Current Literature on Nutrition, Physiology, Reproduction and Genetics of Bison
Abstract: A link between dental abnormalities and loss of genetic variation has been reported for unconfined populations of American bison Bison bison (Linnaeus, 1758) but not for captive populations. From a zoo herd with a small founder population and likely history of inbreeding, we report the first recorded occurrence of dental abnormalities in captive bison and the first case of supernumerary second premolars in bison.
Abstract: Eight external characters distinguishing plains bison (Bos bison bison) and wood bison (B. b. athabascae) were analyzed in six extant populations of plains bison and five populations of animals with ancestry of wood bison to test whether panmixis occurred in Wood Buffalo National Park following the introduction of plains bison and to test whether the variation is ecophenotypic. Character states were polarized from wood to plains bison and scored numerically. Frequencies of individual scores and indices were analyzed by a series of tests, and populations were ranked according to phenotype. Analysis of overall phenotypic variation based on all eight characters revealed three significantly different groups: plains bison; the subpopulation from Pine Lake; the other subpopulations from Wood Buffalo National Park. Results indicate that panmixis has not occurred since the 1925-1928 introduction of plains bison to the Park and that the characters studied are genetically based.
Abstract: The numbers of North American Bison (Bison bison) have increased tremendously since the turn of the century when there were fewer than 2000 head. Today the numbers are in excess of 150,000 residing in over 1000 separate herds(a). The commercialization and privatisation of bison herds has played a major role in increasing their numbers. With the development of the bison ranching business, the application of reproductive technologies which are currently utilized in domestic cattle operations are being considered. Techniques such as pregnancy diagnosis, AI, estrus synchronization, semen collection and preservation and embryo transfer are currently being tested for their effectiveness in bison. The similarities between bison and domestic cattle have made it possible to directly utilize conventional bovine reproductive technology in this wildlife species. However, unique management practices in bison ranching have resulted in limited application and success. To date, there have been successes in the areas of new reproduction technologies but numbers have been limited and results have been somewhat less than that expected in cattle.
Abstract not available
Abstract: Three experiments involving 39 Bos taurus, 14 Bison bison, and 20 Bos x Bison fed diets differing in proportions of roughage and concentrate to evaluate growth, digestive capability, carcass, sind meat characteristics are reported. Bos taurus consumed more (P <.05) feed per day and gained more (P <.05) rapidly than bison br Bos x Bison except during a period of extremely cold weather. Efficiency of gain was similar for all species types. There was no tendency for bison or Bos x Bison. to gain more than Bos taurus on the higher-roughage diets. Bison and Bos x Bison had higher (P <.10 to .01) digestion coefficients for all components evaluated (i.e., DM, CP, GE, MDF, hemicellulose, and cellulose). Species x diet interactions were not significant, indicating that the higher digestion coefficients of bison were not specific to high- roughage diets. Bison and their hybrids had more (P <.05) lean meat and less (P <.01) fat trim in all wholesale cuts except the chuck and rib cuts. Fat thickness at the 12th rib of bison was higher ( P <.01) than that of Bos taurus because most of the carcass fat of bison is located over the thoracic area. Bison and Bos x Bison had higher (P <.01) dressing percentages and a lower (P <.01) proportion of their carcass in the hindquarter than Bos taurus. Shear force and sensory tenderness scores indicated bison were more (P <.05) tender and had a flavor different (P <.01) from that of Bos taurus. Bison and Bos x Bison had more (P <.01) cholesterol in the longissimus muscle and less (P <.05) in the subcutaneous fat than Bos taurus. Bison had a lower ( P <.01) percentage of white and higher percentage of intermediate muscle fibers than Bos taurus with essentially no difference in percentage of red fibers.
Abstract: In animals that defer reproduction until after physiological maturity because of competition by older individuals, one would expect that individuals reproduce earlier when competition decreases. We investigated nine behaviours relevant to reproduction in subadult wood bison males in captivity where mature males have been experimentally removed and compared them to males in a control and a free ranging population. Free- ranging males fed less and walked more with increasing age. Mature males had more back-fat than subadults and they lost most of their fat during the rut. In the captive population, subadults in absence of mature males tended to feed less and were involved in more sexual and aggressive interactions than subadults in a control situation. They significantly increased feeding time from rut to late-rut, while in the control situation neither subadults nor mature males changed. However, the population's age-structure did not affect the pattern of subadults associating with cows, nor did it affect the length of tending bouts by subadults. Our results suggest that subadults can alter some reproductive behaviours depending on the social environment, but without taking on the role of mature males. The finding that some behaviours vary with the social environment while others do not has two implications for studies on reproductive behaviour: (i) researchers are advised to consider potential effects of the age-structure on observed behaviour, and (ii) the kinds of behaviours chosen to study should be considered relative to the potential effects of the age-structure.
Abstract: Adolescent animals are expected to take advantage of mating opportunities, but should expend less reproductive effort than older individuals. We observed aggressive behaviour of free-ranging male wood bison and compared it to behaviour observed in two captive populations, in one of which mature bulls were removed. During the peak of the rut, old free-ranging bulls initiated a higher proportion of their aggressive interactions and engaged in fights more often than younger bulls. During the late-rut, older bulls decreased their involvement in fighting and they interacted relatively more often with younger bulls than during the peak of the rut. However, younger bulls did not fight more than during the peak rut. In captivity subadults were involved more often in aggressive interactions when mature bulls were removed, but they decreased their rate of aggression earlier than subadults in the presence of mature bulls. However, the involvement in fighting among subadults was not affected by the presence of mature bulls: subadults in both populations fought less than mature bulls. We conclude that the willingness of bulls to risk injury in fights increases with age and is unaffected by the social environment. This finding suggests an increase in reproductive effort with age. However, younger bulls take advantage of mating opportunities by adapting those behaviours to the social environment, which do not compromise future reproduction. Adolescent bulls may therefore adopt alternative mating strategies which reflect the age structure of the population.
Abstract: Six highly repeated DNA families were analyzed using Southern blotting and fluorescence in situ hybridization in a comparative study of 46 species of artiodactyls belonging to seven of the eight extant taxonomic families. Two of the repeats, the dispersed bovine-Pst family and the localized 1.715 component, were found to have the broadest taxonomic distributions, being present in all pecoran ruminants (Giraffidae, Cervidae, Antilocapridae, and Bovidae), indicating that these repeats may be 25-40 million years old. Different 1.715 restriction patterns were observed in different taxonomic families, indicating that independent concerted evolution events have homogenized different motifs in different lineages. The other four satellite arrays were restricted to the Bovini and sometimes to the related Boselaphini and Tragelaphini. Results reveal that among the two compound satellites studied, the two components of the 1.711a originated simultaneously, whereas the two components of the 1.711b originated at two different historical times, perhaps as many as 15 million years apart. Systematic conclusions support the monophyly of the infraorder Pecora, the monophyly of the subfamily Bovinae (containing the Boselaphini, Bovini, and Tragelaphini), an inability to resolve any interrelationships among the other tribes of bovids, paraphyly of the genus Bos with respect to Bison, and a lack of molecular variation among two morphologically and ecologically distinct subspecies of African buffaloes (Syncerus caffer cafer and S. c. nanus). Cytogenetically, a reduction in diploid chromosome numbers through centric fusion in derived karyotypes is accompanied by a loss of centromeric satellite DNA. The nilgai karyotype contains an apparent dicentric chromosome as evidenced by the sites of 1.715 hybridization. Telomeric sequences have been translocated to the centromeres without concomitant chromosomal rearrangement in Thompson's gazelle.
Abstract: A survey of mitochondrial D-loop variation in 15 species of ungulates was conducted via amplification by the polymerase chain reaction followed by restriction fragment length polymorphism analysis. This survey included moose (Alces alces), caribou (Rangifer tarandus), mule deer (Odocoileus hemionus hemionus), black-tailed deer (O. h. columbianus), white-tailed deer (O. virginianus), waipiti (Cervus elaphus), pronghorn antelope (Antilocapra americana), bighorn sheep (Ovis canadensis), Stone's sheep (O. dalli), domestic sheep (O. aries), moulflon sheep (O. musimon), mountain goat (Oreamnos americanus), domestic goat (Capra hircus), domestic cattle (Bos taurus), and bison (Bison bison). The results of this preliminary survey indicate that there may be sufficient species specific variation in the D-loop region of the mitochondrial genome of the ungulate species examined here, with the exception of deer (Odocoileus) species, to establish the species origin of the mitochondrial haplotypes of this group. The Odocoileus species are known to hybridize and sharing of mtDNA haplotypes was observed. The chelex DNA extraction technique was successfully used on small blood stains.
Abstract: The hybrid progeny F1 produced by intergeneric crosses of a bison with a domestic cow is characterized by absolute sterility of the male line and fertility of the female line. Crossing of females with fertile males of initial forms permits us to obtain fertile males in the following generations. Any differences in stabilization of spermatogenesis in hybrid males obtained from various crosses and under selection of parental couples were not detected.
Abstract: Many species are currently undergoing reductions in population size due to widespread habitat loss and expanding human activities. Because interspecific hybridization is often a consequence of population decline and fragmentation, identification of individuals or populations with hybrid ancestry is an increasingly important issue in conservation biology. In many wild cattle and bison species, the problem of natural hybridization has been compounded by indiscriminate crossbreeding with domestic cattle for the purpose of improving domesticated stocks. Therefore, a genetic test using the polymerase chain reaction was developed so that wild cattle and bison with domestic cattle mitochondrial DNA (mtDNA) haplotypes could be rapidly identified. Using this genetic test, domestic cattle mtDNA haplotypes were detected in Bos grunniens (yak), Bison bonasus (European bison), and 6 out of the 15 (40%) Bison bison (North American bison) populations tested. In total, 30 out of the 572 (5.2%) North American bison tested, were found to have domestic cattle mtDNA. The hybrid origin of these mtDNA haplotypes was verified in a phylogenetic analysis using the parametric bootstrap. These results are discussed in terms of their implications for the conservation status and future management of wild cattle and bison species.