title: Performance of pureline broiler breeders fed two levels of vitamin E.
abstract: Reported in this paper is an experiment designed to evaluate responses of two commercial broiler dam purelines (A and B) continuously fed 10 or 300 IU of vitamin E/kg from 168 to 441 d of age. Prior to Day 168, all pullets were fed diets containing 10 IU of vitamin E/kg. During the early laying period, percentage hen-day ovulations and percentage hen-day normal egg production were similar for both lines and diets. During the latter part of the laying cycle, there were differences between lines for these traits (A > B), as well as for BW and egg weight for which line differences were reversed (A < B). Also during this period, percentage hen-day ovulations and percentage hen-day normal egg production differed between diets (300 > 10 IU/kg). These differences between diets were consistent with the greater number of females that entered lay and higher hen-housed egg production of the 300- than 10-IU/kg group. Although during the laying cycle all females received a fixed amount of feed, BW gains were greater for Line B than A and for the 300- than the 10-IU/kg level of vitamin E. Heterophil (H):lymphocyte (L) ratios, percentage livability, and relative asymmetries of shank length and diameter were similar among groups. Pullets from Line B and those fed the higher level of vitamin E exhibited more fear than their counterparts. Head shaking did not differ between vitamin E levels; however, there was a line-by-time of day interaction for this behavior. The 30-fold difference in dietary vitamin E was reflected by a 15-fold difference in plasma vitamin E levels in both lines. For vitamin E level in the yolk, however, there was a line-by-diet interaction. The interaction resulted from no difference between lines at the 10 IU/kg level and differences of 10- and 6+-fold in Lines B and A at the 300 IU/ kg level, respectively. Overall, responses to continuous feeding of vitamin E at these levels were influenced by genetic stock, age, duration of feeding, and measurement criteria.
authors.affiliation: Animal and Poultry Sciences Department, Virginia Polytechnic Institute and State University, Blacksburg 24061, USA.
authors.forename: P B
authors.initials: PB
authors.lastname: Siegel
authors.forename: S E
authors.initials: SE
authors.lastname: Price
authors.forename: B
authors.initials: B
authors.lastname: Meldrum
authors.forename: M
authors.initials: M
authors.lastname: Picard
authors.forename: P A
authors.initials: PA
authors.lastname: Geraert
mesh_terms: D000367:Age Factors; D000818:Animals; D000975:Antioxidants / Q000032:analysis / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects*; D001835:Body Weight; D002645:Chickens / Q000097:blood / Q000235:genetics / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004530:Egg Yolk / Q000737:chemistry; D004531:Eggs / Q000032:analysis*; D005260:Female; D010058:Oviposition / Q000187:drug effects*; D013997:Time Factors; D014810:Vitamin E / Q000008:administration & dosage / Q000032:analysis / Q000097:blood / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D014810:Vitamin E