Evaluation of rice offal as energy source for fattening Bunaji bulls
A study was conducted using 20 Bunaji bulls with a live weight range of 210-249kg and age range of 2-3 years to evaluate the feeding value of raw or parboiled rice offal as energy source for bull fattening. Four bulls per treatment were allotted to five dietary treatments in a 2x2 factorial arrangement with a common control. Feeding trials was conducted for 90 days. A concentrate and basal diets of Digitaria smutsii were offered at 2% body weight. The proximate and mineral composition of the feed ingredients showed that raw rice offal (RRO) had 7.69% CP, 6.64% hemicellulose and 24.86% silica while parboiled rice offal had (PRO) 4.38% CP, 6.10% hemicellulose and 36.91% silica. The CP contents of the experimental diets vary between 19.69 and 20.44% while the ME ranged from 10.86 to 11.16MJ/kg DM. The crude fibre varies from 14.59 to 17.84%. The result of the fattening trial showed that there was no significant (P>0.05) difference in concentrate, hay, total dry matter intakes and daily weight gain of bulls fed the control diet (NRO) and diets containing RRO and PRO. Inclusion level of rice offal had no significant effect (P>0.05) on intake of concentrate, hay and total feed intake. However, live weight gain of the bulls on the control diet was significantly (P<0.05) higher than bulls on 20 and 30% rice offal inclusion The intake of concentrate, hay, total feed and daily live weight gain of the bulls were similar (P>0.05) irrespective of type and inclusion levels of the rice offal. All the bulls experimented attained an average weight gain of between 1.11Kg to 1.29Kg which was above 1Kg. Economic parameters such as cost per Kg gain, net benefit (NB) and return to naira invested on feed (RIF) were similar (P>0.05) for bulls on both RRO and PRO. There was no significant (P>0.05) differences in the Value of weight gain (VWG), NB, RIF, Cost of feed and Cost per Kg gain for bulls on varying levels of inclusion of RRO or PRO. The inclusion of raw rice offal or parboiled rice offal lead to reduction in feed cost from N25,001.10 to a range of N22,115.50-N23,639.6 (about 5.45%-11.54% reduction in feed cost). It was concluded from this trial that rice offal of all kind (raw or parboiled) may be used to replace up to 30% of maize offal as source of energy in the fattening diet of Bunaji bulls without any detrimental effect on live weight. Hence it can be adopted by farmers.
Keyword: Bunaji bulls, energy, intake, rice offal, weight gain