Department of Animal Science North Carolina State University Understanding and Applying Nutrition Concepts to Reduce Nutrient Excretion in Swine

Outline Introduction General strategies to reduce nutrient excretion Methods to reduce Nitrogen excretion Methods to reduce Phosphorus excretion Reducing Micro-mineral excretion NC STATE UNIVERSITY

Balance between animal production and crop production Animal production has developed into an intensive industry –production facilities are large and clustered together –feedstuffs are shipped in from crop-producing regions Animal waste not used as a fertilizer –too expensive to ship to crop-producing regions Alternative methods to deal with waste where found: –Store and treat (eliminates N and C) in lagoons –Apply to crop land based on N (which may over-apply P) NC STATE UNIVERSITY

Nutrients in manure should be utilized –process to yield usable products –applied to crop land such that a balance is maintained Jongbloed & Lenis, 1993 us Manure nutrient utilization NC STATE UNIVERSITY

Amounts of N output for different classes of swine, calculated for a 100 sow equivalent (89 productive sows) NC STATE UNIVERSITY

Digestion and retention of N, P, Cu and Zn by different classes of swine NC STATE UNIVERSITY

Efficiency of nutrient utilization and waste Nitrogen retention is only 30% NC STATE UNIVERSITY

General Nutritional Strategies to Reduce Nutrient Excretion Feed Efficiency Improving feed efficiency by 0.1 points ==> 3.3% reduction in nutrient excretion Pelleting Dry matter and N excretion decreased by 23 and 22% Feed efficiency was improved by 6.6% NC STATE UNIVERSITY

General Nutritional Strategies to Reduce Nutrient Excretion (continued) Feed Wastage Reduction in feed wastage of 2% ==> reduction in N and P in manure by approximately 3% Matching Nutrient Requirements Multi-phase feeding reduced urinary N excretion by 15% Ammonia emission was reduced by 17% NC STATE UNIVERSITY

Nutrient requirements and phase feeding 2-Phase feeding program 6-phase feeding program Lysine Requirement NC STATE UNIVERSITY

Phase-feeding in Pig Production - 13% NC STATE UNIVERSITY

Savings in feed costs with phase feeding NC STATE UNIVERSITY

General Nutritional Strategies to Reduce Nutrient Excretion (continued) Concentrations of selected minerals in sow and grower-finisher feeds NC STATE UNIVERSITY

Methods to Reduce N excretion and Ammonia Emission NC STATE UNIVERSITY

Nitrogen flow in swine N Intake, 100% Digestible N, 85% Available N, 80% Retained N, 35% Fecal N, 15% Urinary N, 50% Ammonia, 20% Manure, 45% NC STATE UNIVERSITY

Metabolism Crates NC STATE UNIVERSITY

Feeds are not digested completely: indigestible fraction contributes to waste Protein Undigested N Fecal N Amino acids Digestion Protein NC STATE UNIVERSITY

Improving digestibility of feed 1% decreases waste 1.4% The digestibility of feeds can be improved through: technological treatments (pelleting, extrusion, etc,) Enzymes –Xylanases and beta-glucanases - degrade non-starch polysaccharides (NSP) –Improve digestibility of nitrogen 2-3% in typical diets –Proteases, (hemi) cellulases are being developed NC STATE UNIVERSITY

Protein Undigested N Fecal N Amino acids Endogenous excretion Digestion Digestion of feed causes the animal to loose nitrogen directly through endogenous losses Protein NC STATE UNIVERSITY

25% of the endogenous secretions end up as waste Animal secretes enzymes/protein during the digestive process –only 75% reabsorbed –Loss is accounted for in ileal digestibility tables NC STATE UNIVERSITY

Protein Undigested N Fecal N Amino acids Endogenous excretion NH 3 Digestion inefficiency Feed induced loss of N Losses (catabolism) associated with the synthesis of endogenous secretions Protein NC STATE UNIVERSITY

30% of the amino acids targeted for endogenous secretions are catabolized For the synthesis of these endogenous secretions, some amino acids are catabolized (losses due to inefficiencies) Feedstuffs can influence endogenous secretions, and thus endogenous losses and endogenous-linked catabolism –neutral detergent fiber increases endogenous losses without affecting secretion or catabolism –trypsin inhibitors increases endogenous secretions, thus catabolism as well as secretion Digestibility tables do not account for these losses! NC STATE UNIVERSITY

Protein Undigested N Fecal N Amino acids Endogenous excretion NH 3 Digestion energy inefficiency Amino acids which can not be utilized for protein synthesis are catabolized Protein NC STATE UNIVERSITY

A large proportion of nitrogen is wasted because feeds are not idealy balanced, Feed composition determined through least-cost formulation: –diet of minimal cost to meet nutritional needs Pigs require amino acids, not protein NC STATE UNIVERSITY

Ileal true digestible amino acid patterns for pigs in three different weight classes NC STATE UNIVERSITY

Balance trial for pigs fed a corn-soybean meal-dried whey (C-SBM-DW) diet or a purified amino acid diet N Excretion was reduced by 28% NC STATE UNIVERSITY

Effect of low protein diets on N excretion and ammonia emission N Excretion was reduced by 9% for each 1% reduction in CP N in the air was reduced by 8% for each 1% reduction in CP NC STATE UNIVERSITY

Cost or value of reducing CP in a corn-soybean meal based diet Corn $90, SBM $180, Lysine-HCl $2400, Methionine $2700, Threonine $2.63/lb, Tryptophan $15.80/lb Lysine, lbs/ton Cost/ton NC STATE UNIVERSITY

Ammonia is mainly derived from N excreted in urine: capturing some of the N in feces reduces ammonia emission Protein Undigested N Fecal N Amino acids Endogenous excretion UreaUrinary ureaNH 3 Digestion fermentation Protein energy inefficiency 85% of ammonia is derived from urea (Voermans, 1994) NH 3 (l) NH 4 + NH 3 (g) urease NC STATE UNIVERSITY

Fiber reduces urinary N, thus ammonia emission Nitrogen excretion can be shifted from urine to feces –supply non-starch polysaccharides (NSP) in diet source of energy for microbes in large intestines –stimulates growth of microbes, and thus nitrogen accretion Increasing NSP intake with 100 g/day: –decreases ammonia emission 5% (partially due to a decrease in manure pH) Caution: –NSP decrease nitrogen digestion –NSP might well increase odor emission NC STATE UNIVERSITY

Swine Malodor Emission Laboratory NC STATE UNIVERSITY

Methods to Reduce P Excretion NC STATE UNIVERSITY

Functions of Phosphorus 80 to 85% of P is found in bone Non-skeletal P is concentrated in Red Blood Cells, Muscle, and Nerve Tissue Present in Phosphoproteins, Nucleoproteins, Phospholipids, Phosphocreatine and ATP –Membrane Structure –Energy Metabolism –Buffer System NC STATE UNIVERSITY

Reducing Phosphorus Excretion Through Nutrition Feed to meet the Pigs Requirement –Reduce excess levels in feed –Feed multiple phases Use available P levels rather than total –Ingredient values –Pig requirement Use of phytase or low phytic acid ingredients NC STATE UNIVERSITY

Available P levels in diets formulated to contain 0.5% total P NC STATE UNIVERSITY

Enzymes have many environmental benefits Phytase Phytate is an indigestible form of phosphorus –corn: 90% of phosphorus bound in phytate –soybean meal: 75% of phosphorus bound in phytate Phytase –improves digestibility of phytate reduces phosphorus excretion 32% improves nitrogen digestibility 2% –routinely used in Europe NC STATE UNIVERSITY

Estimated cost of phytase supplementation using least cost diet formulation NC STATE UNIVERSITY

Low Phytate Corn Available P: Availability of P was set at 20% for corn and 75% for low phytate corn Total P Cromwell, 1999 NC STATE UNIVERSITY

Low Phytate Corn and Phytase Total P: Reduction in P Excretion: -- 23% 35% 51% NC STATE UNIVERSITY

Reducing the Excretion of Micro-Minerals NC STATE UNIVERSITY

Excretion of zinc and copper by different classes of swine* NC STATE UNIVERSITY

Effect of Reducing Zn and Cu in pig diets on Zn and Cu excretion in waste Treatments NC STATE UNIVERSITY

Growth Performance of Nursery and Growing-Finishing Pigs Fed Reduced Levels of Trace-Minerals NC STATE UNIVERSITY

Effect of Reducing Trace-Mineral Levels on Mineral Excretion NC STATE UNIVERSITY

Bottom line Phase Feeding ===> 15 % Reducing N –Lowering CP (1.5%) ===> 13.6 % –Adding lysine + methionine ==> 22.1 % –Adding other AA + feedstuffs => 30.6 % Reducing P –Lower Requirement ===> 15.7 % –Adding Phytase ===> 26.5 % –Phytase + feedstuffs ===> 41.0 % Reducing Zn and Cu –Lower dietary levels ===> % But; many of these reductions in waste can only be achieved if a higher production cost is acceptable Jongbloed and Lenis, 1992 Creech, 1998 NC STATE UNIVERSITY