Home About us Contact
|
Home About us Contact | ||
|
|
||
Exercised Horses (exercised + horse)
Selected AbstractsOral vitamin E supplementation on oxidative stress, vitamin and antioxidant status in intensely exercised horsesEQUINE VETERINARY JOURNAL, Issue S36 2006C. A. WILLIAMS Summary Reasons for performing study: Vitamin E is the most commonly supplemented antioxidant in horses; however, previous research is not conclusive as to the recommended level for exercising horses. Objective: To evaluate the effects of 3 levels of vitamin E supplementation on oxidative stress and vitamin/antioxidant status in intensely exercised horses to determine the optimal level of vitamin E supplementation. Methods: Twelve unfit Standardbreds were divided into 3 groups, supplemented orally with 0 (CON), 5000 (MOD), or 10,000 (HI) iu/day of DL-,-tocopheryl acetate. The 3 times 3 Latin square design consisted of three 4 week supplementation periods with 4 week wash out periods between. After each period, horses underwent a treadmill interval exercise test. Blood samples were collected and heart rate (HR) measured before, during and after exercise. Data were analysed using ANOVA with repeated measures in SAS. Results: The CON group had lower HR throughout the test compared to the MOD and HI groups (P<0.05). There was an increase in plasma retinol (RET), ,-carotene (BC), red blood cell total glutathione and glutathione peroxidase with exercise (P<0.05), but all groups returned to baseline after 24 h. Plasma ,-tocopherol (TOC) increased from baseline with exercise (P<0.0001) in all groups; treatment differences were observed at 24 h (P<0.05). The HI and CON groups had lower BC compared to the MOD group (P = 0.05). Conclusions: Horses supplemented with vitamin E, at nearly 10-times the 1989 NRC recommended level, did not experience lower oxidative stress compared to control horses. Additionally, lower plasma BC levels observed in the HI group, which may indicate that vitamin E has an inhibitory effect on BC metabolism. Potential relevance: Supplementation above control levels is not more beneficial to oxidative stress and antioxidant status in intensely exercising horses; indeed, levels 10 times in excess may be detrimental to BC and should be avoided. [source] Effects of hay intake and feeding sequence on variables in faeces and faecal water (dry matter, pH value, organic acids, ammonia, buffering capacity) of horsesJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 1-2 2004A. Zeyner Summary To investigate effects of hay intake and feeding sequence on indicators of the microbial activity within the hindgut, six horses were fed 1.00 kg oats plus 0.50, 0.67, 0.83 or 1.00 kg hay/100 kg body weight (BW) × day, each for 14 days. Oats was offered either 30 min prior to hay (OA) or in the reversed sequence (HA) in a 2 × 8-week crossover design. Because typically exercised horses should be subjected to the study, faeces was used as substrate. Faecal dry matter (DM), the faecal waters' short-chain fatty acids (SCFA, in mmol/l) and molar percentages (mol%) of propionate and iso-butyrate were highest with OA (p < 0.01). Acetate mol%, acetate,propionate quotient (A/P) and buffering capacities 1 and 2 (BC1: current pH to pH 6; BC2: pH 6 to 5) of the faecal water were highest with HA (p < 0.01). While the hay intake rose, faecal pH, acetate mol%, A/P, BC1 and BC2 (the latter with HA only) increased (p < 0.05), but DM, SCFA and propionate mol% declined (p < 0.05). The hay-induced rise in A/P and BC1 was much higher with HA than with OA. l -Lactate and ammonia were unaffected by the feeding sequence and hay intake. In conclusion, hay intake and feeding sequence influence the microbial activity within the hindgut, although the concentrate level remains consistent. In horse rations with 1.00 kg oats/100 kg BW × day amounts of at least 0.83 kg hay/100 kg BW × day and offering the hay first seem to have the potency to protect the hindgut content from acidification. Behavioural abnormality was not observed any longer first with 1.00 kg hay/100 kg BW × day. [source] Effect of loading on the organization of the collagen fibril network in juvenile equine articular cartilageJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 9 2009Pieter A.J. Brama Abstract We investigated the effects of exercise-induced loading on the collagen network of equine articular cartilage. Collagen fibril architecture at a site (1) subjected to intermittent high-intensity loading was compared with that of an adjacent site (2) sustaining continuous low-level load. From horses exposed to forced exercise (CONDEX group) or not (PASTEX group), the spatial parallelism of fibrils and the orientation angle between fibrils and the surface at depths 9 µm apart through cartilage from surface to tidemark were determined using polarized light microscopy, and expressed as parallelism index (PI) and orientation index (OI). PI was significantly higher in site 2 than 1 in CONDEX and PASTEX groups. PI was significantly higher in forced exercised horses at site 2 but not site 1. OI was significantly greater (more perpendicular to the surface) in the superficial and deep cartilage of site 2 than 1 in both CONDEX and PASTEX groups. Superficial zone OI was higher in exercised horses at site 1 but not at site 2. Exercise increased collagen parallelism and affected orientation. The site differences in OI indicate that Benninghoff's classic predominantly perpendicular arcades appear not to be a consistent architectural feature, but adapt to local forces sustained. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source] | ||||||||||