The effect of two growth promoters Metafos and Biomix-DB was studied under 3 treatment groups having 4 animals in each and designed in RBD on growing crossbred bull calves. The treatment groups were: (i) To = Green grass + concentrate (1.5 kg), (ii) Ti = Green grass + concentrate (1.5 kg)+ Metafos and (iii) T2 =r Green grass + concentrate (1.5 kg)+ Metafos + Biomix-DB. The experiment was conducted for a period of 90 days. Digestion trial was performed in the last part of the experiment. Daily feed intake and weekly live weight gain was recorded. There was no significant (P>0.05) difference in daily dry matter intake among the animals of the treatment groups. The total live weight gain and the daily average live weight gain were 27.75, 32.50 and 45.25 kg and 0.308, 0.361 and 0.503 kg/d for treatments To, Ti and T2 respectively, of which T2 was significantly (P<0.05) higher both in terms of total and daily live weight gain than those of the other treatments. Feed conversion efficiency (DMI/BWG) of different treatment groups were 10.17, 8.43 and 6.01 for To, Ti and 12 respectively, where the value for T2 was significantly (P<0.05) higher than that of To. There was no significant (P>0.05) difference among the treatments for co-efficient of digestibility and nutritive value of different nutrients. The average total costs of To, Ti and T2 treatment group were Tk.4888, Tk.4948 and Tk.5010 respectively. The average net returns from To, Ti and T2 treatment group were Tk. 609, 749 and Tk.1238 respectively. It may concluded that, Metafos (15 ml/animal) combined with Biomix-DB (5 g/5 kg concentrate) may be used for fattening of bull calves which gives better results than Metafos alone or without Metafos.
