AMARANTHUS CRUENTUS LEAF MEAL AS A PROTEIN SUPPLEMENT IN BROILER FINISHER DIETS PART 1. PERFORMANCE AND NITROGEN UTILIZATION

Freshly harvested mature leaves of Amaranthus cruentus plant were sun dried to a moisture content of between 12-13%. The sun dried leaves (Amaranthus cruentus leaf meal, ACLM) were milled and analysed for proximate composition. Some inherent antinutritional factors (ANFs) such as phytic acid and oxalate were determined. The mean and standard deviation (mean ± SD) for crude protein was 23.0%±0.55; crude fat, 5.4%±0.01; crude fibre, 8.8%±0.02; ash, 19.3%±0.01 and gross energy, 3.3±0.01kcal/g all on dry matter basis. Methionine and to a lesser extent, lysine, arginine, leucine and aspartate were high compared with other plant sources. Essential mineral elements such as Ca, P, K, Na, Mg, Fe, Mn and Zn were also appreciably present and comparable with other rich sources as found in vegetable plants. However, significant levels of phytates and oxalates (ANFs) were detected. The ACLM was incorporated at inclusion levels of 5%, 10%, 15% and 20% in broiler finisher diets. All diets were isocaloric and isonitrogenous. The control consistently showed better (P<0.05) weight gain (WG), feed efficiency (FE) and protein efficiency ratio (PER) of 52.6±13.01g/bird/day, 2.13±0.05 and 3.14±1.39, respectively. However, the weight gain values recorded for birds on diet 2 (5% ACLM inclusion) and diet 3 (10% ACLM inclusion) were similar (P>0.05) at 47.3±14.87g/bird/day and 48.6±17.10g/bird/day, respectively. This was also true for the FE values for birds on diets 2 and 3 that had similar values of 2.44±2.33 and 2.44±2.14. Birds on diet 3 also had similar (P>0.05) PER value with birds on diets 1 and 2. The WG, FE and PER values obtained for birds on diets 4 and 5 (15% and 20% ACLM inclusion, respectively) were similar (P>0.05) and consistently lower than values obtained for birds on other diets. The highest nitrogen retention (NR) and apparent nitrogen digestibility (AND) values were recorded for birds on the control diet 1 and the poorest were recorded in diet 5. The apparent nitrogen digestibility values of birds on the control diet and diet 2 were similar at 70.39%±8.75 and 65.04%±9.10, respectively. Apparent nitrogen digestibility values for birds on diets 2, 3 and 4 were also similar at 65.04%±9.10, 64.77%±10.09 and 59.64%±8.29, respectively while diets 4 and 5 (55.95%±9.35) also had similar and lowest values (P>0.05) for their birds.