loin in control pigs had higher C18:1 n-9 and n-3 FA concentrations, as well as lower ∑n-6/∑n-3 ratio, than in underfed pigs(P < 0.005).Conclusions: In brief, results showed that the effects of maternal nutritional restriction appeared and increased with offspring age, causing worse developmental patterns for underfed pigs than for control pigs.展开更多
We sought to determine morphological descriptors of Nigerian indigenous pigs (NIP) and crossbred pigs (CBP) based on relationships among live weight (LW) and a suite of 18 morphometric measurements plus the number of ...We sought to determine morphological descriptors of Nigerian indigenous pigs (NIP) and crossbred pigs (CBP) based on relationships among live weight (LW) and a suite of 18 morphometric measurements plus the number of teats. We sampled four locations in southwestern Nigeria and obtained data for a total of 120 NIP and CBP. More female pigs (61.7%) than males (38.3%) were sampled, and they had a mean live weight of 19.9 ± 6.10 kg (range 9 - 32 kg) and 20.1 ± 6.08 kg (range 8 - 37 kg), respectively. The NIP had a longer snout, wider head and longer erect ears than CBP (P 2) of 0.97, 0.92, 0.96, 0.97, 0.91, 0.97, 0.97, 0.90, and 0.93, respectively (all P 2 = 0.93;P 2 = 0.96;P 2 = 0.84;P 2 = 0.94;展开更多
Fragrance pig is a famous miniature local breed in China,which is similar to human on the aspects of physical structure,anatomy,nutrition,metabolism and blood biochemical indicators. The internal organs of Congjiang f...Fragrance pig is a famous miniature local breed in China,which is similar to human on the aspects of physical structure,anatomy,nutrition,metabolism and blood biochemical indicators. The internal organs of Congjiang fragrance pig and Huanjiang fragrance pig with different month ages were weighed. The results showed that the proportion of stomach in body weight in Congjiang fragrance pig was higher than that in Min pig,Harbin white and Landrace,and the proportion of large intestine in body weight in Congjiang fragrance pig was also higher than that in ordinary pigs; the weights of heart,liver and kidney in 8- 10 months old Congjiang fragrance pig were similar to that in Chinese adults. This provided reference data for future in-depth development and utilization of fragrance pig.展开更多
In order to study the feeding effect of fine division of feeding stages on the growing-finishing pigs,96 healthy Duroc × Landrace ×Yorkshire hybrid commercial pigs with similar age in days,size,and body weig...In order to study the feeding effect of fine division of feeding stages on the growing-finishing pigs,96 healthy Duroc × Landrace ×Yorkshire hybrid commercial pigs with similar age in days,size,and body weight about 15 kg,half boars and half sows,randomly divided into3 treatments( each treatment repeated 4 times,and each repetition 8 pigs). According to the body weight division standard,three stages,four stages,and five stages of feeding were adopted separately. The daily ration of with different nutrition levels was used,body weight and feed consumption were measured,and effects of different feeding methods on body weight increase,feed utilization,and economic benefits of growing-finishing pigs. The results showed that compared with the three-stage feeding,the body weight of five-stage and four-stage feeding increased by 4. 18%( P < 0. 01) and 2. 41%( P < 0. 05),respectively,and the body weight of five-stage feeding increased by 1. 74%( P < 0. 05) compared with that of four-stage feeding; the daily feed consumption of five-stage and four-stage feeding increased 3. 10%( P < 0. 01) and 1. 70%(P <0. 01),respectively,and the daily feed consumption of five-stage feeding was 1. 37% higher than that of four-stage feeding. The feed cost of five-stage feeding and four-stage feeding increased 3. 32%( P < 0. 01) and 1. 61%( P < 0. 05) separately,and the feed cost of five-stage feeding was 1. 69% higher than that of four-stage feeding( P < 0. 01). The income from average body weight increase of five-stage and fourstage feeding increased by 5. 47%( P < 0. 01) and 3. 59%( P < 0. 01) respectively,and the benefit of average body weight increase of fivestage feeding was 1. 81% higher than that of four-stage feeding( P > 0. 05). The crude protein consumption from average body weight increase of five-stage and four-stage feeding decreased by 2. 28%( P < 0. 01) and 1. 68%( P < 0. 01),respectively; the crude protein consumption from average body weight increase of five-stage feeding was 0. 67% lower than that of four-stage feeding; the feed conversion ratio of five-stage feeding,four-stage feeding,and three-stage feeding was 2. 92,2. 93,and 2. 95 respectively. The results showed that compared with the threestage feeding,the four-stage and five-stage feeding could significantly increase the body weight of the growing-finishing pigs,improve the feed utilization level and improve the economic benefits,and the effect of five-stage feeding was better than the four-stage feeding.展开更多
基金supported by the Key Projects in the National Science & Technology Pillar Program in the 11th Five Years (2008BADB2B02)
文摘The genetic polymorphism of SLA-DQA gene was investigated by PCR-RFLP. The effects of SLA.DQA gene on birth weight and 30-day-old weight were analyzed in 250 individuals of FI hybrid pig （ Heilongjiang wild boar x Beijing Black sow）. The analysis revealed four poly- morphic loci in the SLA-DQA gene, but only the Pvu II locus in exon 2 of SLA-DQA gene （ BB genotype） greatly increased the 30-day-old weight of piglets.
基金supported by the Key R&D Program of Zhejiang(2022C02050)Zhejiang Provincial Natural Science Foundation of China(ZCLTGN24C1301)。
文摘Since determining the weight of pigs during large-scale breeding and production is challenging,using non-contact estimation methods is vital.This study proposed a novel pig weight prediction method based on a mod-ified mask region-convolutional neural network(mask R-CNN).The modified approach used ResNeSt as the backbone feature extraction network to enhance the image feature extraction ability.The feature pyramid net-work(FPN)was added to the backbone feature extraction network for multi-scale feature fusion.The channel at-tention mechanism(CAM)and spatial attention mechanism(SAM)were introduced in the region proposal network(RPN)for the adaptive integration of local features and their global dependencies to capture global in-formation,ultimately improving image segmentation accuracy.The modified network obtained a precision rate(P),recall rate(R),and mean average precision(MAP)of 90.33%,89.85%,and 95.21%,respectively,effectively segmenting the pig regions in the images.Five image features,namely the back area,body length,body width,average depth,and eccentricity,were investigated.The pig depth images were used to build five regression algo-rithms(ordinary least squares(OLS),AdaBoost,CatBoost,XGBoost,and random forest(RF))for weight value pre-diction.AdaBoost achieved the best prediction result with a coefficient of determination(R^(2))of 0.987,a mean absolute error(MAE)of 2.96 kg,a mean square error(MSE)of 12.87 kg^(2),and a mean absolute percentage error(MAPE)of 8.45%.The results demonstrated that the machine learning models effectively predicted the weight values of the pigs,providing technical support for intelligent pig farm management.
基金Supported by Pig Industry Innovation Team Building Program of Modern Agricultural Industrial Technology System in Shandong Province(SDAIT-06-011-10)"Issues concerning Agriculture,Farmers and Countryside"Soft Science Base Project in Shandong Province
文摘According to the relevant statistical data in National Agricultural cost-benefit Data Compilation(2001- 2013),we use the modified entropy weight- TOPSIS model to research the cost-benefit status of scale pig breeding in Shandong Province from the perspective of comparing it with that of the entire country and 9 other main pig producing areas. The results show that compared with the national average,the cost-benefit ratio of small scale pig breeding in Shandong Province is lower,while the cost-benefit ratio of medium scale and large scale pig breeding is significantly improved; the cost-benefit ratio of small scale pig breeding in Shandong Province is basically the same as that in 9 other main pig producing areas,while the cost-benefit ratio of medium scale and large scale pig breeding is higher; the output value of main products and the purchase price of piglet are two major bottlenecks restricting the cost-benefit improvement of scale pig breeding in Shandong Province.
基金supported by the Agricultural Science and Technology Innovation Program, China (ASTIPIAS02)the National Key Technology R&D Program of China (2011BAD28B01)+2 种基金the National Natural Science Foundation of China (31201781)the Earmarked Fund for Modern Agroindustry Technology Research System, National Technology Program of China (2011ZX08006-003)the Chinese Academy of Agricultural Sciences Foundation (2011cj-5, 2012ZL069 and 2014ywf-yb-8)
文摘Porcine carcass traits and organ weights have important economic roles in the swine industry. A total of 576 animals from a Large White×Minzhu intercross population were genotyped using the Illumina PorcineSNP60K Beadchip and were phenotyped for 10 traits, speciifcally, backfat thickness （6-7 libs）, carcass length, carcass weight, foot weight, head weight, heart weight, leaf fat weight, liver weight, lung weight and slaughter body weight. The genome-wide association study （GWAS） was assessed by Genome Wide Rapid Association using the mixed model and regression-genomic control approach. A total of 31 single nucleotide polymorphisms （SNPs） （with the most signiifcant SNP being MARC0033464, P value=6.80×10-13） were located in a 9.76-Mb （31.24-41.00 Mb） region on SSC7 and were found to be signiifcantly associated with one or more carcass traits and organ weights. High percentage of phenotypic variance explanation was observed for each trait ranging from 31.21 to 67.42%. Linkage analysis revealed one haplotype block of 495 kb, in which the most signiifcant SNP being MARC0033464 was contained, on SSC7 at complete linkage disequilibrium. Annotation of the pig reference genome suggested 6 genes （GRM4, HMGA1, NUDT3, RPS10, SPDEF and PACSIN1） in this candidate linkage disequilibrium （LD） interval. Functional analysis indicated that the HMGA1 gene presents the prime biological candidate for carcass traits and organ weights in pig, with potential application in breeding programs.
基金supported by the National Natural Science Foundation of China(31501931)the 948 Program of China(2011-G11)the Agricultural Science and Technology Innovation Program,China(ASTIP-IAS05)
文摘Porcine reproductive traits are characterized by low heritability, making improvement by traditional selective breeding rather difficult. Molecular breeding offers powerful approaches to overcome previous limitations and is expected to generate economic benefits via progress in pig breeding. Cytochrome P450 family 19 subfamilyA polypeptide 1 （CYP19A1） gene is a key enzyme of estradiol biosynthesis that plays an important role in the establishment of gestation and maintenance of pregnancy. In this study, the sequence and structure characteristics of the porcine CYP19A1 gene was analyzed and expression patterns of CYP19A 1 in different tissues of adult female pigs were detected. Fourteen single-nucleotide poly- morphisms （SNPs） in the exons and introns of porcine CYP19A1 were identified and genotyped using the Sequenom MassARRAY platform, after which the allele frequency of each SNP was analyzed..The association between CYP19A1 SNPs and litter size and piglet birth weight was assessed in a crossbred pig population （n=375）. The expression pattern of CYPf9A1 revealed that it was highly expressed in the ovary, spleen, and uterus and lowly expressed in the other tissues. Moreover, one SNP, rs341891833, was significantly associated with piglet birth weight during the multiparity period （P〈0.01）. We concluded that CYP19A1 could be used as a candidate molecular marker in breeding aimed at rapid improvement of the reproductive characteristics of pigs.
基金supported by funds from the Ministry of Economy and competitiveness(project AGL2013–48121-C3-R and AGL2016–79321-C2–2-R)co-funded by FEDER.More funds were obtained from MEDGAN-REDLAB(project S2013/ABI-2913)CAM,co-funded by FEDER.MVG and CGC are backed by the Spanish Government(MVG:FPU National Program Grant Number FPU014/01285.CGC:FPI National Program Grant Number BES-2014-070464)
文摘Background: The aim of this study was to determine how maternal undernutrition during pregnancy and offspring birth-weight can affect the postnatal development of offspring under farm conditions, which may lead to consequences in its meat and carcass quality. The current study involved a total of 80 litters from Iberian sows fed a diet fulfilling daily requirements(n = 47; control) or providing 70% daily requirements(n = 33; underfed) from d 38 to d 90 of gestation when fetal tissue development begins. After birth, piglets born live were classified as low birthweight(LBW; < 1 kg) and normal birth-weight(NBW; ≥1 kg). During the growing phase, 240 control and 230 underfed pigs(50% males and females) distributed by BW category and sex were studied until the slaughter.Results: At birth and weaning, there were significant differences in all morphological measures and weight between NBW and LBW piglets as expected(P < 0.0005), but few effects of the gestational feed restriction. During the growing phase, NBW pigs continued with higher weight than LBW pigs on all the days of evaluation(P < 0.05),even though control-LBW-females and LBW-males showed a catch-up growth. However, underfed pigs showed slower growth and higher feed conversion ratio than control pigs(P < 0.0001) at 215 days old. Moreover, the average daily weight gain(ADWG) for the overall period was greater for NBW, male and control pigs than for their LBW, female and underfed pigs(P < 0.0001, P< 0.0005 and P< 0.05, respectively) and NBW pigs were slaughtered at a younger age than LBW pigs(P < 0.0001). After slaughtering, control pigs also had higher carcass yield and backfat depth than underfed pigs(P < 0.0005) and the maternal nutritional effect caused main changes in the polar lipid fraction of liver and loin. The fatty acid composition of loin in control pigs had higher C18:1 n-9 and n-3 FA concentrations, as well as lower ∑n-6/∑n-3 ratio, than in underfed pigs(P < 0.005).Conclusions: In brief, results showed that the effects of maternal nutritional restriction appeared and increased with offspring age, causing worse developmental patterns for underfed pigs than for control pigs.
文摘We sought to determine morphological descriptors of Nigerian indigenous pigs (NIP) and crossbred pigs (CBP) based on relationships among live weight (LW) and a suite of 18 morphometric measurements plus the number of teats. We sampled four locations in southwestern Nigeria and obtained data for a total of 120 NIP and CBP. More female pigs (61.7%) than males (38.3%) were sampled, and they had a mean live weight of 19.9 ± 6.10 kg (range 9 - 32 kg) and 20.1 ± 6.08 kg (range 8 - 37 kg), respectively. The NIP had a longer snout, wider head and longer erect ears than CBP (P 2) of 0.97, 0.92, 0.96, 0.97, 0.91, 0.97, 0.97, 0.90, and 0.93, respectively (all P 2 = 0.93;P 2 = 0.96;P 2 = 0.84;P 2 = 0.94;
文摘Fragrance pig is a famous miniature local breed in China,which is similar to human on the aspects of physical structure,anatomy,nutrition,metabolism and blood biochemical indicators. The internal organs of Congjiang fragrance pig and Huanjiang fragrance pig with different month ages were weighed. The results showed that the proportion of stomach in body weight in Congjiang fragrance pig was higher than that in Min pig,Harbin white and Landrace,and the proportion of large intestine in body weight in Congjiang fragrance pig was also higher than that in ordinary pigs; the weights of heart,liver and kidney in 8- 10 months old Congjiang fragrance pig were similar to that in Chinese adults. This provided reference data for future in-depth development and utilization of fragrance pig.
基金Supported by Key Scientific and Technological Planning Project of Shanxi Province(20120311022-5)Project of Scientific and Technological Innovation Team for Safe and Efficient Swine Production in Shanxi Province
文摘In order to study the feeding effect of fine division of feeding stages on the growing-finishing pigs,96 healthy Duroc × Landrace ×Yorkshire hybrid commercial pigs with similar age in days,size,and body weight about 15 kg,half boars and half sows,randomly divided into3 treatments( each treatment repeated 4 times,and each repetition 8 pigs). According to the body weight division standard,three stages,four stages,and five stages of feeding were adopted separately. The daily ration of with different nutrition levels was used,body weight and feed consumption were measured,and effects of different feeding methods on body weight increase,feed utilization,and economic benefits of growing-finishing pigs. The results showed that compared with the three-stage feeding,the body weight of five-stage and four-stage feeding increased by 4. 18%( P < 0. 01) and 2. 41%( P < 0. 05),respectively,and the body weight of five-stage feeding increased by 1. 74%( P < 0. 05) compared with that of four-stage feeding; the daily feed consumption of five-stage and four-stage feeding increased 3. 10%( P < 0. 01) and 1. 70%(P <0. 01),respectively,and the daily feed consumption of five-stage feeding was 1. 37% higher than that of four-stage feeding. The feed cost of five-stage feeding and four-stage feeding increased 3. 32%( P < 0. 01) and 1. 61%( P < 0. 05) separately,and the feed cost of five-stage feeding was 1. 69% higher than that of four-stage feeding( P < 0. 01). The income from average body weight increase of five-stage and fourstage feeding increased by 5. 47%( P < 0. 01) and 3. 59%( P < 0. 01) respectively,and the benefit of average body weight increase of fivestage feeding was 1. 81% higher than that of four-stage feeding( P > 0. 05). The crude protein consumption from average body weight increase of five-stage and four-stage feeding decreased by 2. 28%( P < 0. 01) and 1. 68%( P < 0. 01),respectively; the crude protein consumption from average body weight increase of five-stage feeding was 0. 67% lower than that of four-stage feeding; the feed conversion ratio of five-stage feeding,four-stage feeding,and three-stage feeding was 2. 92,2. 93,and 2. 95 respectively. The results showed that compared with the threestage feeding,the four-stage and five-stage feeding could significantly increase the body weight of the growing-finishing pigs,improve the feed utilization level and improve the economic benefits,and the effect of five-stage feeding was better than the four-stage feeding.
