APPARENT DIGESTIBLE PHOSPHORUS IN THE FEEDING OF PIGS IN RELATION TO AVAILABILITY, REQUIREMENT AND ENVIRONMENT .2. THE REQUIREMENT OF DIGESTIBLE PHOSPHORUS FOR PIGLETS, GROWING-FINISHING PIGS AND BREEDING SOWS

The supply of P with the feed should not exceed the animals requirement too much for environmental reasons. Therefore in addition to knowledge on the digestibility of P in feedstuffs one needs data on the animal's requirement for P. The requirement for digestible P for maintenance, growth, foetal growth and milk production of pigs was estimated based on the factorial approach. With this approach, recommendations of digestible P were formulated for several categories of pigs and types of production. For piglets from 10-20 kg, growing pigs from 30-50 kg, finishing pigs from 50 kg onwards, pregnant and lactating sows, 3.6, 2.3, 2.0, 2.2 and 2.9 g digestible P kg-1 feed, respectively, is recommended. Large differences in recommendations of the P requirements exist between those reported in the literature and our calculations. Those for piglets in the literature were higher compared to our data. For sows further information concerning the P requirement in different phases of pregnancy and lactation is required to allow a more precise estimation of the P requirement.