J. Dairy Sci. 86:3787–3795 American Dairy Science Association, 2003. Phosphorus Feeding Levels and Critical Control Points on Dairy Farms

A viable and cost-effective approach to managing P on dairy farms is to minimize excess P in diets, which in turn leads to less excretion of P in manure without impairing animal performance. A questionnaire survey was conducted, coupled with on-site feed and fecal sam-ple collection and analysis on dairy farms in New York, Pennsylvania, Delaware, Maryland, and Virginia. The purpose was to assess dietary P levels and to identify critical control points pertaining to P feeding manage-ment. Survey responses, 612 out of 2500 randomly se-lected farms, revealed a wide range of dietary P concen-trations for lactating cows, from 3.6 to 7.0 g/kg of feed DM. The mean was 4.4 g/kg, which was 34 % above the level recommended by the NRC for 27.9 kg milk/d, th