The effect of supplementary feeding in browsing Criollo kids and hair sheep naturally infected with gastrointestinal nematodes

Abstract

SummaryThe objective was to highlight the role of supplementary feeding on resilience and resistance of browsing small ruminants against natural gastrointestinal nematode (GIN) infections. GIN infections have a negative impact on productivity of browsing Criollo kids especially during the wet season of Yucátan. Epidemiological studies have demonstrated the threat of GIN infectivity in the native vegetation available for browsing goats. Control of GIN in browsing ruminants is threatened by the emergence of anthelmintic resistant nematodes strains in the local flocks. Browsing trials with kids and lambs have shown that supplementary feeding (100–108g/day) improved resilience and resistance of Criollo kids against GIN. Supplements used successfully include sorghum:soybean meal (74:26 respectively), maize:soybean meal (74:26) and maize only (108g/day). The later result showed that animals might benefit from supplementation with rumen fermentable energy that could improve utilization of available browsing legumes by the goats. Wet season trials showed that, in spite of supplementation, infected animals have lower productivity compared to non-infected animals. However, the combined use of supplementation and copper oxide wire particles or tactic anthelmintic treatment, can improve growth rate of infected kids to maximum production levels. Short-term supplementation strategies have shown to be less effective than long-term strategies in achieving better resilience against GIN in kids. Lambs are more resistant but less resilient against GIN infections than kids. Improved resistance of lambs seemed to require more nutrients than in goats. In conclusion, supplementary feeding can play an important role in improving both resilience and resistance of growing small ruminants in the tropics but it can be further improved through the complementary use of other strategies leading to a more sustainable integrated parasite control strategy.