Abstract
Climate change and effects of heat stress on animals are evident on different biological systems in form of oxidative stress and at cellular membrane level as Na+-K+-ATPase gradient. The present study was planned for genetic characterization of Cholistani cattle (N=25) using three primers for exon14, intron 14, exon 16 and exon and intron 17 regions of ATP1A1 gene. Rectal temperature (RT), respiration rate (RR), vaginal temperature (VT) and ear skin temperature (outer surface) (EST) was recorded in the morning and afternoon of the same day while heat tolerance coefficient (HTC) was calculated for each animal using recorded physiological parameters and adaptability of animals was observed in heat stress. The genetic characterization was done using molecular technique polymerase chain reaction (PCR). The means and standard error values of response variable traits RR, RT and VT were 23.34 +/- 4.41 and 25.14 +/- 4.41 bpm, 38.01 +/- 0.43 and 38.81 +/- 0.35 degrees C, 38.11 +/- 0.37 and 38.86 +/- 0.34 degrees C and corresponding HTC values were 2.01 +/- 0.09 and 2.11 +/- 0.13 in the morning and afternoon, respectively. The average values of RR using primer(1), in genotype AA (23.51 +/- 0.53), AB (24.97 +/- 0.84) and BB (24.48 +/- 0.86 bpm) were not statistically different from one another. The RT and VT for the genotype AA (38.41 +/- 0.04 and 38.44 +/- 0.05 degrees C), AB (38.37 +/- 0.04 and 38.47 +/- 0.05 degrees C) and BB (38.49 +/- 0.03 and 38.61 +/- 0.03 degrees C) were not statistically different from one another. Significant (p < 0.05) effect of genetic variant (BB) of ATP1A1 gene (primer(1)) on VT (higher) of Cholistani cattle was found. Diurnal variations of temperature humidity index (THI) (higher in afternoon) showed significant increase (p < 0.05) in rectal temperature and respiration rate. These genotypes and relative traits can be used as biological indicators for assessment of heat stress tolerance in Cholistani cattle.