Vol. 12, Special Issue 11 (2023)

Author(s):
Lata Kant, Priyanka M Kittur, Amit Kumar, Susmita Majumder, Neha Rajawat, Hari Abdul Samad, Vikrant Singh Chouhan, Gyanendra Singh and VP Maurya

Abstract:
Thyroid hormones are regarded to be significant biomarkers for monitoring stress levels. The objective of this research was to determine the metabolic thyroid hormone profile of Tharparkar and Sahiwal calves during chronic heat stress. The concentrations of triiodothyronine (T₃) and thyroxine (T₄) in serum were determined. In the study, healthy male animals aged 1.5 to 2 years were divided into two distinct groups (five animals in each group). The study included seven days of acclimatization, 49 days of heat exposure at 38 °C (6 hours per day), and seven days of recovery. The collection of blood was done on day -7, 0, 7, 14, 21, 28, 35, 42, 49 and 56 day. During the experimental period, the levels of T₃, T₄ were found to be significantly (p<0.05) lower in both during the heat stress period. When both breeds are subjected to heat stress, serum T₃ and T₄ concentrations decrease. The serum T₄ levels were significantly (p<0.05) lower in Sahiwal than in Tharparkar, but the reduction in T₃ levels was not statistically significant. As a result, thyroid hormone profiles indicate that Tharparkar is more thermo-adaptable than Sahiwal.