GENETIC EVALUATION OF PERFORMANCE AND BLOOD BIOCHEMISTRY IN JAPANESE QUAIl

Thesis Abstract

A study was conducted in a Northern Guinea Savannah region to evaluate the growth, reproductive and blood biochemistry parameters of parents and their offspring in Japanese quail. A total of two hundred and twenty Day-old chicks (DOC) were used in the base generation and six hundred and thirty DOC were used in the first generation. A digital scale of sensitivity (0.01 g) was used to take the weights. The body measurements taken were the 4-week body weight (BW4), 8-week body weight (BW8), overall average growth rate (Agr) and relative growth rate (Rgr). The reproductive parameters studied were the age at sexual maturity (ASM), weight at sexual maturity (WtAsm), egg weight at sexual maturity (EgAsm), average egg weight (Aveg), egg laid at the 11th week of age (Egg11) and the ratio of egg weight to 4-week body weight (EgB4), taken from female quails which were individually housed. In the 6th-week blood biochemistry studied, glucose (Glu) was measured according to Trinder, 1969 while Alkaline-Phosphatase (ALP) was determined according to Kind and King, 1954. For body weight, sexual dimorphism was observed within and across generations. In the base and first generation, the females and males showed no significant (P>0.01) difference for BW4 but the females had a significantly (P<0.01) higher BW8 than the males. In addition, the base generation had a significantly (P<0.01) higher BW4 and BW8 than the first generation. This difference observed in growth parameters had an effect on reproductive performance. The faster growing birds in the base generation were significantly (P<0.01) heavier in weight at sexual maturity and had a heavier egg weight but were significantly (P>0.01) lower for age at sexual maturity. The study on the blood biochemistry revealed that in each generation, the females and males showed no significant (P>0.01) difference for respective blood parameter; however, the first generation had a significantly (P<0.01) higher Glu but a significantly (P>0.01) lower ALP when compared to the base generation. The females had a higher coefficient of variation for the blood biochemistry when compared to those of the males in both generations. For this study it was observed that positive phenotypic correlation coefficient exists between growth rate and ASM. Reproductive traits are generally positively correlated while ALP and Glu are negatively correlated. The magnitude of repeatability estimates showed that the growth traits had higher inherent transmission ability than blood biochemistry and reproductive traits.