Sustainability & efficiency

A Metabolomic Perspective on the Interaction between Feed Efficiency and Parasite Resistance in Lambs

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Abstract

This study profiled serum metabolomic signatures of Rideau Arcott ewe lambs to assess the interaction of feed efficiency and parasitic challenge during a controlled infection cycle. Sixty parasite-free lambs (6-7 months; 44.6 ± 6.08 kg) were initially tested for the residual feed intake (RFI) test for 64 days and then randomly allocated to one of two groups for another 57-day trial of parasite challenge. They randomly allocated in two groups of a parasite-free control group (n=30) or an inoculated group (n=30). On day 1, the inoculated group received a single oral dose of 5,000 L3 H. contortus larvae. To control the parasite infection, lambs in the inoculated group were treated with ivermectin and fenbendazole on day 28, while all lambs received toltrazuril for coccidia on day 35. Health status was monitored throughout via body weight, fecal egg counts, and blood parameters. Blood samples were collected at seven timepoints (days 0, 7, 21, 28, 35, 42, 57 days post inoculation) for metabolic analysis. Among the control and inoculated group, animals with  high- and low-RFI profile were identified making two groups of high RFI resistance and low RFI resistant groups (n=4 animals per group), and a targeted metabolomic analysis was performed. Significant metabolites were identified via a t-test (p2.0), and PLS-DA with VIP scores >1.5, using MetaboAnalyst 6.0. At the pre-infection baseline (Day 1), eight candidate biomarkers were identified, among them ketoglutaric acid, fumaric acid, and indole acetic acid, implicating five key metabolic pathways including arginine biosynthesis, the TCA cycle, alanine-aspartate-glutamate metabolism, butanoate metabolism, and pyruvate metabolism. The groups remained metabolically different during the infection phase (Days 1-28), with 16 potential metabolites differentiating the RFI groups. The post-treatment recovery phase (Days 35-57) revealed 13 candidate biomarkers, highlighting distinct metabolic recovery profiles between high- and low-RFI resistant lambs. The metabolic profile of feed-efficient lambs, low-RFI, reveals a distinct signature characterized by early alterations in the TCA cycle and arginine biosynthesis, suggesting an innate ability to manage physiological stress even prior to infection. Additionally, shifts in metabolites such as TMAO, spermidine, and butyrate (C4) may indicate a healthier gut environment that supports a more controlled response to parasitic challenge. The sustained elevation of β-hydroxybutyric acid further suggests an enhanced capacity to maintain energy balance during infection. Overall, this study shows that high RFI and low RFI lambs have different metabolic profiles and pathways and suggests that the metabolic signature of feed-efficient lambs could contribute to better resilience to parasitic infection, providing a promising biochemical framework to guide future strategies in livestock selection, management, and sustainable productivity.  

Keywords: 2026

How to Cite:

Borzouie, S., Jawad, H., Manafiazar, G., Miar, Y. & Osonowo, O., (2026) “A Metabolomic Perspective on the Interaction between Feed Efficiency and Parasite Resistance in Lambs”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2295839. doi: https://doi.org/10.31274/wcgalp.24377

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