Effects of supplementation with foliage from the tree legumes Acacia angustissima, Cajanus cajan, Calliandra calothyrsus and Leucaena leucocephala on feed intake, digestibility and nitrogen metabolism of sheep given maize stover ad libitum

Foliage (leaves, small-diameter stems and flowers and fruits if present) was harvested in March 1994 from Acacia angustissima, Cajanus cajan, Calliandra calothyrsus and Leucaena leucocephala and given as a supplement at four levels (0, 50, 100 and 150 g dry matter/day) to a diet of maize stover fed ad libitum to sheep. Sixteen sheep were used and divided into four groups of four, each with a mean weight of 18 kg. Each group was allocated at random to one of the legumes. Four 4 × 4 Latin square design experiments were carried out using 14-day periods and during the second week of each period feed intake, digestibility, nitrogen balance and microbial protein yield were measured. For each legume, other than C. calothyrsus, there was a significant increase (P < 0.05) in dry matter intake as the level of supplement increased. For all four legumes, there was a significant increase (P < 0.05) in digestibility of organic matter, nitrogen balance (NB) and microbial protein yield as the level of supplement increased. As judged by increases in intake of digestible organic matter and NB, A. angustissima gave the best response, followed by C. calothyrsus and L. leucocephala which were similar and then C. cajan gave the poorest response.