Use of bovine somatotropin in lactating dairy cows receiving timed artificial insemination.
Use of bovine somatotropin in lactating dairy cows receiving timed artificial insemination.
复制标题
在接受定时人工授精的泌乳奶牛中使用牛生长激素。
DOI：
--
复制
发表时间：
2000
影响因子：
3.5
通讯作者：
W. Thatcher
中科院分区：
文献类型：
--
作者：
F. Moreira;C. Risco;Maria de Fátima Ávila Pires;J. Ambrose;M. Drost;W. Thatcher
本研究的目的是研究牛生长激素（bST）对定时人工授精方案妊娠率的影响，并测试两个连续同步服务的再同步系统。将403头泌乳荷斯坦奶牛分为以下处理：产后63 +/- 3 d开始bST （500 mg）治疗，同时开始定时人工授精，或产后105 +/- 3 d开始bST治疗。在产后63 +/- 3 d，所有奶牛接受GnRH (100 μ g)， 7 d后注射pgf2 α (25 mg)， pgf2 α后48 h注射GnRH， 16 ~ 20 h后进行受精。母牛在检测到发情时重新受精，或在受精后20天再次注射GnRH。授精后第27天，对奶牛进行妊娠检查。重新同步诊断为未怀孕的奶牛接受pgf2 α注射，并在检测到的发情时进行受精，或在pgf2 α后48小时注射GnRH，并在16至20小时后进行受精。27 d妊娠的奶牛在受精后45 d复查妊娠情况。与产后105 +/- 3 d开始bST治疗的奶牛相比，在产后63 +/- 3 d开始bST治疗的奶牛第45天的首次妊娠率分别增加了37.7 +/- 5.8%和22.1 +/- 4.2%，但在奶牛重新同步时，bST治疗的效果不明显（分别为25.6 +/- 4.3%和25.8 +/- 5.5%）。因此，bST增加了怀孕率，以定时人工授精方案。
Objectives of the research were to examine the effect of bovine somatotropin (bST) on pregnancy rates to a timed artificial insemination protocol and to test a resynchronization system with two consecutive synchronized services. Lactating Holstein cows (n = 403) were assigned to the following treatments: bST treatment (500 mg) was initiated at 63 +/- 3 d postpartum concomitantly with initiation of the timed artificial insemination protocol or bST treatment was initiated at 105 +/- 3 d postpartum. At 63 +/- 3 d postpartum, all cows received GnRH (100 microg), an injection of PGF2alpha (25 mg) 7 d later, and a GnRH injection at 48 h after PGF2alpha and were inseminated 16 to 20 h later. Cows were reinseminated at detected estrus or resynchronized with a GnRH injection at 20 d after insemination. At 27 d after insemination, cows were examined for pregnancy. Resynchronized cows diagnosed nonpregnant received an injection of PGF2alpha and were inseminated at detected estrus or received an injection of GnRH at 48 h after PGF2alpha and inseminated 16 to 20 h later. Cows pregnant at d 27 were reexamined for pregnancy at 45 d after insemination. First-service pregnancy rates at d 45 were increased in cows not resynchronized that initiated bST treatment at 63 +/- 3 d postpartum, compared with cows initiating bST treatment at 105 +/- 3 d postpartum (37.7 +/- 5.8% and 22.1 +/- 4.2%, respectively), but the effect of bST treatment was not observed when cows were resynchronized (25.6 +/- 4.3% and 25.8 +/- 5.5%, respectively). Thus, bST increased pregnancy rates to a timed artificial insemination protocol.