Seike N, Utaka K, Kanagawa H
Department of Theriogenology, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
Jpn J Vet Res. 1990 Jan;38(1):1-9.
Sixty-five chromosomal preparations from bisected bovine embryos were examined and 43 embryos (66.2%) with metaphase plates were observed; however, only 25 embryos (38.5%) were sexed. Fifteen of the bisected embryos sexed by chromosomal analysis were transferred to each of the 15 recipients, and 5 recipients became pregnant. Female calves were born on December 28, 1985, August 2, 1986 and July 18, 1988. The first female calf born from a sexed-bisected embryo (December 28, 1985) was the first case in Japan. The gestation lengths and birth weights of these calves were 277, 278 and 274 days, and 42.0, 44.0 and 37.0 kg, respectively. These two calves grew within the range of the "Standard developmental growth curve of the Holstein heifer" of the Japanese Holstein Association. The milk yield from 2 sexed-bisected cows were recorded. In the first cow (Case 1), she produced 8,575 kg of milk, 5.0% fat and 9.4% solids-non-fat (SNF) per year. In the other cow (Case 2), her expected milk volume was 7,800 kg per year. Confirmation of parentage was done by blood typing, and certified by the Japanese Livestock Animal Improvement Association.
检查了65份来自二分牛胚胎的染色体标本，观察到43个胚胎（66.2%）具有中期板；然而，仅对25个胚胎（38.5%）进行了性别鉴定。通过染色体分析鉴定性别的15个二分胚胎分别移植到15个受体中，5个受体怀孕。雌性犊牛分别于1985年12月28日、1986年8月2日和1988年7月18日出生。第一头由性别鉴定二分胚胎出生的雌性犊牛（1985年12月28日）是日本首例。这些犊牛的妊娠期和出生体重分别为277天、278天和274天，以及42.0千克、44.0千克和37.0千克。这两头犊牛的生长在日本荷斯坦协会“荷斯坦小母牛标准发育生长曲线”范围内。记录了2头性别鉴定二分母牛的产奶量。第一头母牛（病例1）每年产奶8575千克，含脂肪5.0%，非脂固形物（SNF）9.4%。另一头母牛（病例2）预计每年产奶量为7800千克。通过血型鉴定进行亲子关系确认，并由日本家畜改良协会认证。
