CASSAVA OR MAIZE MEAL FOR BROILERS AND THE EFFECT OF SUPPLEMENTATION WITH METHIONINE AND SULPHATE IN CASSAVA BASED DIETS

Three experiments were carried out with growing chicks to investigate the effect of substituting cassava for maize and to establish optimal levels of methionine and sulphate in practical cassava based diets. ln the first experiment 150 day-old chicks were fed for 8 weeks on diets in which the level of replacement for maize by cassava meal was 0, 33, 67 and 100%. }n a sixth treatment 10% of the cassava in the diet containing no maize was replaced by cane molasses. Liveweight gain and conversion efficiency decreased linearly as the proportion of cassava in tbe diet increased. The inclusion of 10% molasses in a cassava based dier gave little improvement in performance. Thyroid weight increased when cassava completely replaced maize. In the second experiment 270 day-old chicks were fed for three weeks on a practical cassava based diet supplemented with 0, 0.15. 0.30% methionine, 0, 0.15 or 0.30%. sodium sulphate, in a 3 x 3 factorial arrangement of treatments. Ihere was a linear increase in liveweight gain with additions of methionine with either 0 or 0.15% additional sodium sulphate but additional methionine had no effect with 0.30% additional sodium sulphate. There was no significant effect on liveweight gain when sulphate alone was added to the diet. Food consumption and food conversion were not affected by any of the treatments. In the third experiment 240 day-old chicka were fed for three weeks on practical cassava based diets containing either 0, 0.20,.0.40 or 0.60% added methionine or 0.15. 0.30, 0.45 or 0.60% added sodium sulphate. There was a linear decrease ir liveweight gain as the level of methionine increased. There were no significant effects of sulphate on weight gain, or of either sulphate or methionine on food consumption or food conversion efficiency