Abstract: Branched-chain amino acids (BCAAs) play a crucial role in regulating nutritional metabolism in lactating animals. However, limited research has been conducted on BCAAs in equines. This study aimed to investigate the effects of different doses of BCAA supplementation on plasma and milk amino acid profiles in Yili mares, as well as the growth performance of their suckling foals, thereby providing a scientific basis for optimizing feeding management practices. Eighteen pairs of Yili mares and their sucklings were randomly assigned to four groups: a control group (Group D, no BCAA supplementation) and three experimental groups (S1, S2, and S3, receiving 38 g/day, 76 g/day, and 114 g/day of BCAA supplementation, respectively). The trial lasted for 67 days. The concentrations of 22 amino acids in plasma and milk were quantified using liquid chromatography-mass spectrometry (LC-MS), and their correlations with the body height, length, and weight of the foals were analyzed using SPSS software (one-way analysis of variance and Pearson correlation test). In mare plasma amino acids, the serine (Ser) content in group S1 was significantly higher than that in group D ( < 0.05). Additionally, in group S3, tryptophan (Trp), histidine (His), and aspartic acid (Asp) contents were markedly elevated. For mare milk amino acids, Ser content in group S1 was extremely significantly higher than in group D ( < 0.01), while aspartic acid (Asp) and alanine (Ala) contents were significantly increased in group S3. Regarding foal growth performance, body weight in group S3 was significantly greater than in group D. Moreover, group S2 exhibited superior trends in body height and length growth. Correlation analysis demonstrated that plasma Ser and creatine (Cr) were positively correlated with mare milk Ser and Cr. Mare milk threonine (Thr) showed a positive correlation with foal body height and length. Studies indicate that branched-chain amino acids (BCAA) regulate protein synthesis and amino acid metabolism via the mTOR pathway. In this experiment, 38 g/d BCAA enhanced mammary gland Ser transport, thereby increasing its content. Furthermore, 114 g/d BCAA promoted Asp and Ala accumulation, likely due to enhanced catabolic activity. The positive correlation between mare milk Thr, His, and skeletal development suggests that BCAA indirectly promotes growth through milk composition regulation. However, given the small sample size of this study, long-term validation is necessary.
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The research article investigates the impact of differing doses of Branched-chain amino acids (BCAAs) supplementation on the plasma and milk amino acid profiles in Yili mares and the growth performance of their foals. The study provides significant insights for better feeding management practices in equines.
Research Design
The study involved eighteen pairs of Yili mares and their sucklings which were randomly divided into four groups: a control group receiving no BCAA supplementation and three experimental groups S1, S2, and S3, receiving BCAA supplementation of 38 g/day, 76 g/day, and 114 g/day respectively.
The research was conducted over a period of 67 days. Post that, the concentration levels of 22 amino acids in the plasma and milk of the mares were estimated with the help of liquid chromatography-mass spectrometry (LC-MS).
The correlation between these concentration levels and body measurements (height, length, and weight) of the foals were statistically analyzed using one-way analysis of variance and Pearson correlation test.
Research Findings
The research found that serine content in the mare plasma of group S1 was significantly higher than the control group. Additionally, for group S3, the levels of tryptophan, histidine, and aspartic acid were noticeably increased.
Similarly, in mare milk amino acid profiles, serine content in group S1 was extremely higher than the control group. Moreover, for group S3, the levels of aspartic acid and alanine were significantly increased.
It was identified that the body weight of suckling foals in group S3 was significantly higher than the control group. Furthermore, group S2 displayed better growth in terms of body height and length.
Research Implications
The study shows that BCAAs can regulate protein synthesis and amino acid metabolism via the mTOR pathway in mare’s milk.
In the given experiment, supplementation of 38 g/d of BCAA resulted in the enhancement of mammary gland Ser transport, thereby increasing its content.
Supplementation of 114 g/d BCAA promoted the accumulation of Asp and Ala which is likely due to enhanced catabolic activity.
The positive correlation between mare milk threonine, histidine, and the foals’ skeletal development suggests that BCAA indirectly encourages growth through regulating the milk composition.
However, it is recommended that validation of these findings should be supported by further research considering the small sample size of the study.
Cite This Article
APA
Ren X, Xue Y, Shen Z, Liu X, Chang X, Meng J, Ren W, Wang J, Yao X, Zeng Y.
(2025).
Effects of BCAA supplementation on plasma and mare’s milk amino acid contents in Yili mares and growth performance of suckling foals.
Front Vet Sci, 12, 1602363.
https://doi.org/10.3389/fvets.2025.1602363
Xinjiang Horse Industry Association, Urumqi, China.
Xue, Yuheng
School of Animal Science, Xinjiang Agricultural University, Urumqi, China.
Shen, Zhehong
School of Animal Science, Xinjiang Agricultural University, Urumqi, China.
Liu, Xiaotian
School of Animal Science, Xinjiang Agricultural University, Urumqi, China.
Chang, Xiaokang
School of Animal Science, Xinjiang Agricultural University, Urumqi, China.
Meng, Jun
School of Animal Science, Xinjiang Agricultural University, Urumqi, China.
Ren, Wanlu
School of Animal Science, Xinjiang Agricultural University, Urumqi, China.
Wang, Jianwen
School of Animal Science, Xinjiang Agricultural University, Urumqi, China.
Yao, Xinkui
School of Animal Science, Xinjiang Agricultural University, Urumqi, China.
Zeng, Yaqi
School of Animal Science, Xinjiang Agricultural University, Urumqi, China.
Conflict of Interest Statement
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
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