摘要
针对敞棚奶牛舍西晒严重的问题,本试验通过在舍西侧种植乔木遮蔽阳光以缓解生产中夏季西晒引起的奶牛热应激。选择360头健康、体况和胎次相近的泌乳奶牛[泌乳天数(185±25)d,胎次(2.5±0.5),产奶量(31.02±1.25)kg],随机分于2栋建筑结构相同的南北朝向敞棚舍中,其中一栋舍(遮阴舍)西侧山墙外种植高15 m的杨树(冠长6 m,冠幅下宽0.8 m,上宽0.3 m),另一栋舍西侧山墙外没有种树(对照舍)。试验分3个阶段进行,即热季前期(5月)、热季期(7-8月)和热季后期(10月),测定每个试验期的舍温及奶牛生理和行为指标,并测定各阶段的产奶量和乳成分以及养分表观消化率,同时测定各阶段的全血常规指标和血清生化指标。结果表明:1)树木遮阴对热季期奶牛的效果较好,对热季前期和后期影响较小。热季期遮阴显著降低了舍温,遮阴舍日均温较对照舍降低了0.99℃,其中09:00-20:00降低了1.13℃(P<0.05)。2)热季期遮阴舍奶牛呼吸频率较对照舍降低8.21%,差异显著(P<0.05),且躺卧比例较对照舍提高7.42%。3)遮阴提高了热季期奶牛的养分表观消化率,干物质采食量较对照舍提高了9.81%(P<0.05),平均日产奶量提高了4.69%(P<0.05),粗蛋白、中性和酸性洗涤纤维较对照舍均表现出不同程度的提高,分别达12.80%、9.87%和19.40%。4)热季期遮阴舍奶牛全血中白细胞数目、淋巴细胞比率及血小板压积较对照舍显著增加(P<0.05),血细胞比容和血小板数目显著降低(P<0.05),且热季期和热季后期遮阴显著增加了血清葡萄糖和总蛋白的含量(P<0.05),并降低了皮质醇含量(P<0.05)。综上,敞棚舍西侧种植树木可有效降低舍温,一定程度上缓解了高温季节奶牛的热应激,提高了奶牛的泌乳性能。该研究结果可为奶牛场的绿化遮阴提供借鉴。
In this experiment,tall trees were planted on the west side of a cowshed to shade sunlight from the west in summer.Three hundred and sixty dairy cows with similar health,body condition,and parity[lactation days(185±25),parity(2.5±0.5),milk yield(31.02±1.25 kg)]were randomly assigned to two groups.The two groups were housed in cowsheds with the same building structure and a south-north orientation.Poplar trees with a height of15 m(crown length of 6 m,lower crown width of 0.8 m,and upper crown width of 0.3 m)were planted outside the west gable of one shed(shed-shaded),and the other shed was left unshaded with no trees planted outside(control shed).This study was carried out through three stages;The early hot season in May,the hot season from July to August,and late-hot season in October.The physiological and behavioral parameters of the cows,their milk yield,and nutrient digestibility of feed consumed were measured at all stages,and whole blood and serum biochemical parameters were measured throughout the experiment.It was found that:1)Shading positively affected dairy cows in the hot season,but had little effect in the early and late stages of hot season.Shading reduced the ambient temperature in the shed during the hot season.The average daily temperature was 0.99℃lower in the shaded shed than in the control shed,and the temperature was 1.13℃lower in the shaded shed than in the control shed between09:00 and 20:00(P<0.05).2)During the hot season,the respiratory rate of cows in the shaded shed was 8.21%lower than that of cows in the control shed(P<0.05),and the proportion of cows lying down in the shaded shed was increased by 7.42%.3)Shading also improved nutrient digestibility of feed consumed in the hot season,with dry matter intake increased by 9.81%(P<0.05)and milk yield increased by 4.69%(P<0.05)for cows in the shaded shed compared with those in the control shed.The crude protein,neutral detergent fiber,and acid detergent fiber contents were also improved,with increases of 12.80%,9.87%,and 19.40%,respectively,for cows in the shaded shed compared with those in the control shed.4)The number of white blood cells,the lymphocyte ratio,the and platelet volume in whole blood were significantly higher in cows in the shaded shed(P<0.05)than in those in the control shed in the hot season,while the hematocrit and number of platelets were significantly lower in cows in the shaded shed(P<0.05).In both the hot season and late-hot season,shading also increased the serum glucose and total protein contents(P<0.05)and decreased the serum cortisol content(P<0.05).In summary,planting trees on the west side of cowsheds can effectively reduce the ambient temperature inside the shed,thereby relieving heat stress in cows during the hot season and improving their lactation performance.The results of this study provide a reference for improving productivity by managing greening and shading on farms.
作者
赵俐辰
王晓芳
赵心念
李永亮
王亚男
冯曼
高玉红
郭建军
ZHAO Li-chen;WANG Xiao-fang;ZHAO Xin-nian;LI Yong-liang;WANG Ya-nan;FENG Man;GAO Yu-hong;GUO Jian-jun(College of Animal Science and Technology,Hebei Agricultural University,Baoding 071000,China;Hebei Institute of Animal Husbandry and Veterinary Medicine,Baoding 071000,China;Animal Husbandry Research Institute,Chengde Academy of Agriculture and Forestry,Chengde 067000,China)
出处
《草业学报》
CSCD
北大核心
2023年第4期183-196,共14页
Acta Prataculturae Sinica
基金
河北省现代农业产业技术体系奶牛创新团队建设项目(HBCT2018120202)
河北省奶业振兴重大技术创新专项(19226632D)资助。
关键词
奶牛
遮阴
环境温度
泌乳性能
血液理化指标
dairy cow
shade
ambient temperature
lactating performance
blood physicochemical parameter
