Authors: Ren Xiang, Xue Yuheng, Shen Zhehong, Liu Xiaotian, Chang Xiaokang, Meng Jun, Ren Wanlu, Wang Jianwen, Yao Xinkui, Zeng Yaqi
Journal: Frontiers in veterinary science
Summary
# Editorial Summary: BCAA Supplementation in Lactating Mares and Foal Development Branched-chain amino acids represent a promising but understudied nutritional intervention for equine lactation, prompting researchers to evaluate supplementation protocols in 18 pairs of Yili mares and foals across four treatment groups (control, 38 g/day, 76 g/day, and 114 g/day BCAA) over a 67-day period. Using liquid chromatography-mass spectrometry to quantify 22 plasma and milk amino acids, the trial revealed dose-dependent metabolic responses: the lowest supplementation (38 g/day) significantly elevated serine in both plasma and milk (p < 0.01), whilst the highest dose (114 g/day) substantially increased tryptophan, histidine, and aspartic acid in plasma and aspartic acid and alanine in milk. Foals born to supplemented dams demonstrated measurable growth advantages, with group S3 achieving significantly greater bodyweight than controls and group S2 showing superior trends in height and length gain, whilst correlation analysis identified mare milk threonine as positively associated with foal skeletal development. These findings suggest BCAA supplementation modulates amino acid metabolism through the mTOR pathway to enhance milk composition and subsequently support foal growth, though the mechanism differs subtly across dose ranges—a distinction with practical implications for tailoring supplementation protocols. Despite these encouraging results, the relatively small sample size warrants cautious interpretation and calls for larger, longer-term validation studies before widespread adoption in breeding programmes.
Read the full abstract on PubMed
Practical Takeaways
- •BCAA supplementation at 76-114 g/day may improve foal growth metrics; moderate doses (76 g/day) appear optimal for skeletal development while higher doses (114 g/day) maximize weight gain
- •Milk amino acid composition directly influences foal growth, particularly threonine levels correlating with height and length—managing mare nutrition through BCAA supplementation offers an indirect lever to optimize lactation quality
- •Results are preliminary with small sample size (18 pairs); apply cautiously until larger, longer-term studies validate optimal dosing protocols for your breeding operation
Key Findings
- •38 g/day BCAA supplementation significantly increased serine content in mare plasma (p<0.05) and milk (p<0.01)
- •114 g/day BCAA supplementation elevated tryptophan, histidine, and aspartic acid in plasma, with significantly greater foal body weight compared to control (p<0.05)
- •76 g/day BCAA supplementation showed superior trends in foal body height and length growth
- •Mare milk threonine demonstrated positive correlation with foal body height and length development