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Philipsson, J., Arnason, T., & Bergsten, K. (1990). Alternative selection strategies for performance of the Swedish warmblood horse. Livestock Production Science, 24(3), 273–285.
Abstract: The Swedish riding horse population includes about 6000 broodmares and 150 breeding stallions. The overall breeding goal is to produce riding horses competitive in several disciplines, i.e. dressage as well as showjumping and eventing. The effectiveness of this multi-purpose objective was studied in alternative strategies for selecting stallions and mares as candidate dams for them. The alternative selection strategies for stallions included 1-stage (conformation), 2-stage (conformation and performance test) and 3-stage (conformation, performance test and competition results at advanced levels) selection schemes. The mare selection schemes included the corresponding 1- and 2-stage selection schemes. The results clearly showed the 2-stage selection procedure to be most efficient, especially for stallions. It is important that the intensity in selection after the performance test is kept high. Differences in defining the breeding objective are less important, provided the selection is based on a performance test including both dressage and jumping. According to the results, the development of the Swedish performance testing scheme, in which now only 30% of the tested stallions are selected for breeding, seems justified. In mare selection schemes, performance tests also seem to be justified, especially if jumping ability is to be improved. Differences between field and station tests are only minor and since the volume of testing can be much higher in the field this would allow a much stronger selection and should thus be preferred.
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Huizinga, H. A., & van der Meij, G. J. W. (1989). Estimated parameters of performance in jumping and dressage competition of the Dutch Warmblood horse. Livestock Production Science, 21(4), 333–345.
Abstract: The objective of this study is to estimate several genetic parameters in the Dutch Warmblood riding horse population. The traits involved are performances in jumping and dressage competition. The following parameters are estimated: heritabilities for jumping and dressage; phenotypic and genetic correlations between jumping and dressage; and phenotypic and genetic correlations between performances at different ages. These parameters are estimated by restricted maximum likelihood (REML). Data are from 6899 horses with performances in jumping and 10 408 horses with performances in dressage competition. The horses are sired by 205 and 237 stallions for the two traits, respectively. The progeny range in age from 4 to 8 years old. The performance trait is a cumulatively derived score, that reflects the level of performance in competition. A square root transformation of the score is most appropriate to normalize the data. For estimation of phenotypic and genetic parameters the data is split into two data sets according to the age of the sires (offspring sired by older vs. younger stallions). For estimating correlations between performances at 4, 5 and 6 years of age, performances of the offspring out of previous years are linked to the data. The most unbiased estimates of heritability for jumping and dressage are from data derived from the youngest offspring sired by the younger stallions and are 0.20 and 0.10, respectively. Genetic correlation between jumping and dressage ranges from -0.27 to 0.10. The phenotypic correlation between these traits ranges from 0.15 to 0.26. Phenotypic and genetic correlations between performances at 4, 5 and 6 years average 0.95 and 0.75, respectively. These latter results have important implications for genetic evaluation of breeding candidates in the population.
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Langlois, B., Minkema, D., & Bruns, E. (1983). Genetic problems in horse breeding. Livestock Production Science, 10(1), 69–81.
Abstract: The purpose of this paper is to give a short survey of the present problems concerning the genetic improvement of horse breeds. The evolution of these populations in Europe, characterized by a deep change from production of draught horses towards that of leisure horses, is described and the influence of the demographical parameters on the selection of these horse populations, is discussed. The generation interval represents an important handicap only surmounted in the case of racing breeds where a high selection intensity can be practised since all animals are subjected to performance testing. In the other cases, the farmer usually does not use modern breeding techniques, but uses crosses instead, which lead more easily to visible results. The available selection criteria are also dealt with. A distinction is made between direct estimates evaluating the abilities of the animals in practice and the indirect estimates measuring a character in correlation to previous ones. For the former estimates, a distinction is made between those resulting from competitions (handicap, records or earnings) and those resulting from direct in-station measurements (saddle, jumping, dressage abilities, draught power). For the indirect estimates, often used especially for the selection of mares, the most important analysis is obviously that of the conformation. However, in the future early selection criteria according to more physiological data should be sought and developed. Estimation of the breeding value according to a given ability is thereafter pointed out. There are two situations: “the panmictic case” concerning sport and draught horses and “the non-panmictic case” corresponding to racing horses, which give rise to some problems. The setting up of breeding plans is discussed. Due to the different economic situations and various objectives of horse production, conclusions are drawn about the role played by geneticists in the present development of this sector.
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Bruns, E. (1981). Estimation of the breeding value of stallions from the tournament performance of their offspring. Livestock Production Science, 8(5), 465–473.
Abstract: Data from horse-riding competitions recorded in Germany in 1976 and 1977 have been analysed to estimate genetic parameters for performance traits of riding horses measured in dressage, jumping competitions and trials. The performance traits analysed were logarithmic earnings per start, relative place number, and place value. The results are the following. 1. (1) Heritability and repeatability estimates for performance in dressage shows are 0.2 and 0.4 respectively. Corresponding estimates for performance in jumping competitions are 20% less. No genetic differences are found between stallions for performance in trials.2. (2) A selection index for estimating the breeding value of stallions was constructed by using the repeated performances of their offspring in dressage and jumping shows. For this purpose, performance data for at least ten progeny should be available. The correlation between the breeding values estimated from the dressage and jumping performances of the same stallions was approximately zero.3. (3) Reliable progeny-testing requires that the assumptions of mating stallions at random, selecting progeny randomly, and distributing them equally across environmental effects be fulfilled.4. (4) The genetic use of breeding values of stallions estimated from the performance of their progeny is opposed by the prolongation of the generation interval. This can be partly overcome by sampling young stallions and making use of the test results for young progeny only.
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Lewczuk, D., Sloniewski, K., & Reklewski, Z. (2006). Repeatability of the horse's jumping parameters with and without the rider. Livestock Science, 99(2-3), 125–130.
Abstract: The total number of 4323 jumps with and without the rider of 141 young stallions were filmed and measured using video image analysis. Horses were filmed on the doublebarre fence (100, 110 and 120 cm) with the same width of 90 cm. The style of jump was characterised by measurements of taking off and landing distances, as well as some measurements of the silhouette of the horse over the obstacle. The repeatability was 0.40-0.58 for distances of the jump's length, 0.37-0.56 for bascule's measurements and about 0.20 for legs' lifting above the fence. Traits measured under the rider and on the highest fences were more repeatable.
Keywords: Via; Jumping; Linear parameters; Stallion's test
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Bello, T. R. (2002). Practical treatment of body and open leg wounds of horses with bovine collagen, biosynthetic wound dressing and cyanoacrylate. Journal of Equine Veterinary Science, 22(4), 157–164.
Abstract: Horses with severe and deep lacerations are represented by ten cases in which treatment emphasized the use of bovine collagen preparations to promote controlled second-degree repair. Traumatized areas were tarsal, metatarsal, neck, forearm, metacarpal and pastern. Wound size changes were recorded. Depending on the wound type, the site was treated with antibiotic-steroid ointment, organic acid cream, sterile collagen particles, suspension or dressings protected by hydrogel dressing, non-adherent pads, occlusive skin dressings, roll gauze and elastic tape. In three cases, a fiberglas cast was applied over a hind leg wound and lacerated tendon for stability. When controlled granulation of the deeper wounds reached skin level, the area often was stabilized by only cyanoacrylate spray. As these cases presented a wide range of trauma each with a unique history, healing rates were based on initial measurements. An overall progression of wound reduction occurred at a predictable rate. The exogenous collagen formulations were used to stimulate controlled granulation, ie. to “jump start” the healing process. Collagen particles, suspension or dressings were packed into depressions, placed under suture lines, secured over abraded tissue, and placed under protective bandage or cast. To further evaluate the use of cyanoacrylate tissue spray in wound treatments, an additional ten cases are presented. The variety of wounds were produced experimentally in Center-owned ponies or provided as clinical cases. Wound size changes and healing progress were recorded. Wounds occurred on the neck, abdomen, metacarpal, metatarsal, fetlock and pastern areas. Depending on wound type, the site was treated with cyanoacrylate only; or treated as above until controlled granulation attained skin level. In one case punch grafts of skin were transferred from one foreleg to the opposite with the horse standing. Cyanoacrylate spray provided a water proof barrier protecting the wound from dirt, debris and insects as well as stabilizing full-thickness skin lacerations by bridging normal to traumatized skin allowing uninterrupted granulation and epithelialization. The use of a neck cradle prevented wound disturbance and stall confinement aided stabilization.
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Andersen, N. H., Norgaard, A., Jensen, T. J., & Ulstrup, J. (2002). Sequential unfolding of the two-domain protein Pseudomonas stutzeri cytochrome c4. Journal of Inorganic Biochemistry, 88(3-4), 316–327.
Abstract: P. stutzeri cytochrome c4 is a di-haem protein, composed of two globular domains each with His-Met coordinated haem, and a hydrogen bond network between the domains. The domain foldings are highly symmetric but with specific differences including structural differences of ligand coordination, and different spin states of the oxidised haem groups. We have studied unfolding of oxidised P. stutzeri cyt c4 induced thermally and by chemical denaturants. Horse heart cyt c was a reference molecule. Isothermal unfolding induced by guanidinium chloride and acid was followed by Soret, α/β, and 701-nm band absorption, and by far-UV circular dichroism spectroscopy. Multifarious patterns emerge, but the two domains clearly unfold sequentially. One phase, assigned to unfolding of the N-terminal domain, proceeds at guanidinium concentrations up to [approximate]1.0 M. This is followed by two overlapping phases at higher concentrations. The intermediate state maintains Fe-Met coordination, assigned to the C-terminal domain. Interdomain interaction is reflected in decreasing values of the cooperativity parameters. Differential scanning calorimetry shows a single peak, but two peaks appear when guanidinium chloride up to 0.4 M is present. This reflects different chemical action in chemical and thermal unfolding. Acid-induced unfolding kinetics was addressed by pH jumps using diode array stopped-flow techniques. Three kinetic phases in the 701 nm Fe-Met marker band, and four phases in the Soret and α/β bands, spanning 4-1000 ms could be distinguished on pH jumps from 7.5 to the range 2.5-3.5. In this range of time and pH cyt c appears to unfold in no more than two phases. Spectral properties of the kinetic intermediates could be identified. Sequential domain unfolding, formation of high-spin states, and an intermediate state with Fe-Met coordination to a single haem group are features of the unfolding kinetics.
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Cioni, P., & Strambini, G. B. (1999). Pressure/temperature effects on protein flexibilty from acrylamide quenching of protein phosphorescence. Journal of Molecular Biology, 291(4), 955–964.
Abstract: Pressure is an effective modulator of protein structure and biological function. The influence of hydrostatic pressure ([less-than-or-equals, slant]3 kbar, 10-50[degree sign]C) on conformational dynamics was assessed from the rate of migration of acrylamide through the protein interior. Migration rates in apoazurin, alcohol dehydrogenase and alkaline phosphatase were obtained from the phosphorescence quenching rate constant (kq) of the deeply buried Trp residues. The dominant effect of applied pressure is to slow the diffusion process, although at low temperature, high pressure may also accelerate it. For apoazurin, alcohol dehydrogenase and alkaline phosphatase the activation free volumes, ΔVobs++, derived from the pressure-dependence of kq, ranges from +10, +16 and +20 ml mol-1 at 50[degree sign]C to -20, +5 and 0 ml mol-1 at 10[degree sign]C, respectively. Analysing ΔVobs++ in terms of a positive contribution from cavity expansion and a negative one from peptide hydration, the results emphasise that whereas at warm temperature the formation of cavities plays a dominant role in the migration process, at low temperature the required flexibility may be conferred by internal protein hydration. The relatively small magnitude of both ΔVobs++ and the activation enthalpy (ΔH++=10-20 kcal mol-1) indicates that acrylamide diffusion jumps inside these proteins appear to involve relatively small amplitude structural fluctuations not requiring major unfolding-like transitions. The implication of these findings for the thermodynamic stability of proteins under pressure is discussed.
Keywords: phosphorescence; tryptophan; acrylamide; quenching; protein dynamics
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Denoix, J. M. (1991). Approche mecanique des allures et du saut chez le cheval. Science & Sports, 6(2), 117–124.
Abstract: Resume La locomotion du cheval implique des contraintes mecaniques elevees sur les os, les articulations, les muscles et les tendons. Son etude permet de mieux connaitre les interventions actives ou passives de ces organes au cours des allures et du saut. Ces elements sont utiles pour la mise en oeuvre rationnelle d'exercices d'entrainement chez le cheval de sport ou de courses, en fonction des exigences de la discipline et des eventuels problemes locomoteurs du sujet. L'etude mecanique de la locomotion du cheval est par ailleurs indispensable pour l'amelioration de la connaissance des boiteries. Elle permet de preciser la genese des lesions osteoarticulaires et musculo-tendineuses et contribue a ameliorer leur traitement.Summary Locomotion of the horse is correlated with a great variety of mechanical stresses on bones, joints, muscles and tendons. Research on locomotion increases the knowledge of passive and active interventions of these structures during gaits and jump. These data are useful to manage the training of sport and jump horses, especially to fit with the particularities of the sport speciality and individual locomotor problems of horses. Beside, studies of locomotion in the horse are of importance to improve the knowledge of lamenesses. They contribute to precise the pathogenesis of osteoarticular and musculotendinous injuries and improve their treatment.
Keywords: cheval; locomotion; biomecanique; horse; locomotion; biomechanics
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Cho, K. C., & Chan, K. K. (1984). Kinetics of cold-induced denaturation of metmyoglobin. Biochimica et Biophysica Acta (BBA) – Protein Structure and Molecular Enzymology, 786(1-2), 103–108.
Abstract: Using a slow temperature-jump spectrophotometer, we have studied the kinetics of cold-induced denaturation of metmyoglobin between 0[degree sign]C and 20[degree sign]C at acidic pH. The time-scale of the transition is slow and is of the order of minutes. The results are consistent with the transition's involving a total of three states, native (N), transient intermediate (I) and denatured (D), which are converted from one to the other in that order.
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