title: Energy balance influences number of ovulations rather than embryo quality in the pig.
abstract: The present study was undertaken to examine the effect of feed restriction on ovulation rate and in vivo blastocyst development in gilts and sows. In the first experiment, gilts were feed restricted (1 vs. 2.5 times maintenance requirement) during the luteal and follicular phases before ovulation. In the second experiment, primiparous sows were feed restricted (ad lib vs. 60% thereof) during the last week of lactation before weaning. Gilts and sows were slaughtered at 5 days after ovulation to determine ovulation rate and blastocyst development. Blastocysts were also differentially stained to determine the effect of feed restriction on total, trophectoderm, and inner cell mass cell numbers. In both experiments, feed restriction delayed ovulation and reduced the number of ovulations in gilts (14.8 ± 1.3 vs. 12.0 ± 0.2; P < 0.05) and in sows (19.9 ± 1.0 vs. 18.4 ± 0.7). The number of blastocysts recovered on Day 5 was similarly reduced in gilts (12.0 ± 1.7 vs. 9.1 ± 1.1; P < 0.10) and in sows (15.9 ± 1.5 vs. 14.7 ± 1.0). However, feed restriction did not affect total, trophectoderm, or inner cell mass cell numbers in gilts or sows. In conclusion, the present study reported that energy balance influences ovulation rate and blastocyst number rather than blastocyst viability as measured by cell number.
authors.affiliation: South Australian Research and Development Institute, Roseworthy Campus, Roseworthy, South Australia. Electronic address: pieter.langendijk@trouwnutrition.com.
authors.forename: Pieter
authors.initials: P
authors.lastname: Langendijk
authors.affiliation: South Australian Research and Development Institute, Roseworthy Campus, Roseworthy, South Australia.
authors.forename: Tai-Yuan
authors.initials: TY
authors.lastname: Chen
authors.affiliation: Robinson Institute, School of Medicine, University of Adelaide, Adelaide, South Australia, 5005, Australia.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: McIlfatrick
authors.affiliation: Robinson Institute, School of Medicine, University of Adelaide, Adelaide, South Australia, 5005, Australia.
authors.forename: Mark B
authors.initials: MB
authors.lastname: Nottle
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D005508:Food Deprivation / Q000502:physiology*; D010060:Ovulation / Q000502:physiology*; D010298:Parity; D011247:Pregnancy; D013552:Swine / Q000196:embryology / Q000502:physiology*
keywords: Embryo; Energy balance; Ovulation; Swine