Understanding the symptoms of estrus in sows is a crucial aspect of the breeding process. The characteristics of a sow's estrous cycle vary depending on the stage of estrus, so farmers must be familiar with these symptoms. So what are the symptoms of estrus in sows? Let's find out.
Symptoms of Estrus in Sows
1. Symptoms in the Early Stage of Estrus:
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Swelling of the vulva, which may turn red.
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Excretion of watery mucous from the vulva.
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Restlessness and mounting of other sows or boars.
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Audible grunting and squealing.
2. Symptoms in the Middle Stage of Estrus:
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Standing heat, where the sow remains still when pressure is applied to her back.
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This is the ideal time for breeding, as conception rates are highest.
3. Symptoms in the Late Stage of Estrus:
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Decreased activity and return to normal vulvar appearance.
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Loss of standing heat response, indicating the end of estrus.
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Breeding is no longer advisable, and the sow must wait for the next estrous cycle.
What to Do If Sows Do Not Enter Estrus?
1. Change Pens:
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Move sows to a different pen as they approach estrus to facilitate activity.
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Group sows of similar size and shape together to encourage mounting behavior.
2. Boar Exposure:
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Starting at 165-170 days of age and weighing over 200 pounds, gilts should have daily exposure to boars for 15 minutes twice a day.
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Using different boars with strong libido can enhance estrus induction.
3. Enhanced Management:
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Ensure proper body condition by providing 2-4 hours of exercise daily for overweight sows and increasing the amount of green feed.
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Adjust the diet according to the sow's lactation status to prevent weight loss and provide adequate energy and protein.
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Avoid feeding moldy or high-metal feed.
4. Hormonal Stimulation:
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Use hormonal drugs such as pregnant mare serum gonadotropin (PMSG) strictly according to the instructions for sows experiencing estrus.
In conclusion, the symptoms of estrus in sows vary at different stages, and it is essential to make accurate judgments to determine the optimal breeding period.
Frequently Asked Questions (FAQ)
1. What are the symptoms of estrus in sows?
The symptoms of estrus in sows vary depending on the stage of estrus. In the early stage, sows may exhibit vulvar swelling and redness, excrete watery mucous from the vulva, display restlessness, mount other sows or boars, and emit audible grunting and squealing. In the middle stage, sows stand still when pressure is applied to their back. In the late stage, sows become less active, the vulva returns to its normal appearance, and the standing heat response diminishes.
2. What should be done if sows do not enter estrus?
If sows do not enter estrus, several measures can be taken:
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Change pens to facilitate activity and encourage mounting behavior.
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Provide daily exposure to boars for 15 minutes twice a day, starting at 165-170 days of age and weighing over 200 pounds.
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Enhance management by ensuring proper body condition, adjusting the diet according to the sow's lactation status, and avoiding feeding moldy or high-metal feed.
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Use hormonal stimulation with drugs such as pregnant mare serum gonadotropin (PMSG), following the instructions for sows experiencing estrus.
3. When is the best time to breed sows?
The best time to breed sows is during the middle stage of estrus when they exhibit standing heat, indicating optimal fertility. This stage usually occurs after the early symptoms of estrus and before the late-stage symptoms.
4. How can farmers determine the stage of estrus in sows?
Farmers can determine the stage of estrus in sows by observing their behavior and physical signs. Early-stage symptoms include vulvar swelling and redness, watery mucous excretion, restlessness, and mounting behavior. Middle-stage symptoms include standing heat, where sows remain still when pressure is applied to their back. Late-stage symptoms include decreased activity and the return of the vulva to its normal appearance.
5. What factors affect the estrous cycle in sows?
Several factors can affect the estrous cycle in sows, including genetics, nutrition, environment, and management practices. Poor nutrition, inadequate housing conditions, and stress can disrupt the estrous cycle and reduce fertility.
