Hawk H W, Conley H H, Wall R J, Whitaker R O
Reproduction Laboratory, Animal Science Institute Agricultural Research Service, USDA Beltsville, MD 20705, USA.
Theriogenology. 1988;29(5):1131-42. doi: 10.1016/s0093-691x(88)80038-4.
Three experiments were conducted with 105 superovulating Holstein dairy cows in attempts to improve the fertilization rate. Cows were superovulated with follicle-stimulating hormone (FSH) and time of estrus was regulated with prostaglandin F(2)alpha (PGF(2)alpha). Semen was deposited on each infundibulum through a laparoscope inserted through the flank (Experiment 1) or near the uterotubal junctions through flexible tubing passed through the cervix and uterine horns (Experiment 2). In the third experiment, high numbers of sperm in fresh semen were deposited in the uterus. Cows were necropsied and ova were recovered and examined about 3.5 d after the beginning of estrus. Deposition of 0.5 ml of frozen-thawed semen on each infundibulum (Experiment 1) reduced both ovum recovery and fertilization. In ten cows inseminated on the infundibulum, ova representing 43% of ovulation points were recovered and 9% of these recovered ova were fertilized. In ten control cows, ova representing 80% of ovulation points were recovered and 62% of them were fertilized. In a 2 x 2 experiment with 36 superovulating cows (Experiment 2), 1 ml of diluted fresh or frozen semen was deposited either near the uterotubal junction or in the uterine body. The overall fertilization rate was 61%, with no significant effect of site of semen deposition or type of semen used. In Experiment 3, 2 or 3 ml of neat semen (average of 4.4 billion sperm) was deposited in the uterus of 12 cows; 183 of 197 intact ova (93%) were fertilized. In 56 control cows inseminated with 0.5 to 1.5 ml of frozen diluted semen (average of 70 million sperm), 502 of 947 intact ova were fertilized (53%, P<0.001). Insemination with high numbers of fresh sperm overcame problems of sperm loss or sperm transport and improved the fertilization rate.
用105头超排的荷斯坦奶牛进行了三项实验，试图提高受精率。奶牛用促卵泡素（FSH）进行超排，发情时间用前列腺素F（2）α（PGF（2）α）调节。精液通过插入侧腹的腹腔镜放置在每个输卵管漏斗部（实验1），或通过穿过子宫颈和子宫角的柔性导管放置在子宫输卵管连接处附近（实验2）。在第三个实验中，将大量新鲜精液中的精子放置在子宫内。奶牛在发情开始约3.5天后进行剖检，回收并检查卵子。在每个输卵管漏斗部放置0.5毫升冻融精液（实验1）降低了卵子回收率和受精率。在10头在输卵管漏斗部输精的奶牛中，回收了占排卵点43%的卵子，其中9%的回收卵子受精。在10头对照奶牛中，回收了占排卵点80%的卵子，其中62%受精。在一项用36头超排奶牛进行的2×2实验（实验2）中，将1毫升稀释的新鲜或冷冻精液放置在子宫输卵管连接处附近或子宫体中。总体受精率为61%，精液放置部位或所用精液类型无显著影响。在实验3中，将2或3毫升纯精液（平均44亿个精子）放置在12头奶牛的子宫内；197个完整卵子中有183个（93%）受精。在56头用0.5至1.5毫升冷冻稀释精液（平均7000万个精子）输精的对照奶牛中，947个完整卵子中有502个受精（53%，P<0.001）。用大量新鲜精子输精克服了精子损失或精子运输问题，提高了受精率。
