EFFECTS OF VARYING DIETARY ENERGY AND PROTEIN LEVELS ON GROWTH PERFORMANCE OF ISA-BROWN STARTER COCKERELS

Résumé

An experiment was carried out to assess and ascertainthe energy and protein levels required by Isa-brown cockerels reared in Southern rainforest zone of Nigeria for optimal performance. Four hundred and fifty (450) day old Isa-brown cockerels were randomly distributed to fifteen treatment groups of ten birds per replicate and three replicates per treatment for an experiment duration of six weeks.Experimental diets comprised of five (5) Metabolizable Energy (ME) levels (2600, 2700, 2800, 2900 and 3000kcalME/kgDM)and three (3) protein levels (18, 20 and 22%CP). The data obtainedwassubjected to descriptive statistics and Analysis of Variance (ANOVA) in a Completely RandomizedDesign (CRD) of 3x5 factorial arrangement and the means were separated using the Duncan MultipleRange Test (DMRT). The result obtained showed that Feed Intake (FI) reducedwith an increasing dietary energy level while Body Weight Gain (BWG) and Final Body Weight (FBW) increased with an increasingcrude protein level. Feed Conversion Ratio (FCR) was significantly (P<0.05) affected by the variations in the energy levels. The least FCR was obtained with birds fed diets containing 2900kcalME/kgDM and 22% CP (diet 12). This diet was also the most economical with cost of feed intake per KG body weight gain being ₦1099.Interaction of energy and protein level did not significantly (P>0.05) affect any of the parameters measured. Conclusively, Isa-brown starter cockerels (0 – 6 weeks) can be reared in southern rainforest zone of Nigeria with a least cost feed containing 2900kcalME/kgDM and 22%CP for optimal performance.