title: Failure of vitamin A to increase litter size in sows receiving injections at various stages of gestation.
abstract: To determine the effectiveness of a single injection of vitamin A to increase litter size, 1,375 sows were assigned randomly to 11 treatment groups (125 sows per treatment). Treatments included injection of 1 x 10(6) IU of vitamin A dissolved in corn oil at weaning or on d 0, 2, 6, 10, 13, 19, 30, 70, or 110 after breeding. Sows in the control group were injected with corn oil on corresponding days. A total of 396 sows were removed from the study following treatment or treatment assignment. Therefore, farrowing data were collected for 979 sows. Injection of vitamin A did not influence (P > . 10) total litter size, live litter size, litter weight, pig weight, number of runts, or number of mummies. Mean live litter size was 10.1 +/- .1 for all sows that farrowed in the experiment. Parity group affected total litter size, live litter size, live litter weight, and number stillborn (P < .01) but not pig weight, number of runts, number of mummies, or gestation length (P > . 10). In this study, a single injection of vitamin A at any time from weaning to farrowing did not increase litter size in sows.
authors.affiliation: Department of Animal Sciences, Purdue University, West Lafayette, IN 47907-1151, USA.
authors.forename: A E
authors.initials: AE
authors.lastname: Pusateri
authors.forename: M A
authors.initials: MA
authors.lastname: Diekman
authors.forename: W L
authors.initials: WL
authors.lastname: Singleton
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D005260:Female; D007275:Injections, Intravenous; D008098:Litter Size / Q000187:drug effects*; D008297:Male; D010298:Parity; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000187:drug effects*; D013552:Swine / Q000502:physiology*; D014801:Vitamin A / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D014801:Vitamin A