Gee C D, Gaden E R, Harper P A
Pastures Protection Board, Goulburn, New South Wales.
Aust Vet J. 1989 Sep;66(9):293-5. doi: 10.1111/j.1751-0813.1989.tb13954.x.
A study of parturient calf mortality in a herd of 250 Shorthorn cattle on the Southern Tablelands of New South Wales is reported. Death rates as high as 44% from heifer groups are described. There were 30 parturient deaths of which 27 were confirmed as due to maternal dystocia. Pathological changes in many of the dystocia-caused deaths were minimal, but a congested, swollen tongue was a definitive lesion. The death rate was not significantly higher in heifers mated at 14 to 16 months of age than in those mated at 20 to 22 months, but significantly more male than female calves died from maternal dystocia. As two dead calves were affected with goitre, a comparative trial using parenteral iodine was designed. Ratios of thyroid weight to calf body weight were examined for 24 of the calves where the mean was 0.52 gm/kg. Goitre was found not to be a contributing factor to the calving mortality problem. The use of a Jersey bull for heifer matings eliminated the dystocia problem. The Jersey cross allowed safe, early mating at 14 months of age.
本文报道了对新南威尔士州南部台地一群250头短角牛的产犊小牛死亡率的研究。据描述，小母牛群体的死亡率高达44%。共有30例产犊死亡，其中27例被确认为因母体难产所致。许多因难产导致的死亡病例病理变化极小，但舌头充血、肿胀是一个明确的病变。14至16月龄配种的小母牛死亡率并不显著高于20至22月龄配种的小母牛，但因母体难产死亡的雄性小牛明显多于雌性小牛。由于有两头死犊患有甲状腺肿，因此设计了一项使用肠胃外碘的对比试验。对24头小牛的甲状腺重量与犊牛体重的比率进行了检查，平均值为0.52克/千克。发现甲状腺肿并非产犊死亡率问题的一个促成因素。使用泽西公牛与小母牛配种消除了难产问题。泽西杂交种允许在14月龄时安全、提前配种。
