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.
Mohammad Hossein Palizdar; Mohammadreza Pourelmi; Hamidreza Mohammadian-Tabrizi; Zahra Sepehr
Volume 18, Issue 1 , April 2016, , Pages 95-106
Abstract
Effect of GLOBACID® acidifier in different stocking densities on performance and blood metabolites was examined using 576 one-day broiler chickens Ross 308 in a completely randomized design with 6 treatments and four replications for each treatment through a (3 × 2) factorial arrangement with ...
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Effect of GLOBACID® acidifier in different stocking densities on performance and blood metabolites was examined using 576 one-day broiler chickens Ross 308 in a completely randomized design with 6 treatments and four replications for each treatment through a (3 × 2) factorial arrangement with three levels of stocking densities (14, 16 and 18 chicks per square meter) and two levels of GLOBACID® acidifier (zero and one kg per each ton of feed). The lowest feed intake was seen in 18 stoking density treatment which fed one kg of acidifier in the ration and this treatment was significantly different with other treatments (P<0.05). Feed intake was significantly lower in broilers which received acidifier compared with others that did not receive acidifier (P<0.05). Increasing the density from 14 to 18 birds per square meter increased feed conversion ratio (P<0.01). Birds that received acidifier had lower feed conversion ratio than others (P<0.05). Feeding diets containing acidifier lead to a reduction in glucose and antibody titers against SRBC and an increase in cholesterol and triglyceride in broilers blood plasma (P<0.05). The interaction between stocking densities and acidifier on body weight and blood metabolites was not significant. Therefore, using acidifiers in high stocking densities have some advantageous in broiler performance.