Factors affecting cow's eclampsia and estrus symptoms
Variety Cattle of different breeds, or even within the same breed, can show varying performances during the early and late stages of puberty and estrus. In general, larger breeds tend to reach their first estrus later than smaller ones. For example, small dairy cows like Juanjuan may begin estrus at around 8 months, while racing cattle and Holsteins typically start at 11 months. Breeds raised for beef often have a later onset compared to dairy breeds, with an average of 13 to 18 months, while yaks usually start at about 24 months. Natural Factors Due to long-term natural and artificial selection, different cattle breeds have developed unique estrus characteristics influenced by geographical and environmental factors. Although these traits have evolved with changes in feeding practices, some natural influences can still be observed today. The duration of estrus in cows is also affected by climate. During hot seasons, the estrus period tends to be shorter. In summer, cows may secrete more progesterone from the adrenal cortex, in addition to the normal production by the corpus luteum, which shortens the estrus period. Cows grazing on grasslands often have shorter estrus periods compared to those in farming areas when feed is limited. Nutritional Level Nutritional status plays a crucial role in determining the onset of puberty and the intensity of estrus in cows. The impact of the environment on estrus is also partly due to variations in nutrition. A well-balanced diet can enhance growth rates, promote earlier sexual maturity, and improve estrus expression. Changes in body weight are directly linked to the timing of puberty. Good husbandry and management contribute to healthy development and timely sexual maturity. Studies have shown that cows with higher nutritional levels can reach puberty 6 to 9 months earlier than those with lower nutrition. Under good conditions, Qinchuan cattle typically mature at around 9.3 months (280 days), but under poor feeding conditions, they may mature 3 to 6 months later. Some plants naturally consumed by cattle may affect puberty and reproductive cycles. For instance, phytoestrogens found in legumes like clover can influence estrus patterns. In traditional Chinese practices, certain plants were used in early spring to stimulate animal fertility, showcasing the use of phytoestrogens. Prolonged consumption of clover has been associated with increased abortion rates and signs of pseudo-estrus in virgin cows. Similarly, plants like North American madder contain estrogen-like compounds that may interfere with reproductive functions. Research shows that such plant-based estrogens can hinder follicle development, affecting fertility in cattle. Production Level and Management Practices Estrus behavior in cows is closely related to their production level. Beef cattle often display less obvious estrus signs compared to dairy cows. However, high-producing dairy cows sometimes exhibit no clear estrus symptoms, possibly due to the strong metabolic demands of milk production, which can suppress reproductive hormones. Obese cows may also show reduced estrus signs, potentially linked to hormonal imbalances. In practice, it's important to manage feeding and recovery periods after calving. For example, high-yielding dairy cows may produce milk for about 9 days before others, and the more frequently they are milked, the longer the interval between estrus events. Cows that are undernourished or weak tend to have longer intervals between estrus. Feeding energy-rich diets pre- and post-calving can help shorten the first estrus interval. For instance, providing sufficient energy before calving and lower energy after can extend the interval, sometimes delaying breeding. If these cows need to be bred ahead of schedule, measures like early weaning may be necessary to encourage estrus. Disposable Knee Arthroscopy Pack Knee Arthroscopy Pack,Sterile Knee Arthroscopy Packs,Surgical Arthroscopy Knee Pack,Disposable Knee Arthroscopy Pack Xinxiang Huaxi Sanitary Materials Co., Ltd. , https://www.huaximedical.com