Evaluation of the nutritional potentials of physically treated cowpea seed hulls in poultry feed

Feeding has been reported to be responsible for the high cost observed in poultry production. The use of unconventional feedstuff for poultry production is however limited due to their fibrousness and inability of birds to possess the cellulase enzyme that can digest the fibre, nevertheless, physical treatments of these unconventional feedstuffs enhance their possibility in poultry production. The objective of this study therefore, was to evaluate the nutrient status of cowpea seed hull after being subjected to different treatment. The Cowpea seed hull that was not subjected to any form of treatment served as the control i.e. Untreated cowpea seed hull (UCH), while a portion was soaked and boiled (soaked and boiled cowpea seed hull, SBCH) and another portion soaked for 3 days, soaked cowpea seed hull (SCH). The seed hull in each treatment were analysed for their proximate composition, metabolisable energy (ME) and fibre fraction. The trial revealed a steady increase in crude protein (CP) of the test materials with the highest increase (18.43%) in crude protein recorded in SCH substrate compared to 6.73% increase in SBCH substrate. A corresponding decrease in crude fibre (CF) was recorded with 15.00% loss for SCH substrate while 6.97% loss in crude fibre was observed for SBCH substrate. Changes of 1.73% and 4.22% were recorded for nitrogen free extract (NFE) in SBCH and SCH respectively, while ME changes by 1.67% and 5.39% for SBCH and SCH substrates respectively. The effects of both physical treatments on ash and insoluble ash were not significant. Fibre analysis revealed that 7.55% (53.00% to 49.00%) and 18.87% (53.00% to 43.00%) of acid detergent fibre (ADF), 7.41% (81.00% to 75.00%) and 16.05% (81.00% to 68.00%) of neutral detergent fibre (NDF) and 2.5% (40.00% to 39.00%) and 22.5% (40.00% to 31.00%) of cellulose were loss in SBCH and SCH substrates respectively. There were no significant effects on the acid detergent lignin (ADL) and hemicellulose components of the test samples due to these physical treatments. The result revealed that the different processing methods resulted in increase in the crude protein contents with a corresponding reduction in crude fibre of the seed hull. The changes observed must have been due to fermentation that occurred during the soaking of the seedhull.