Effect of partial replacement of commercial sheep ration with Trichanthera gigantea (Nacedero) leaves on feed intake and carcass yield of barbados blackbelly lambs

The effect of partial replacement of commercial sheep ration (CSR) with Trichanthera gigantea (Nacedero) leaves (TGL) was studied using 27 Barbados Blackbelly lambs (12 males and 15 females) aged between 12 and 15 weeks. The diet consisted of (i) Tanner grass (Brachiara arrecta) offered ad libitum + CSR @ 2% of the body weight as a supplement-TGL-0 (ii) Tanner grass offered ad libitum + 20% of CSR replaced by TGL on dry matter (DM) basis-TGL-20 and (iii) Tanner grass offered ad libitum + 40% of CSR replaced by TGL on dry matter basis-TGL-40. The daily allowance of CSR for individual lambs for maintenance and weight gain of 60–70 g was calculated based on body weight. The feeding trial lasted for 11 weeks during which DM intake (DMI) and body weights (BW) were measured. In the last week of feeding trial, serum levels of total protein, albumin, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and carcass yield were determined. The CSR contained 14.6% crude protein (CP), 33.9% neutral detergent fibre (NDF) and 22.3% acid detergent fibre (ADF). The respective components in TGL were 18.1, 28.8 and 21.4 and in tanner grass, 6.5, 55.9 and 29.6%. The DMI (% BW) for TGL-0, TGL-20 and TGL-40 were 3.76, 3.61 and 3.67 respectively. Live weight gain for lambs in TGL-0, TGL-20 and TGL-40 were 4.70, 2.40 and 1.44 kg, respectively. The TGL-0 had a significantly higher weight gain than the TGL-20 and TGL-40 (P<0.001). The total protein concentrations in serum were 7.00, 6.43 and 7.04 g/dl for TGL-0, TGL-20 and TGL-40. Similarly serum AST and ALT levels did not differ significantly. The dressing yields were 34.9, 40.3 and 37.4% respectively for TGL-0, TGL-20 and TGL-40 and the difference was not significant. Non-significant differences in carcass weight, dressing yield among the three groups and also in DMI, serum protein, albumin, ALT and AST levels is suggestive of the potential of Trichanthera gigantea leaves feeding as a protein source in growing lambs. However, a significant reduction in weight gain in lambs fed with TGL warrants further studies.