Sows do not show estrus. It is important for the majority of sows to avoid excessive investigation and analysis of their estrus after weaning. Instead, we can use data from the weaning-to-breeding interval to compare with historical records. Ideally, the weaning-to-breeding interval should be less than 10 days, with 7 days or fewer being the optimal range. If this interval is too long, it delays the sow’s farrowing date, which reduces the number of litters per sow annually. A common cause of this issue is the "thin sow syndrome," often resulting from poor nutrition during lactation in young sows. Checking the parity distribution can help identify if the problem is concentrated in the younger sows. It's important not to assume that low breeding efficiency is due to infectious diseases and rely solely on antibiotics. Post-weaning estrus is typically a management issue rather than an infectious one.
Observing the sow’s vulva for redness, swelling, and mucus discharge is essential, but inexperienced staff may miss signs of estrus, leading to missed breeding opportunities. The best time to observe is in the morning and evening, as this increases the chances of identifying estrus early and improving fertility rates. Hot weather can delay the onset of estrus after weaning. Heat stress causes sows to lose appetite, leading to nutrient deficiencies and contributing to the thin sow syndrome. Keeping sows and boars together or providing them with proper feeding can encourage estrus.
Poor boar fertility is another concern. Improper management of boars during their development can lead to reduced libido. Young boars may experience temporary sexual impotence during their first mating, but this is usually short-lived and doesn’t require immediate culling. High temperatures negatively affect boar performance and reduce sexual drive. On hot and humid afternoons, boars may appear lazy. Conditions like foot dysplasia, arthritis, or leg injuries also impact their ability to mate. Boars that are permanently unable to breed should be removed from the herd.
Estrus after mating indicates a failure in pregnancy. A typical replantation rate is below 15%, but a high rate extends the farrowing interval and reduces annual productivity. Sows that return to estrus between 18–24 days post-mating may have experienced a miscarriage within 12 days. One key factor affecting pregnancy rates is the timing of breeding. The best time to breed is 21–22 hours after the sow shows signs of estrus. If estrus is only observed once a day, it becomes difficult to determine when sows are actually in heat. Sows ovulate 24–36 hours after the start of estrus, and without accurate timing, breeding may occur too early or too late, reducing pregnancy success. Observing estrus twice daily, with a 4–12 hour gap, significantly improves pregnancy rates and litter size. Efficient sows should spend most of their time pregnant, giving birth, and nursing. Minimizing the interval between weaning and rebreeding is crucial for maximizing productivity.
Boar usage also plays a role in pregnancy success. Boars that are underused may have poor semen quality. Young boars under two weeks old produce very little sperm in their first ejaculation. Some farmers worry about overusing boars, but as long as they are not used more than four times a week, their fertility remains unaffected. Infectious diseases such as porcine reproductive and respiratory syndrome (PRRS), porcine parvovirus, and brucellosis can lead to high return rates.
Empty sows are those that fail to show estrus despite being pregnant. This can happen due to misdiagnosis or lack of proper estrus detection. Normally, the empty rate is around 5%, but it can increase due to either infectious diseases or management issues. Poor estrus detection leads to inaccurate pregnancy diagnosis, inflating the perceived pregnancy rate while increasing the actual empty rate. For example, a farm with a 90% pregnancy rate but only an 80% farrowing rate may indicate problems with both estrus detection and pregnancy diagnosis. Early detection of abortions or undiagnosed diseases can also raise the empty rate. Brucellosis can cause infertility, while PRRS can lead to high return rates or low birth rates.
Pedestrian Passing Equipment,Advertising Barrier Gate,Swing Wrought Iron Side Gate,Community Advertising Door
Shandong Changchongyun Intelligent Technology Co., Ltd. , https://www.ccyparking.com