Voluntary intake and digestibility of fresh, wilted and dry Leucaena (Leucaena leucocephala) at four levels to a basal diet of guinea grass (Panicum maximum)

Abstract

Sixty crossbred Anglo-Nubian goats (growing females), 18-24 mo of age, with a mean pre-experimental live weight of 20.9±0.44 kg were used to investigate voluntary dry matter intake (DMI) and digestibility of supplements of Leucaena leucocephala (LL) leaves to a basal diet of guinea grass. The experiment was a 3 forms of presentation: fresh, wilted and dryx4 levels of supplementation: 10, 20, 30 and 40% of total forage allowance with LL leaves. The goats were assigned based on weight and age to one of the twelve diets in a randomized manner and each level had five animals (replicates) per diet for 56 days. The form of presentation of LL leaves had effects on dry matter (DM) and nutrient composition. DM and NDF were higher in the dry LL leaves (p<0.05). In the diets, CP increased as the level of supplementation with LL leaves increased (p<0.05). Mean CP was similar in the fresh (14.8±3.5%), wilted (14.3±3.3%) and dry forms (13.9±3.1%). Neutral detergent fibre (NDF) decreased linearly (p<0.05) with increase in levels of supplementation. Organic matter (OM) followed the trend of CP concentration (p<0.05). Drying was observed to reduce the availability of CP at the different levels of supplementation and subsequently this affected the NDF of the diets. DM intake of the goats on the fresh and wilted LL leaves was significantly higher (p<0.05) than in those on the dry LL leaves. DM intake of the basal diet was observed to decrease as the level of supplementation (p<0.05) increased regardless of the form of presentation of LL. Growth rate was best (p<0.05) on the fresh form followed by wilted and the least in the dry form. Growth rate decreased linearly (p<0.05) with increase in the level of supplementation in the dry form. The form of presentation and level of supplementation influenced DM, CP and OM digestibility (p<0.05). Except for NDF, the digestibility of DM, CP and OM were better (p<0.05) in the goats on fresh LL leaves compared to the wilted and dry leaves. Based on the data on DMI, growth rate and apparent nutrient digestibility coefficients, the results suggest that LL leaves is best utilized when fed fresh or wilted to goats. In the dry form of presentation, the best level of supplementation without a reduction in voluntary DMI and growth rate is the 20%. In the fresh and wilted form, LL leaves could be fed up to the 40% level with improved DMI, growth rate and nutrient utilization.