Thyroid hormones and metabolic rate during induction of vitamin B12 deficiency in goats

Authors: Badamana MS, Kamau JMZ, Mburu JN
Publication: New Zealand Veterinary Journal, Volume 42, Issue 5, pp 187-189, Oct 1994
Publisher: Taylor and Francis

Animal type: Goat, Livestock, Production animal, Ruminant
Subject Terms: Cobalt/vitamin B12, Trace elements, Diet/rations/food, Endocrine/autocrine/paracrine, Metabolic disease, Nutrition/metabolism, Thyroid, Vitamins
Article class: Short Communication

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Abstract: Vitamin B₁₂ deficiency was induced in 15 small East African goats by feeding cobalt deficient Chloris gayana hay (containing 0.02 mg of Co/kg dry matter) over a 25 week experimental period. Cobalt was supplemented as an oral drench to supply 0.3 g of Co/goat/week to 15 treated goats. At intervals of 3-4 weeks, serum concentrations of Vitamin B₁₂ , total thyroxine (TT₄), free tetra-iodothyronine (FT₄) and free tri-iodothyronine (FT₃) were determined by radioimmunoassay, while the rate of resting metabolism was determined by measuring the goats` rate of oxygen consumption. Serum Vitamin B<sub>12</sub> concentration was significantly higher (p<0.01) in cobalt-treated (289.6 ± 40.76 pg/ml) than in control (142.8 ± 28.27 pg/ml) goats. The mean serum TT<sub>4</sub> concentration was signifieantly (p<0.01) higher in control (59.0 ± 1.70 nmol/l) than in cobalt-treated (51.6 ± 2.45 nmol/l) goats. However, the levels of FT<sub>4</sub>, FT<sub>3</sub> and the rate of resting metabolism were unaffected by the goats` cobalt status. Furthermore, the goats did not lose weight or become anaemic.

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