Supplementation with Rumen-Protected Methionine Reduced the Parasitic Effect of Haemonchus contortus in Goats

SIMPLE SUMMARY: In this study, we investigated the impact of rumen-protected methionine supplementation on the response of Creole goat kids to an experimental infection with Haemonchus contortus, a gastrointestinal parasite that affects small ruminants. We found that while serum IgA anti-ESP was increased in methionine-supplemented animals, no significant effect on the level of parasitism was observed. However, our results suggested that methionine supplementation mitigated the detrimental pathophysiological impact of the infection. This study highlights the need for further research on ruminants to better understand how amino acids can influence the host’s immune response to parasitic infections. This knowledge could potentially lead to new strategies for controlling these infections in livestock, benefitting both animal health and welfare and production performances. ABSTRACT: The present study investigated the impact of rumen-protected (RP) methionine supplementation on the resistance and resilience to Haemonchus contortus experimental infection of goat kids. Twenty-seven 6-month-old goat kids (14.55 ± 2.7 kg body weight) were placed in individual pens during an experimental period of forty-two days. Each kid was placed under one of three distinct diets (n = 9 animals/diet) corresponding to the following experimental groups: Control (C, Hay + concentrate), Low Methionine (LM, Hay + concentrate + 3.5 g/Kg of Dry Matter (DM) of RP methionine, or High Methionine (HM, Hay + concentrate + 11.5 g/Kg of DM of RP methionine). After a 4-week period of adaptation to the diets, all the animals were experimentally infected with a single oral dose of 10,000 H. contortus third-stage infective larvae (L3). No significant effect of RP methionine supplementation was observed for feed intake, digestibility and growth performance. The faecal egg counts (FEC) and worm burdens were not impacted by RP methionine supplementation either. In contrast, Packed cell volume (PCV) and haemoglobin concentration were higher in kids supplemented with RP methionine. Similarly, the level of serum IgA directed against adult H. contortus excretion and secretion products (ESP) was higher in supplemented kids. These results suggested that RP methionine supplementation improved goat kids’ resilience against H. contortus infection.