PERFORMANCE OF BROILER CHICKS FED MASH OR PELLETED DIETS CONTAINING CORN-WITH-COBS MEAL WITH OR WITHOUT ENZYME SUPPLEMENTATION.

Abstract

The objective of present study was to investigate the effect of feeding diets containing different levels (0, 15, 30 or 45 %) of corn-with-cobs (CWC) meal in two forms (mash or pellets) with or without adding exogenous enzyme preparation (Sicozyme) on the broiler growth performance, carcass traits, blood  constituents, and nutrient digestibility. Five hundred seventy-six Hubbard broiler chicks were randomly divided into 16 equal experimental groups; each contained 3 equal replications. The chicks were kept in brooding and growing batteries during the starter and finisher periods, 0-3 and 3-7 weeks of age. Sixteen starter and finisher experimental diets were formulated and used. Each experimental group was given its respective diet and all birds were managed similarly and had free access to feed and water. The results obtained can be summarized in the following:      Apart from the effect of diet form (DF) or enzyme addition (EA), feeding CWC-diets had no adverse effect on live body weight (LBW) or body weight gain (BWG) of broilers during the entire experimental period. When the dietary CWC level reached 45% feed intake (FI) of broilers was significantly increased while feed conversion (FC) was negatively affected compared with their control counterparts. Birds fed pellets exhibited significantly better LBW and BWG than those of birds fed the mash diets, while FI and FC were not affected, regardless of the effect of dietary CWC level or EA. Similarly, LBW and BWG of broilers were positively affected due to dietary EA as compared to those of birds fed the un-supplemented diets, irrespective of the effect of DF or dietary CWC level. Increasing dietary CWC level to 30 or 45% adversely affected digestibilities dry matter, organic matter and crude protein and rate of nitrogen retention. Birds fed the pelleted diets had better digestibilities for crude protein and ether extract and nitrogen retention compared with those fed the mash diets. Dietary EA  led to an increase in the rate of nitrogen retention. Carcass traits of broilers were not significantly affected by dietary CWC level with the exception of significant reductions in dressing-out and abdominal fat percentages and an increase in relative weight of gizzard for birds fed the 45% CWC-diets compared with the controls. Dietary EA and DF had no effect on carcass traits, except that gizzard percent slightly  reduced due to feeding pellets as compared to feeding the mash diets. There were significant  reductions in serum levels of triglycerides, total cholesterol, and LDL-cholesterol for broilers fed the CWC-containing diets, particularly having the 45%level. However, blood parameters were not affected by EA or DF, with the exception of a significant decrease in triglycerides level in broilers fed pellets as compared to those fed the mash diets. Economic efficiency of broiler production was not affected by including CWC up to 30% in their diets; pelleting of diets and enzyme addition might have a beneficial effect. It could be concluded that corn-with-cobs meal can be included up to 30% in diets of broilers without adverse effects on broiler performance; pelleting of diets and enzyme addition had positive effects in this respect.