An Evaluation Of The Potential Of Selected Indigenous Namibian Forage Legumes For Feeding Goats

ABSTRACT

The objectives of this research were to determine the chemical composition, palatability, voluntary feed intake (VFI) and effects on body weights of Boer goats fed native forage legumes compared to lucerne and lablab. In experiment 1, the chemical composition of 14 legumes was determined. In experiment 2, the palatability of Crotalaria argyraea, C. podocarpa, Otoptera burchellii and Vigna lobatifolia was determined relative to Lucerne in a cafeteria feeding system over a 10-day period. In experiment 3 on VFI, 32 goats were randomly allocated to nine treatments with the legumes Lablab purpureus (LP), O. burchellii (OB), V. lobatifolia (VL) and Medicago sativa (LC) as follows: control (C); 18% inclusion (LP18, OB18, VL18 and LC18); and 31% inclusion (LP31, OB31, VL31 and LC31). All forage legumes except Meulobium candicans had CP ≥ 15%; the NDF (%) ranged from 30.3 ± 3.8 (C. heidmannii) to 56.1 ± 3.2 (L. purpureus) subsp. Uncinatus verde.var. rhomboideus. All the four legumes in experiment 2 were highly palatable relative to Lucerne, but a 5-day adaptation period was required for the Crotalaria species. Least squares means of VFI (g DM/day) were: 668.7± 8.8 (C), 821.2 ± 10.8 (LP18), 783.1 ± 9.9 (OB18), 777.7 ± 10.8 (VL18), 802.8 ± 10.8 (LC18), 994.4 ± 9.9 (LP31), 992.8 ± 10.8 (OB31), 1009.2 ± 10.8 (VL31) and 970.6 ± 10.8 (LC31). Legume supplementation of basal grass hay increased VFI at 31% compared to 18% inclusion level. Body weights were affected (P < 0.05) by treatment; the least squares means (kg) for C, LP18, OB18, VL18, LC18, LP31 OB31, VL31 and LC31 were: 19.2 ± 0.8, 22.1 ± 0.9, 17.6 ± 0.9, 18.1 ± 0.9, 16.4 ± 0.9, 18.9 ± 0.8, 16.6 ± 0.9, 21.1 ± 0.9 and 20.4 ± 0.9, respectively. Native forage legumes have the potential to improve nutrition of goats.