Reproductive performance of lactating dairy cows managed for first service using timed artificial insemination with or without detection of estrus using an activity-monitoring system
Reproductive performance of lactating dairy cows managed for first service using timed artificial insemination with or without detection of estrus using an activity-monitoring system
复制标题
DOI：
10.3168/jds.2013-7366
复制
发表时间：
2014-05-01
影响因子：
3.5
通讯作者：
Carvalho, P. D.
中科院分区：
文献类型：
--
作者：
Fricke, P. M.;Giordano, J. O.;Carvalho, P. D.
将商业奶牛场的泌乳奶牛（n = 1，025）在10 +/-3天的牛奶（DIM）中随机分配至3种处理中的1种，以使奶牛进行第一次人工授精（AI），并配备活性监测标签（Heatime; SCR Engineers Ltd.，内坦亚，以色列）在24 3 DIM。处理1中的奶牛（n = 339）基于从自愿等待期结束（50 DIM）直到提交Ovsynch方案的增加的活动进行授精;从21至65 DIM活动没有增加的奶牛在65 3DIM开始Ovsynch方案，而从21至50 DIM而不是从51至79 DIM活动没有增加的奶牛在79 ± 3 DIM开始Ovsynch方案。处理2中的奶牛（n = 340）基于第二PGF（2 α）后的活动进行授精，在50 DIM时注射预同步-Ovsynch方案，而活动没有增加的奶牛在65 ± 3 DIM时开始Ovsynch方案。在第二次PCF 2 α注射预同步-Ovsynch方案后，监测处理3中的奶牛（n = 346）的活动，但所有奶牛在完成预同步-Ovsynch方案后均接受75 ± 3DIM的定时AT（TAI）。活动监测系统检测到增加活动的56，69和70%的奶牛在治疗1，2和3，分别。治疗组2头奶牛的首次AI平均天数最少（62.5），治疗组3头奶牛的首次AI平均天数最多（74.9），治疗组1头奶牛的首次AT平均天数居中（67.4）。与治疗组3头奶牛（所有奶牛均在完成预同步-Ovsynch方案后接受TAI）相比，治疗组1和治疗组2头奶牛（在活动增加和TAI之间联合进行授精）在Al后35天每AT（P/AI）的总妊娠率更低（两种治疗组均为32%）。基于生存分析，虽然奶牛授精率不同的治疗，治疗并没有影响怀孕的奶牛的比例300 DIM。因此，使用活动监测系统的基础上的活动减少天的第一个AI的奶牛授精，而奶牛接受100% TAI后，完成预同步-Ovsynch协议有更多的P/AI。AT服务率和P/AT的奶牛怀孕率之间的权衡得到了经济分析的支持，其中净现值（$/奶牛每年）治疗之间的差异仅为4美元至8美元。我们的结论是，各种策略使用AT的基础上增加活动，使用活动监测系统和同步排卵和TAI的组合，可用于提交奶牛的第一个AI。
Lactating dairy cows (n = 1,025) on a commercial dairy farm were randomly assigned at 10 +/- 3 d in milk (DIM) to 1 of 3 treatments for submitting cows to first artificial insemination (AI) and were fitted with activity-monitoring tags (Heatime; SCR Engineers Ltd., Netanya, Israel) at 24 3 DIM. Cows (n = 339) in treatment 1 were inseminated based on increased activity from the end of the voluntary waiting period (50 DIM) until submission to an Ovsynch protocol; cows without increased activity from 21 to 65 DIM began an Ovsynch protocol at 65 3 DIM, whereas cows without increased activity from 21 to 50 DIM but not from 51 to 79 DIM began an Ovsynch protocol at 79 3 DIM. Cows (n = 340) in treatment 2 were inseminated based on activity after the second PGF(2 alpha), injection of a Presynch-Ovsynch protocol at 50 DIM, and cows without increased activity began an Ovsynch protocol at 65 3 DIM. Cows (n = 346) in treatment 3 were monitored for activity after the second PCF2 alpha, injection of a Presynch-Ovsynch protocol, but all cows received timed AT (TAI) at 75 3 DIM after completing the Presynch-Ovsynch protocol. The activity-monitoring system detected increased activity in 56, 69, and 70% of cows in treatments 1, 2, and 3, respectively. Treatment-2 cows had the fewest average days to first Al (62.5), treatment-3 cows had the most average days to first Al (74.9), and treatment-1 " cows had intermediate average days to first AT (67.4). Treatment-1 and -2 cows in which inseminations occurred as a combination between increased activity and TAI had fewer overall pregnancies per AT (P/AI) 35 d after Al (32% for both treatments) compared with treatment-3 cows, all of which received TAI after completing the Presynch-Ovsynch protocol (40%). Based on survival analysis, although the rate at which cows were inseminated differed among treatments, treatment did not affect the proportion of cows pregnant by 300 DIM. Thus, use of an activity-monitoring system to inseminate cows based on activity reduced days to first AI, whereas cows receiving 100% TAI after completing a Presynch-Ovsynch protocol had more P/AI. The trade-off between AT service rate and P/AT in the rate at which cows became pregnant was supported by an economic analysis in which the net present value ($/cow per year) differed by only $4 to $8 among treatments. We conclude that a variety of strategies using a combination of AT based on increased activity using an activity-monitoring system and synchronization of ovulation and TAI can be used to submit cows for first AI.