Global warming is an international alarming phenomenon that affects all aspects of life including animal biology. Environmental heat stress is associated with compromised reproductive performance in mammals, particularly animals under stressful conditions (De Rensis et al., 2021). Temperature-humidity index (THI) is the most important indicator of the degree of heat stress to which dairy animals are exposed (Ratchamak et al., 2021) as it combines effects of both ambient temperature and relative humidity. Heat-stressed cows show poor reproductive performance and achieve lower conception rates when compared to non-stressed herd-mates, particularly when inseminated using sexed semen (Oikawa et al., 2019). Despite the modern cooling technologies and its favourable consequences on conception rates during hot summer months, embryo transfer (ET) is still representing the most effective strategy to overcome the negative impacts of heat