LEVEL OF THYROID HORMONES IN THE BLOOD OF LAMBS AFTER USING
IN THEIR DIET AMINO FCIDS LYSINE, METHIONINE AND SULFUR
O. S. Druzhyna
Institute of Animal Biology NAAS, Stus str., 38, Lviv, 79034, Ukraine
The effect of essential amino acids lysine, methionine and sulfur as the main supplements to the diet of 4-month lambs of Meryno landshaft breed on the content of thyroid hormones (triiodothyronine and thyroxine ) in their blood have been studied. It has been shown that the thyroxine (T4) level in lambs blood, which received a diet consisting of basic amino acids lysine (3 g) and 2 g of sodium sulfate per head /per day was almost like as in control animals (69.6 vs. 40.0 nmol/L), and the level of triiodothyronine (T3) decreased by 32.6 % (1.76 vs 2.13 nmol/L; P <0.1)compared to control group. At the same time, the inclusion to the diet of lambs elevated levels of sulfur — sulfur-containing amino acids methionine and sodium sulfate (2 g per head /per day, the second experimental group) contributed the increasing T3 on 18.7 % (P<0.05) and T4 on 36.1 % (P<0.01) in blood plasma. The inclusion to lambs diet the amino acid lysine (3 g per head/per day), methionine and sodium sulfate (2 g per head/per day, the third experimental group) resulted in increased plasma levels of both hormones compared with animals in the control group. In particular, T4 content significantly (P<0.01) increased by 20.4 % compared with the control group of animals and decreased by 13.0 % (P<0.05) compared with animals of the second experimental group. The content of T3 was the same with animals in the control group and significantly decreased (P<0.05) on 18.7 % compared to the first experimental group of animals.
It was concluded that lysine as an essential amino acid leads to a decrease in the level of thyroid hormones (especially T3) in the blood of lambs and sulfur-containing substances (methionine, Na2SO4), on the contrary — to increase the thyroid hormones content.
Keywords: LAMBS, BLOOD, THYROID HORMONES, LYSINE, METHIONINE, SULFYR, DIET