Different Reproductive Hormone Regulation Of The Same Period On Cow Estrus Effect And Application

Reproductive hormones play a very important role in the reproductive performance of dairy cows. Reproductive hormone mainly include hypothalamic hormones, placental hormones, prostaglandins. They specifically target organs, involved in the regulation of various physiological activities, with a collaborative, contend and specificity effects. Hormone immunoreactivity (Hormoneimmononeutral, HIN) is the basic principle of gonadal hormones and macromolecular material coupling, forming immunogens, injecting animals, the body produces corresponding hormone antibody, active or passive and animal in vivo gonadotropin hormone bioactivity, making the total or partial loss, resulting in endocrine balance alterations, i.e. reduced the gonadal hormones in the hypothalamus and pituitary gland of the negative feedback, to achieve the purpose of promoting ovulation. The technology used in cattle and sheep breeding and growth, received a significant effect. Clinical immunology is mainly applied to the reproductive regulation of hormone, growth hormone, immune regulation, physiology of animal behavior have played a certain role, and this method is simple, no matter on animal rights and interests protection or raising stock raising levels are useful.In order to study the effect of different reproductive hormones on the regulation of synchronization of estrus in dairy cows,120Holstein cows (1.5-5years) were selected. The cows were randomly divided into3experimental groups and1control group according to a rectal examination. In experimental group1, cows were artificially inseminated in fixed time after intramuscular injection with0.4mg prostate hormone (Prostaglandin, PG) at7days and intramuscular injection with100μg GnRH at9days. In experimental group2, cows were injected with0.4mg PG intramuscularly. In experimental group3, cows were injected with1000IU of pregnant mare serum gonadotropin (PMSG) intramuscularly. The results showed that the estrous rates of experimental group1, experimental group2and experimental group3were70%(21/30) and80%(24/30) and80%(24/30), repectively; the pregnancy rates of them were63%(19/30),57%(17/30) and60%(18/30), repectively. The optimal effect on synchronization of estrus were obtained in young cows and the follicular phase.In order to investigate the application of PMSG in Shanghai area,90multiparous Holstein cows were selected which were1-7fetal and postnatal60days according to the rectal examination. The cows were randomly divided into1control group and2experimental groups. In control group, there was no drug treatment and the cows were artificially inseminated after after estrus. In experimental group1, the cows whose ovarian function were normal by rectal examination after60days postpartum, were injected with1500IU PMSG by intramuscularly. In experimental group2, the cows whose ovarian function were normal by rectal examination after60days postpartum, were injected with3000IU PMSG by intramuscularly. The results showed that the effective estrus rates of experimental group1and2were73%(22/30), and67%(20/30), repectively; the conception rates of experimental group1and2were82%(18/22) and75%(15/20), repectively. The optimal effect of PMSG on estrus and conception were obtained in1000-2000IU and1.5-3.0IU/kilogram.