Effects of different superovulation protocols on sex-controlled embryo production in Holstein dairy cows
The experiment was conducted to analyze the effects of different superovulation protocols on the production of sex-controlled embryos in Holstein dairy cows.A total of 89 healthy Holstein dairy cows aged 12 to 14 months were used as donors,in which embryos were collected in vivo using the flushing technique to compare the effects of two superovulation protocols.Protocol 1 involved the use of follicle-stimulating hormone-Ningbo(FSH-N,total dose of 500 IU),with a decreasing dose(4 mL to 1 mL)administered over 4 d,followed by the injection of human chorionic gonadotropin(hCG)on the 9th day to induce ovulation and timed insemination.Protocol 2 involved the use of follicle-stimulating hormone-Reprobiol(FSH-R,total dose of 500 IU),with a lower dose decreasing scheme(2 mL to 0.5 mL),and the insemination was carried out on the 9th day of estrus.Both protocols involved the placement of a vaginal sponge and the injection of estradiol(E2)and progesterone(P4)on the first day,the injection of prostaglandin(PG)and removal of the sponge on the 7th day,and embryo flushing was done on the 16th day.The number of embryos recovered per head,the number of high-quality embryos per head,and the rate of high-quality embryos were recorded and statistically analyzed.The results showed that protocol 2 was more effective than protocol 1 in terms of the number of embryos recovered per head(9.75±4.54 vs.4.16±2.49)and the number of high-quality embryos per head(3.96±2.65 vs.1.66±1.34,P<0.05),while there was no significant difference in the rate of high-quality embryos(40.64%vs.39.87%,P>0.05).In conclusion,under the conditions of this experiment,protocol 2(using FSH products from Reprobiol,Belgium)was more effective.
Holstein dairy cowsfollicle-stimulating hormonesuperovulation procedurein vivo embryo productionnumber of fine embryos
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