Effect of dietary crude fibre level on intake, digestibility and productivity of slow-growing indigenous Venda chickens aged one to 91 days

摘要

Two experiments were conducted to determine diet crude fibre (CF) levels for optimal productivity of slow-growing indigenous Venda chickens. In each experiment the diets were isocaloric and isonitrogenous but with different CF levels of 2, 3, 5, 6 and 8%. A complete randomised design was used in both experiments, the starter (1-49 days) and finisher (50-91 days). A quadratic equation was used to determine CF levels for optimal productivity. Dietary CF levels of 3.4, 4.0 and 3.0 % optimised growth rate, feed conversion ratio (FCR) and live weight of unsexed Venda chickens (starter), respectively; and higher dietary CF levels resulted in lower (P0.05) intake and digestibility. Dietary CF levels of 6.5, 4.3, 3.2 and 4.4 % optimised feed intake, growth rate, nitrogen retention and live weight of male Venda chickens (finisher), respectively; while higher dietary CF levels resulted in poor (P0.05) FCR and nutrient digestibility. The results indicate that different CF levels optimised production parameters, and dietary CF levels for optimal productivity increased as chickens grew older.