Litter Size of Swine Confined during Gestation

Abstract

Effects of individual and group confinement prior to and during gestation on various reproductive traits of sows and gilts were studied. All animals were fed individually; opportunity for exercise was severely limited in individual confinement and was likely inhibited in group confinement. All aspects of reproduction were within the normal range for sows; birthweight per pig was the only trait in which the treatment groups differed significantly. Twenty-eight and 16%, respectively, of the gilts confined individually and in groups exhibited some interference with normal expression of estrus and mating behavior; 17 and 6%, respectively, failed to breed. There were no statistically significant differences in numbers of pigs born alive, dead or total, nor in average birthweight per pig for litters from gilts confined in the two systems. Data from previous seasons when the herd was non-confined and in a subsequent season when all were group-confined further indicate no significant effects of confinement on litter traits. Exercise requirements during gestation are met even in the 0.61 × 2.44 m. individual pens. Comparison of data from all groups indicates that there is no cumulative adverse effect of confinement on litter traits and that the primary inadequacy is the failure of some gilts to exhibit normal estrus and mating behavior. Copyright © 1969. American Society of Animal Science . Copyright 1969 by American Society of Animal Science