Thyroxine, triiodothyronine and iodide in different breeds of newborn calves

Abstract

Summary. Plasma thyroxine (T 4 ), triiodothyronine (T 3 ) and iodide levels were measured from birth until 30 days of age in 17 Holstein x Friesian (HF), 7 Salers and 7 Charolais calves born at term. The response of plasma T 4 and T 3 levels to bovine thyrotropin (TSH) injection was also compared in two groups of 9 HF calves 3hrs and 21 days, respectively, after birth.In the HF calves, plasma T 4 and T 3 levels increased from birth to 6 hrs (when the rectal temperature of these calves decreased slightly), then diminished until day 7 and remained stable until 30 days of age. In Salers calves, changes in the plasma T 4 and T 3 levels were not different from those observed in HF animals. However, in Charolais calves, there was no significant increase in plasma T 4 and T 3 levels after birth. Twelve and 24 hrs after birth, the plasma iodothyronine levels measured in these animals were lower than in HF calves. In Salers and Charolais calves a positive linear relationship was demonstrated between plasma T 4 (or T 3 ) levels at birth and the birth weight. In the three groups of calves, plasma iodide levels decreased from birth until 10 days of age, then remained stable until the end of the first neonatal month.Intravenous injection of the same dose of bovine TSH (5 mU/kg of body weight) induced a rise in the plasma T 4 and T 3 levels which was significantly more intense in 21-day old calves than in 3-hr old calves.Introduction.

Neonatal levels of plasma thyroxine in male and female calves fed a colostrum or immunoglobulin diet or fasted for the first 28 hours of life

“…This may be because not enough samples were studied or that they were not collected at the exact postpartum time when the transient rise occurred. On the contrary, the frequent and precise sampling practiced by Davicco et al (1982) (Balsam and Ingbar, 1979 ;Kaplan and Utiger, 1978 ;Naito et al, 1981) and piglets (Slebodzinski et al, 1982), has been shown to result in a decrease of circulating T3 in these species (Chopra, 1980 ;Hastings and Zeman, 1979 ;Heinen et al, 1981 andSlebodzinski et al, 1982, respectively) ; this phenomenon has also been shown in humans (Azizi, 1978 ;Burman et al, 1979 ;Suda et al, 1978), adult sheep (Blum et al, 1980), growing bulls Tveit and Almlid, 1980), deer (Bahnak et al, 1981), chickens (May, 1978) …”

“…The subsequent profile depended on the diet ( fig. 1 ) (Cabello and Michel, 1974 ;Davicco et al, 1982 ;Kahl et al, 1977 ;Nathanielsz and Thomas, 1973). However, all of them, except Davicco et al (1982) found that the blood sampling closest to birth gave the maximal plasma T4 level.…”

Endocrine And Metabolic Adaptations Of Calves To Extra-Uterine Life

“…The thyroid function prior to birth strongly interferes with cardiovascular and lung adaptation, as well as with thermogenesis in the newborn lamb [51]. At birth T 3 and T 4 levels are high [23,43] and increase during the fi rst hours of life due to both cortisol surge which supports the maturation of the thyroid axis and increased TSH secretion [52]. This peak in thyroid hormone concentration at birth considerably increases heat production and regulates cold thermogenesis.…”

Iodine nutrition in ewes. 2. Effects of low to high iodine intake by ewes on the I content of biological fluids and plasma immunoglobulins G in newborn lambs

“…However, it was one-fifth of that reported in newborn lambs (Davicco et al, 1980) and in newborn calves (Davicco et al, 1982) Vigouroux (1976) was used, where I is separated from organic-bound I by perchloric acid protein precipitation. In our method, unbound thyroxine was removed from the plasma by ion― exchange chromatography (Aumont and Tressol, 1987).…”