Effects Of Different Dietary Protein Levels On The Performance And Carcass Characteristics Of Broilers

Abstract

ABSTRACT

A feeding trial was conducted in the early rainy season of 1999 in Ibadan to determine the performance and carcass characteristics of broilers fed varying levels of dietary protein .  Ninety day-old Anak 2000 broiler chicks were randomly allotted to three dietary treatments, with two replicates for each treatment.  The treatments A,B and C, contained 19,21 and 22% crude protein (CP) for starter phase and 17, 19 and 20% CP for finisher phase, respectively.  Differences observed in terms of feed intake, feed conversion ratio, final body weight and weight gain, in both phases were significant (P< 0.05).  Significant (P<0.05) treatment effects were also observed with dressed, eviscerated, breast and abdominal fat weights.  Abdominal fat weight (% E.W) was highest in the broilers fed lowest protein level (diet A.) Length of small intestine varied significantly (P< 0.05) compared with length of large intestine.  Protein levels significantly (P<0.05) affected nitrogen intake and retention, protein efficiency ratio and apparent digestible crude protein, but did not influence total digestible nutrient.  Broilers fed 19% CP (diet B) had least cost of feed per kg weight gain (N94.92/kg) at finisher phase, while at starter phase, those placed on diets A (22% CP) had fed cost of  N53.40/kg live weight gain.  Mean body weight gain at starter (746.0kg/bird) and finisher (1286.2kg/bird) phases were better on the broilers fed diets C (22% CP) and B (19% CP), respectively.  Broiler starters and finishers fed diets containing 19 and 17% CP, respectively did not have encouraging performance at market age.  Broiler starters should be fed diets containing 21 to 22% CP, in the starter phase, while those in the finisher phase should be fed diets containing 19% CP.