Since the Beginning of Autumn, temperatures have fluctuated sharply. Daytime brings the “Autumn Tiger,” while nights are “Cold Frost Autumn,” with a large difference between day and night temperatures. Seasonal changes are particularly pronounced in areas north of the Yangtze River. The rates of abortion and stillbirth among sows due to farrow have risen noticeably, and sudden deaths among sows have also become more frequent. Today, two pig farmers told Teacher Zhang that several litters of sows had recently been aborted, and some sows had died. There was no time to treat them, and some piglets in the nursery period had also died. Pig farms are becoming increasingly unstable as autumn sets in. Teacher Zhang has summarized the causes of these symptoms.
First, seasonal characteristics: the large difference between daytime and nighttime temperatures and unstable weather cause a sharp rise in the likelihood of sows catching colds. When a sow develops a persistent fever or high fever, fever-reducing medication will inevitably be used. Most fever-reducing medications are contraindicated during pregnancy in sows, and using them can easily cause abortion. If the high fever persists and no medication is used, that can also lead to abortion. This is a difficult dilemma: “sacrifice the piglets to save the sow.” There is no better solution.
Second, by autumn, summer husbandry practices may not yet have been changed. As for pigsty hygiene, farmers may continue flushing the pens with clean water. Even if the weather still feels hot, wait until midday to flush the pen once. Do not assume that pigs feel the same way people do; consider whether pigs can tolerate this practice, as it can easily cause sows to catch colds and abort. Husbandry and management practices for sows should be adjusted as the seasons change.
Third, sharp fluctuations in the weather create favorable conditions for the spread of certain viral diseases. In particular, diseases such as parvovirus and pseudorabies may break out. Before this season, vaccinate against both diseases to ensure effective immunity.
Fourth, prevent tapeworm and protozoal infections. Protozoal diseases are specific to autumn, and sows are most susceptible to them. These diseases damage red blood cells and reduce their oxygen- and nutrient-carrying capacity, which can easily lead to abortion in sows. Therefore, before autumn begins, sows should be dewormed and treated for protozoa in the body, clearing both at the same time. It is recommended to use ivermectin for deworming before piglets are weaned, for seven consecutive days. About one and a half months after the sows have been bred, use doxycycline to eliminate blood protozoa for 5 consecutive days.
Fifth, streptococcal disease is one of the diseases that most needs to be guarded against in autumn. There is little time for effective treatment, as it generally develops rapidly. It is mainly caused by septicemic streptococcal infection, with symptoms including a persistent high fever in sows, systemic sepsis, and abortion. A typical finding at necropsy is rubbery lungs. Once septicemic streptococcal infection occurs, even the best veterinarian cannot treat it. To prevent this disease, mix preventive medication into the feed for all sows on the farm when autumn begins.