1. Feed Inputs to Animals Bob von Bernuth

2. Considerations in a Ration/Diet Energy Proteins & Amino Acids Minerals Vitamins Non-nutritative additives

3. Energy Energy is produced when organic molecules undergo oxidation. C 6 H 12 O 6 + 6 O 2 => 6 CO 2 + 6 H 2 O + energy

4. Proteins and Amino Acids Proteins are amino acids There are limiting amino acids Lysine Methionine A lot of others! They should be balanced Amino acids are the main source of N Limiting amino acids results in reducing N excretion.

5. Minerals Animals generally have a dietary requirement for Calcium Chlorine Copper Iodine Iron Magnesium Manganese Phosphorus Potassium Selenium Sodium Sulfur Zinc

6. Importance of Phosphorus One of the most important minerals required by livestock and poultry. Complexes with calcium to give rigidity to bones. An integral part of many organic compounds – plays important roles in energy and protein metabolism. Almost every biochemical reaction that occurs in muscle, blood and other soft tissues involves phosphorus. Affects protein synthesis, lean deposition in growing animals.

7. Phosphorus Requirements Best source of unbiased information on requirements is the nutrient requirement publications of the National Research Council (NRC). NRC is part of the National Academy of Sciences – a private organization established 140 years ago by President Abraham Lincoln to advise the nation on issues of science and technology. The Committee on Animal Nutrition of the NRC has established guidelines for feeding animals for past 75 years.

8. Swine versus Dairy Swine are a monogastric Dairy cattle are ruminants Ruminants have a rumen (large stomach) Rumen contains bacteria which produce phytase enzyme—breaks down phytate feedstuffs Nonruminants don’t

9. Swine Considerations Since they don’t have phytase—we have to overfeed P in order to ensure adequate available P. Or—we can add phytase—it works in swine, it just isn’t produced there (it also works for poultry) Or—we can use low phytate corn

10. Phosphorus Essential for skeletal system development Generally low availability Feedstuffs—60-75% is phytate (not available)  Corn grain—14%  Soybean meal—23-30% What happens to the rest?

11. Nitrogen and Phosphorus in Animal Manures N P (% of DM) Manure from: Swine4.712.97 Poultry5.131.62 Beef3.961.07 Dairy3.750.79 Sheep3.890.56 Sweeten (1992).

12. Swine and Poultry Manure High in Phosphorus - Why? Diets (especially swine diets) generally tend to be oversupplemented with phosphorus. Grains, oilseed meals in swine and poultry diets are high in phytate phosphorus. Pigs and poultry are unable to degrade phytase and utilize the phosphorus - no phytase in their digestive tract. As a result, most of dietary phosphorus from the natural ingredients is excreted in the feces.

13. Phytic Acid – The Culprit P O-O- -O-O O O P O-O- -O-O O O P O-O- -O-O O O P O-O- -O-O O O P O-O- -O-O O O P O-O- -O-O O O

14. Phytate Phosphorus P O-O- -O-O O O P O-O- -O-O O O P O-O- -O-O O O P O-O- -O-O OO P O-O- -O-O O O P O-O- -O-O O O Zn ++ Ca ++ Cu ++ Zn ++ Mg ++ Fe ++

15. Phytate Phosphorus Content of Cereal Grains, Byproducts, and Oilseed Meals Phytate Phosphorus % of total P % of total P Barley56Wheat bran70 Oats56Wheat middlings74 Corn66 Wheat67Soybean meal61 Grain sorghum68Cottonseed meal70 Sesame meal81 Nelson et al. (1968).

16. Nutritional Strategies to Reduce Phosphorus in Swine Manure Feed diets that are not excessive in phosphorus. Formulate diets on an “available phosphorus” basis. Use feedstuffs that are low in phytate or that have endogenous phytase. Wheat, wheat byproducts, triticale, barley. Reduce dietary phosphorus and supplement with phytase. Use low-phytate cereals and oilseed meals.

17. Model-Predicted P Excretion (kg) in Growing-Finishing Pig Fed Corn-Soy Diet from 20 to 120 kg 79% More P Excreted

18. Phytase – What Does it Do? Increases phytate digestibility - increases bioavailability of P in cereal grains and oilseed meals. Reduces the amount of supplemental inorganic P needed to maximize growth and bone mineralization. Markedly reduces fecal P excretion. Increases the absorption of Ca, Mg, Zn, and other divalent cations. May improve the utilization of dietary protein and energy.

19. Low-Phytate Corn

20. Forms of Phosphorus in Germ of Normal and Mutant lpa1 Corn Raboy et al. (1990) Phytic Acid P Inorganic P Other Organic P

21. Soluble Carbohydrates in Soybean Sucrose UDP UDP-Glu Glucose + Fructose UDP Galactinol Myo-Inositol Sucrose Raffinose 1 1 Myo-Inositol, 1P Synthase ATP ADP Glu6P 2 Galactinol Synthase 2 3 Raffinose Synthase 3 4 Stachyose Synthase 4 UDP-Gal Myo-Inositol Phytic Acid Phytic Acid Galactinol Myo-Inositol Stachyose

22. Dairy Considerations A dairy cow has phytase. Perhaps because of the large amount of feed she eats (50-60 lb/day) some phytase might help. However, we tend to overfeed P.

23. Why Do We Overfeed P? Safety marginNot needed Increased milk yieldDoesn’t work HypophasphatemiaDoesn’t help Improves reproductionData ??? P in feed unknownNo excuse

24. You Get Back What You Put In! P has no gaseous phase It can’t escape to the air If you fed it, it’s in the animal, the milk or the excretion. If you manure sample doesn’t show it, you better look for it.

25. Dairy Phosphorus Balance

26. Nutrients retained by animals (Elemental) AnimalNPK Beef0.0160.0070.002 Dairy0.0120.0070.002 Pork0.0230.0070.002 Layers0.0220.0060.002 Broilers0.0260.0060.002 Turkeys0.0210.0060.002