Estimation of genetic parameters for body weight in different periods of Japanese quail that selected for immune responses and fed different levels of dietary L-arginine

Abstract

      The current study was done in the farm of animal production department, college of agriculture, Kirkuk University from (1/6/2021 until 1/7/2022), to estimation of genetic parameters for body weight in different periods of Japanese quail that selected for immune responses and fed different levels of dietary L-arginine, by using 750 quail chicks breeding for four generation. The body weight was recorded in three periods, at the sexual maturity (BWSM), at age 90 day (BW90), and 120 day (BW120). Electronic balance was used to record the weight at sensitivity of (0.001) g. Data analysis was conducted using the general linear model method within SAS program to estimate the effect of factors influencing the studied traits. The general weight mean of Japanese quail at the ages of sexual maturity 90 and 120 days was (186, 192 and 201) g, respectively. The current study showed a highly significant effect of the four generations on the weight of birds at sexual maturity, 90 and 120 days. The weight of the birds at sexual maturity was highest in the birds of the base generation. The lowest weight at the age of sexual maturity was in third generation. The weight of the bird was also at the age of 90, and 120 days, the highest weight in the base generation, compared to third generation, which had the lowest weight. The Japanese quail was significantly higher than the males. Also, the weight of females and males differed significantly in the Japanese quail bird, depending on the genetic line that used. The study also showed the presence of positive and high genetic correlations (0.9061) between The weight of the bird at the age of 90 days or the weight at the age of 120 days, and a high and positive morphology (0.9058) between the weight of the bird at the age of sexual maturity and the weight at the age of 90 days.