Effect of Feeding Different Dietary Protein Levels with Iso-Caloric Ration on Nutrients Intake and Growth Performances of Dual-Purpose Koekoeck Chicken Breeds

The study was conducted to investigate the effect of feeding different levels of crude protein (CP) but similar levels of energy on nutrients intake and growth performance traits of Koekoeck chickens. Two hundred chicks irrespective of their sexes were randomly assigned to 4 treatment diets (T) containing 16% CP (T1), 18% CP (T2), 20% CP (T3) and 22% CP (T4). Each treatment groups were replicated 4 times with ten chicks per replicate. The feed (offered and refusal) was measured using a digital balance every morning before offering the daily feed. The body weight was assessed on a weekly basis. The results indicated that there was a significant (P<0.05) increase in feed consumption as the level of protein increased in the diet. The dry matter intake was (P<0.05) higher for chickens receiving T3 and T4 diets. The overall feed consumption was higher among the chickens receiving T3 and T4 diets, while it was the lowest among those receiving T1 diet. The result also indicated that the intake of protein was (P<0.05) different and positively associated with the intake of CP. The intake of calcium was higher for chicks fed on T2 diet as compared to those receiving T3 diet. Chickens receiving T1 diet had a significantly lower energy intake when compared to those reared on T4 diet. Whereas chickens reared on diets containing T2 and T3 diets had intermediate value between the two. The results indicated that by increasing in the level of protein in the diets did not influence the overall body weight gain and final live weight of chickens. Though not significantly, the chickens reared on diets containing higher levels of protein (T4) showed poor growth performance, this may be attributed to differences in energy protein ratio among the diets. The Koekoeck chickens reached the highest growth rate at 9 week and followed by 11 and 13 week of the experimental periods. The feed conversion ratio (FCR) showed no significant difference among the dietary treatment groups. However, the FCR improved numerically with increasing levels of protein in the diet. From the current work it can be concluded that 16% dietary CP is optimum for Koekoeck chickens.