Behaviour of White Fulani calves grazing panicum/stylo pasture in Southwest Nigeria

- White Fulani yearling calves possess the capability to increase grazing time to obtain maximum intake when access to pasture is restricted.
- Dense plots cut to 15 cm height is presumed to maintain suitable grazing production on Panicum/Stylo mixture and is therefore encouraged to be adopted by livestock owners in Nigeria.
- Self-licking behaviour was more prominent in sparse plots at 20 cm height. This suggests that the animals result to lick themselves as a way of comfort owing to limited forage resources.
- The highest grazing time was observed for dense plots cut to 15 cm height.
- The WF calves engaged more in walking while grazing in plots with sparse pasture biomass compared to dense pasture plots where herbage density was high. It is worthy of note that walking also constitute energy loss in grazing animals.

The objective of this study was to investigate the behaviour of White Fulani (WF) yearling calves grazing a Panicum maximum/Stylosanthes guianensis mixture under traditional management system in south western Nigeria. The effects of two biomass spatial distribution (dense and sparse) were evaluated in association with three pasture heights (10, 15 and 20 cm), with calves allowed access to the pasture for 2:00 h. The experiment was laid out in a split plot design with the two biomass spatial distribution assigned to the main plot and sward height assigned to the sub plot to give six treatments; this was replicated three times. The experiment took place from November to December, 2015. Grazing behaviour was recorded with the aid of a Chloride UK 8 channel, H.264 digital video recorder and Chloride UK IR waterproof camera fitted with 3.6 mm lens. Data on grazing time, walking time, idling/resting/rumination time and time spent by the animals exhibiting self-licking behavior were collected from the recorded CCTV video player. There was a significant difference in the time spent grazing by the calves with those grazing the pasture with dense biomass at 15 cm height recording more grazing time (87.33 min). Animals on the pasture with sparse biomass at 10 cm height recorded more (p < 0.05) idling/resting/rumination time (18.33 min). The time spent by the calves walking was similar for the pasture with dense biomass at 10 cm and 15 cm above the ground. Self-licking behaviour was generally exhibited by the calves across the treatments. However, calves grazing in the plot with sparse biomass at 20 cm height engaged in more self-licking behaviour than those in the dense biomass pasture. The differences observed in the behavioural parameters examined clearly indicated the capability of WF yearling calves to increase grazing time, reduce the time spent walking, idling/resting/rumination and self-licking time, thereby improving their efficiency of grazing. From management perspective, plots with dense pasture biomass cut to 15cm height is suggested for optimal production of grazing calves on sown Panicum/Stylosanthes mixture under the present production systems in south western Nigeria.