Emospheric cycle of beef cattle – Furwood – China Animal Husbandry Website – A useful animal husbandry website
After the first estrus appeared, the physiological state of its reproductive organs and the entire body had a series of periodic changes, and the initial renewal has been referred to until it stops reproducing the age, and this periodic sexual activity is called estrus cycle or sexual cycle. . Its calculations generally start estrus from this time to the next start, the cow is generally 21 days (18 ~ 25 days), and the boy cow is 20 days (18 ~ 24 days). The estrus cycle of the cow, according to the mental state, ovarian changes and the physiological changes of the reproductive tract into four periods:
(1) Emotional early estrus, the preparation stage of estrus, with the previous estrus The gradual shrinkage degradation of cyclod, the new follicles began development, and slightly increased, the concentration of female hormones in the blood increased, and the reproductive organs began to congest, and the mucous membrane hyperplasia, the cervical port is slightly open, but there is no sexual desire Performance, this period lasts for 1 to 3 days.
(2) The estrus is that the cow continues from the beginning of estrus to the end of the estrus, that is, the ethics. The cow has sex, the vulvine, the cervix and the uterus are congested, and the adrenal secretion activity is enhanced, and the mucus, the cervical tube is loose, and the ovarian is developing very fast. The cow is relatively short, and the yellow cattle is 30 hours (17 ~ 45 hours). The length of this time is affected by variety factors, and is also affected by factors such as climate and nutritional conditions. The season of high temperature is shorter than other seasons. In the hot summer, in addition to the ovarian yellow body, it is also born from the cow’s adrenal cortex to shorten the resumption of estrus. When the grassland cow feed is inadequate, estrus is shorter than the cows raised by the farm.
(3) Emotional later, the cow has changed from sexual excitement to quiet, and there is no estrus. The number of estrogens is reduced, and the cervical tube is gradually contracted, and the secretion of the gland has gradually weakened. The endometrium has gradually thickened, and hemoglitterin is formed on the ovary of ovulation. The post-transition is yellow body, the secretion of progesterone is gradually increased, during this period About 90% of the births of cows and 50% of adult cows flow out from the vagina, indicating that the cow is estrus 2 to 4 days ago, if mismatch, you can pay attention to the estrus after 16 ~ 19 days, this time is about 3 to 4 days.
(4) The relative physiological stationary period after the end of the curse. The main feature is that the yellow body is graduallyIt turns slightly atrophy, and the secretion of progesterone is also growing to gradually decline. Sexual desire has completely disappeared, the mental state has returned to normal, the endometrium is thickened, the gland is highly developed, large and variable, the branch is more, the secretion is strong. In the late relationship, the endometrial retraction, the gland is small, the secretion activity is stopped, and the ovarian is completely retracted. The length of the rest period often determines the length of the estrus cycle. This period is about 12 to 15 days.
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