Influence of Diet and Sex on the Performance of Three Breeding Groups of Pigs Marketed at Three Different Weights PDF Download

Author: Peter Joseph Skitsko
Publisher:
ISBN:
Category : Swine
Languages : en
Pages : 0

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Book Description
Experiments were designed to study the influence of high and low energy diets under conditions of limit-feeding imposed by allowing pigs access to feed for two, 1 hr periods per day on the performance of three breeding groups of pigs marketed at three different weights. The diets contained approximately 3650 and 2750 kcal digestible energy per kg and had similar ratios of crude protein, lysine, methionine and cystine and calcium to digestible energy. Performance of the pigs was based on average daily gain, average daily feed consumption, feed conversion, digestibility of energy and nitrogen, nitrogen retention and carcass characteristics. A 2x2x2x3x3 factorial design consisting of two replicates, two diets, two sexes, three breeding groups and three market weights was used in these studies. In addition a Ix2x2x3 factorial experiment consisting of one breeding group, two diets, two sexes and three market weights was used to study the aforementioned parameters under self-feeding conditions. The high energy diet significantly improved average daily gain and feed conversion as compared to the low energy diet. However, when converted to the basis of digestible energy in Experiment 1, there were no differences in energetic efficiency between the pigs fed the high and low energy diets. Males had higher average daily feed consumption and, when the high energy diet was fed they had higher average daily gain than females. The males were less efficient converters of feed to gain when the low energy diet was fed but no differences in feed conversion existed between sexes when the high energy diet was fed. A significant difference between breeding groups was found for average daily gain and feed conversion; the Duroc and Hampshire-sired groups had a higher average daily gain and were more efficient converters of feed to gain than the Yorkshire-sired group. The digestibility of dietary energy and nitrogen was not affected by sex or breeding group. Nitrogen digestibility was increased when the high energy diet was fed. Nitrogen retention was not affected by diet, sex or breeding group. Carcasses of pigs receiving the high energy diet were fatter as evidenced by higher dressing percentages, greater total backfat thickness, decreased ratio of loin area to backfat thickness, lean in the ham face, ham as a percent of carcass and Record of Performance (ROP) score. Females were superior to the males in all carcass measurements except dressing percentage where differences were not significant. The Yorkshire-sired group were inferior to the Duroc and Hampshire-sired groups in dressing percentage and loin area but were superior in carcass length. Market weight had a significant effect on carcass characteristics. Dressing percentage, carcass length and loin area were improved with increases in carcass weight while the total backfat thickness, ham as a percent of carcass and ROP score were inferior with increases in carcass weight. Feeding system had significant effects on average daily gain, average daily feed consumption and feed conversion. Self-fed pigs had higher average daily gains and average daily feed consumption but were less efficient converters of feed to gain. Carcassses of self-fed pigs were inferior to those of limit-fed pigs in total backfat thickness, loin area, ratio of loin area to backfat thickness and ROP score.