Effects of Different Levels of Dietary Crude Protein and Threonine on Performance, Humoral Immune Responses and Intestinal Morphology of Broiler Chicks
| dc.creator | MA Abbasi | |
| dc.creator | AH Mahdavi | |
| dc.creator | AH Samie | |
| dc.creator | R Jahanian | |
| dc.date | 2014 | |
| dc.date.accessioned | 2026-07-07T03:24:44Z | |
| dc.description | The present study aimed at investigating the effects of different dietary crude protein (CP) and threonine (Thr) levels on the performance, immune responses and jejunal morphology of broiler chicks. A total of 432 broiler chicks were randomly assigned to a 3×3 factorial arrangement of treatments including three different CP dietary levels (90, 95, and 100% of Ross 308 recommendations) and Thr (100, 110, and 120% of Ross specifications) dietary levels. Performance parameters were recorded for the starter (1-12 days), grower (13-24 days) and finisher (25-42 days) periods. Birds were subjected to different antigen inoculations to evaluate antibody responses. At day 42 of age, two randomly-selected birds per replicate were slaughtered to measure carcass traits. Although Thr dietary supplementation had no marked effect on Newcastle antibody titers, particularly the supplementation of Thr up to 110% of Ross specifications improved (p<0.05) antibody titers against sheep red blood cells during both primary and secondary responses. Reduction of dietary CP level resulted in significant decrease in villus height (p<0.05) and crypt depth (p<0.01) in jejunal epithelial cells, but the supplementation of low-CP diets with Thr up to 110 and 120% of the recommended values allowed overcoming these changes. Except for the starter period, reducing dietary CP level to 90% of Ross recommendations had no harmful effects on performance parameters; however, the best values were obtained with diets containing 110% Thr. The present results indicate that it is possible to reduce dietary CP level up to 10% after the starter period without any detrimental impact on growth performance, and dietary Thr supplementation up to 110% of Ross values may compensate for low CP-induced growth delay in broiler chicks. | |
| dc.format | application/pdf | |
| dc.identifier | 1516-635X | |
| dc.identifier | https://www.redalyc.org/articulo.oa?id=179730644005 | |
| dc.identifier.uri | http://hdl.handle.net/123456789/433229 | |
| dc.language | en | |
| dc.publisher | Fundação APINCO de Ciência e Tecnologia Avícolas | |
| dc.relation | http://www.redalyc.org/revista.oa?id=1797 | |
| dc.rights | Revista Brasileira de Ciência Avícola | |
| dc.source | Revista Brasileira de Ciência Avícola (Brasil) Num.1 Vol.16 | |
| dc.subject | Agrociencias | |
| dc.title | Effects of Different Levels of Dietary Crude Protein and Threonine on Performance, Humoral Immune Responses and Intestinal Morphology of Broiler Chicks | |
| dc.type | artículo científico |