Studies on stocking density and stress reactions in broiler chicken

The present study was conducted to investigate the effect of stocking density on stress reaction of broiler chicken. A 500 day-old straight run commercial broiler strain “VENCOB” chicks were divided in two batches. Each batch was subdivided in 3 equal groups viz. I.C.A.R., Venky's and Amrit. All the birds were raised on pucca floor with saw dust as litter material providing equal managemental practices. The blood samples were collected at 4^th, 5^th and 6^th week of the study. H: L ratios were calculated by dividing the number of heterophils by the number of lymphocytes counted. The results showed that, number of lymphocytes decrease and the number of heterophyl increase in response to stressors. The heterophyl and lymphocyte count (%) was significant (P<0.01) in all the weeks under study. Higher HET count (%) was observed under Amrit followed by Venky's and I.C.A.R. floor space recommendation during last three weeks. The almost similar but reverse pattern of LYM count (%) have been observed like HET count (%) of broiler chickens under three stocking densities at week 4, 5 and 6. At week 4, H: L ratio under I.C.A.R. (00.67±0.015) significantly (P<0.01) higher than that of both Venky's (00.52±0.009) and Amrit (00.52±0.005) recommendations which did not differ each other. At week 5 the H: L ratio in Amrit (00.66±0.012) recommendation was significantly (P<0.01) more than rest recommendations which, however did not differ each other. At week 6 the highest and lowest H: L ratio were 0.71±0.008 (Amrit) and 0.50±0.005 (I.C.A.R.) respectively. There were significant (P<0.01) differences among all the three ratios. This can be concluded that H: L ratio was higher under Amrit's recommendation than those in Venky's and I.C.A.R.