Kobra Sookhtehzari; Ali Khatibjoo; Hoshang Jafari; Mohammad Akbari-Gharaei; Kamran Taherpour
Volume 21, Issue 4 , January 2020, , Pages 533-543
Abstract
The effects of high stocking density and threonine (Thr) supplementation on performance and immunity in broiler chickens was evaluated. In this experiment 495 male Ross-308 broiler chickens were allocated to 4 treatments with 5 replicates in a completely randomized design. The dietary treatment ...
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The effects of high stocking density and threonine (Thr) supplementation on performance and immunity in broiler chickens was evaluated. In this experiment 495 male Ross-308 broiler chickens were allocated to 4 treatments with 5 replicates in a completely randomized design. The dietary treatment consisted of: 1) basal diet as control with low density (10 birds/m2), 2) high density group (15 birds/m2 which fed basal diet) and 3 and 4) high density group which fed diet containing 10 and 20 percent Thr higher than requirment, respectively. The results showed that high stocking density decreased feed intake, body weight and feed conversion ratio at different period of production and increased European production efficiency factor (EPEF). Thr supplementation also reduced growth performance parameters (P < 0.05).Dietary treatments deseased antibody titer against NewCastle, but avian influenza virus, cell mediated immunity against phytoheamaglutinin, blood metabolites, blood cell count, and serum spartat aminotransferase and malondialdehyde concentration did noy change significantly. Serum alanine aminotransferase concentration in broiler chickens fed diet containing 20 percent Thr higher than requirment was higher than the others (P < 0.05). In conclusion, under the condition of this study (15 birds/m2), Thr supplementation (both of the levels) did not improved broiler chickens performance and immunity and more research is needed in this subject.