The use of metabolomics tools in the evaluation of the fattening performance of lambs

This study aimed to determine the metabolomic characteristics associated with the fattening performance of the Awassi lamb breed under intensive fattening for 90 days. Twenty-four lambs were used in the research. The lambs were divided into two groups according to their fattening performance (good fattening performance, n = 12, and poor fattening performance, n = 12), and their metabolomic properties were evaluated. The differences between the two research groups in the amino acids of alloisoleucine, aspartic acid, histidine, hydroxylysine, isoleucine, lysine, methionine, phenylalanine, tryptophan, valine, and 1-methylhistidine were found to be statistically significant (P ≤ 0.001). Moderately significant negative correlations were found between daily concentrate feed intake and 3-methylhistidine (r = −0.469; P = 0.021), hydroxylysine (r = −0.408; P = 0.048), and serotonin (r= −0.467; P = 0.021); as well as between the average daily weight gain (ADWG) and alloisoleucine (r = −0.528; P = 0.008), 3-methylhistidine (r = −0.440; P = 0.032), and hydroxylysine (r = −0.577; P = 0.003). A moderate positive correlation was found between hydroxyisovalerylcarnitine and ADWG (r = 0.476; P = 0.019), and a negative correlation was found between hydroxyisovalerylcarnitine and the feed conversion ratio (r = −0.430; P = 0.036). Pathway analysis revealed that the most important biological pathway was the phenylalanine, tyrosine, and tryptophan biosynthesis pathway. The results of the research reveal the potential for plasma free amino acid and carnitine profiles to be used as candidate biomarkers in the evaluation of fattening performance in lambs.