Leucine is an essential amino acid that is important in the diet of horses due to its role in protein synthesis and muscle metabolism. As a branched-chain amino acid (BCAA), leucine is not synthesized by the body and must be obtained through dietary sources. It is involved in various metabolic processes and is particularly noted for its role in promoting muscle protein synthesis and recovery. Research in equine nutrition examines the impact of leucine supplementation on muscle development, performance, and recovery in horses. This page gathers peer-reviewed research studies and scholarly articles that explore the metabolism, dietary requirements, and physiological effects of leucine in equine species.
Li X, Ma J, Li H, Li H, Ma Y, Deng H, Yang K.The objective of this study was to examine the effects of supplemental β-alanine feeding on the athletic performance of Yili horses involved in speed racing, focusing on alterations in plasma free amino acid patterns pre and post exercise. Additionally, the research aimed to evaluate the effects of carnosine on the plasma acid-base buffering capacity and antioxidant levels in these horses. Twelve Yili horse stallions, averaging 3 years in age and 346.50 ± 21.39 kg in weight, were chosen and randomly divided into two groups: a control group and a test group, each comprising six horses...
Johansson L, Ringmark S, Bergquist J, Skiöldebrand E, Jansson A.The plasma metabolomic profile of elite harness horses subjected to different training programmes was explored. All horses had the same training programme from 1.5 until 2 years of age and then high-intensity training was introduced, with horses divided into high and low training groups. Morning blood samples were collected at 1.5, 2, 2.5 and 3.5 years of age. The plasma was analysed using targeted absolute quantitative analysis and a combination of tandem mass spectrometry, flow-injection analysis and liquid chromatography. Differences between the two training groups were observed at 2 yea...
Xing J, Xie L, Qi X, Liu G, Akhtar MF, Li X, Bou G, Bai D, Zhao Y, Dugarjaviin M, Zhang X.The proliferation and differentiation of skeletal muscle satellite cells (SCs) are necessary for the development of mature skeletal muscle. Leucine (Leu) is both an essential amino acid (EAA) and a branched-chain amino acid (BCAA), which has attracted worldwide attention due to its ability to repair and become new fibers. We separated the equine SCs into the control group (CON) and the Leu-supplemented group (LEU), which the cells were cultured in Leu-deprived and Leu-supplemented media respectively. We combined the transcriptome (RNA-Seq) and quantitative proteome (TMT) profiling analyses on ...
Wouters CP, Toquet MP, Renaud B, François AC, Fortier-Guillaume J, Marcillaud-Pitel C, Boemer F, De Tullio P, Richard EA, Votion DM.Atypical myopathy (AM) is a severe rhabdomyolysis syndrome that occurs in grazing horses. Despite the presence of toxins in their blood, all horses from the same pasture are not prone to display clinical signs of AM. The objective of this study was to compare the blood metabolomic profiles of horses with AM clinical signs with those of healthy co-grazing (Co-G) horses. To do so, plasma samples from 5 AM horses and 11 Co-G horses were investigated using untargeted metabolomics. Metabolomic data were evaluated using unsupervised, supervised, and pathway analyses. Unsupervised principal component...
Arfuso F, Giannetto C, Giudice E, Fazio F, Panzera M, Piccione G.The current study aimed to investigate whether peripheral modulators of serotoninergic function and neurohumoral factors' changes in athletic horses during an official jumping competition, and to evaluate their relationship with the physical performance of competing horses. From 7 Italian Saddle mares (6-9 years; mean body weight 440 ± 15 kg), performing the same standardized warm-up and jumping course during an official class, heart rate (HR) was monitored throughout the competition. Rectal temperature (RT) measurement, blood lactate and glucose concentration, serum tryptophan, leucine, vali...
Arfuso F, Assenza A, Fazio F, Rizzo M, Giannetto C, Piccione G.Physical exercise induces several adaptations involving modulation of the energetic pathways to meet the energy demand during physical exercise. The branched-chain amino acids, leucine in particular, are considered as the most relevant amino acids, especially for exercise physiology. In this study, the change of leucine, valine, and tryptophan concentration was investigated in athletic horses before and after different exercise type. A total of 40 sport horses were equally divided into 4 groups according to the exercise type: group A (jumping), group B (reining), group C (32 km ride), and grou...
DeBoer ML, Martinson KM, Pampusch MS, Hansen AM, Wells SM, Ward C, Hathaway M.Leucine has been shown to stimulate the mammalian/mechanistic target of rapamycin (mTOR) signaling pathway which plays numerous key regulatory roles in cell growth, survival, and metabolism including protein synthesis in a number of species. However, previous work with equine satellite cells has suggested distinct species differences in regards to physiological effects and the magnitude of responses to growth factors and regulators. Because there is limited research available regarding the role of leucine in regulating equine skeletal muscle protein synthesis, the objective of this study was t...
Nostell KE, Essén-Gustavsson B, Bröjer JT.The branched chain amino acid leucine is a potent stimulator of insulin secretion. Used in combination with glucose it can increase the insulin response and the post exercise re-synthesis of glycogen in man. Decreased plasma amino acid concentrations have been reported after intravenous or per oral administration of leucine in man as well as after a single per oral dose in horses. In man, a negative correlation between the insulin response and the concentrations of isoleucine, valine and methionine have been shown but results from horses are lacking. This study aims to determine the effect of ...
Urschel KL, Geor RJ, Waterfall HL, Shoveller AK, McCutcheon LJ.Providing protein or amino acid mixtures in combination with glucose to post exercise in man has resulted in increases in the post feeding insulin response and in muscle glycogen and protein synthesis rates. However, whether protein and/or amino acids can modify the post exercise insulin responses in horses remains to be fully elucidated. Objective: To determine whether whey protein or leucine addition to a glucose solution affects the post gavage plasma insulin, glucose and amino acid responses in horses and whether these responses are different following a period of exercise vs. rest. Method...
Assenza A, Bergero D, Tarantola M, Piccione G, Caola G.During long-distance exercise, branched-chain amino acid (BCAA) catabolism could lead to an increase in the blood tryptophan/BCAA ratio and an early onset of 'central fatigue'. Based on these considerations, we studied the modifications of blood serum BCAA and tryptophan (Try) levels in 30 endurance horses competing in rides varying in distance from 20 to 72 km. From all horses, blood samples were drawn just before and just after the end of the ride. Samples were analysed for their leucine (Leu), valine (Val), isoleucine (Iso) and Try levels. Data were processed by anova, using sampling moment...
Reitnour CM.The influence of administering caecal corn starch (0.0, 0.2, 0.4 or 0.6 g/kg body weight/day) on protein utilisation in 4 ponies was analysed with a latin square experimental design. The basal diet was dehydrated alfalfa pellets. Determinations were made of nitrogen retention, protein and dry matter digestions, total plasma protein, plasma urea nitrogen, plasma ammonia and plasma-free amino acids. Twice daily administration of corn starch into the caecum resulted in an increased nitrogen retention (P less than 0.01). Maximum nitrogen retention was observed with the caecal administration of 0.4...
Reitnour CM.Utilisation of nitrogen was studied in 4 crossbred ponies. A latin square design was used to study the effects of corn gluten meal, casein or urea when added to a low protein basal diet. Apparent nitrogen digestion, nitrogen retention, total plasma protein, plasma urea and plasma-free amino acids were measured. The addition of corn gluten meal, casein or urea to the basal ration increased apparent digestion of nitrogen. Casein produced a significantly greater (P less than 0.05) nitrogen retention than corn gluten meal or urea. Plasma urea nitrogen increased significantly (P less than 0.01) in ...
Assenza A, Bergero D, Tarantola M, Piccione G, Caola G.During long-distance exercise, branched-chain amino acid (BCAA) catabolism could lead to an increase in the blood tryptophan/BCAA ratio and an early onset of 'central fatigue'. Based on these considerations, we studied the modifications of blood serum BCAA and tryptophan (Try) levels in 30 endurance horses competing in rides varying in distance from 20 to 72 km. From all horses, blood samples were drawn just before and just after the end of the ride. Samples were analysed for their leucine (Leu), valine (Val), isoleucine (Iso) and Try levels. Data were processed by anova, using sampling moment...
Arfuso F, Assenza A, Fazio F, Rizzo M, Giannetto C, Piccione G.Physical exercise induces several adaptations involving modulation of the energetic pathways to meet the energy demand during physical exercise. The branched-chain amino acids, leucine in particular, are considered as the most relevant amino acids, especially for exercise physiology. In this study, the change of leucine, valine, and tryptophan concentration was investigated in athletic horses before and after different exercise type. A total of 40 sport horses were equally divided into 4 groups according to the exercise type: group A (jumping), group B (reining), group C (32 km ride), and grou...
Arfuso F, Giannetto C, Giudice E, Fazio F, Panzera M, Piccione G.The current study aimed to investigate whether peripheral modulators of serotoninergic function and neurohumoral factors' changes in athletic horses during an official jumping competition, and to evaluate their relationship with the physical performance of competing horses. From 7 Italian Saddle mares (6-9 years; mean body weight 440 ± 15 kg), performing the same standardized warm-up and jumping course during an official class, heart rate (HR) was monitored throughout the competition. Rectal temperature (RT) measurement, blood lactate and glucose concentration, serum tryptophan, leucine, vali...
DeBoer ML, Martinson KM, Pampusch MS, Hansen AM, Wells SM, Ward C, Hathaway M.Leucine has been shown to stimulate the mammalian/mechanistic target of rapamycin (mTOR) signaling pathway which plays numerous key regulatory roles in cell growth, survival, and metabolism including protein synthesis in a number of species. However, previous work with equine satellite cells has suggested distinct species differences in regards to physiological effects and the magnitude of responses to growth factors and regulators. Because there is limited research available regarding the role of leucine in regulating equine skeletal muscle protein synthesis, the objective of this study was t...
Urschel KL, Geor RJ, Waterfall HL, Shoveller AK, McCutcheon LJ.Providing protein or amino acid mixtures in combination with glucose to post exercise in man has resulted in increases in the post feeding insulin response and in muscle glycogen and protein synthesis rates. However, whether protein and/or amino acids can modify the post exercise insulin responses in horses remains to be fully elucidated. Objective: To determine whether whey protein or leucine addition to a glucose solution affects the post gavage plasma insulin, glucose and amino acid responses in horses and whether these responses are different following a period of exercise vs. rest. Method...
Nostell KE, Essén-Gustavsson B, Bröjer JT.The branched chain amino acid leucine is a potent stimulator of insulin secretion. Used in combination with glucose it can increase the insulin response and the post exercise re-synthesis of glycogen in man. Decreased plasma amino acid concentrations have been reported after intravenous or per oral administration of leucine in man as well as after a single per oral dose in horses. In man, a negative correlation between the insulin response and the concentrations of isoleucine, valine and methionine have been shown but results from horses are lacking. This study aims to determine the effect of ...
Wouters CP, Toquet MP, Renaud B, François AC, Fortier-Guillaume J, Marcillaud-Pitel C, Boemer F, De Tullio P, Richard EA, Votion DM.Atypical myopathy (AM) is a severe rhabdomyolysis syndrome that occurs in grazing horses. Despite the presence of toxins in their blood, all horses from the same pasture are not prone to display clinical signs of AM. The objective of this study was to compare the blood metabolomic profiles of horses with AM clinical signs with those of healthy co-grazing (Co-G) horses. To do so, plasma samples from 5 AM horses and 11 Co-G horses were investigated using untargeted metabolomics. Metabolomic data were evaluated using unsupervised, supervised, and pathway analyses. Unsupervised principal component...
Reitnour CM.Utilisation of nitrogen was studied in 4 crossbred ponies. A latin square design was used to study the effects of corn gluten meal, casein or urea when added to a low protein basal diet. Apparent nitrogen digestion, nitrogen retention, total plasma protein, plasma urea and plasma-free amino acids were measured. The addition of corn gluten meal, casein or urea to the basal ration increased apparent digestion of nitrogen. Casein produced a significantly greater (P less than 0.05) nitrogen retention than corn gluten meal or urea. Plasma urea nitrogen increased significantly (P less than 0.01) in ...
Reitnour CM.The influence of administering caecal corn starch (0.0, 0.2, 0.4 or 0.6 g/kg body weight/day) on protein utilisation in 4 ponies was analysed with a latin square experimental design. The basal diet was dehydrated alfalfa pellets. Determinations were made of nitrogen retention, protein and dry matter digestions, total plasma protein, plasma urea nitrogen, plasma ammonia and plasma-free amino acids. Twice daily administration of corn starch into the caecum resulted in an increased nitrogen retention (P less than 0.01). Maximum nitrogen retention was observed with the caecal administration of 0.4...
Xing J, Xie L, Qi X, Liu G, Akhtar MF, Li X, Bou G, Bai D, Zhao Y, Dugarjaviin M, Zhang X.The proliferation and differentiation of skeletal muscle satellite cells (SCs) are necessary for the development of mature skeletal muscle. Leucine (Leu) is both an essential amino acid (EAA) and a branched-chain amino acid (BCAA), which has attracted worldwide attention due to its ability to repair and become new fibers. We separated the equine SCs into the control group (CON) and the Leu-supplemented group (LEU), which the cells were cultured in Leu-deprived and Leu-supplemented media respectively. We combined the transcriptome (RNA-Seq) and quantitative proteome (TMT) profiling analyses on ...
Johansson L, Ringmark S, Bergquist J, Skiöldebrand E, Jansson A.The plasma metabolomic profile of elite harness horses subjected to different training programmes was explored. All horses had the same training programme from 1.5 until 2 years of age and then high-intensity training was introduced, with horses divided into high and low training groups. Morning blood samples were collected at 1.5, 2, 2.5 and 3.5 years of age. The plasma was analysed using targeted absolute quantitative analysis and a combination of tandem mass spectrometry, flow-injection analysis and liquid chromatography. Differences between the two training groups were observed at 2 yea...
Li X, Ma J, Li H, Li H, Ma Y, Deng H, Yang K.The objective of this study was to examine the effects of supplemental β-alanine feeding on the athletic performance of Yili horses involved in speed racing, focusing on alterations in plasma free amino acid patterns pre and post exercise. Additionally, the research aimed to evaluate the effects of carnosine on the plasma acid-base buffering capacity and antioxidant levels in these horses. Twelve Yili horse stallions, averaging 3 years in age and 346.50 ± 21.39 kg in weight, were chosen and randomly divided into two groups: a control group and a test group, each comprising six horses...
