The current study was aimed to investigate the impact of THI on productive and reproductive indices of PE and F₁ crosses (50% PE and 50% Italian buffaloes) and back crosses (BC) (75% PE and 25% Italian buffaloes) under hot conditions. In this study, 8385 records used PE (1914, 1518, and 1737), F₁ (387, 447, and 657), and BC (495, 585, and 645) for low, medium, and high THI, respectively. The high THI reduced the conception rate after first insemination in PE, F₁, and BC ((odds ratio, OR) = 1.187, P = 0.007; 2.361, <0.0001 and 1.603, <0.0001, respectively) when compared with low THI. But, stillbirth and calving condition were not significantly influenced by different THI levels in BC and F₁. BC was more bearable to the harsh environment; they possessed the highest incidence of conception after first insemination (72.70, 72.60, and 62.40%), producing live calves (98.50, 100, and 99.40%) with easy calving condition (98.50, 100, and 99.40%) when compared to PE and F₁ at different levels of THI, respectively. The average daily milk yield and peak of milk production were decreased in PE (4.02 and 5.12%), BC (13.33 and 10.95%), and F₁ (25.29 and 12.20%) from low to high THI. However, BC revealed no significant changes in days open, dry period, calving interval, gestation length, service per conception, and the first service post-partum at different levels of THI when compared with PE and F₁. Therefore, rearing BC is recommended for improving buffalo productive and reproductive performance under hot conditions.

In order to enhance the profitability of dairy buffaloes, it is necessary to develop an understanding of the factors affecting their reproduction and milk production ability. Thus, the objective of this study was to elucidate the economic impacts of calving season and parity on reproduction and production indices of Egyptian dairy buffaloes (1180) reared under subtropical environmental conditions. Buffaloes calving in the autumn season had lesser days open, calving interval, and service per conception (108.25 days, 414.16 days, and 1.67, respectively), while spring calvers showed the greater calculations (210.27 days, 522.82 days, and 2.39, respectively). The buffaloes calving for the first time had the longest days open, calving interval, and number of services per conception among different parities (176.21 days, 490.05 days, and 2.18, respectively), then decreased thereafter. Furthermore, buffaloes calving in the winter season had the significantly highest total milk yield, milk revenue, total revenue, profit, and profit/cost ratio (1981.4 kg, 1769.1 $, 2019.5 $, 662.9 $, and 0.49, respectively) in comparison with other seasons. The total milk yield, lactation period, profit, and profit/cost ratio were increased to reach the peak values in the fourth parity (2051.5 kg, 252.44 days, 674.8 $, and 0.48, respectively), then decreased thereafter. In conclusion, buffaloes at the fourth parity and those calving in the winter season had the best milk yield, milk revenue, total revenue, and profit/cost ratio. Therefore, breeders must pay more attention to calving season and parity as they play an important role in the farm profitability and productivity and should counteract the adverse effects of periodical and seasonal changes. It is recommended to make estrus synchronization for more calvings in the winter season. Finally, choose the best lifetime for keeping the animal in production.