Breeding pig farms and large-scale pig farms are encouraged to give birth at suitable time in spring and autumn, and the delivery period is concentrated in 1 month.
The benefits of seasonal centralized delivery are as follows:
(1) is beneficial to improve the breeding rate and cultivate healthy piglets: it is divided into two seasons every year, that is, 1 1 starts from 65438+2 and gives birth in March of the following year; Breeding from early May to early June, giving birth in September.
These two farrowing months are the best season for breeding piglets, and also the better breeding season for sows after weaning, which is conducive to improving the conception rate and litter size.
In this season, the effect of cultivating piglets is very good as long as the cold protection care in early spring is done well.
Some pig farms give birth too early or too late, that is, in summer or winter, most of them have low mating rate and small weaning weight.
Of course, pig farms with good delivery room facilities can try to give birth in batches or throughout the year, constantly sum up experience and improve the reproductive effect.
Because babies are born all year round, heat preservation measures can be taken in winter, but it is difficult to cool down and reduce humidity in summer.
(2) Breeding can be avoided in high temperature season: high temperature and long-term sunshine have great adverse effects on the reproductive function of breeders and sows.
According to the observation results in Jianshi County, Hubei Province, the ovarian function of about 80% sows decreased from July to September, and the clinical manifestations were no estrus, no obvious estrus or irregular estrus.
At the same time, high temperature also affects the uterine environment of sows, reducing the conception rate, litter size, stillbirth and abnormal fetus number.
Boars are more sensitive to high temperature. Short-term high temperature will inhibit the function of testis to produce androgen, resulting in decreased sexual desire and mating ability.
From July to September, about 20% boars can't collect sperm or lose their reproductive ability, the number of spermatozoa is obviously reduced, the dead sperm and abnormal sperm are increased, and the density and vitality are decreased.
The pregnancy rate of 32086 Taihu sows in Danyang City, Jiangsu Province in different months was analyzed. The results show that LL ~ 65438+February is the highest, all above 90%, while L-May and 65438+ 10 are slightly lower, ranging from 88% to 90%. The lowest in July was 83.55%; June and September, which are similar to this period, are 87.6% and 86.6% respectively.
The best breeding season for Shandong pigs is also11-65438+February. Some pig farms think that sows have obvious estrus and high pregnancy rate during this period. Piglets born in spring are better than those born in autumn, but it is difficult to breed after May. Since the middle and late May, especially for some imported pig breeds, some sows are not affected by the dry temperature and long sunshine time.
Therefore, after the start of breeding in May, we should seize the favorable opportunity and strive to complete the breeding of pigs in a short time.