Influence of Season, Sex and Dietary Energy Concentration on Performance and Carcass Characteristics of Swine

Abstract

Eighty weanling Duroc pigs were individually fed to study effects of season (summer and winter), sex (barrow and gilt) and dietary energy concentration (25% corn cobs; 8% corn cobs; basal; 4% tallow; and 8% tallow) on performance and carcass traits of growing-finishing swine. In winter, pigs consumed more feed per day, required more feed per unit of gain, and yielded carcasses that were fatter than in summer. However, the rankings of the relative performance of the pigs by diets were alike for both seasons. Barrows consumed more feed per day and required more feed per unit of gain than gilts, but gilts yielded carcasses that were longer, with a larger loin-eye area, a higher yield of lean cuts than barrows, and there was no sex x dietary treatment interaction. Feed required per unit of gain decreased with each advance in energy concentration, and average daily gain of pigs fed 25% cobs was 11% less than average daily gain of pigs fed 8% cobs which in turn was 11% less than gains of pigs fed the other three diets. Backfat of pigs fed the 25% cobs diet was less than backfat of pigs fed the 8% cobs and basal diets which yielded less backfat than pigs fed tallow diets. Pigs fed 25% cobs had a lower dressing percent and larger loin-eye area than pigs fed tallow.