In ovo L-Threonine feeding modulates the blood profile and liver enzymes activity of CARIBRO Vishal broiler chickens

This study assessed influence of in ovo Thr levels on blood profile and liver enzyme activities of CARIBRO Vishal broiler chickens. On 18^th day of incubation, fertile eggs were randomly allotted to 5treatments of Thr injection into the yolk (un-injected; sterile water, 0.5ml; 15; 30; and 45 mg Thr/egg). After hatch, chicks were fed a corn–soybean diet up to 42 d. Blood samples were collected at hatch (d 0), d 3, 7, 21 and 42 post-hatch for analysis. Daily weight gain and FCR remain unaltered among L-Thr treated groups. The non-linear regression predictions for in-ovo L-Thr dosage was 15.29, 15.81 and 15.65 mg/egg for weight gain, FCR, and production index, respectively. PCV and Hb were positively influenced (P<0.001) at different periods, and by group x period interaction. PCV levels increased from day of hatch to d 7, 21, and 42, by 16%, 31%, and 68.5%, respectively. Chicks treated with 45mg/egg Thr had higher total protein (about 24% at d 0, and 12% at 42 d) and albumin (≈20% at d 3, and 10% at d 7) than untreated birds. Globulin level increased by up to 15%, 31% and 71% in chicks treated with 15mg, 30mg and 45mg/egg, in that order. Glucose level increased by 4.3, 35, and 9.4% in broilers treated with 45 mg Thr/egg on d 3, 7, and 21, respectively. Also, in ovo Thr feeding enhanced AST and ALT activities estimates progressively as the day increased. PCV had significant positive correlation with Hb, albumin and ALT. Also, protein exhibited positive correlation with albumin, globulin, glucose, AST and ALT. From this study, the reference value for blood profile indices of CARIBRO Vishal broiler chickens was established. There is significant linear increase in blood profile parameters as CARIBRO Vishal broiler chickens grow older. In ovo threonine feeding resulted in higher haematological and serum chemistry indices.