Abstract
This survey was carried out to assess the effect of cow's breed, calving season and parity on productive and economic parameters of dairy cows under the Egyptian condition. Longitudinal data from 7 commercial dairy herds in Behira, Alexandria and Kafr El-Sheik provinces were collected from 2014 to 2016. Breed classified into Holstein and Brown Swiss, calving season and parity are classified into four categories (winter, spring, summer and autumn), and (1, 2, 3 and ≥4), respectively. Holstein cows yielded 1374.15, 1.42, and 757.68 kg, higher for total milk yield, daily milk yield, and corrected milk yield (305 milk yields), respectively than Brown Swiss cows. Veterinary services costs were higher in Holstein cows than Brown Swiss ones (652.37±2.80 vs. 630.08±4.50 EGP, respectively), while, breeding and cow's depreciation costs were higher in Brown Swiss cows than Holstein ones (386.91±3.49 and 1178.57±3.25 vs. 305.96±3.85 and 1152.44±2.36 EGP, respectively). Although the similarity in total variable costs and total cost costs between the two breeds, Holstein cows had higher return parameters, than Brown Swiss cows. Cows that calved in the winter season had the highest total milk yield, daily milk yield, and corrected milk yield (305 milk yield), than other seasons. Breeding costs were higher for spring calvers. In spite of the higher labor, feed, variable and total costs, there is a superior increase profitability of winter calvers in comparison with other seasons. Cows in first, second and third parity had higher total milk yield, daily milk yield, and corrected milk yield (305 milk yield) than subsequent lactations, consequently, they showed a higher return parameters. At the same trend, veterinary services, breeding costs, feed costs, total variable costs and total costs were higher in first and second parities. Our findings cleared that, Holstein cows, winter calving and first three parity were more profitable for dairy producers.

Key words: breed, calving season, parity, productive, economic, dairy cows