Backfat thickness during gestation and lactation period in respect to reproductive performance of primiparous and multiparous sows

Abstract

The aim of the study was to determine the effect of backfat thickness measuredduring gestation and after lactation of primiparous and multiparous sows on the value of reproductive traits. Backfat thickness was determined at mating, at 105 day of gestation and after weaning and were correlated with selected reproductive indicators including placenta weight. The study was carried out 20 primiparous and 20 multiparous sows of Polish Landrace breed. The nutrition and housing conditionswere the same for all pigs. Backfat and loin depth (P2, P4 , P4 M) were measuredusing PIGLOG 105 device. The evaluation of reproductive performance included the weight of placenta at parturition, the number of born piglets, litter weight, piglet bodyweight at birth, at 21 and at weaning (28 days). Multiparous sows were characterizedby greater fatness than primiparous sows in all periods of use. In all examined sowsthe backfat depth during gestation increased and decreased after lactation. Thosechanges were more pronounced in multiparous sows than in primiparous sows (P ≤0.01). Multiparous sows born and reared more piglets to 21 and 28 days of life (P ≤0.01). There have not been dead piglets in primiparous litters. Litters weight from multiparous sows were higher than from primiparous sows only at birth (P ≤ 0.01)and similar in rest periods of rearing. Individual body weight of piglets from primiparous was higher than that from multiparous sows at 21 and 28 days of life (P ≤0.01). Fatness changes during lactation, particularly in multiparous sows, were positively correlated with litter weight at birth and negatively correlated with piglet’s weight at 21 and 28 days of life and their daily gains (P ≤ 0.05). Correlations between placenta weight and backfat thickness during lactation were positive in both groups of sows (P ≤ 0.01).