srjalsSRJALSSRJALS2788-9386https://doi.org/10.47310/srjals.2025.v05i02.008Evaluation of the Productive Performance of Simmental Cows in Central IraqThe study was conducted at Taj Al-Nahrain dairy breeding station in Al-Diwaniya district, Qadisiya governorate, Iraq, between July 31, 2023 and June 1, 2024. In this study, 11 cows of Simmental breed were used, which were used at the beginning of milk production and in the first production season. The results showed that the highest values ​​of daily and monthly milk production occurred in the third month of the dairy season, and the average daily and monthly milk production and the percentage of monthly milk production 1.94±16 kg, 58.34±480 kg, 13.81% were deceptive. After that, it gradually began to decline until the lowest value was reached in the 10th month of the dairy season, with an average value of 1.48±5 kg, 44.49±150 kg, 4.31%. The herd persistence index L.P exceeded 90%, and the average total milk production value for 305 days was 3564.90 kg. The highest average percentages of fat, protein, and fat-free solids appeared in the tenth month of the milking season, with average values ​​of 0.33±4.25, 0.16±3.24, 0.42±8.76, respectively. The lowest average values ​​of fat, protein, and non-fat solids appeared in the third month of the dairy season, with average values ​​of 0.20±3.92, 0.18±2.99, 0.41±8.08, respectively. The highest average lactose value appeared in the third month of the milking season, which was 0.56±4.90; the lowest average lactose value appeared in the tenth month of the milking season, which was 0.10±4.52. There was a highly significant negative correlation between monthly milk production p<0.05. and the fat percentage, protein percentage and non-fat solids percentage. As for the correlation between the milk production quantity and the lactose percentage, it was positive and insignificant p<0.05. The highest average fat yield and protein yield were found in the third month of the milking season, with averages of 4.79±20.32, 2.27±13.68 kg, while the lowest average fat yield and protein yield were found in the tenth month of the milking season, with averages of 0.93±6.85, 0.82±5.45 kg, respectively. There was a strong positive significant correlation p<0.05 between milk production quantity and fat yield and protein yield. There was a significant effect p<0.05 of the season of the year on milk production and its components.