Franciszek Kobryńczuk

Navicular syndrome in sport horses as a result of the disorder of biological bone tissue turnover rhythm: a review

This review summarizes the macroanatomical changes affecting the navicular bone in terms of mechanisms of bone turnover. Many researchers associate the disorders described in this review with limb overloads occurring periodically during training. As a result of intensified and repetitive biomechanical strains, accumulation of microcracks occurs in the bone tissue. It can disrupt the natural rhythm of tissue regeneration. The rhythm comprises a short resorption stage as well as bone formation stage, which lasts several months in horses. The article also dwells on different forms of macroscopic lesions of the navicular bone, which may occur in the uncoupled Basic Multicellular Unit. They lead to the navicular syndrome, which is irreversible and most often eliminates the horse from sport competitions.

Morphometric variation of the skull during postnatal development in the Lowland European bisonBison bonasus bonasus

We studied the variation of linear measurements and skull capacity in Lowland European bisonBison bonasus bonasus (Linnaeus, 1758) during postnatal development, and the dependencies of the parameters in relation to sex, age, and body mass of the animals. Material consisted of 599 bison skulls (310 males and 289 females), within the age range of 1 month to 21 years (males) and to 27 years (females). In the group of calves to 1 year old, no sex connected differences in skull measurements were observed, whereas the skull capacity in older calves was significantly larger (0.01>p>0.001) in males than in females. From the third year of life, most skull measurements display characteristics of sexual dimorphism. Skull development in both sexes is most intensive during the first three years of life, and slows from the age of 5. In older individuals of both sexes (≥ 6 years), orbital breadth continues growing and, in females, breadth of splanchnocranium continues increasing. Growth in a bison’s skull capacity is most intensive up to the third year of life and slows from the age of 5. During postnatal development, a bison skull grows proportionally except the neurocranium, which grows slightly slower in comparison with basal length and its development finishes earlier than that of splanchnocranium. In ontogenesis, a bison skull grows much slower compared to body mass. In relation to body mass, skull capacity and the height of neurocranium grow most slowly while orbital breadth grows most intensively. The results obtained were compared with data on skull sizes of bison born in 1930–1950 and bred in captivity and with skulls of the American bisonBison bison. Inbreeding is probably responsible for some types of phenotypic abnormalities in the skull which appear in modern European bison.

Sexual dimorphism in skulls of the lowland European bison, Bison bonasus bonasus

The research was conducted on 600 (311 male and 289 female) European bison skulls of the Lowland line collected between 1967 and 2006. The specimens came from the bison breeding centre in Białowieza (n = 67) and from the free-ranging population of the Polish part of the Białowieza Forest (n = 533). Two indices best differentiating male and female skulls were selected: one being the quotient of the orbital breadth EctEct and the length of the splanchnocranium StP, the second being the quotient of the neurocranium length BSt and the basal skull length BP. Using these indices we constructed an equation which produced negative values for females and positive values for males; 223 (74%) of the male skulls produced positive values consistent with sex, and 82 (26%) produced negative values, indicating female features. Those features were present mainly in skulls of young males (< 4 years old). 230 (80%) of the female skulls had shapes typical of the female sex, whereas 59 (20%) displayed male features.

Bisoniana LVIII. Growth rate of bones in the postembryonic development of the European bison

Przeprowadzono pomiary kości ramiennej i udowej u 100 zubrow (57 samcow i 43 samice) w pieciu grupach wiekowych (Tabela 1) i określono szybkośc tworzenia tkanki kostnej wg wzoru Szmalhauzena-Brodi. Wyrozniono cztery okresy szybkości wytwarzania tkanki kostnej.

Bisoniana 104. Shape of the mandible in European bison and domestic cattle hybrids

The shape of the mandible of European bison and domestic cattle hybrids and the parental forms was compared by means of a discriminant function. In most cases it was observed that the mandibles of hybrids of backcross generations are similar or identical to cattle. Exceptions were found in F1 hybrids and some backcross generations whose mandibles were more similar to bison than to cattle. The transformation of the mandible shape in hybrids with increasing cattle genes is similar to changes in the skull shape of the same animals.

Bisoniana LXI. Joints and ligaments of hind-limbs of the European bison in its postnatal development

Badania przeprowadzono na zwlokach 71 zubrow (47 samcow i 24 samic). Ponadto dokonano obserwacji powierzchni stawowych na kośccach 48 zubrow (27 samcow i 21 samic) stanowiących cześc zbiorow muzealnych Ośrodka Badan nad Anatomią Żubra przy Akademii Rolniczej w Warszawie. Padle zwierzeta pochodzily z krajowych ośrodkow hodowlanych.

Bisoniana LVII. Muscle belly volume of the pes joints in the European bison

Zbadano przy pomocy menzurki objetośc brzuśccow mieśni obslugujących staw stepowy i stawy palcow 25 zubrow Bison bonasus (Linnaeus, 1758) w roznym wieku (13 samcow i 12 samic). Stwierdzono, ze najwiekszy brzusiec posiada m. gastrocnemius a nastepnie m. flexor digitorum profundus.