Effects of amino acid levels during rearing on Cobb 500 slow-feathering broiler breeders: 1. Growth and development

Poultry Science

Hernan A. Cordova-Noboa¹  Gustavo A. Quintana-Ospina²  Viviana San Martin³  Ivan C. Ospina-Rojas³  Justina V. Caldas³  Edgar O. Oviedo-Rondón³  Maria Camila Alfaro-Wisaquillo³ 

[1] Corresponding author:;Cobb-Vantress Inc. Siloam Spring, AR 72761-1030, USA;Prestage Department of Poultry Science, North Carolina State University, Raleigh, NC 27695-7608, USA;

关键词: pullet;    body weight;    flock uniformity;    body composition;    ideal protein;   

DOI  :  

来源: DOAJ

【 摘 要 】

ABSTRACT: Adequate pullet nutrition is essential to reach BW and suitable body composition for reproduction. An experiment was conducted to determine the effects of 4 dietary amino acid (AA) levels on BW, flock uniformity, body conformation, organ, leg, and feathering development of broiler breeder pullets during the rearing phase from 5 to 24 wk. A total of 1,360 Cobb-500 slow-feathering (SF) pullets were randomly placed in 16-floor pens with 85 females per pen. Diets with corn, soybean meal, and wheat-midds were formulated without protein restriction maintaining minimum ratios between essential AA and Lys on a digestible (dig) ideal basis. Treatments consisted of 4 dietary AA levels with 80% (low-AA), 90% (moderate-AA), 100% (standard-AA), and 110% (high-AA) of the Cobb-Vantress recommendations guided by dig Lys using balanced protein. Up to 4 wk, all pullets were fed a common starter crumble diet. Grower and developer mash diets were fed to pullets from 5 to 15 wk and from 16 to 24 wk, respectively. Pullets fed standard-AA and high-AA diets were heavier (P < 0.001) than those fed low-AA diets at 10, 15, and 20 wk of age. High-AA diets resulted in better (P = 0.040) flock uniformity at 10 wk. Pullets fed a high-AA diet had the highest (P = 0.041) relative breast weight at 20 wk of age and the lowest (P = 0.044) deposits of abdominal fat at 15 wk of age. Fleshing increased (P < 0.05) as AA content rise in the diet, while the relative shank length (P < 0.001) and the number of wing juvenile feathers (P = 0.004) decreased. Pullets fed the lowest dietary AA level had the longest (P = 0.007) small intestine relative to BW at 10 wk of age, but a smaller (P = 0.001) liver than those fed moderate and standard-AA diets at 20 wk of age. Dietary AA levels have important effects on pullet BW, fleshing, and organ development during rearing with potential reproductive performance impacts.

【 授权许可】

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