Dynamics of endocrine markers and liver enzymes in laying hens after protein and probiotics supplementation in the post-moult phase

Serum lipid profile, hormones and liver enzymes were studied to determine the health status in moulted layers supplemented with protein, probiotics and symbiotics. Four equal groups (n=50 each) as control (CONT; CP16% diet), high protein (HP; CP18% diet), symbiotic (SYM; CP16% diet, symbiotic @ 85mg/L orally) and probiotic (PRO; CP16% diet, probiotic @ 85mg/L orally) were studied. Fifteen birds were slaughtered at 5%, peak and end of post-moult production periods from each group to collect blood. A two-factorial completely randomized design along with the DMR test was applied. The serum was analysed to determine various parameters by commercially available kits. The LDL-cholesterol (LDL-C; mg/dL) and cortisol (mu g/dL) concentration in HP, SYM and PRO and thyroxin (T4; mu g/dL) in PRO and SYM were significantly reduced as compared to CONT. Triiodothyronine (T3; ng/mL) concentration in HP, SYM, PRO; HDL-cholesterol (HDL-C; mg/dL) in HP and AST (U/L) concentration in PRO were significantly increased (P.05) as compared to CONT. The decrease (P.01) in LDL-C and cortisol levels and increase in HDL-C level indicate the reducing effect of these supplementations on stress, whereas an increase in T3 in supplemented birds (HP and PRO) signifies its metabolic boosting impact in post-moult laying hens