Use of Aspergillus niger for improving the feeding value of rice offal

Abstract

Undegraded and degraded rice offals (RO) were used to compound rations for broiler birds for eight weeks. The undegraded was used at 7% inclusion level and the degraded was used at 3, 5 and 7% inclusion levels. A hundred and sixty five (165) day old chicks were randomly selected and allotted to five (5) treatments. Each treatment had three replicates and each replicate had eleven birds. Aspergillus niger was inoculated into RO through solid state fermentation for a period of seven (7) days and this was used as the degraded sample. There was improvement in the crude protein and ether extract of the degraded sample, while the crude fibre content reduced. The crude protein increased from 8.79 to 12.24% while the crude fibre reduced from 15.89 to 10.82% after biodegradation. The results from the feeding trials showed significant (P< 0.05) differences in the average feed intake and average body weight gain at the starter phase. The highest feed consumption was found in treatment 5 which contained 7% degraded RO (DRO) and it was 65.11 g/b/d. At the finisher phase, there were significant (P<0.05) differences in both the average feed intake and the average body weight gain of the birds. The highest feed intake was found in treatment 5 and it was 201.84 g/b/d. The highest body weight gain was also found in treatment 5 and it was 75.52 g/b/d. The relative cost benefit (RCB) showed that economically, the birds placed on degraded rice offal (DRO) gave better profit margin than the ones placed on the undegraded rice offal (URO). The results reveal that A. niger was able to improve the energy, crude protein and other nutrients in rice offal which will bring economic benefits to farmers.

Keywords: Aspergillus niger, rice offal, degraded, undegraded, nutrient contents, feed improvement

African Journal of Biotechnology Vol. 12(20), pp. 3083-3087