What factors affect cattle estrus?
Several factors affecting cattle estrus
1. Breed: Different breeds of cattle, or different individuals of the same breed, differ in the timing of puberty and the signs of estrus. For example, the Jersey, a small dairy breed, reaches puberty at 8 months of age, while the Guernsey and Holstein reach it at 11 months; beef breeds often reach puberty later than dairy breeds; female water buffalo reach puberty even later, generally at about 13-18 months; female yaks reach puberty at an average of 24 months.
2. Natural factors: The duration of estrus in cows is also affected by climate. In hot seasons, the duration of estrus in cows is shorter than in other seasons. In the hot summer, in addition to the normal secretion of progesterone by the ovarian corpus luteum, progesterone is also secreted by the adrenal cortex of the cow, which shortens the duration of estrus.
3. Nutritional level: This is a very important factor affecting the puberty and estrous behavior of livestock, and the influence of the natural environment on cow estrus is, to a certain extent, also caused by changes in nutritional level. In general, a good feeding level can increase the growth rate of cattle, advance their sexual maturity, and also strengthen their estrous behavior. Changes in body weight of cattle are directly related to puberty; therefore, under good feeding and management conditions, healthy growth of cattle is conducive to their sexual maturity. The feed that cattle consume naturally may contain certain substances that affect the puberty of cattle and the return to estrus of cows that have calved.
4. Production level and management methods: The estrous behavior of cows is related to production performance. Beef cattle often show estrus less obviously than dairy cattle, and individual dairy cows with high milk yield sometimes also show estrus less obviously than other cattle. The reason may be related to the vigorous metabolic function of milk production in high-yielding dairy cows, which to a certain extent suppresses the reproductive endocrine function related to estrus. Obese cattle often show no obvious estrous characteristics, which may also be related to hormone secretion. Therefore, in production, the time interval for cows to resume estrus after calving should be avoided in relation to cattle feeding and management measures. For example, high-yielding dairy cows may take about 9 days longer to show estrus than low-yielding dairy cows, and the more times they are milked or suckled each day, the longer the interval. Song Yingjun