Effect of Qualitative and Quantitative Feed Restriction on Growth Performance and Immune Function in Broiler Chickens

I S Jang,S Y Kang,Y S Moon,Y H Ko,S H Sohn

doi:10.5713/ajas.2009.80513

Abstract

The current study was conducted to investigate the effect of early feed restriction (FR, 8 to 14 d of age) on growth performance and immune function in broiler chickens. Birds were fed corresponding diets from 3 to 35 d of age, which consisted of three phases: starter (3 to 7 d of age), FR (8 to 14 d of age) and re-alimentation (15 to 35 d of age) phases. During the FR period, each group of birds was fed the basal diet ad libitum (CON), 85% (EN85) and 70% (EN70) of lower calorie diet ad libitum (qualitative FR), and 85% (FI85) and 70% (FI70) of voluntary intake on a daily basis (quantitative FR). As a result, there was no statistical difference in weight gain, feed intake and feed conversion ratio between the CON and quantitative or qualitative FR groups during the entire (3 to 35 d) periods. In particular, the EN85 group resulted in a significant (p<0.05) increase in weight gain compared with the EN70, FI85 and FI70 groups. Plasma total protein and albumin at 14 d of age (during FR) were significantly (p<0.05) lower in the quantitative and qualitative FR groups, but these parameters at 35 d of age (after re-alimentation) were higher (p<0.05) in the EN85 and EN70 groups than in the CON group. Plasma IgG level was unaffected by dietary FR procedure. In cytokines, there was no significant difference in the expression of lymphocytic IL-4 and IFN-y at 14 d of age between the FR and the CON groups, whereas lymphocytic IL-6 and iNOS expression were significantly (p<0.05) lower in FI85 and FI70 groups. Moreover, lymphocytic iNOS was also significantly (p<0.05) lower in birds fed qualitative and quantitative diets compared with those fed ad libitum. In the thymus, IL-4 expression was higher (p<0.05) in FI85 and FI70 groups, whereas IL-6 expression was lower (p<0.05) in the FI85 and FI70 groups than in the CON group. Thymic iNOS was significantly (p<0.05) lower in birds fed qualitatively and quantitatively restricted diets compared with those fed ad libitum. At 35 d of age, there was no difference in the expression of IL-4, IL-6 and IFN-y of lymphocytes and thymus between the FR and CON groups. In conclusion, 85% of quantitative and qualitative FR would have a beneficial effect on the expression of some cytokines including IL-4 and iNOS without change in growth performance of birds.

Highlights

Growth performance of broiler chickens has been increased spectacularly over the last 30 years mainly due to the genetic progress, improvements of nutrition and controlled environment so that it takes only 33 days to reach finishing BW of about 2 kg (Wilson, 2005)
During 3 wk of realimentation period, the FI85 group resulted in a significantly (p
15 to 30% of both quantitative and qualitative feed restriction (FR) groups during realimentation (15 to 35 d) and the whole (3 to 35 d) periods did not show a statistical difference in final BW, weight gain and FCR compared with the CON group, indicating that early FR could be overcome by compensatory growth during the later stage of realimentation

Summary

INTRODUCTION

Growth performance of broiler chickens has been increased spectacularly over the last 30 years mainly due to the genetic progress, improvements of nutrition and controlled environment so that it takes only 33 days to reach finishing BW of about 2 kg (Wilson, 2005). Effects of FR on plasma profiles and cytokine attempts have been conducted to find way to improve expression in lymphocytes and thymus were determined at welfare of broiler by supplying ad libitum access to lower 14 d and 35 d of age. At the end of FR (on 14 d of age) and caloric diets (qualitative FR; Sandilands et al, 2005) or 3 wk of realimentation (on 35 d of age), five broiler chicks moderate restriction of voluntary intake The present study was carried out to assess Assays the effects of early qualitative and quantitative FR program To measure plasma biochemical profiles, AST (aspartate on growth performance, plasma biochemical profiles and aminotransferase), ALT (alanine aminotransferase), total several cytokine expressions including IL-4, IL-6 and iNOS protein and albumin were assayed by the Automatic Serum in lymphocytes and thymus of broiler chickens

MATERIALS AND METHODS

RESULTS

D: iNOS

Findings

DISCUSSION