Animal Science Department

 

Date of this Version

2011

Comments

Published in 2010 Nebraska Swine Report. Published by Extension Division, Agricultural Research Division, Institute of Agriculture and Natural Resouces, University of Nebraska-Lincoln. Copyright ©2010 Regents of the University of Nebraska.

Abstract

This experiment evaluated the effects of developing gilts with ad libitum access to feed to breeding age (226 days) or feed intake restriction from 123 to 226 days of age. Gilts were managed in groups of 10 per pen. Those in the restricted group were fed two meals per day so that energy intake was 75% of that of the ad libitum group. Protein, vitamins , and minerals in their diet were increased so that daily intake of these nutrients was not restricted. A total of 661 gilts of two genetic lines that differed in reproductive rate and in lean growth rate started the experiment at 60 days of age, and one-half of the gilts of each line were developed with each feeding regimen. Growth and backfat were recorded at 14-day intervals from 60 to 226 days of age. Boar exposure to determine age at puberty was initiated at 140 days of age. A total of 509 gilts that could be mated at second or later post-pubertal estrus were designated as breeders and their production through four parities was recorded. Females were managed alike after 230 days of age and were culled only for reproductive failure, death, ruptures, or severe foot and leg problems. No interactions of genetic line by treatment were significant as females of both lines responded similarly to the developmental regimens. Developing gilts with energy restriction significantly decreased the proportion of gilts that expressed a pubertal estrus by 230 days of age, from 96% to 86% and increased their age at puberty from 174.1 to 177.5 days. Thereafter, females developed with both regimens had similar reproductive performance. Measures of productivity through parity 4 were 8 to 11% greater for females developed with energy restriction, but none of the differences were significant (P ≥ 0.14).

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