Factors affecting cow's eclampsia and estrus symptoms
Diversity Cattle of different breeds, even within the same breed, show varying performances during the early and late stages of puberty and estrus. Generally, larger breeds reach their first estrus later than smaller ones. For example, small dairy cattle like Juanjuan may begin estrus at 8 months, while racing cows or Holsteins typically start at around 11 months. Veterinary cattle often have a later onset compared to dairy breeds, with an average of 13 to 18 months, and yaks may not show estrus until about 24 months. Natural Factors Geographical and environmental factors influence the estrus patterns of different cattle breeds. Over time, these characteristics have been shaped by both natural and artificial selection. Although modern feeding practices have altered some traits, certain natural influences still remain visible. The length of estrus in cows is also affected by weather conditions. During hot seasons, estrus tends to be shorter. In summer, cows may secrete additional progesterone from the adrenal cortex, which shortens the estrus period. Cows grazing on grasslands may have shorter estrus periods when feed is limited, compared to those in farming areas. Nutritional Level Feed quality plays a crucial role in determining the timing of puberty and the intensity of estrus. The impact of the environment on estrus is closely linked to nutritional status. A well-balanced diet can speed up growth, promote sexual maturity, and enhance estrus behavior. A cow’s body weight directly affects its puberty timeline. Good management and proper nutrition support healthy development and earlier sexual maturity. Studies show that high-nutrient-fed cattle can reach puberty 6 to 9 months earlier than those with poor diets. For instance, Qinchuan cattle usually mature at around 9.3 months (280 days) under good conditions, but may delay by 3 to 6 months if fed poorly. Naturally consumed feed may contain substances that affect puberty and reproductive cycles. For example, phytoestrogens found in legumes like clover can interfere with estrus. In traditional Chinese practices, certain plants are used in spring to stimulate animal fertility, showcasing the use of phytoestrogens. Prolonged consumption of clover has been linked to increased abortion rates and abnormal physical signs in young cows. Similarly, North American madder contains estrogen-like compounds that may harm reproductive functions. Research indicates that plant-based estrogens can inhibit follicle development in cattle, affecting fertility. Production Level and Management Estrus behavior is closely related to a cow's productivity. Beef cattle often show less obvious estrus signs compared to dairy cows. High-producing dairy cows may exhibit weak or no estrus due to the metabolic demands of milk production, which can suppress reproductive hormones. Obese cows may have unclear estrus signs, possibly due to hormonal imbalances. In practice, it's important to manage post-calving recovery through feeding and care. For example, high-yield dairy cows may take about 9 days before they start producing milk, while lower-yielding cows may take longer. More frequent milking or nursing leads to longer intervals between estrus. Cows that are undernourished or weak also tend to have extended estrus intervals. Feeding energy-rich diets pre- and post-partum can help shorten the first estrus interval. For example, feeding high-energy diets before calving and low-energy after can prolong the interval, sometimes causing cows to miss breeding season. If such cows need to be bred early, measures like early weaning may be necessary to induce estrus in advance. Extremity Pack,Sterile Extremity Pack,Disposable Extremity Pack,Disposable Sterile Extremity Pack Xinxiang Huaxi Sanitary Materials Co., Ltd. , https://www.huaximedical.com