Correlation of serum levels of T3 and T4 during the dry and postpartum periods with ovarian rebound in primiparous and multiparous cows

Subject Areas : Veterinary Clinical Pathology

افشین Davasaztabrizi ¹ , خشایار Mehrani ²

1 - Department of Clinical Sciences, Tabriz Branch, Islamic Azad University, Tabriz, Iran.
2 - Student of Veterinary Medicine, Tabriz Branch, Islamic Azad University, Tabriz, Iran.

Received: 2015-08-17 Accepted : 2017-05-10 Published : 2017-04-21

Keywords:

Abstract :

The thyroid gland is one of the major endocrine glands which plays an important role in vital balance of the body by secreting two hormones, T3 and T4. Because effects of these two hormones affect the activity of many body organs, in this survey the effects of these two hormones on the return of ovarian activity in Holstein cows were examined. For this purpose, 60 primiparous cows (having one pregnancy) and 60 multiparous (having two or more pregnancies) were considered for this survey. In both groups, the blood samples were taken 10 days before parturition and 10 to 20 days after parturition.  After centrifugation and serum separation, samples were stored at -20 o C. Afterwards in laboratory, T3 and T4 values were measured by using ELISA kit. The results indicate that the values of T3 and T4 in primiparous cows in the prenatal and postpartum period were more than multiparous cows (p<0.05). In both groups, values of T3 and T4 in postpartum period were reduced compared to prenatal period. T4 values in multiparous cows in the postpartum period showed significant correlation with the return time of ovarian activity. Finally, it can concluded that decreasing thyroid function and thyroid hormones deficiency, particularly T4, in the postpartum period can influence the prolongation of the onset of ovarian activity in multiparous cows but in primiparous cows due to the sufficient activity of the thyroid gland, the onset of ovarian activity should be sought in other factors.  

References:

• Drackley, J.K. (1999).Biology of dairy cows during the transition period: The Final Frontier. Journal of Dairy Science, 82(11): 2259-2273.


• Gorji dooz, M. (1999). Large Animal Internal Medicine. Tehran, Noorbakhsh, Vol. 4, pp: 144-145. [In Persian]


• Grummer, R.R. (1995). Impact of changes in organic nutrient metabolism on feeding the transition dairy cow. Journal of Animal Science, 73(9): 2820-2833.


• Huszenicza, G.Y., Kulcsar, M. and Rudas, P. (2002). Clinical endocrinology of thyroid gland function in ruminants. Veterinarni Medicina, 47(7): 199-210.


• Mojabi, A. (2001), Veterinary Clinical Biochemistry. Iran: Tehran University Press, pp: 63-251.


• Papasouliotis, K. (2003).Fundamentals of Veterinary Clinical Pathology. 1^st ed., USA: Wiley-Blackwell, pp: 149-150.


• Pezzi, C., Accorsi, P., Vigo, D., Govoni, N. and Gaiani, R. (2003).5′-Deiodinase Activity and Circulating Thyronines in Lactating Cows. Journal of Dairy Science, 86 (1): 152-158.


• Radostits, O.M., Gay, C.C., Hinchcliff, K.W. and Constable, P.D. (2007). Veterinary Medicine: A Textbook of the Diseases of Cattle, Horses, Sheep, Pigs and Goats. Elsevier Health Sciences, pp: 2047-2048.


• Rasooli, A., Nouri, M., Khajeh, G. and Rasekh, A. (2004). The influences of seasonal variations on thyroid activity and some biochemical parameters of cattle. Iranian Journal of Veterinary Research, 5(2): 55-62.


• Spicer, L., Alonso, J. and Chamberlain, C. (2001).Effects of thyroid hormones on bovine granulosa and thecal cell function in vitro: Dependence on insulin and gonadotropins. Journal of Dairy Science, 84(5): 1069-1076.