奶牛的繁殖管理(谷物协会).ppt

* * * * * * * * * * * * Open circles denote cows that were dried off immediately after calving to ensure rapid return to positive energy balance. Data indicates that for both dry and lactating cows, first ovulation occurs approximately 10 days following maximum negative energy balance. Although not shown on this graph, there has also been relationships to cumulative or average EB, indicating that severity or magnitude of negative EB also affects reproduction. It is important to note that LH pulse frequency significantly increases within 3 days after the nadir in negative energy balance and is maintained until the first ovulation. * * * Fresh Date DIM at 1st AI 二月February, 2007 August, 2006 八月 Distribution of DIM at 1st AI Service On the Web: 网址 /ces/dairyrepro/ Department of Dairy Science University of Wisconsin – Madison 威斯康星大学奶业科学系- 麦迪逊 * * * * * * * * * * * * * * * * * * * * * * * * * * * Relationship Between Days to Energy Balance Nadir and Days to First Ovulation 第一次排卵和最低能量平衡天数的关系Butler and Canfield, 1989 从最低能力平衡回复过来因牛而异，也是重新恢复卵巢活动的标志 能量平衡后10天第一次排卵 第一次排卵天数 最低能量平衡 Effect of Body Condition Score at Timed AI on Fertility in Lactating Holstein Cows Sterry et al., 2006膘情鉴定对荷斯坦泌乳牛适时输精的影响 膘 情 Item ? 2.5 2.5 P value PG 33 (%) 39 (64/164) 55 (334/605) 0.001 PG 61 (%) 36 (59/162) 50 (303/601) 0.003 Loss (%) d 33 to 61 5 (3/62) 8 (27/330) 0.117 Maintenance of Body Temperature in Dairy Cattle 奶牛体温的维持 Homeothermy恒温: HP + EH = HL Hyperthermia高热: HP + EH HL Environmental Heat (EH) 环境加热 热量损失到外界 Heat Loss to Environment (HL) 4 种方式: 传导 对流 辐射 蒸发 体内产热 Internal Heat Production (HP) 代谢: 生长 泌乳 Effects of Heat Stress 热应激的作用 Mean rectal 平均直肠温度 育成牛接受热平衡或热点环境 温度 Rectal Temprature 直肠温度 严重热应激是可接近华氏107 度 Data from Putney et al., 1989 Body Temperature 体温 热平衡 热应激 时间 （小时） 直 肠 温 度 Athens, WI 雅典、威斯康星(纬度 45° 07’; 经度 90° 20’) Conception Rate to TAI by month 月受胎率(Fricke et al., 2003) 受胎率 气温 气温 受胎率 Effects of Heat Stress 热应激的作用 Effects on Late Follicular and Early Embryoni