Plasma thyroxine and triiodothyronine concentrations in growing and adult meat type birds fed "00" rapeseed-containing diet during the first seven weeks of life
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Department of Poultry Breeeding, Warsaw Agricultural University, Przejazd 4, 05-840 Brwinów, Poland
Institute for Cattle Breeding and Dairy Science, Warsaw Agricultural University, Przejazd 4, 05-840 Brwinów, Poland
Publication date: 1995-02-16
J. Anim. Feed Sci. 1995;4(1):35–42
In two series of experiments plasma thyroxine and triiodothyronine concentration were examined in 56 adult hens and 139 meat type chickens of Biała Brwinowska strain fed up to 7 weeks of age a diet containing "OO" rape seeds, wheat and barley (diet B) or maize, soyabean meal and wheat (diet C). Relationship between reproductive performance of adult hens and plasma thyroid hormone concentration was assessed. At the age of 7 weeks, chickens fed diet B had significantly lower body weight (except of males in 1994) and, despite of its low (0.7-0.9 µmol/g) glucosinolate content, significantly higher plasma thyroxine concentration than control birds. No significant diet-related difference was found in their plasma T3 level and T3/T4 ratio. Also no differences were found in reproductive perfomance of one year old hens related to the diet fed in the first 7 weeks of life. In addition, in both series of experiments plasma T4 concentration was positively correlated with egg fertility (P≤0.05) while T3, negatively to the hatchability rate (P≤0.01).
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