The Effects of Different Protein and Energy Levels and Time of Change from Starter to Finisher Ration on the Performance of Broiler Chickens in the Tropics

Abstract

Three experiments were conducted to determine the optimum protein and energy levels for starting and finishing broiler chickens and the optimum time of change from broiler starter rations to broiler chicken finisher rations. We tested four protein levels (17, 20, 23, and 26%), each fed at three energy levels (2800, 3000, and 3200 kcal/kg diet). For starting chickens, maximum weight gains, feed efficiency, and lowest feed cost per kilogram live weight gain were obtained on the rations containing 23 or 26% protein. Differences in dietary energy levels did not significantly affect weight gain and feed consumption. Feed efficiency improved with increase in dietary energy levels although the differences in feed efficiency between any two consecutive groups were not significant. Feed cost tended to increase nonsignificantly with increase in energy level. For finishing broiler chickens, dietary protein level did not have any significant effects on weight gains. The poorest weight gain, feed efficiency, and feed cost per kilogram gain were obtained on the rations containing 17% protein. The differences in feed efficiency between protein levels of 20, 23, and 26% were not significant while no two consecutive protein levels among the 20, 23, and 26% protein diets gave feed cost per kilogram gain that was significantly different from each other. Weight gain, feed consumption, and feed cost per kilogram gain were not significantly affected by dietary energy levels. Efficiency of feed conversion tended to improve with increase in dietary energy levels, although differences in feed efficiency between 3000 and 3200 kcal/kg diet were not significant. Performances of birds fed the starter ration for 0, 1, 2, 3, or 4 weeks before changing to the finisher ration were not as good as those fed the starter ration for 5 or 6 weeks before being change) to the finisher ration or those fed the starter ration for the 9 weeks experimental period. The results of the present work indicate that a protein level of 23% and energy level of 2800 to 3000 kcal/kg diet may be recommended for starting broiler chicks raised in Nigeria. For finishing broiler chickens, a protein level of 20% and energy level of 3000 kcal/kg diet may be recommended. The optimum time of change from broiler starter to broiler finisher may be recommended at 5 or 6 weeks of age.

Effect of feeding muscovy ducklings different protein sources: Performance, θ‐3 fatty acid contents, and acceptability of their tissues

“…There were no significant differences in feed conversion due to dietary protein source. Coinciding with the current results, Olomu and Offiong (14) found that flax oil had no effect on body weight, feed consumption, and conversion of broiler chickens during 2-21 d of age. Feed intake and body weight were not affected by dietary polyunsaturated fatty acids (PUFA), although the feed-to-gain ratio exhibited a linear increase with increasing PUFA intake (15).…”

Effects of different levels of date pits on performance, carcass characteristics and blood parameters of broiler chickens

“…This result had adverse relation with the report of Olomu and Offiong (1980) and Olomu (1995) and was disagreement with those obtained by Olomu (2004, 2008) and Iyayi and Davies (2005). In earlier, feed intake increased as metabolisable energy of diet decreased.…”

Níveis protéicos na ração de frangos de corte na fase de crescimento

“…Tais resultados diferem dos encontrados por Lisboa & Silva (1999), que observaram diminuição linear no rendimento de carcaça com o aumento do teor de proteína da dieta. Entretanto, Olomu & Offiong (1980) e Moran et al (1982 não observaram efeito significativo para tal variável quando avaliaram diferentes níveis de pro-teína na ração de frangos de corte. Por sua vez, Salmon et al (1983) e Cahaner et al (1997 observaram que o rendimento de carne total aumentou com o nível de proteína da dieta final.…”