Studies on conservation and utilization of Kuchinoshima feral cattle as endangered animal genetic resources

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The present study was conducted to promote conservation and utilization of Kuchinoshima feral cattle (feral cattle for short) as endangered animal genetic resources from the standpoint of ecology, morphology, pathology, genetics, breeding, reproduction and beef productivity. Thirty-two to fifty-five head of feral cattle, which formed 3-5 groups at least comprising 3-5 individuals, were found in southeastern area of Kuchinoshima Island during 2000-2003. The measurements of the cranium and limb bones of fetal cattle were smaller than those of Japanese Black and Mishima cattle. The muscle fiber of feral cattle had higher density, smaller diameter and higher composition of type II fiber than those of Japanese Black and Holstein cattle. Survey of feral cattle and Japanese Black cattle in the island for endoparasites at the fecal examination and dissection of deceased 4 stray cattle for pathological inspection indicated that the both fauna of parasites were almost same circumstances and the cause of death were various, as insenescence, external injury, premature labor, however no specific pathogenesis was found. Rota virus and toxicogenic E. Coli were not detected from feces with diarrhea. The serum antibody titters for Adeno virus and infection diarrhea virus were negative, but these titters for Parainfluenza 3 virus and Corona virus were positive. An experiment, using biochemical and molecular marker (RFLP and AFLP), suggested that heterozygosity of the feral cattle was lower than those of other Japanese cattle breeds, and inbreeding the coefficient of inbreeding in feral cattle population. By employing several biotechnology techniques for the reproduction of feral cattle, the cryopreservation of spermatozoa, the production of transferable embryo and the birth of calves were feasible. The carcass grading of fattened feral cattle (2 steers) was medium.