Influence of cycle stimulation in weaned sows on fertility depend on season

Abstract

In summer high temperatures are stress for sows mostly. This situation often affects the reproduction physiology in animals strongly. As a result of that the fertility and reproduction performance of sows can be reduced. High environmental temperatures and especially heat accumulation in body of the animals affect the metabolism in high performance sows. That is important in very sensitive phases in reproduction cycle of sows like heat, pregnancy and lactation. Young sows (gilts and primiparous sows) are more sensitive than older sows. This situation demands zoo- and biotechnical activities expecting assistance for reproduction endocrinology in sows. Regarding this aim, the stimulation of cycle with eCG in weaned sows with different age was investigated. Following results were found: The effect of cycle stimulation with 800 IU eCG in weaned sows differ depend on age of sows, season and temperature. Cycle stimulation with eCG in summer (July, August, September) reduces risk of low fertility in sows. In other seasons the positive effect of biotechnical cycle stimulation is not clear generally. Especially in primiparous sows there is a positive effect of biotechnical treatment in summer. In older sows in 3rd to 5th litter the cycle stimulation has no significant positive effect on fertility. In sows with more than 5 litters cycle stimulations are necessary to save a high reproduction performance generally.