Effect of cutting height on nutritional characteristics of three agroforestry tree legume species and their feed supplement value on Chloris gayana Kunth

This study investigated the effect of cutting height (30 and 100 cm) on chemical composition and in vitro digestibility in field-grown Acacia angustissima (Mill.) Kuntze. (Prairie acacia), Leucaena pallida Britton & Rose (guaja) and Mimosa scabrella Bentham. (bracatinga) legumes and their value in supplementing a basal diet of Chloris gayana Kunth. (Rhodes grass). Cutting height did not affect major chemical composition. Crude protein (CP) was highest in A. angustissima and lowest in M. scabrella, while neutral detergent fibre (NDF) and acid detergent fibre (ADF) were highest in M. scabrella. Degradation parameters were greater at 100 cm cutting height. L. pallida showed high in vitro organic matter digestibility but A. angustissima had the highest metabolisable energy. Addition of A. angustissima, L. pallida and M. scabrella to the basal diet increased improved the nutritional value and increased the CP content from 8.4 to 19.8% and 18.1 and 16.1%, respectively. Cutting height of A. angustissima, L. pallida and M. scabrella had no effect on their nutritional value. Their other functions and benefits will determine choice of cutting height as management practice when used on farms. Key words: Legume trees, cutting height, chemical composition, in vitro degradability.