摘要：Cows that are milked once-a-day (OAD) produce less milk than when milked twice-a-day (TAD). However, these cows also require less feed because of their lower milk production. Hence stocking rates can be increased. New Zealand evidence shows that the benefits from OAD milking can include per cow savings in animal health, labour and electricity costs, plus improved pregnancy rates. A linear programming model was used to evaluate the whole farm impact of these changes. This showed that OAD milking is likely to reduce profitability. This was based on recent New Zealand research showing an average per cow production decrease of 29% for Friesian cows and 20% for Jersey cows. However, given that some cows can perform under OAD at a similar level to TAD, it is likely that selective breeding will eventually lead to per-cow losses of production that are much less than this. If per cow production losses under OAD milking can be reduced to about 10%, then this will allow cow numbers to be increased by about 6% and will provide a similar whole farm profit as under TAD. There would also be lifestyle advantages for farmers. If per cow production losses could be eliminated, then the farm working expenses under OAD on a typical New Zealand dairy farm would be reduced by about 6.5%.
关键词：Once-a day milking;milk harvesting;linear programming;pastoral dairy farming
