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

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 (P<0.05) 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 (P<0.05) 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.