The role of nutritional supplements and feeding strategies in equine athletic performance

The role of an equine nutritionist in equine health, performance and wellbeing: Ideas stemming from an equine science society symposium workshop

In the United States, there is little clarity on the qualifications and availability of equine nutritionists. Currently, no regulatory body exists for formal credentialing outside of veterinary medicine. Most equine nutritionists are not veterinarians but do have advanced scientific degrees (Master of Science and/or Doctor of Philosophy) in the field of Animal Science. However, not all reporting to be equine nutritionists have formal education in the field of equine nutrition. To discuss this, a workshop was held at the 2023 Equine Science Society (ESS) meeting. The purpose of this discussion was to share ideas among equine nutrition professionals about how best to provide support for the inclusion of the specialty as part of a horse's health team, alongside the veterinarian, farrier and other equine health specialists. In human, small animal and livestock practices, the importance of nutrition as part of an overall health, production (livestock) and well-being plan has been documented. However, surveys of veterinarians, the top source of information for horse owners, reveal a lack of confidence in the area of nutrition after graduating from veterinary school and a lack of available continuing education opportunities to learn more. Further, it appears that many horse owners may unknowingly be obtaining nutrition information from unverified sources (such as the internet). The discussion included formal and informal education of equine nutritionists, as well as avenues to open lines of communication with the veterinary community to provide nutrition resources for horse owners, managers and veterinarians.

Conditionally immortalised equine skeletal muscle cell lines for in vitro analysis

Background

Thoroughbred racehorse performance is largely influenced by a major quantitative trait locus at the myostatin (MSTN) gene which determines aptitude for certain race distances due to a promoter region insertion mutation influencing functional phenotypes in skeletal muscle. To develop an in vitro system for functional experiments we established three novel equine skeletal muscle cell lines reflecting the variation in phenotype associated with MSTN genotype (CC/II, CT/IN and TT/NN for SNP g.66493737C > T/SINE insertion 227 bp polymorphism). Primary equine skeletal muscle myoblasts, isolated from Thoroughbred horse gluteus medius, were conditionally immortalised and evaluated to determine whether cell phenotype and metabolic function were comparable to functional characteristics previously reported for ex vivo skeletal muscle isolated from Thoroughbred horses with each genotype.

Results

Primary myoblasts conditionally immortalised with the temperature sensitive SV40TtsA58 lentivirus vector successfully proliferated and could revert to their primary cell phenotype and differentiate into multinucleated myotubes. Skeletal muscle fibre type, MSTN gene expression, mitochondrial abundance, and mitochondrial function of the three MSTN genotype cell lines, were consistent with equivalent characterisation of ex vivo skeletal muscle samples with these genotypes. Furthermore, addition of coenzyme Q₁₀ (CoQ₁₀) to the cell lines improved mitochondrial function, an observation consistent with ex vivo skeletal muscle samples with these genotypes following supplementation with CoQ₁₀ in the diet.

Conclusions

The observation that the phenotypic characteristics and metabolic function of the cells lines are equivalent to ex vivo skeletal muscle indicates that this in vitro system will enable efficient and cost-effective analyses of equine skeletal muscle for a range of different applications including understanding metabolic function, testing of nutritional supplements, drug test development and gene doping test development. In the multi-billion-euro international Thoroughbred horse industry research advances in the biological function of skeletal muscle are likely to have considerable impact. Furthermore, this novel genotype-specific system may be adapted and applied to human biomedicine to improve understanding of the effects of myostatin in human physiology and medicine.

Equine dietary supplements: an insight into their use and perceptions in the Irish equine industry

Background

Nutritional supplements are frequently used by horse owners/caregivers to supplement their horse(s) diets. Some work has been done to identify the types of supplements fed and the reasons for doing so; however, this has been predominantly disciple-specific and with little focus on participants’ perceptions of supplement testing and regulation. The aim of this study was to gain an insight into the use and perceptions of equine dietary supplements in the Irish equestrian industry.

Methods

An online survey was designed to ascertain the following information: demographics, types of supplements fed and reasons for use, factors that influenced respondents’ choice of supplement, where advice was sought and perceptions of testing and regulation of equine supplements

Results

The survey yielded 134 responses, 70% non-professionals and 30% professionals. A greater percentage of professionals included supplements in their horse(s) diets (98%) compared to non-professionals (86%). Almost 70% of professionals fed more than two supplements, whereas 80% of non-professionals reported to feed only one supplement. Joint supplements were most commonly fed by all respondents (22%) followed by calming supplements (13%). The enhancement of performance (35%) and prevention of joint disorders (34%) were the most common reasons reported by respondents for using a supplement. Over 53% of respondents sought advice on choosing a supplement from their feed merchant, followed by their veterinarian (46%). Veterinary recommendation was given as the most influential factor when choosing a supplement by 90% of respondents, followed by cost (69%). Most (93%) respondents thought that feed supplements had to meet legal standards, with each batch analysed for quality (72%) and the supplement tested on horses before being launched on to the market (92%).

Conclusion

This study has identified the main types of supplements used in the Irish equestrian industry along with the reasons for their use. However, it has also highlighted major misperceptions in how supplements are tested before being launched for sale and further work on this aspect of the findings would be beneficial.

Meirelles P. Dimethylglycine supplementation in horses performing incremental treadmill exercise

Our objective was to verify the effect of the period of dimethylglycine (DMG) supplementation in horses subjected to incremental treadmill exercise, on the metabolic and physiologic variables and indices related to physical performance. Four adult Arabian horses with a mean age of 8±1.5 years and a mean body weight of 340±10.8 kg were used. The utilised experimental design was the 4×4 Latin square, constituted by four periods of four weeks of evaluation, intercalated with four weeks of wash-out periods. The treatments consisted of periods of DMG (30 g of commercial product) administration: without supplementation, and with supplementation for 10, 20 and 30 days. There was a significant effect of the DMG supplementation given during 30 days over the reduction in the lactate concentration after the test exercise. Alterations of V200 (speed in which the horse reaches 200 heart beats/min) and VL4 (speed which corresponds to a blood lactate of 4 mmol/l) were not observed (P>0.05), however there was a travelled distance elevation in the tests in function of the increase on the days of supplementation, by linear regression (P<0.05) analysis. It was verified that there was no effect from the DMG supplementation in horses on the heart rate and there was only a significant difference between treatments for the rectal temperature after exercise, where the supplementation for 30 days resulted in values statistically superior to the control group. Therefore, we can conclude that the equine supplementation with a DMG product in the dosage of 30 g/day for a one-month period affects the lactate metabolisms, as well as increases the travelled distance during an incremental treadmill test.