Morotti Fábio, Moretti Rogério, Dos Santos Gustavo Martins Gomes, Silva-Santos Katia Cristina, Ramos Cerqueira Pedro Henrique, Seneda Marcelo Marcondes
Laboratory of Animal Reproduction, University of Londrina, Parana, Brazil.
Sheep Embryo Reprodução Animal, Assaí, Parana, Brazil.
Anim Reprod Sci. 2018 Jan;188:170-177. doi: 10.1016/j.anireprosci.2017.12.001. Epub 2017 Dec 6.
Two experiments in Nelore cows subjected to timed artificial insemination (TAI) were designed to compare the influence of the antral follicle count (AFC/AFCs) on (1) ovarian follicular dynamics and (2) conception rates. First, multiparous cows with high (≥45 follicles; n=43) or low (≤15 follicles; n=32) AFCs were selected to undergo a TAI protocol to monitor ovarian follicular dynamics. Second, the AFCs of 962 cows also subjected to TAI were determined and classified as groups of high (G-high; ≥45 follicles; n=194), intermediate (G-intermediate; ≥20≤40 follicles, n=397) or low (G-low; ≤15 follicles; n=243) AFCs. In study I, the ovarian measurements (diameter, perimeter and area) were greater (P≤0.05) and there was a greater consistency in number of antral follicles during the period of synchronization for TAI in the high than low group. Effects of the AFC and ultrasonic evaluation interval on the follicular diameter were observed (P≤0.05); however, there was no interaction (P>0.05). Dominant follicles had greater diameters (P≤0.05) in the G-low than in the G-high at D (7.3±2.2 vs. 6.2±1.4mm, respectively, P=0.06), D (11.2±1.8 vs. 9.5±1.8mm, respectively), D (12.3±1.7 vs. 10.6±1.7mm, respectively), and D (13.4±1.3 vs. 12.2±1.8mm, respectively), as well as greater estimated diameters of ovulatory follicles (14.4±1.5 vs. 13.4±2.1mm, respectively, P=0.08). In study II, the cows with fewer AFCs had greater (P≤0.05) conception rates (61.7%) than the cows with the intermediate (52.9%) and greater (49.5%) AFCs. Nelore cows with fewer AFCs subjected to synchronization of time of ovulation had a larger follicular diameter and a greater conception rate than the groups with intermediate and a greater AFCs.
在接受定时人工授精（TAI）的内洛尔牛身上进行了两项实验，旨在比较窦卵泡计数（AFC/AFCs）对（1）卵巢卵泡动态和（2）受孕率的影响。首先，选择多胎且AFC高（≥45个卵泡；n = 43）或低（≤15个卵泡；n = 32）的母牛进行TAI方案，以监测卵巢卵泡动态。其次，测定了962头同样接受TAI的母牛的AFCs，并将其分为高（G-高；≥45个卵泡；n = 194）、中（G-中；≥20≤40个卵泡，n = 397）或低（G-低；≤15个卵泡；n = 243）AFC组。在研究I中，与低AFC组相比，高AFC组在TAI同步期的卵巢测量值（直径、周长和面积）更大（P≤0.05），窦卵泡数量的一致性更高。观察到AFC和超声评估间隔对卵泡直径有影响（P≤0.05）；然而，不存在交互作用（P>0.05）。在D1（分别为7.3±2.2对6.2±1.4mm，P = 0.06）、D2（分别为11.2±1.8对9.5±1.8mm）、D3（分别为12.3±1.7对10.6±1.7mm）和D4（分别为13.4±1.3对12.2±1.8mm）时，G-低组的优势卵泡直径比G-高组更大（P≤0.05），排卵卵泡的估计直径也更大（分别为14.4±1.5对13.4±2.1mm，P = 0.08）。在研究II中，AFC较少的母牛受孕率（61.7%）高于AFC中等（52.9%）和较多（49.5%）的母牛。与AFC中等和较多的组相比，排卵时间同步的AFC较少的内洛尔母牛卵泡直径更大，受孕率更高。
