Abstract

Telfairia occidentalis leaves were purchased fresh from local farmers, sun dried and milled into T. occidentalis leaf meal (TOLM). The proximate analyses revealed that TOLM contained 35.14 ± 0.44% crude protein; 9.61 ± 0.01% fat; 12.68 ±  0.02% crude fibre; 10.87 ± 0.02% ash; 9.04 ± 0.13% dry matter and 3.25 ± 0.01 kcal/ g gross energy. Eight broiler starter diets were formulated to be isocaloric and isonitrogenous. Diet 1 was duplicated such that the enzyme combination of cellulase, glucanase and xylanase (Roxazyme G2) was incorporated into one while Roxazyme G2 was lacking in the other (control diets 1a & 1b, with and without enzyme supplementation). Diets 2 and 3 were duplicate diets at 10% TOLM inclusion levels with the only difference being the Roxazyme G2 supplementation in diet 3. Diets 4 and 5 were also duplicates at 20% TOLM inclusion level with Roxazyme G2 supplementation in diet 5. Diets 6 and 7 at 30% TOLM inclusion were also in duplicate with diet 7 having Roxazyme G2 supplementation. The weight gain (WG) value for chickens on diet 1b with enzyme supplementation was highest at 19.51 ± 2.10g/chick although similar (P > 0.05) to WG values for birds on diets 1a (without enzyme supplementation), 2 and 3 while diet 7 with 30% TOLM inclusion with Roxazyme G2 supplementation had the lowest WG of 11.09 ± 0.39g/chick. Feed consumption (FC) was similar and higher in birds on diets 1a & b, 2 and 3. FC was also similar and lower in birds on diets 4, 5, 6 and 7. Feed conversion ratios did not differ significantly among the experimental diets except Diet 7. The operative protein efficiency ratio (PER) was higher and similar (P > 0.05) for birds on diets 1a & b, 2 and 3 on one hand and lower and similar (P>0.05) for birds on diets 4, 5, 6 and 7 on the other hand. The nitrogen retention (NR) value was highest for diet 1b (with enzyme supplementation) at 72.37 ± 0.10 but similar (P > 0.05) to birds on diets 1a, 4 and 5. There were no significant differences (P > 0.05) among means of the heamatological parameters tested. The mortality during the experimental period was insignificant and less than 1% of the total number of birds used.

Key words: Enzyme supplementation, le