21. Improving phytate phosphorus availability in corn and soybean meal for broilers using microbial phytase and calculation of phosphorus equivalency values for phytase.
Yi,-Z.; Kornegay,-E.T.; Ravindran,-V.; Denbow,-D.M.
Poultry-sci. Savoy, IL : Poultry Science Association, Inc. Feb 1996. v. 75 (2) p. 240-249.
NAL Call Number: DNAL 47.8-Am33P
Descriptors: broilers. feed-additives. phytase. phosphorus. calcium. phytic-acid. liveweight-gain. dosage-effects. bone-ash. digits. digestibility. maize. soybean-oilmeal.
Abstract: Two experiments were conducted to determine the effectiveness of Natuphos phytase for improving P availability of soybean meal-based semi-purified diets (SP, Experiments 1 and 2) and corn-soybean meal-based diets (CS, Experiment 2) fed to broilers (1 to 21 d). There were 360 and 288 birds fed the SP diets in Experiments 1 and 2, respectively, and 288 birds were fed the CS diets in Experiment 2. Phosphorus equivalency values for phytase were calculated. The basal diets were formulated to contain 0.27% nonphytate P (nP); the SP basal diet contained 0.45% total P (tP) that included 0.17% P as defluorinated phosphate; the CS basal diet contained 0.51% tP that contained 0.12% P as defluorinated phosphate. Both basal diets were supplemented with defluorinated phosphate to provide 0.36, 0.45, or 0.54% nP or with 350, 700, or 1,050 U of phytase/kg diets. Supplementing defluorinated phosphate and phytase linearly increased BW gain (P < 0.001), feed intake (P < 0.001), and percentage ash of dried toes (P < 0.01). Phytase addition increased apparent retention of P (P < 0.02), Ca (P < 0.005 in Experiment 2), and N (P < 0.06 in Experiment 2 for CS), increased apparent digestibility of DM (P < 0.04), and linearly decreased (P < 0.005) P excretion. In comparison to the 0.45% nP diet, P excretion was reduced 42 to 51% by addition of phytase. The addition of defluorinated phosphate linearly decreased apparent retention of P (P < 0.02) and Ca (P < 0.005 in Experiment 2), and increased P excretion (P < 0.007). The average of released P by phytase calculated by solving nonlinear or linear response equations of P and phytase levels for SP diets in Experiments 1 and 2 gave a P equivalency value of 1 g P = 1,146 U of phytase. The P equivalency value for CS diets fed only in Experiment 2 was 785 U of phytase = 1 g P as defluorinated phosphate. These studies show that microbial phytase is effective for improving P availability and for decreasing P excretion. Added phytase can also increase Ca and N retention.

22. Managing agricultural phosphorus for protection of surface waters: issues and options.
Sharpley,-A.N.; Chapra,-S.C.; Wedepohl,-R.; Sims,-J.T.; Daniel,-T.C.; Reddy,-K.R.
J-environ-qual. Madison : American Society Of Agronomy,. May/June 1994. v. 23 (3) p. 437-451.
NAL Call Number: DNAL QH540.J6
Descriptors: phosphorus. pollution. soil-management. crop-management. losses-from-soil. eutrophication. runoff. erosion. soil-fertility. manures. pollution-control. watershed-management. nonpoint-source-pollution.
Abstract: The accelerated eutrophication of most freshwaters is limited by P inputs. Nonpoint sources of P in agricultural runoff now contribute a greater portion of freshwater inputs, due to easier identification and recent control of point sources. Although P management is an integral part of profitable agrisystems, continued inputs of fertilizer and manure P in excess of crop requirements have led to a build-up of soil P levels, which are of environmental rather than agronomic concern, particularly in areas of intensive crop and livestock production. Thus, the main issues facing the establishment of economically and environmentally sound P management systems are the identification of soil P levels that are of environmental concern; targeting specific controls for different water quality objectives within watersheds; and balancing economic with environmental values. In developing effective options, we have brought together agricultural and limnological expertise to prioritize watershed management practices and remedial strategies to mitigate nonpoint-source impacts of agricultural P. Options include runoff and erosion control and P-source management, based on eutrophic rather than agronomic considerations. Landowner options to more efficiently utilize manure P include basing application rates on soil vulnerability to P loss in runoff, manure analysis, and programs encouraging manure movement to a greater hectareage. Targeting source areas may be achieved by use of indices to rank soil vulnerability to P loss in runoff and lake sensitivity to P inputs.

23. Microbial phytase improves amino acid utilization in young chicks fed diets based on soybean meal but not diets based on peanut meal.
Biehl,-R.R.; Baker,-D.H.
Poultry-sci. Savoy, IL : Poultry Science Association, Inc. Feb 1997. v. 76 (2) p. 355-360.
NAL Call Number: DNAL 47.8-Am33P
Descriptors: chicks. feed-additives. phytase. maize. soybean-oilmeal. peanut-oilmeal. amino-acids. liveweight-gain. feed-intake. feed-conversion. digestibility. metabolizable-energy.

24. New corn varieties to provide feed options in the future.
Stilborn,-H.L.; Crum,-R.C.-Jr.
Feedstuffs. Carol Stream, Ill. : Miller Publishing Company. Oct 6, 1997. v. 69 (41) p. 12, 14-16.
NAL Call Number: DNAL 286.81-F322

Descriptors: maize. new-variety. metabolizable-energy. energy-content. phytic-acid. phosphorus. fat. animal-nutrition. poultry-feeding. equations. feed-composition-tables. supplemental-fat. high-oil-corn. true-metabolizable-energy.

25. Nutrient content of dairy manure from three handling systems.
Rieck-Hinz,-A.M.; Miller,-G.A.; Schafer,-J.W.
J-prod-agric. [Madison, WI] : American Society of Agronomy, c1987. Jan/Mar 1996. v. 9 (1) p. 82-86.
NAL Call Number: DNAL S539.5.J68
Descriptors: cattle-manure. nutrient-content. determination. seasonal-variation. composition. correlation. handling. systems. nitrogen-content. ammonium-nitrogen. phosphorus-pentoxide. potassium. iowa. percentage-solids. dairy-feedlots. dairy-barn-cleaners. dairy-bedded-packs.
Abstract: Animal manure is often used as a source of crop nutrients. Unfortunately the nutrient content of manure is quite variable. The objectives of this study were to: (i) evaluate the nutrient content of dairy manure from different handling systems and determine if published nutrient credits are outdated, (ii) determine if the nutrient content could be estimated from the solid content of the manure, and (iii) determine the seasonal variation of the nutrient content of manure. Three dairy-manure handling systems, dairy feedlots, dairy barn cleaners, and dairy bedded packs, were sampled sequentially from June 1990 to April 1992. Manure was sampled by handling system at 13 farms located in northeastern Iowa Samples were analyzed for total Kjeldahl N (TKN), ammonium-N, P2O5, K2O, and solid content. The nutrient values found in this study were higher than values previously reported in Iowa and other midwest states. For dairy feedlot manure, solid content of the manure was correlated with the nutrient content of the manure. The use of manure in a nutrient management program is dependent on accurate nutrient recommendations based on thorough and timely manure sampling.

26. Nutrient emissions from agriculture in the Netherlands causes and remedies.
Boers,-P.C.M.
Water science and technology; v. 33, no. 4/5. iffuse pollution '95 selected proceedings of the 2nd IAWQ International Specialized Conference and Symposia on Diffuse Pollution, held in Brno and Prague, Czech Republic, 13-18 August 1995 /. 1st ed. Oxford ; New York : Pergamon Press, 1996. p. 183-189.
NAL Call Number: DNAL TD420.A1P7-v.33-no.4/5
Descriptors: water-pollution. nitrogen. phosphorus. runoff. agricultural land. nitrogen fertilizers. phosphorus-fertilizers. pollution-control. leaching. surface-water. animal-manures. water-quality. environmental-management. wetlands. grass-strips. groundwater-level. eutrophication. low-input-agriculture. netherlands. nonpoint-source-pollution.