Knights M, Maze T D, Bridges P J, Lewis P E, Inskeep E K
Division of Animal and Veterinary Sciences, West Virginia University, Morgantown 26506, USA.
Theriogenology. 2001 Mar 15;55(5):1181-91. doi: 10.1016/s0093-691x(01)00476-9.
The objectives were to evaluate, in anestrous ewes, the effectiveness of a CIDR-G device (0.3 g progesterone) administered for 5 d to induce estrus; and FSH (Folltropin; 55 mg NIH-FSH-P1 equivalent) in saline:propylene glycol (1:4) 24 h before insert removal (Day 0), to increase ovulation rate and prolificacy. Ewes of mixed breeding were assigned at random to 3 treatments: control (C; n = 125), 5 d progesterone (P5; n = 257) and 5 d progesterone plus FSH (P5F; n = 271). Intact rams were joined at insert removal and ewes were observed every 24 h for 3 d. On Day 14, the ovulation rates of all ewes detected in estrus in the treated groups were determined using transrectal ultrasonography. Rams were removed on Day 26 to 31. Ewes were examined for pregnancy then, and again 20 to 25 d later to detect ewes that conceived to the second service period. Percentage of ewes marked by rams was higher in progesterone-treated (77%) than in C (20%; P < 0.01), but did not differ between P5 and P5F. The ovulation rate (1.95+/-0.04) did not differ due to FSH. Conception (68%) and pregnancy (52%) rates were higher in progesterone-treated (P < 0.01) than in C (0%) ewes. Estrous response varied quadratically with time after ram introduction, and the conception rate varied quadratically with the time of observation of onset of estrus. Over two service periods more progesterone-treated than C ewes lambed (65 vs 45%; P < 0.01). Lambs born per ewe exposed (0.7+/-0.1, 1.0+/-0.1, and 1.1+/-0.1 for C, P5 and P5F, respectively) was increased by progesterone (P < 0.05). Litter size to the first service period (1.59+/-0.04) and overall (1.54+/-0.03) did not differ among treatment groups. FSH-treated ewes tended to have more lambs (1.67+/-0.1) than did ewes receiving progesterone alone (1.5+/-0.1; P = 0.06) and than did ewes lambing to the second service period (1.5+/-0.1; P = 0.06). In summary, a 5-d progesterone pre-treatment of anestrous ewes induced estrous cycles and increased the pregnancy rates. A single injection of FSH only tended to increase litter size.
本研究旨在评估在乏情母羊中，使用含0.3克孕酮的CIDR - G装置处理5天诱导发情的效果；以及在取出装置前24小时（第0天），在生理盐水与丙二醇（1:4）中注射促卵泡素（Folltropin；相当于55毫克NIH - FSH - P1），以提高排卵率和繁殖力。将混种母羊随机分为3组处理：对照组（C；n = 125）、5天孕酮处理组（P5；n = 257）和5天孕酮加促卵泡素处理组（P5F；n = 271）。在取出装置时放入未阉割的公羊，每24小时观察母羊3天。在第14天，使用经直肠超声检查确定处理组中所有检测到发情的母羊的排卵率。在第26至31天移走公羊。随后检查母羊是否怀孕，并在20至25天后再次检查，以检测在第二个配种期受孕的母羊。经孕酮处理的母羊被公羊标记的百分比（77%）高于对照组（20%；P < 0.01），但P5和P5F组之间无差异。促卵泡素对排卵率（1.95±0.04）无影响。经孕酮处理的母羊的受孕率（68%）和妊娠率（52%）高于对照组（0%）母羊（P < 0.01）。发情反应随引入公羊后的时间呈二次方变化，受孕率随发情开始观察时间呈二次方变化。在两个配种期内，经孕酮处理的产羔母羊比对照组多（65%对45%；P < 0.01）。每只参与配种的母羊所产羔羊数（对照组、P5组和P5F组分别为0.7±0.1、1.0±0.1和1.1±0.1）因孕酮处理而增加（P < 0.05）。各处理组第一个配种期的产仔数（1.59±0.04）和总体产仔数（1.54±0.03）无差异。促卵泡素处理的母羊产羔数（1.67±0.1）倾向于多于仅接受孕酮处理的母羊（1.5±0.1；P = 0.06），也多于在第二个配种期产羔的母羊（1.5±0.1；P = 0.06）。总之，对乏情母羊进行5天孕酮预处理可诱导发情周期并提高妊娠率。单次注射促卵泡素仅倾向于增加产仔数。
