Effects of processed cowpea (Vigna unguiculata L. Walp) haulms as a feed supplement on voluntary intake, utilization and blood profile of West African dwarf sheep fed a basal diet of Pennisetum purpureum in the dry season

The objective of this study was to evaluate intake, digestibility, growth performance and haematological variables of West African dwarf (WAD) sheep fed commercial and improved cowpea haulm diets. Thirty WAD sheep with initial body weight (BW) of 8.9 +/- 0.12 kg and aged 10 +/- 1.3 months were balanced as closely as possible for BW and randomly allotted to one of six dietary treatments. The six dietary treatments consisted of milled haulms from six varieties of cowpea. The haulms were fed as supplements to a basal diet of Pennisetum purpureum. A metabolic study was conducted after 106 days and balances of nutrients were determined. Dry matter intake was higher (P=0.005) in sheep fed improved cowpea haulm diets (467 g/day) than those on commercial haulm diets (430 g/day), but there was no difference in intake of crude protein (CP) in sheep fed improved versus commercial haulm diets. Digestibility of nutrients was not affected in sheep fed commercial versus improved haulms. Sheep fed commercial cowpea haulm diets gained more (P=0.007) BW and had a lower (P<0.001) feed conversion ratio of 7.1 compared with 30 g/day and 9.2 for sheep on improved haulm diets. All sheep were in positive N balance. Results show that cowpea haulms can be utilized as a supplement for livestock production and its inclusion in the diet of sheep had no deleterious effects while improving the haematological and serum biochemical variables. (C) 2010 Elsevier B.V. All rights reserved.