Coat color genetics, when successfully adapted and applied to different mammalian species, provides a good demonstration of the powerful concept of comparative genetics. Using cross-species techniques, we have cloned, sequenced, and characterized equine melanocortin-1-receptor (MC1R) and agouti-signaling-protein (ASIP), and completed a partial sequence of tyrosinase-related protein 1 (TYRP1). The coding sequences and parts of the flanking regions of those genes were systematically analyzed in 40 horses and mutations typed in a total of 120 horses. Our panel represented 22 different horse breeds, including 11 different coat colors of Equus caballus. The comparison of a 1721-bp genomic fragment of MC1R among the 11 coat color phenotypes revealed no sequence difference apart from the known chestnut allele (C901T). In particular, no dominant black (ED) mutation was found. In a 4994-bp genomic fragment covering the three putative exons, two introns and parts of the 5'- and 3'-UTRs of ASIP, two intronic base substitutions (SNP-A845G and C2374A), a point mutation in the 3'-UTRs (A4734G), and an 11-bp deletion in exon 2 (ADEx2) were detected. The deletion was found to be homozygous and completely associated with horse recessive black coat color (Aa/Aa) in 24 black horses out of 9 different breeds from our panel. The frameshift initiated by ADEx2 is believed to alter the regular coding sequence, acting as a loss-of-function ASIP mutation. In TYRP1 a base substitution was detected in exon 2 (C189T), causing a threonine to methionine change of yet unknown function, and an SNP (A1188G) was found in intron 2.

Dressage is one of the Olympic equestrian sports practiced in several countries using different horse breeds. Specific characteristics of the walk, trot and canter are required for dressage. It has been assumed that some of these traits could be selected for genetically and contribute to dressage performance. The purpose of this study was to compare the walk, trot and conformation characteristics in young horses of different breeds used for dressage. A total of 142 horses age 3 years were classified into 3 groups of breeds (German, French and Spanish saddle horses) and tested using the same procedure. The skeletal conformation measurements were made by image analysis. Gait variables of the walk and trot were measured by the accelerometric gait analysis system Equimetrix. Discriminant analysis could explain the variability between the groups by taking into account the walk (P<0.0003), trot (P<0.0001) and conformation variables (P<0.0001). Many gait and conformation variables were significantly different between the breeds. In summary, the German horses had gait characteristics more adapted for dressage competition, and the results of this group could be used as a reference for early evaluation in dressage. Purebred Spanish horses could be considered as a reference for collected gaits used for farm work and old academic dressage. The gait and conformation tests could be applied in a breeding or crossing plan to detect more accurately young horses with good dressage ability.

-Declarations of matings (535 746) and 308 549 consecutive declarations of birth from 1989 to 1999 were analysed by logistic regression in order to determine the effects of year, breed and age of parents on numerical productivity (the number of foals declared per mated mare per year). For the years 1994 to 1999, the status of the mare, type of mating and month of first mating, were also available. The effect of inbreeding and, for warm-blooded horses, the effect of the level of performances or the effect of the level of breeding value estimation were also analysed. The main results are the following: numerical productivity progressed in France more for draught breeds than for saddle breeds and trotters. Thoroughbreds progressed less and just reached the level of significance. Cold-blooded horses, however, appeared less productive than warm-blooded horses for which thoroughbreds were at the lower level. It cannot be concluded if this figure reveals biological differences in fertility or if it is only the result of differences in managing the official declarations. For warm-blooded horses, the absence of negative relationships between the trends of selection and numerical productivity results appeared clearly. A high performance level for the mare was positively associated with higher productivity results in sport and trotting horses and showed no significant influence for galloping horses. The relationships with breeding value estimation illustrated the same trends.horse / fertility / logistic model / factors of variation / selection / inbreeding

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