Medycyna Wet. 62 (1), 36-39, 2006
| Güler T., Kul S., Ertaş O. N. |
| Effects of various energy levels and ambient temperatures on serum thyroid hormones and some biochemical values in Holstein steers |
| This 2x2 factorial study was designed to test the effects of different diet energy levels (Low: 5.39 NEf MJ/kg and High: 6.60 NEf MJ/kg) and environmental temperature (Low: 19.84°C and High: 28.5°C) on triiodothyronine (T3), thyroxine (T4) and blood serum parameters of Holstein steers. A total of 28 10-month old steers were divided into 4 groups, each containing 7 steers. According to this design, steers which were subjected to housing in barns were either offered normal energy (Barn-NE group) or high energy (Barn-HE group) diets; steers which were subjected to housing outside were also either offered normal energy (Outside-NE group) or high energy (Outside-HE group) diets. The highest levels of T3 and T4 were in the Outside-HE group followed by Outside-NE group, Barn-HE group and Barn-NE group, respectively (p<0.05). Serum glucose, cholesterol and triglyceride levels were higher in all the outside groups (p<0.05). No differences were found between the groups in the total protein, albumin, uric acid, inorganic phosphor, Ca, Na and K levels. The levels of SCOT, SGPT, amylase, alkaline phosphates and creatinin were similar in all groups. The results of the study indicated that increasing energy levels and ambient temperatures increased T3 and T4 levels and did not affect serum metabolites except for glucose, cholesterol and triglyceride. |
| Keywords: energy, ambient temperature, thyroid hormones, serum constituents |