Tightly Bunched Herding Improves Cattle Performance in African Savanna Rangeland

Abstract

Rotational grazing approaches are regarded as strategies for sustaining or increasing rangeland productivity, and continue to be applied across many parts of the world. In Africa, livestock farmers implementing rotational grazing often switch from the traditional loosely bunched herding, where animals within a herd are allowed to spread out naturally when foraging, to tightly bunched herding with limited herd spread to increase animal impact on the range. However, there is little scientific information on the actual direct (short-term) effects of this herding strategy on livestock productivity. We investigated the direct effects of tightly versus loosely bunched herding on foraging behaviour, nutrition and performance (weight gain) of cattle in a semi-arid savanna rangeland in central Kenya. We conducted the study across two habitat types; a heterogeneous red soil habitat and a relatively homogeneous black cotton soil habitat. Across both habitats, cattle travelled 9-15% less, foraged 10-29% more efficiently, and put on 14-39% more weight when managed with tightly bunched herding as compared to loosely bunched herding. These changes occurred despite the fact that stock densities were twice to several times higher under tightly bunched herding, and cattle under this herding regime foraged less selectively, consuming preferred plants less (especially in the black cotton soil habitat) and consuming diets with lower crude protein content (in the red soil habitat). Financial projection showed that the benefit of increased cattle performance under tightly bunched herding could sufficiently outweigh increased cost of additional labour required to implement this herding strategy. These findings suggest that tightly bunched herding, as practiced here, can be implemented without livestock production or financial losses. Further, the demonstrated reduced grazing selectivity under tightly bunched herding indicates that this herding strategy could potentially be used to reduce grazing pressure on preferred forage plants and maintain herbaceous species diversity without sacrificing cattle performance.