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28 Mitochondrial adaptations to submaximal exercise training in the gluteus medius and triceps brachii of young equine athletes
Abstracts / Journal of Equine Veterinary Science 35 (2015) 392e397
but the use of electrolyte pastes in races was less common (31%). Analyzing the data set using logistic regression, there was a trend (P ¼ 0.10) for metabolic failure to increase 0.66 for each increasing level of alfalfa feeding (0 ¼ none, 1 ¼ occasional, 2 ¼ regular, 3 ¼ daily). OR for metabolic failure reduced by 0.10 for each additional ride > 90 km the rider had entered in the last 2 years (P < 0.05). Highest current level of competition and total distance completed over 90 km also approached significance for reducing the risk of metabolic failure. Electrolyte use is common among endurance riders competing at all levels in the UK. In this small survey, experience of horse and rider appeared to have a greater influence on the risk of metabolic failure than electrolyte use or nutrition per se.
28 Mitochondrial adaptations to submaximal exercise training in the gluteus medius and triceps brachii of young equine athletes S.H. White*, L.K. Warren, C. Li, and S. Wohlgemuth University of Florida, Gainesville, FL, USA Exercise training has been shown to enhance mitochondrial biogenesis and efficiency in human and rodent models. We hypothesized that low- to moderate-intensity exercise training would result in similar mitochondrial improvements in skeletal muscle of young horses, and that responses would be muscle dependent. Quarter Horse long-yearlings (mean ± SE, 21 ± 0.2 mo, 410 ± 9 kg) were randomly assigned to either: submaximal exercise training (TR; n ¼ 18) comprised of walk-trot-canter exercise in a round-pen or while being ridden 30e45 min/d, 3 d/wk; or no controlled exercise (UT; n ¼ 6). UT horses were grouphoused on 16-ha pastures, whereas housing for TR horses was split between pasture and stall (~6 h/d). Biopsies were taken from the gluteus medius of all horses (n ¼ 24) and from the triceps brachii of a randomly selected subset of TR (n ¼ 6) and all UT (n ¼ 6) before (wk 0) and after 9 wk of training. Muscle was assessed for activities of cytochrome c oxidase (CCO) and citrate synthase (CS) as indicators of mitochondrial function and number, respectively. Additionally, saponin-permeabilized muscle fibers were analyzed for mitochondrial function via high-resolution respirometry, and data were normalized to mitochondrial number in the sample (CS activity). Data were analyzed using a mixed-model ANOVA. The triceps had greater CS activity (P < 0.0001) and lower CCO activity (P < 0.0001) than the gluteus in all horses; however, enzyme activities were unaffected by time or training. An overall effect of time across both muscle groups and training levels was observed, whereby electron transport system capacity (ETSC) increased (P ¼ 0.02), and state 3 respiration (P ¼ 0.06) and the respiratory control ratio (P ¼ 0.06) tended to increase during the 9-wk observation period. Leak respiration (P ¼ 0.01) and state 3 with both complex I and II substrates (GMS; P ¼ 0.007) were higher across both muscle groups in TR compared with UT horses. The gluteus in TR horses appeared to be most greatly affected, as demonstrated by an increase in state 3 with complex I substrates (P ¼ 0.04), state 3 GMS (P ¼ 0.005), ETSC (P ¼ 0.04), and the phosphorylation system control ratio with complex I substrates (P ¼ 0.01) from wk 0 to 9. As both young untrained and trained horses exhibited improvements in mitochondrial adaptations over time, these changes could reflect alterations in mitochondria due to growth. Nevertheless, submaximal exercise training appeared to further enhance mitochondrial efficiency in the gluteus medius of young horses.
Key Words: training, oxidative phosphorylation, horse
395
Posters 29 Attitude and behavior of veterinarians surrounding the use of complementary and alternative veterinary medicine (CAVM) in the treatment of equine musculoskeletal pain A.E. Bergenstrahle*1, and B.D. Nielsen 2 1 University of Edinburgh, Edinburgh, Scotland; 2 Michigan State University, East Lansing, MI, USA A high proportion of horse owners use complementary and alternative veterinary medicine (CAVM) in the treatment of equine musculoskeletal back pain (EMBP) without informing or consulting with their regular veterinarian. This exclusion of veterinarians from diagnosis and treatment of EMBP is potentially harmful to both the client-veterinarian relationship and horse welfare. Little is known about veterinary attitude and behavior surrounding CAVM in the treatment of EMBP. The aim of this study was to explore veterinary attitude toward CAVM and assess its level of integration in the treatment of EMBP. A web-based survey was distributed to equine veterinarians via social media. Of the 127 responses collected, the majority worked in equine specialty practice (71%) and the highest proportion (43%) worked predominantly with sport horses. Forty-two percent (n ¼ 52) reported treating horses with EMBP once or twice a week. Attitude toward CAVM was positively correlated with CAVM training (P < 0.001, rs ¼ 0.40), as well as treating horses with EMBP more frequently (P < 0.001, rs ¼ 0.32). Respondents who provided acupuncture (Mdn ¼ 4) and chiropractic (Mdn ¼ 4) treated horses with EMBP more frequently than respondents who did not provide acupuncture (Mdn ¼ 2) (Mann Whitney U test, U ¼ 1147, Z ¼ 3.42, P ¼ 0.001) and respondents who did not provide chiropractic (Mdn ¼ 3) (Mann Whitney U test, U ¼ 962, Z ¼ 3.15, P ¼ 0.002). Respondents were most familiar with acupuncture and chiropractic and had referred more often to chiropractic (71%), acupuncture (63%) and massage (61%) than physiotherapy (32%). Forty-four percent of respondents (n ¼ 54/123) provided acupuncture, 33% (n ¼ 39/120) chiropractic, 16% (n ¼ 19/118) physiotherapy, and 13% (n ¼ 16/119) massage. Only 3 respondents felt CAVM should be involved as a last resort in the treatment of EMBP and only one respondent felt it should never be considered. These results indicate a level of knowledge and integration of CAVM into the treatment of EMBP that does not seem to warrant owner exclusion of veterinarians from the decision to use CAVM. However, a perceived discrepancy between horse owners' and veterinarians’ opinions regarding CAVM became apparent, suggesting an opportunity for veterinarians to function as educators regarding CAVM and thus facilitate inclusion of CAVM into the treatment of EMBP in a way that optimizes horse welfare.
Key Words: acupuncture, chiropractic, physiotherapy
30 Post-exercise dietary supplementation leads to improved muscle recovery in fatigued horses R.D. Jacobs*1, R.K. Splan 1,2, K.L. Urschel 3, S. Mastellar 4, and A.L. Wagner 5 1 Virginia Tech, Blacksburg, VA, USA; 2 Virginia Tech Middleburg Agricultural Research and Extension Center, Middleburg, VA, USA; 3 University of Kentucky, Lexington, KY, USA; 4 South Dakota State University, Brookings, SD, USA; 5 Cooperative Research Farms, Richmond, VA, USA Exhaustive exercise depletes glycogen stores and elicits protein degradation in equine skeletal muscle. Post-exercise (PE)
but the use of electrolyte pastes in races was less common (31%). Analyzing the data set using logistic regression, there was a trend (P ¼ 0.10) for metabolic failure to increase 0.66 for each increasing level of alfalfa feeding (0 ¼ none, 1 ¼ occasional, 2 ¼ regular, 3 ¼ daily). OR for metabolic failure reduced by 0.10 for each additional ride > 90 km the rider had entered in the last 2 years (P < 0.05). Highest current level of competition and total distance completed over 90 km also approached significance for reducing the risk of metabolic failure. Electrolyte use is common among endurance riders competing at all levels in the UK. In this small survey, experience of horse and rider appeared to have a greater influence on the risk of metabolic failure than electrolyte use or nutrition per se.
28 Mitochondrial adaptations to submaximal exercise training in the gluteus medius and triceps brachii of young equine athletes S.H. White*, L.K. Warren, C. Li, and S. Wohlgemuth University of Florida, Gainesville, FL, USA Exercise training has been shown to enhance mitochondrial biogenesis and efficiency in human and rodent models. We hypothesized that low- to moderate-intensity exercise training would result in similar mitochondrial improvements in skeletal muscle of young horses, and that responses would be muscle dependent. Quarter Horse long-yearlings (mean ± SE, 21 ± 0.2 mo, 410 ± 9 kg) were randomly assigned to either: submaximal exercise training (TR; n ¼ 18) comprised of walk-trot-canter exercise in a round-pen or while being ridden 30e45 min/d, 3 d/wk; or no controlled exercise (UT; n ¼ 6). UT horses were grouphoused on 16-ha pastures, whereas housing for TR horses was split between pasture and stall (~6 h/d). Biopsies were taken from the gluteus medius of all horses (n ¼ 24) and from the triceps brachii of a randomly selected subset of TR (n ¼ 6) and all UT (n ¼ 6) before (wk 0) and after 9 wk of training. Muscle was assessed for activities of cytochrome c oxidase (CCO) and citrate synthase (CS) as indicators of mitochondrial function and number, respectively. Additionally, saponin-permeabilized muscle fibers were analyzed for mitochondrial function via high-resolution respirometry, and data were normalized to mitochondrial number in the sample (CS activity). Data were analyzed using a mixed-model ANOVA. The triceps had greater CS activity (P < 0.0001) and lower CCO activity (P < 0.0001) than the gluteus in all horses; however, enzyme activities were unaffected by time or training. An overall effect of time across both muscle groups and training levels was observed, whereby electron transport system capacity (ETSC) increased (P ¼ 0.02), and state 3 respiration (P ¼ 0.06) and the respiratory control ratio (P ¼ 0.06) tended to increase during the 9-wk observation period. Leak respiration (P ¼ 0.01) and state 3 with both complex I and II substrates (GMS; P ¼ 0.007) were higher across both muscle groups in TR compared with UT horses. The gluteus in TR horses appeared to be most greatly affected, as demonstrated by an increase in state 3 with complex I substrates (P ¼ 0.04), state 3 GMS (P ¼ 0.005), ETSC (P ¼ 0.04), and the phosphorylation system control ratio with complex I substrates (P ¼ 0.01) from wk 0 to 9. As both young untrained and trained horses exhibited improvements in mitochondrial adaptations over time, these changes could reflect alterations in mitochondria due to growth. Nevertheless, submaximal exercise training appeared to further enhance mitochondrial efficiency in the gluteus medius of young horses.
Key Words: training, oxidative phosphorylation, horse
395
Posters 29 Attitude and behavior of veterinarians surrounding the use of complementary and alternative veterinary medicine (CAVM) in the treatment of equine musculoskeletal pain A.E. Bergenstrahle*1, and B.D. Nielsen 2 1 University of Edinburgh, Edinburgh, Scotland; 2 Michigan State University, East Lansing, MI, USA A high proportion of horse owners use complementary and alternative veterinary medicine (CAVM) in the treatment of equine musculoskeletal back pain (EMBP) without informing or consulting with their regular veterinarian. This exclusion of veterinarians from diagnosis and treatment of EMBP is potentially harmful to both the client-veterinarian relationship and horse welfare. Little is known about veterinary attitude and behavior surrounding CAVM in the treatment of EMBP. The aim of this study was to explore veterinary attitude toward CAVM and assess its level of integration in the treatment of EMBP. A web-based survey was distributed to equine veterinarians via social media. Of the 127 responses collected, the majority worked in equine specialty practice (71%) and the highest proportion (43%) worked predominantly with sport horses. Forty-two percent (n ¼ 52) reported treating horses with EMBP once or twice a week. Attitude toward CAVM was positively correlated with CAVM training (P < 0.001, rs ¼ 0.40), as well as treating horses with EMBP more frequently (P < 0.001, rs ¼ 0.32). Respondents who provided acupuncture (Mdn ¼ 4) and chiropractic (Mdn ¼ 4) treated horses with EMBP more frequently than respondents who did not provide acupuncture (Mdn ¼ 2) (Mann Whitney U test, U ¼ 1147, Z ¼ 3.42, P ¼ 0.001) and respondents who did not provide chiropractic (Mdn ¼ 3) (Mann Whitney U test, U ¼ 962, Z ¼ 3.15, P ¼ 0.002). Respondents were most familiar with acupuncture and chiropractic and had referred more often to chiropractic (71%), acupuncture (63%) and massage (61%) than physiotherapy (32%). Forty-four percent of respondents (n ¼ 54/123) provided acupuncture, 33% (n ¼ 39/120) chiropractic, 16% (n ¼ 19/118) physiotherapy, and 13% (n ¼ 16/119) massage. Only 3 respondents felt CAVM should be involved as a last resort in the treatment of EMBP and only one respondent felt it should never be considered. These results indicate a level of knowledge and integration of CAVM into the treatment of EMBP that does not seem to warrant owner exclusion of veterinarians from the decision to use CAVM. However, a perceived discrepancy between horse owners' and veterinarians’ opinions regarding CAVM became apparent, suggesting an opportunity for veterinarians to function as educators regarding CAVM and thus facilitate inclusion of CAVM into the treatment of EMBP in a way that optimizes horse welfare.
Key Words: acupuncture, chiropractic, physiotherapy
30 Post-exercise dietary supplementation leads to improved muscle recovery in fatigued horses R.D. Jacobs*1, R.K. Splan 1,2, K.L. Urschel 3, S. Mastellar 4, and A.L. Wagner 5 1 Virginia Tech, Blacksburg, VA, USA; 2 Virginia Tech Middleburg Agricultural Research and Extension Center, Middleburg, VA, USA; 3 University of Kentucky, Lexington, KY, USA; 4 South Dakota State University, Brookings, SD, USA; 5 Cooperative Research Farms, Richmond, VA, USA Exhaustive exercise depletes glycogen stores and elicits protein degradation in equine skeletal muscle. Post-exercise (PE)