Feed selection and dietary preferences of forage by small ruminants grazing natural pastures in the Sahelian zone of Cameroon

The grazing behaviour of two mixed flocks of sheep and goats on a Sahelian rangeland was observed in the Far North Province of Cameroon. The area was dominated by thorn shrubs and a herbaceous layer made up of annual grasses. The study ran for 9 months, covering the rainy (June–September), post-rainy (October–December) and cold dry (January–March) seasons. A simple method was adapted for estimating the dietary preference of goats and sheep, and variation in plant biomass. Observation on the vegetative cycles of some browse species was also done to see whether this influenced dietary preference. It was noticed that sheep and goats possess a certain degree of nutritional wisdom and that contrary to what most people might think, no amount of feed scarcity could force them to feed on some undesirable forage species. Browse species with high preference indices were Acacia seyal, A. senegal, Pterocarpus lucens and Ziziphus mauritiana. Goats spent 75% of their grazing time browsing, while the reverse was true for sheep. Maximum plant biomass was noticed in the month of September and high preference indices in the rainy season were seen to correspond to stages of maximum foliation of the browse species. The fruits, blossoms and pods produced by some of the browse species made a reasonable contribution to the diet of both goats and sheep, particularly in the dry season. Given the reputation of goats as highly-selective feeders, range management programmes should aim at preserving plant communities that are highly diversified in botanical structure as well as ensuring the survival of the tree species that are highly browsed by herbivores.