Effect of betaine and air ammonia concentration on broiler performance, plasma corticosterone level, lymphoid organ weights and some haematological indices

This study was initiated to examine the effect of betaine supplementation (1g/kg) on hematocrit level, erythrocyte and leukocyte number, heterophil/lymphocyte ratio, plasma corticosterone, rectal temperature, relative lymphoid organ weights and average daily gain in broiler chickens reared in a poultry house under natural ambient conditions and high air ammonia level. A total of 100 broiler chickens at the age of 45 d were allocated into 2 groups: control and betaine supplemented. The broilers were kept on deep litter in windowless poultry house. The results of this study indicated no significant changes in terms of hematocrit, erythrocyte number, leukocyte number, lymphoid organ weights and average daily gain.Betaine supplemented broilers had lower heterophil/lymphocytes ratio at d8 (P<0.05) relative to control broilers inspite of the similar values of plasma corticosterone between the groups. Plasma corticosterone concentration in betaine supplemented broilers increased (P<0.05) at d 15, relative to d8. The observed increase in plasma corticosterone was not accompanied by increase in heterophil to lymphocyte ratio. These results are interpreted to suggest that the decreased heterophil/lymphocyte ratio in experimental broilers was due to the modulatory effects of ammonia on NO synthesis rather than to the modulatory effect of corticosterone.