DURATION OF SOWS GESTATION AND ITS INFLUENCE ON TECHNOLOGICAL PROCESS OF A PIG OPERATION

Sows in large pig farms are transferred to the far rowing sector on the 111-112 day of pregnancy; therefore, some of them with a shorter duration of pregnancy arrow in the section of pregnant animals in group pens, which sometimes leads to crushing and eating of sows’ piglets. Sows, the duration of pregnancy of which is more than 115 days, are disadvantageous in that they require additional costs for transfers from sector to sector before far rowing. Studies have been held using the breeding records of the Agricultural Open Joint-Stock Company "Agro-Plant" Kalitain Kyiv region. We have investigated into the duration of pregnancy of sows of large white breed and its changes with the age of sows, the repeatability and heritability ratios are determined in 128 randomly selected pigs with different lengths of the pregnancy period. All experimental sows were given the same feeding and keeping conditions. The experimental animals received wet feed. It has been established that the duration of pregnancy (from 106 to 122 days) is not constant and has significant fluctuations, which should be considered when developing technologies for the industrial production of pork. The sows in which during several far rowing the duration of pregnancy was shortened and averaged 112.3 days and the second group with extended pregnancy duration of 116.86 days have been identified. The duration of pregnancy of sows has rather high rates of heritability (from 0.47 to 0.72) and repeatability (from 0.17 to 0.74) which increase with their age. It is possible to select sows with a shortened and stable duration of pregnancy, the use of which will shorten the reproduction cycle, as well as increase the safety of piglets and reduce the costs related to additional transfers of pigs.