Poult Yolk Sac Amount and Composition upon Placement: Effect of Breeder Age, Egg Weight, Sex, and Subsequent Change with Feeding or Fasting

Abstract

Hatching eggs from 48 and 55-week-old Small White turkey breeders were used to examine the yolk sac of these poults. Influences due to flock age, egg weight, poult sex, and a two day postplacement regimen of feeding or fasting were evaluated in a factorially designed experiment. Each variable was found to act independent of the other. Older breeders gave eggs having a greater percentage yolk and with more ether extract than if they were from younger hens. For the most part, these fundamental differences remained with the poult's yolk sac at and after placement. Examining egg weight effects apart from hen age showed that heavier eggs had heavier yolks but their percentage of the total was to the converse and no compositional differences appeared. Poults from large eggs had a greater amount of yolk sac that contained proportionately less ether extract than if they were from small eggs. In total, yolk sac found ca. 12 h after poult removal from the hatcher corresponded to reserves that would remain ca. two days after formal hatching. The yolk sac free carcass failed to exhibit any compositional differences regardless of egg source or weight upon placement, but 48 hr later changes occurred that could largely be attributed to interim yolk resorption. Fasting delayed yolk sac uptake and favored removal of moisture and lipid to a greater extent than protein while the converse was true if access to feed and water was permitted. All parameters were unaltered because of poult sex.

Effects of Posthatch Glucose on Poults Fed and Fasted During Yolk Sac Depletion

“…Egg weight and feeding regimen exerted independent effects on both yolk sac and carcass compositions (except ash), which parallels results of an earlier study by Moran and Reinhart (1980).…”

Commonality and Biosynthesis of the O-Methyl Phosphoramidate Capsule Modification in Campylobacter jejuni

“…One-dayold specific pathogen-free chicks were orally gavaged with 300 l of inoculum containing ϳ3 ϫ 10 10 bacterial cells. Because chicks typically do not consume feed during the first 48 h after hatching (23), cecal contents were analyzed 48 h post oral gavage to minimize the amount of particulate matter within the cecal contents that could potentially interfere with HR-MAS NMR. Furthermore, only adherent bacteria should be present at 48 h post oral gavage because the rate of passage through the gastrointestinal tract of leghorns is ϳ4 h (24).…”

Functional development and intestinal absorption in the young poult

“…The incubation period of the poult is longer than that of the chick and, since yolk supplies most of the metabolic requirements of the embryo during incubation, at hatch the residual yolk is relatively smaller (Moran, 1990;Reidy et al, 1998;. Furthermore, since the yolk provides metabolic fuel until this role is performed by exogenous feed this may be the reason why mortality is often higher in poults than in chicks during the posthatch days (Moran, 1980;Phelps et al, 1987).…”