Eefect of Defaunation and Two Levels of Protein on Nutrient Utilisation and Growth of Crossbred Heifers

Sixteen crossbred (Sahiwal x Jersey) heifers (11–19 months, 80–177 b.wt. kg) were divided into two groups. One group was defaunated using a solution of sodium iauryl sulphate (9.0g/100.0 kg b.wt.) for 3 consecutive days. Both the groups were further divided into 2 sub groups of four animals each. Oat hay was given ad-libitum to the animals in the four sub-groups. However, concentrate mixture was given to meet either 100 or 75% of CP requirements for growth (500g/day) in the sub groups. Voluntary dry matter intake was higher (P<0.05) in the faunated group than in defaunated group. Defaunation increased (P<0,05) the apparent digestibility of DM, OM, CP and ADF. The digestibility of OM and CP was higher (P<0.05) in heifers fed sub optimal protein diet (67.62 vs 63.18 and 61.03 vs 52.99% respectively). Average daily gain (g/day) and feed conversion efficiency were higher (P<0.05) in defaunated than in faunated heifers.