Performance of Dorper lambs fed buffel grass and browse as basal diet and sorghum bran as supplement

Abstract

Sixteen weaned lambs (10 castrates and 6 females) were used in a feeding trial at Malotwana Silvopastoral Farm
in an on-farm investigation lasting 134 days. The study was undertaken to investigate the growth rates of lambs
fed cultivated Leucaena spp. browse in comparison with those fed sorghum bran as supplements. The main
basal diet was buffel grass (Cenchrus ciliaris), which is a common grass that the animals in Botswana graze on
the range. Feed and water were provided ad. lib. Animals were supplemented with idiosed salt and dicalcium
phosphate. The average daily mass gain of bran-supplemented lambs was lower than that for browse
supplemented lambs (83.95  9.49 g/day/head compared to 103.33  2.72 g/day/head). The metabolic rate was
also higher for the browse-fed group: 12.19  0.19 g/day/head compared to 11.90  0.52 g/day/head for bran-fed
lambs (P = 0.1538). Throughout the study the browse-fed lambs performed better, and by day 49 had a
significantly greater mean mass (P = 0.0245) than the bran-fed group. Unseasonally cold weather in November
affected both groups, leading to loss of weight, with the bran-fed lambs recording a significantly lower mean
mass by day 98 of the trial (P = 0.0174). The results showed that crude protein requirements of lambs can be
met through the use of Leucaena browse.