Effect of parity and reproductive status on peak milk yield and some reproductive traits of Holstein cows.

The purpose of this study was to investigate the effect of parity and reproductive status on peak milk yield and some reproductive traits of Holstein cows reared in a private dairy farm of Konya province. Parities were 1 (n=105), 2 (n=97), 3 (n=42), 4 (n=72) and 5+ (n=24). Investigated characters were peak milk yield (PMY), calving interval (CI), number of artificial insemination per pregnancy (AIN) and service period (SP). Parity least squares means (1, 2, 3, 4, 5+), respectively, were; PMY (24.11±1.89, 32.90±1.33, 33.28±2.57, 29.47±1.58, 35.72±1.62 kg), BA (528.77±29.45, 438.37±20.78, 417.18±40.07, 406.57±24.63, 424.46±25.27 days), AIN (2.56±0.46, 1.92±0.33, 2.03±0.63, 1.76±0.39, 2.26±0.40) and SP (137.63±13.00, 96.60±9.17, 92.94±17.69, 85.46±10.87, 77.81±11.16 days). Reproductive status least squares means (aborted, open, pregnant, inseminated), respectively, were; PMY (30.58±1.38, 32.13±1.88, 29.60±0.40, 34.59±0.79 kg), CI (510.66±22.18, 403.47±30.38, 418.41±6.50, 390.64±12.81days), AIN (3.11±0.35, 1.23±0.48, 2.02±0.10, 1.69±0.20) and SP (90.94±9.89, 115.87±13.54, 87.34±2.90, 84.78±5.71 days). Parity significantly affected PMY (P<0.001), CI (P<0.05) and SP (P<0.01). Reproductive status significantly affected PMY (P<0.001), CI (P<0.001) and AIN (P<0.01) The Significant phenotypic correlations were found between PMY and CI (-0.12; P<0.05), PMY and AIN (-0.19; P<0.001), CI and AIN (0.71; P<0.001), CI and SP (0.29; P<0.001) and AIN and SP (-0.14; P<0.01). As as result, better feeding and herd management practices should be provided to improve the reproductive performance of Holstein cows in this dairy farm