Effects of metabolizable energy intake and body weight restriction on layer pullets: 2 - Body composition and onset of lay

Thiago L. Noetzold; Jo Ann Chew; Douglas R. Korver; René P. Kwakkel; Laura Star; Martin J. Zuidhof

Poultry Science (Jan 2025)

Effects of metabolizable energy intake and body weight restriction on layer pullets: 2 - Body composition and onset of lay

Thiago L. Noetzold,
Jo Ann Chew,
Douglas R. Korver,
René P. Kwakkel,
Laura Star,
Martin J. Zuidhof

Affiliations

Thiago L. Noetzold: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5; Corresponding author.
Jo Ann Chew: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5
Douglas R. Korver: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5
René P. Kwakkel: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5; Department of Animal Sciences, Animal Nutrition Group, Wageningen University, 6700 AH Wageningen, The Netherlands
Laura Star: Schothorst Feed Research, Meerkoetenweg 26, 8218 NA Lelystad, The Netherlands; Department of Applied Research, Aeres University of Applied Sciences, De Drieslag 4, 8251 JZ Dronten, The Netherlands
Martin J. Zuidhof: Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada T6G 2P5

Journal volume & issue: Vol. 104, no. 1
p. 104640

Abstract

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This study aimed to determine the effects of dietary ME and BW restriction on layer pullet sexual maturation, carcass composition and reproductive organs. Two trials were conducted: a precision feeding (PF) (Experiment 1) and a conventional (CON) experiment (Experiment 2). Experiment 1 was a 2 × 4 factorial arrangement with two feed allocation (FA) levels: meal every visit (MEV) or restricted to the lower limit of Lohmann Brown-Lite recommended BW; and three dietary ME levels: Low, Standard (Std), and High (2,600, 2,800, and 3,000 kcal/kg, respectively); the fourth treatment enabled birds to choose from the three diets (Choice). Experiment 2 was a 2 × 3 factorial arrangement with two FA levels: ad libitum or restricted to the lower limit of the strain recommended BW; and three dietary ME levels: Low, Std, and High. In Experiment 1, age at first egg (AFE), BW at first egg (BWFE), and carcass composition estimations were recorded. In Experiment 2, age at 50 % of egg production (A50), BW at 50 % of egg production (BW50), and chemical carcass composition were determined. Weight of reproductive organs were measured only in Experiment 2. Data were submitted to ANOVA on each experiment with the two main effects and age as fixed factors. Differences were reported where P ≤ 0.05. The BWFE and BW50 were greater in the MEV- and ad libitum-fed compared to the feed restricted birds in Experiments 1 and 2, respectively. Carcass lean and fat percentage were greater and lower in the feed restricted compared to the MEV- and ad libitum-fed pullets at 20 and 18 wk of age, respectively. Carcass fat percentage around photostimulation age (18 and 20 wk) was greater in the High ME compared to the Low ME fed pullets. Large yellow follicles (number and weight) and ovary (weight and percentage) were greater in ad libitum-fed compared to feed restricted birds. In conclusion, pullets fed greater dietary ME increased fat deposition and feed restricted birds had delayed sexual maturation.

Published in Poultry Science

ISSN: 0032-5791 (Print); 1525-3171 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Agriculture: Animal culture
Website: https://www.journals.elsevier.com/poultry-science

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