|Yen, Jong Tseng|
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/2/2001
Publication Date: 10/1/2001
Citation: Klindt, J., Yen, J.T., Christenson, R.K. 2001. Level of dietary energy during prepubertal growth and reproductive development of gilts. Journal of Animal Science. 79:2513-2523.
Interpretive Summary: Development of gilts that conceive early and continue to produce offspring is a primary objective of swine production. In swine production a large proportion of gilts selected as maternal animals fail to exhibit estrus and become pregnant in a timely manner. Nutrition is the most manipulable environmental factor that effects reproductive development and performance. .In this study different patterns of growth on reproductive development and performance of gilts through d 30 of gestation were investigated. At 13 wk of age, crossbred gilts were penned individually and assigned to receive 87.5%, 75%, 62.5%, and 50% of ad libitum energy intake. At 25 wk of age, gilts were moved to group pens and allowed ad libitum access to feed and estrous detection initiated. Pregnant gilts were slaughtered at 30 d of gestation and numbers of corpora lutea and live embryos recorded. Gilts subjected to the greatest feed restriction during development consumed the greatest quantity of feed during breeding. The treatment group that entered breeding lightest and leanest consumed the most feed during breeding and exhibited estrus the soonest, followed by the fattest, heaviest group, the group that consumed the least feed during breeding. Treatment groups did not differ in ovulation rate or live embryo numbers. Gilts restricted to 50% of calculated ad libitum intake from 13 to 25 wk of age and provided ad libitum access to feed during breeding were the most efficient producers of embryos at 30 d of gestation. In contemporary, highly managed swine production systems use of managed nutritional strategies, periods of restriction, as well as, periods of ad libitum access to feed, may allow improvements in efficiency of pork production.
Technical Abstract: Objective of this study was to determine the degree of feed restriction during development required to optimize reproductive performance and efficiency in gilts. Different patterns of growth on reproductive per- formance of gilts through d 30 of gestation were investigated. At 13 wk of age, 192 white crossbred gilts were penned individually and assigned to receive 87.5% (7/8AL), 75% (3/4AL), 62.5% (5/8AL) and 50% (1/2AL) of ad libitum energy intake. At 25 wk of age, gilts were moved to group pens and given ad libitum access to feed, and estrous detection was begun. Gilts were inseminated at first and subsequent observed estruses. Pregnant gilts slaughtered at 30 d of gestation, reproductive tracts collected and numbers of corpora lutea and embryos were recorded. Feed restriction during development resulted in differences in BW and backfat thickness at the start of the breeding period and differences in feed intake during breed- ing. Gilts subjected to the greatest feed restriction during development consumed the greatest quantity of feed during breeding. Feed intake during breeding was associated with BW and backfat gain during breeding. The 1/2AL group entered breeding lightest and leanest, and had the least number of days to first estrus, followed by 7/8AL, the fattest, heaviest group. Treatment groups did not differ in ovulation rate or live embryo numbers. Significant relationships between quantity of gross energy consumed during development and many variables considered important in reproductive development and performance were evident. Coupling restricted energy in- take during development with ad libitum intake during breeding negates many of the effects of feed restriction during the development period.