Wyniki wyszukiwania - Biblioteka Nauki

1

Coat colour versus performance in the horse [Equus caballus]

100%

Stachurska A. , Ussing A. P.

Polish Journal of Natural Sciences

|

2007

|

tom 22

|

nr 1

43-49

EN

The coat colour in the horse being mainly a protective trait is also a factor which contributes to the maintenance of the thermal equilibrium in the body. A relationship between the colour and performance in the horse is possible since the genes producing the colour may be linked with genes which affect the horse’s performance or can be pleiotropic simultaneously influencing both kinds of traits. Current studies performed on racehorses have not shown a considerable relationship between the loci controlling the grey colour as well as eumelanogenesis in bay and black horses and the racing records. Instead, a few loci are known which control certain colours and involve pathologic signs in the organism or are lethal in homozygotes.

PL

Barwa włosów u koni odgrywająca głównie rolę ochronną jest też czynnikiem wspomagającym utrzymanie równowagi cieplnej organizmu. Związek rodzaju maści z dzielnością konia jest możliwy, gdyż geny powodujące powstanie maści mogą być sprzężone z genami wpływającymi na dzielność konia, a także oddziaływać równocześnie na oba rodzaje cech. Najnowsze badania przeprowadzone na koniach wyścigowych nie wykazały istotnego związku genów maści siwej oraz wytwarzania eumelaniny u koni gniadych i karych z wynikami wyścigów. Znanych jest natomiast kilka loci kontrolujących pojawienie się określonych maści, które równocześnie powodują patologiczne zmiany ustrojowe, a u homozygot są letalne.

2

White markings in the horse

100%

Stachurska A. , Ussing A. P.

Medycyna Weterynaryjna

|

2012

|

tom 68

|

nr 02

EN

White markings in horses result from the lack of melanocytes in the skin and hairs. The trait is characteristic of most breeds of domestic horses. In the breeding of the Polish Konik horse, which should resemble its wild ancestors, the lack of white markings was accepted as a selection criterion. The heritability of the markings is high. MC1R and ASIP loci, as well as two other putative QTLs are involved in the appearance of white markings. A foal should inherit a number of genes from both parents to make it possible for the markings to appear. The ultimate extent of markings is caused by the genes, as well as by intrauterine factors. The latter consist of accidental and random events which disturb the survival, migration and clonal proliferation of melanoblasts. The recessive e allele from MC1R locus and the dominant A allele from ASIP locus cause a greater extent of the markings, behaving as major genes. The most desired genotype of the Polish Konik horse, aaEEDD, which in inter se matings produces solely blue dun foals, is also the most desired with regard to the low amount of markings. To increase the progress in the Polish Konik breeding with regard to the absence of the markings, marked individuals and identified carriers of e allele should be consistently eliminated from reproduction.

3

Tobiano and leopard alleles in felin pony population

80%

Stachurska A. , Ussing A. P. , Kolstrung R.

Electronic Journal of Polish Agricultural Universities. Series Animal Husbandry

|

2002

|

tom 05

|

nr 1

EN

The phenotype in 19 tobianoleopard ponies has been described. The tobiano pattern has been identified in them according to the arrangement of white and dark areas, sharp and smooth edges of the areas, rather big white markings on heads, white legs or large markings on the legs and sometimes wall eyes. The leopardspotted pattern has been recognised thanks to the dark leopard spots of the base colour or darker, the roaned or frosted areas emerging from white patches or occupying the whole dark patches, jagged patch edges, fragments of mottled skin, eyes with visible sclera and striped hooves. Sometimes, only the visible sclera or a blurred part of the patch edge has indicated the presence of the leopardspotted pattern.

4

Hoof wall angulation in the horse (Equus caballus)

70%

Kolstrung R. , Stachurska A. , Pieta M. , Silmanowicz P. , Ussing A. P.

Medycyna Weterynaryjna

|

2013

|

tom 69

|

nr 03

EN

The objective of the study was to determine the variation of hoof wall angles in horses of different types. Seventy-six mares at the ages of 4 - 13 years were examined. They belonged to four breeds of different origin types: Purebred Arabians, halfbred Anglo-Arabians, primitive Polish Koniks, and Polish Coldbloods. The angles of the toe, of the medial and lateral walls, as well as of the coronary band, were measured in raised fore and hind feet. The hoof wall angulation differs considerably between fore and hind hooves, as well as between horse breeds. Among the breeds studied, the largest differences occurred between the Purebred Arabians and the Coldbloods. The Purebred Arabian hoof has a low toe angle, a low coronary band angle and high quarter angles, unlike the Polish Coldblood hoof, with a high toe, a high coronary band and low medial wall angles. Distinct differences between fore and hind hooves, as well as between the breeds, indicate that the angles of the hoof capsule cannot be considered uniform but these factors should be regarded.