MITIGATING THE NUTRITIONAL LIMITATIONS TO ANIMAL PRODUCTION FROM TROPICAL PASTURES: A REVIEW

Abstract

Pasture represents the cheapest, most abundant and available feed resource for ruminant animals in the tropics. However, because of high variability in chemical composition and sward morphology due to seasonality, species/ pasture types, environment and management factors which resulted in low intake and inefficient utilization, tropical pastures are usually insufficient, as a sole feed to sustain high levels of production. On the other hand, the inability of farmers to exploit the growth advantage and high dry matter produced by tropical pasture species by adopting and using the available technologies have contributed significantly to the low productivity from tropical pastures. It is an accepted fact that optimizing herbage dry matter intake at pasture is the single most important factor limiting production from tropical pastures. Cognizant of this limitation researchers have endeavored to find solutions to optimize herbage intake and improve utilization efficiency while exploiting the proven advantages of tropical pastures. To this effect, several strategies have been successfully identified inclusive of; preferred grazing, optimizing carrying capacity and stocking rate, mixed specie grazing, semi and or zero grazing, improving sward state to enhance grazing efficiency, concentrate supplementation, grass/legume pasture association, forage conservation and synchronizing animal type/breed with the available feed resources. Importantly, the success of any tropical pasture-based production systems is heavily dependent on optimum management and integration of several of these strategies as part of their production practice. The inability of producers to make informed and timely decision regarding the nutritive value and sward characteristics prior to grazing has been cited as additional constraints. This review aims to examine the distinct characteristics of tropical pasture species and their effects on animal production, in addition to highlighting and discussing management strategies to offset likely feeding limitations and improve the utilization and grazing efficiency of tropical pastures.