It was hypothesized that values for fertility variables would vary with number of rams ewes mated with in a group mating management system. In Experiment 1, for adult ewes (n = 872) joined with rams for 35-38 days, 19.0 ± 2.2 %, 19.2 ± 3.5 %, 34.4 ± 1.3 % and 27.4 ± 3.3 % were marked by zero, one, two or three rams during the first 17 days, respectively. In general, as number of rams with which ewes mated increased, number of lambs born (NLB) increased, however, ovulation rate (OR) did not. In mated ewes, embryo survival (ES) increased (P < 0.05) as number of rams with which ewes mated increased. In Experiment 2, ewes that mated with zero or one ram had lesser concentrations of estradiol than ewes that mated with two or three rams when evaluated 30 h after initiation of the follicular phase. Following breeding on the subsequent estrus, number of fetuses at mid-gestation was less in ewes that had mated, in the previous estrus, with zero or one ram compared to two or three rams. In summary, ewes mating with a larger number of rams had greater values for the fertility variables that were evaluated compared with those mating with fewer rams. When ewes mated with fewer rams during the estrous period there were lesser concentrations of estradiol, potentially associated with the decreased ES.

中文翻译：

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生育能力与母羊群体交配行为的关系。

假设生育率变量的值会随着群体交配管理系统中公羊的数量而变化。在实验1中，对于成年母羊（n = 872）与公羊连成一体的35-38天，分别以零，一，二或三来标记19.0±2.2％，19.2±3.5％，34.4±1.3％和27.4±3.3％在前17天内分别进行公羊活动。通常，随着母羊交配的公羊数量的增加，出生羔羊的数量（NLB）增加，但是排卵率（OR）却没有。在交配母羊中，随着母羊交配的公羊数量的增加，胚胎存活率（ES）增加（P <0.05）。在实验2中，在卵泡期开始30小时后评估，与零只或一只公羊交配的母羊的雌二醇浓度比与两只或三只公羊交配的母羊的雌二醇浓度低。在随后的发情期繁殖后，与之前的两到三只公羊相比，在前发情期交配零头或一头公羊的母羊，妊娠中期的胎儿数量要少。总之，与较少公羊交配的母羊相比，与大量公羊交配的母羊的育性变量值更高。当母羊在发情期与较少的公羊交配时，雌二醇的浓度降低，可能与ES降低有关。