1Department of Animal Science, Faculty of Science and Agriculture Technology, Rajamangala University of Technology Lanna, Nan, 55000, Thailand
Department of Animal Science, Faculty of Agriculture at Kasetsart University, Bangkok-10900, Thailand
*Corresponding author's e-mail: wiriyal@yahoo.com
Online published on 15 March, 2019.
The study investigated the effects of low protein diet and amino acid supplementation on production performance of laying hens from 49–57 weeks. A total of 135 chickens were divided into 3 groups: 17%CP, 15%CP and 15%CP supplemented with amino acid (AA). The results showed that the 15% CP group consumed less feed (P<0.01). Adding AA to 15%CP improved feed intake, Met intake, BWG, egg mass (P<0.01) and egg production (P<0.05), while FCR and egg quality were not affected. The percentage of abdominal fat and ANT gene expression were highest in the 15%CP + AA group (P<0.05). Nitrogen retention in manure of 15% CP + AA hens was lower than in 17%CP (P<0.01). These results indicated that the reduced-CP diets supplemented with AA improved production performances and decreased nitrogen excretion.
ANT gene expression, Low protein diet, Laying hens, Methionine, Nitrogen excretion
