Biting rate of White Fulani calves as influenced by spatial distribution of pasture biomass and sward height

Abstract

Grazing ruminants are faced with the dilemma of making decisions when searching for and defoliating forage to meet their nutrient requirements, particularly in situations of heterogeneity in forage abundance and sward height. Knowledge of sward-animal interaction at bite level is essential for animal intake, performance and productivity of grazing systems. Here, we investigated the effect of two spatial distributions of forage biomass (dense and sparse) assigned to main plot, and three sward heights (10, 15 and 20 cm) allotted to sub-plot in a split plot design, with three replicates totalling six treatments, aimed at assessing the biting rate of White Fulani (WF) calves. The study was carried out between November and December 2015. Biting rate was recorded with the aid of a Chloride UK 8 channel, H.264 digital video recorder and Chloride UK IR waterproof camera equipped with 3.6 mm lens. WF calves altered their biting rate in an attempt to meet their intake requirement on Panicum maximum/Stylosanthes guianensis sward, notably with decrease in bite number as access time advanced. The calves, grazing pasture with dense biomass, recorded higher bite number during the occupation time (p < 0.05). Measurement of grazing bites of WF calves indicates that the herbage could be defoliated by ruminants on tropical pasture relatively easily.