Effect of split-weaning interval on return to estrus and sow fertility
نویسنده
چکیده
Methods: Primiparous (n=181) and multiparous (n=759) sows of Large White and Landrace breeding on a commercial swine farm were assigned at the time of parturition to be either split weaned (n=628) or to serve as controls (n=312). Sows were split weaned by removing the heaviest piglets at 21 days of lactation, leaving five to seven piglets with the sow until full weaning 5, 6, or 7 days later. Control litters were weaned at 22±4 days of lactation. Sows were bred at the first observed estrus after full weaning.
منابع مشابه
Effect of mating frequency and weaning-to-mating interval on sow reproductive performance
Methods: Reproductive data were collected from 20 Minnesota and Iowa breeding herds, covering a 7-year period from January 1, 1986–December 31, 1992. Natural mating was used in all herds during the study period. Females bred one, two, or three times during a single estrus were included in the study to compare fertility rates (conception rate, farrowing rate, and adjusted farrowing rate) and lit...
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In 45 primiparous sows, we examined endocrine, ovarian and reproductive responses to split-weaning or five injections per day of 800 ng GnRH from 18 to 21 days of lactation. There was no effect of treatment on absolute or changes in sow weight or backfat depth during lactation. Average piglet growth rates were similar among treatments except that piglets suckling split-weaned sows grew faster (...
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A rapid return to estrus after weaning maximizes productivity in sow herds. Return to estrus is influenced by season and production factors (eg, parity and body condition).1-4 The effects of season and production factors on postweaning interval to estrus are mediated by ovarian follicular development.5,6 Sows with small follicles (< 4 mm) at day 3 after weaning were more likely to experience an...
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