West African dwarf goat in Ghana (photo credit: ILRI/Paul Karaimu).

A new paper by scientists at in the International Livestock Research Institute (ILRI) and Wageningen University and Research (WUR) compared the lifetime performance of West African Dwarf goats (WAD) kept under various feeding systems. They conclude that West African smallholders can best enhance their goat production systems by supplementing the diets of their grazing goats with farm-generated feeds.

Comparisons of the lifetime productivity of individual animals raised by farmers using alternative livestock interventions allowed the research team to assess, reliably and over the long term,  the investment opportunities for smallholder farmers.

A dynamic modelling approach was used to explore the effects of different feeding strategies on the lifetime productivity of West African Dwarf goats in southwestern Nigeria. These goats, which are markedly stunted, with typical heights of 30 to 50 cm (12 to 20 in), are more disease resistant than other breeds of domestic goat and are important in the rural village economy of West Africa.

The research team modified the current version of ‘Livestock Simulator’ (LIVSIM), an individual-based livestock production model that simulates animal production (meat, milk, progeny and manure) and maintenance requirements. Different livestock units can be taken into account, each characterized by production objectives, animal species and breeds. The research team used LIVSIM to test the impacts of changes in inputs such as the quality of feed in West African Dwarf goat raising, which confirmed the sensitivity of the modelled weight development and reproductive performance. The values of simulated model outputs corresponded well with observed values for most of the variables, except for the pre-weaning mortality rate in cut-and-carry feeding systems, where a wide discrepancy between simulated (2.1%) and observed (23%) data was found.

A scenario analysis showed that simulated goats raised in a free-grazing system attained sexual maturity and kidded much later than those raised in grazing plus feed supplementation and in cut-and-carry feed systems. The simulated results indicate that supplementing goat feed with protein and energy sources enhances the lifetime productivity of these goats, as seen in their early sexual maturity and higher birth weights. In terms of economic returns based on feed costs alone, the ‘moderately intense’ feed system produced the greatest profits over the lifetime of the goats.

Read the limited-access article: Assessment of lifetime performance of small ruminants under different feeding systems, by Tunde Amole (ILRI), Mink Zijlstra (Wageningen University and Research), Katrien Descheemaeker (Wageningen University and Research), Augustine Ayantunde (ILRI) and Alan Duncan (ILRI), in Animal, 29 Dec 2016.