Differential response to stocking rates and feeding by two genotypes of Holstein-Friesian cows in a pasture-based automatic milking system

摘要: The throughput of automatic milking systems (AMS) is likely affected by differential traffic behavior and subsequent effects on the frequency milk production cows. This study investigated effect increasing stocking rate partial mixed ration (PMR) production, dry matter intake (DMI), feed conversion efficiency (FCE) use AMS two genotypes Holstein-Friesian cows in mid-lactation. lasted 8 weeks consisted a factorial arrangement dairy cattle, United States Holstein (USH) or New Zealand Friesian (NZF), pasture-based feeding treatments, low system (2 cows/ha) fed temperate pasture concentrate, high (HSR; 3 same concentrate plus PMR. A total 28 cows, 14 USH NZF, were used for comparisons, with 12 six also tracking animal movements. Data analyzed repeated measure models completely randomized design. No differences (P>0.05) pre- post-grazing herbage mass, DMI FCE detected response to increases PMR HSR. However, there was significant (P<0.05) grazing treatment×genotype×week interaction explained responses changes mass over time (P<0.001). reduction (P<0.01) hours spent supplementation HSR; this greater (P=0.01) than NZF (6 v. 2 h, respectively). Regardless treatment, had (P=0.02) (2.51 2.26±0.08 milkings/day) yield (27.3 16.0±1.2 kg/day), energy-corrected (24.8 16.5±1.0 (22.1 16.6±0.8 kg/day) (1.25 1.01±0.06 kg/kg) There different distribution milkings/h between (P<0.001), patterns shifting (P<0.001) as consequence Results confirmed improved suggested potential tactical decision managing HSR milkings/day farms.