Comparison of serum triiodothyronine, tetraiodothyronine and thyroid stimulating hormone concentrations in pregnant and lactating Beetal-cross and native goats in Garmsar township

BACKGROUND: The preliminary survey made about congenital goiter in goats in Garmsar township indicated that the disease occurs much more in Beetal-cross than native goats raised in the same area. OBJECTIVES: The aim of the present study was to compare serum triiodothyronine (T3), tetraiodothyronine (T4) and thyroid stimulating hormone concentrations in pregnant and lactating Beetal-cross and native goats in Garmsar township. METHODS: One hundred Beetal-cross (n=50) and native (n=50) does in 4 groups (25 pregnant Beetal-cross, 25 lactating Beetal-cross, 25 pregnant native and 25 lactating native) were used in this study. Blood samples were obtained via jugular venipuncture and analyzed for serum T3, T4 and TSH concentrations. RESULTS: Breed had a significant (p 0.05) effect on T4 concentration and pregnancy had a significant (p 0.05) effect on T3 and TSH concentrations. No significant differences were seen for serum T3, T4 and TSH concentrations between pregnant and lactating native does. However, in the pregnant Beetal-cross, serum T3 and T4 concentrations were lower (p 0.05) and TSH concentration was higher (p 0.05) than lactating Beetal-cross does. CONCLUSIONS: The results of the present study highlight the relationships between thyroid activity and breed in the goat species that may play a role in more occurrence of congenital goiter in Beetal-cross in Garmsar township.