Cabello G, Levieux D
Ann Rech Vet. 1978;9(2):309-18.
Observations of 68 Friesian and Holstein X Friesian calves in a single herd with low neonatal mortality gave the following results: --The calves which will suffer from diarrhoea but survive were in a hyperthyroid state (high levels of hormonal iodine, T3 and free thyroxine index) compared with the healthy animals. --The concentration of plasma globulins, after colostrum intake was lower in diarrhoeic subjects calves than in the healthy ones. --For the whole group of animals, plasma hormonal iodine, at birth, was negatively correlated with the concentration of plasma globulins at 48 hours (r = 0,37, P less than 0,05). Thus, by reducing the absorption capacity of colostral globulins, an excess of thyroid hormones at birth could increase young calves sensitivity to various infections. To test this hypothesis, 12 Holstein X Friesian calves, born in the same stable and then transferred to outside individual boxes, were used. Six animals received thyroxine injections at birth and after 24 hours. All the calves received colostrum in the same conditions. The following results were obtained. --All the treated calves became ill (1/6 of the controls), independantly of their plasma IgG1 concentrations. --The capacity of calves to acquire colostral IgG1 varies considerably between individuals (maximum IgG1 concentrations and, probably, duration of intestinal absorption of IgG1). --The T4 injections at birth do not noticeably after IgG1 absorption. --Thyroxinemia at birth, reflecting the foetal concentration, is negatively correlated (r = 0,74, P less than 0.01) with the period of IgG1 absorption. --The outside temperature at birth is negatively correlated with the maximum IgG1 concentration (r = 0.78, P less than 0.01). These results indicate that a hyperthyroid state at birth, and, probably, during foetal development compromise the calves health: --by direct or indirect action, the intermediates of which are not known, --by reducing the period of intestinal absorption of immunoglobulins in addition. Moreover climatic factors such as ambient temperature at birth may influence acquisition of passive immunity.
对某一新生犊牛死亡率较低的牛群中的68头弗里生犊牛以及荷斯坦×弗里生犊牛进行观察，得到以下结果：——与健康犊牛相比，患腹泻但存活下来的犊牛处于甲状腺功能亢进状态（激素碘、T3和游离甲状腺素指数水平较高）。——摄入初乳后，腹泻犊牛血浆球蛋白浓度低于健康犊牛。——对于整组动物，出生时血浆激素碘与48小时时血浆球蛋白浓度呈负相关（r = 0.37，P < 0.05）。因此，出生时甲状腺激素过量可能会通过降低初乳球蛋白的吸收能力，增加犊牛对各种感染的易感性。为验证这一假设，选用了12头出生于同一牛舍、后转移至室外单独牛栏的荷斯坦×弗里生犊牛。6头犊牛在出生时及出生24小时后接受甲状腺素注射。所有犊牛均在相同条件下摄入初乳。得到以下结果：——所有接受治疗的犊牛均发病（对照组为1/6），与它们的血浆IgG1浓度无关。——犊牛获取初乳IgG1的能力在个体间差异很大（最大IgG1浓度以及可能的IgG1肠道吸收持续时间）。——出生时注射T4对IgG1吸收后无明显影响。——反映胎儿浓度的出生时甲状腺素血症与IgG1吸收期呈负相关（r = 0.74，P < 0.01）。——出生时的外界温度与最大IgG1浓度呈负相关（r = 0.78，P < 0.01）。这些结果表明，出生时以及可能在胎儿发育期间的甲状腺功能亢进状态会损害犊牛健康：——通过直接或间接作用，其作用中间环节尚不清楚，——此外还会缩短免疫球蛋白的肠道吸收期。而且气候因素，如出生时的环境温度，可能会影响被动免疫的获得。
