1995 Volume 48 Issue 11 Pages 848-851
Chromosomal anomalies were found in 5 cases of Japanese Black calves with congenital defects. Case 1 had complicated defects of atresia ani, recto-vaginal fistula and fused kidney. Chromosome studies showed structural anomalies such as isochromatid gap, chromatid gap, chromatid break and fragment in 77% of the cells examined. These anomalies were also found in 3 to 16% of the cells from her maternal grand mother, dam and sire. Case 2 had dupulicated uterus and umbilical inflammation. Chromosome studies showed chromatid gap and autosomal trisomy. Case 3, 4, and 5 had atresia ani, prolonged gestation and rib fracture, and umbilical hernia and short mandible, respectively. Each of them showed autosomal trisomy. As the maternal age at parturition of these 5 calves were 8 to 14 years, its high age may be a contributing factor for these chromosomal anomalies.