Nick Altena schreef op donderdag 29 november 2007, 2:08:
> Ik ben benieuwd naar Frans zijn antwoord op mijn vragen en de
> onderzoeks-bronnen van Fred
Gelukkig een mailtje teruggevonden die ik een tijd geleden naar een klant gestuurd heb:
Hieronder enkele abstracten (de artikels zijn niet electronisch beschikbaar) (Ze liggen in de bibliotheek op de faculteit)
Ik heb in het rood, de conclusies onderstreept, hopelijk blijft de opmaak zoals ik ze doorstuur - mocht dit berichtje niet leesbaar zijn, dan stuur ik alles wel eens apart door zonder de opmaak... Veel leesplezier!
Effect of supplementary dietary biotin on hoof growth and hoof growth rate in ponies: a controlled trial.
Reilly JD, Cottrell DF, Martin RJ, Cuddeford DJ.
Department of Preclinical Veterinary Sciences, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Summerhall, UK.
The effect of dietary biotin supplementation, at a dose rate of 0.12 mg/kg bwt, on growth and growth rate of the hooves of 8 match-paired poines was investigated in a controlled feeding trial. Treatment animals had a mean hoof growth at the midline dead centre of the hoof capsule of 35.34 mm after 5 months of biotin supplementation compared to control animals 30.69 mm (P < 0.05). Comparison of regression analysis also showed that biotin supplementation produced a significantly higher (P < 0.02) growth rate of hoof horn in this trial. Treatment animals had a 15% higher growth rate of hoof horn and 15% more hoof growth at the midline dead centre, after 5 months of biotin supplementation compared to control ponies. No differences were found between feet for growth of horn, but the older animals in the trial had significantly lower hoof growth (P < 0.05) than the remaining poines.
Histological and physical assessment of poor hoof horn quality in Lipizzaner horses and a therapeutic trial with biotin and a placebo.
Zenker W, Josseck H, Geyer H.
Institute of Veterinary Anatomy, University of Zürich, Switzerland.
This paper represents the second part of a study searching for factors which could be responsible for an inferior hoof horn quality of the Lipizzaner horses of the Viennese Spanish Riding School (SRS) noticed in the late 1980s. It includes an evaluation of a treatment with biotin and 42 Lipizzaner horses were tested in a double blind study. The following parameters were evaluated: 1) the histology of the hoof horn in samples from the bearing border 2) the tensile strength of the coronary horn in bearing border samples and 3) the influence of biotin upon the histological changes and the tensile strength after application of 20 mg/day of biotin during 38 months. The histological alterations of bearing border specimens were assessed by use of a grading system (Grade 0 = unchanged; Grade 1 = slight changes; Grade 2 = moderate changes; Grade 3 = severe changes). Initially more than two thirds of the horses showed moderate to severe changes: microcracks visible in the transition from the middle to the inner zone of the coronary horn; separation of the sole from the coronary horn in the region within the white zone. The tensile strength of the coronary horn, with a mean of 39 N/mm2, was 13 N/mm2 lower compared with the unchanged hooves of 10 Warmblood horses, which were investigated by Küng (1991). After 19 months of biotin treatment, the horn quality showed a small but significant improvement. This could be shown by comparing the histological tissue structure before and after treatment, as well as treated animals vs. a placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)
Hoof horn abnormalities in Lipizzaner horses and the effect of dietary biotin on macroscopic aspects of hoof horn quality.
Josseck H, Zenker W, Geyer H.
Institute of Veterinary Anatomy, University of Zürich, Switzerland.
This study involved a macroscopic evaluation of hoof quality in 152 Lipizzaner horses (130 from Austria and 22 from other countries) and a controlled double blind trial of the effects of biotin on hoof horn growth and quality over 19 months in 42 stallions from the Spanish Riding School (SRS) in Vienna. Using a grading system that incorporated evaluation of horn wall, white line, sole and frog, the macroscopic study revealed the following: 90% of the Austrian Lipizzaners had soft white lines and crumbling, fissured horn at the bearing border of the walls; 39% of the stallions of the SRS, > 4-years-old, had medium to severe hoof horn changes. Daily administration of 20 mg biotin to a test group of horses (n = 26) and a placebo to a control group (n = 16) showed that after 9 months the test group had significantly improved compared to the beginning of the trial and the placebo group (P < 0.01). In the test group, further improvement was observed during the following 5 months and, subsequently, the same good level of hoof condition was maintained over 3 further years of observation. Growth rate of the horn wall was equal in the biotin and placebo group, being 7 mm/28 days, giving a wall renewal period of 11 months. Mean plasma biotin level of untreated horses was 350 ng/l; plasma levels of biotin supplemented horses were > 1000 ng/l. It was concluded that continuous dietary supplementation with biotin at a daily dose of 20 mg is indicated to improve and maintain hoof horn quality in horses with less than optimum quality hoof.
The long-term influence of biotin supplementation on hoof horn quality in horses.
Geyer H, Schulze J.
Institute of Veterinary Anatomy, University of Zürich.
The influence of dietary biotin in horses with brittle hoof horn and chipped hooves was investigated in a long-term study, which was performed over a period from one to six years. 97 horses received 5 mg of biotin per 100 to 150 kg of body weight, per os, daily; 11 horses were not supplemented with biotin and served as controls. The hooves of all horses were evaluated macroscopically every three to four months. Hoof horn specimens of the proximal wall were examined histologically and physically in 25 and 15 horses, respectively. The tensile strength of normal coronary horn was 60 N/mm2 or greater; it was reduced in areas of histological alterations, the lowest value being 20 N/mm2. The hoof horn condition of the biotin-supplemented horses improved after eight to 15 months of supplementation as determined by macroscopic and histologic examinations. The hoof horn condition of most control horses remained constant throughout the study. The growth rate of the coronary horn of horses supplemented with biotin and of control horses was the same. The hoof horn condition deteriorated in 7 of 10 horses after biotin supplementation was reduced or terminated. It was concluded that biotin should be continuously supplemented at the full dosage in horses with severe hoof horn alterations.
Effect of dietary biotin supplement on equine hoof horn growth rate and hardness.
Buffa EA, Van Den Berg SS, Verstraete FJ, Swart NG.
Department of Surgery, Faculty of Veterinary Science, Onderstepoort, Republic of South Africa.
Over a 10-month period, 24 randomly selected riding horses were fed various amounts of biotin. Statistically significant improvements in growth rates and hardness of hooves were produced by biotin supplementation. Greater growth rates and hardness were achieved at a daily dose of 15 mg than at 7.5 mg. Increased hoof hardness was greatest in the hoof quarters and toe. No ring formation occurred in hooves of horses fed biotin intermittently.
[The effect of vitamin H substitution on the growth and condition of hooves]
[Article in German]
Wintzer HJ.
A long-term treatment with biotin (vitamin H) in 5 warm-blooded horses and 10 trotter horses is reported. The dose of 0.031-0.037 mg/kg body weight was well tolerated, and with a therapy period up to 10 months an improvement of the horn quality of the growing hoof could be attained as it had not been possible before with other measures. Biotin (Gabiotan) is recommendable as a therapeutic in all cases of hoof problems which are based on disturbed horn elasticity
Hopelijk heb je er wat aan. Stuur jij me het onderzoek door dat jij gelooft?
F
Warboel
