Pereira L L, Ferreira A P, Vale W G, Serique L R, Neves Kal, Morini A C, Monteiro B M, Minervino Ahh
Instituto de Biodiversidade e Florestas, Universidade Federal do Oeste do Pará (UFOPA), Santarém, Pará, Brazil.
Faculdade de Medicina Veterinária e Zootecnia (FMVZ), Universidade de São Paulo (USP), São Paulo, Brazil.
Reprod Domest Anim. 2018 Jun;53(3):624-628. doi: 10.1111/rda.13150. Epub 2018 Feb 9.
This study had the aim of investigating the efficiency of timed artificial insemination (TAI) through the progesterone-releasing intravaginal device (PRID), used in new condition and for the second and third times in Nelore cows. The effects of device reuse and body condition score (BCS) on the conception rate (CR) were evaluated in 1,122 multiparous Nelore cows (mean BCS of 2.7 ± 0.4), which were randomly distributed into three groups that received new (n = 330), once (n = 439) and twice used (n = 353) PRID. Among the 1,122 females that underwent TAI, 573 became pregnant, thus representing an overall CR of 51.06%. Cows with BCS between 2.75 and 4.0 had greater (p < .0001) CR (69.75%) than cows with BSC of 2.0-2.5 (32.98%). It was observed that the CR through using PRID was 60.00%, 51.71% and 41.93% for new, once and twice used PRID, respectively, with difference between all groups (p < .0001). Under tropical conditions, animals with BCS greater than 2.5 had a higher CR, and the CR decreased proportionally with the number of times that the PRID had been used.
本研究旨在调查在新条件下以及在 Nelore 母牛第二次和第三次使用时，通过孕酮释放阴道内装置（PRID）进行定时人工授精（TAI）的效率。在 1122 头经产 Nelore 母牛（平均体况评分 2.7 ± 0.4）中评估了装置重复使用和体况评分（BCS）对受孕率（CR）的影响，这些母牛被随机分为三组，分别接受新的（n = 330）、使用过一次（n = 439）和使用过两次（n = 353）的 PRID。在接受 TAI 的 1122 头母牛中，573 头怀孕，因此总体受孕率为 51.06%。BCS 在 2.75 至 4.0 之间的母牛受孕率（69.75%）高于 BSC 为 2.0 - 2.5 的母牛（32.98%）（p <.0001）。观察到使用新的、使用过一次和使用过两次的 PRID 时，受孕率分别为 60.00%、51.71%和 41.93%，所有组之间存在差异（p <.0001）。在热带条件下，BCS 大于 2.5 的动物受孕率较高，并且受孕率随着 PRID 使用次数的增加而成比例下降。
