Conditional requirements, such as the duration of the growth phase, also affect phosphate requirements. These standard criteria are however characterised by the unlimited use of feed concentrates and phosphate. As a result, the coefficients for phosphate use are low and they will probably increase by restricting the use of phosphate (Peet-Schwering et al., 1999). A restricted use of phosphate contents can be obtained by: Re-evaluating the phosphorus requirements of the animal. (Valk & Beynen, 200313; Krimpen et al., 201014). The actual phosphorus intake by dairy cattle is, on average, 1.5 times higher than current intake standards recommend, which could lead to a 33 percent intake reduction. Increasing the availability of phosphate in feed concentrates. In feed of plant origin, two thirds of total P is present as phytic acid P, which is almost indigestible for pigs (Peet-Schwering et al., 199915). Cattle and poultry are able to partly digest phytic acid P. Microbial phytase has been used since 1991 to increase phosphate digestibility. New strains of phytase-producing micro organisms (Aspergillus ficuum) can increase P digestibility (Krimpen et al., 2010). Plant breeding techniques (including DNA techniques) are used to produce cultivars of maize, wheat, barley, soya and rape with lower phytate contents (Bohlke et al., 200516 and Spencer et al., 200017). Increasing the use of feed with a lower phosphate content. 13 Valk, H. & A.C. Beynen, 2003. 47 Proposal for the assessment of dairy cows. Livestock Production Science 79: 267-272. Krimpen, M. van, J. van Middelkoop, L. Sebek, A. Jongbloed & W. de Hoop, 2010. Effect van fosforverlaging in melkveerantsoenen en varkensvoeders op fosfaatexcretie via mest. rapport 324, Wageningen UR Livestock Science / Animal Science Group Veehouderij B.V., Lelystad. Peet-Schwering, C.M.C. van der, A.W. Jongbloed & A.J.A. Aarnink, 1999. Nitrogen and phosphorus consumption, utilisation and losses in pig production: The Netherlands. Livestock Production Science 58: 213-224. Bohlke, R.A., R.C. Thaler & H.H. Stein, 2005. Calcium, phosphorus, and amino acid digestibility in low-phytate. corn, normal corn, and soybean meal by growing pigs. J. Anim. Sci. 83, 2396–2403. Spencer, J.D., G.L. Allee & T.E. Sauber, 2000. Phosphorus bioavailability of normal and genetically modified low-phytate corn for pigs. J. Anim. Sci. 78, 675-681. dicalciumphosphate (hydrated/ dehydrated, monocalciumphosphate, mono-dicalciumphosphate, magnesiumphosphate, monoammoniumphosphate, calcium-magnesiumphosphate and their sodium forms. Other dietary phosphates are proteins (meat) from animal origin. Regulation (EC) No 1774/2002 of the European Parliament and of the Council of 3 October 2002 laying down health rules concerning animal by-products not intended for human consumption Official Journal L 273, 10/10/200. Regulation (EC) No 1069/2009 of the European Parliament and of the Council of 21 October 2009 laying down health rules as regards animal by-products and derived products not intended for human consumption and repealing Regulation (EC) No 1774/2002 (Animal by-products Regulation) Official Journal L 300/1 14.11.2009. In 2008 the mineral phosphate fertiliser 36.6 kg P2O5/ha was used. Ministry of Agriculture, Nature and Food Safety (LNV), 2008. Fourth Action Programme Nitrate Directive (2010-2013). 14 15 16 17 2. Reduced import of dietary phosphates18 Dietary phosphates are selected for, amongst other reasons, their digestibility which differs between animal species. Dicalciumphosphate has the highest digestibility. Recycling phosphate from animal bones and proteins used to be common practice but was abandoned to prevent the contagion of diseases (Bovine Spongiform Encephalopathy (BSE) or mad cow disease)19. This ban was later partially lifted, although feeding animal by-products to the same animal species is still prohibited 20. Dietary phosphates can be obtained from recycling processes (see 6.3) which creates an opportunity to replace imported dietary phosphate with recycled products. 3. Reduced use of phosphate from mineral fertilisers Consumption of mineral phosphate fertilisers has declined since 1986 when 82 kg P2O5/ha was applied as mineral phosphate fertiliser. This amount was reduced in 2005 to 48 kg P2O5/ha 21. The reduction was obtained by: A mineral accounting system, introduced in 1998, which was replaced by phosphate use standards as of 2006. As of 1-1-2010 phosphate use standards are differentiated with respect to the soil P status (LNV, 200822). Valorisation of phosphate from animal manures and other organic soil amendments (compost, sludge). The more efficient use of mineral fertiliser through placement in the plant row (as opposed to broadcasting), and by actually following the recommendations for phosphate fertiliser based on the actual phosphate status of the soil. 18 19 20 21 22 Pagina 56

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