Yearly excretion estimates of various nutrients by 1400 lb Holstein cows Fraction Total for year Milk 21750 lbs DMI 14462 lbs Raw manure (feces & urine) 47475 lbs Total N (low NRC) 223 lbs Total N (high NRC) 260 lbs P (.40% P RDM) 40 lbs P (.45% P RDM) 46 lbs P (.60% P RDM) 69 lbs K (.8% K RDM) 88 lbs K (1.2% K RDM) 146 lbs Similar trends Ca, Mg, Na, Cl UIP and DIP minimums metNRC 1989
Composition of Fresh Manure N: 9.4 lb actual N/ton wet manure P: 1.9 lb actual P/ton wet manure K: 3.7 lb actual K/ton wet manure Total solids 12.8% Composition will change with scraping and loading moisture content and volatilization of N
Phase Feeding Opportunities to lower N and P intakes during the latter stages of the finishing period. Consequently, this will lower N and P output Allows nutritionists to more effectively optimize performance w/o overfeeding.
Yearlings (Trial 1; Nebraska 1998) CP (%) UIP (%) P (%) CTL188.8.131.52 Fin 184.108.40.206 Fin 220.127.116.11 Fin 318.104.22.168
Performance : Yearlings Item Control Balanced SE Initial Wt.6526602.8 Final Wt.124912499.8 DMI26.225.0*.2 ADG4.064.01.06 F/G6.456.21 Erickson, et al; 1998
Phosphorus Balance (lbs/hd) ItemControlBalanced 135 d/period for both yearlings and calves treatments
Management Practices to Improve N & P Retention IMPLANTS?
Effect of TBA + E 2 on Nitrogen Retention of Steers TreatmentLW (lb) N Retention (g/d) Period (days) CTL TBA + E 2 CTL TBA + E 2 -1477777419.323.2 + 782183421.643.6* +2887690621.052.1** +4990297219.657.0** +70953104318.536.5* Lobley et al, 1985; Br. J. Nutr. 54:681-694.
Phosphorus Balance ItemCTLIMP P Intake, g/d26.1427.19 P m, g/d6.896.99 Carcass Protein Gain, g/d114207 WB Protein Gain, g/d142259 P g, g/d5.5410.10 P Excreted, g/d20.617.09 P Calculated (.68) g/d18.325.1 P Excess, g/d7.82.09
Synthetic Lysine Replace 100 lbs of SBM with 3 lbs synthetic lysine and 97 lbs of corn Save $3.96/ton –Corn @$1.70/bu & SBM @ $205/ton Save $1.32/pig Reduce N excretion by 22% Reduce odor from ammonia
Split-Sex Feeding Gilts eat less feed and put on more lean tissue Feed gilts higher AA < 80 lbs Save $1.40/pig Reduce N excretion by 5%
Phase Feeding By feeding more diets, you decrease the amount of time you are over-and under- feeding AA. By using 5 Grower-Finisher diets instead of 2, save $1.60/pig Decrease N excretion by 5-8%
Genotypical Feeding Pig will only perform to genetic capability. Increasing protein/AA levels to a genetically average pig will NOT increase muscle. Match genetics to nutrition Reduce N excretion & odor Save $$$$
Antibiotics Some preliminary data shows that certain antibiotics may be nitrogen sparing. Potentially less N excretion and ammonia production
Balance on Available Amino Acids When using something besides a corn- SBM diet Add less N to the diet Reduce N excretion and ammonia production
Dietary Modifications Reduced protein from 13 to 8% and added synthetic AA to meet requirement Replaced copper sulfate with copper oxide Replaced ferrous sulfate with ferric chloride
Results Reduced N in manure by 45% Reduced volatile fatty acids (VFA’s) by 61% Reduced sulfur compounds in air by 63%
Adding 5% Cellulose to Diet Reduced pH from 7.8 to 6.4 Reduced ammonia emissions by 68% Reduced sulfur volatile organic compounds by 12%
While these may not all be practical at the present, it does demonstrate that we can affect nutrient excretions by how we feed the pig.
Phosphorus (P) Only 30% of P in grain is available Rest is in phytate form and is unavailable
Add Phytases Phytases are enzymes that make phytate P more available Reduce P excretion by 30% Add less dicalcium phosphate Economic“wash” when compare to dical price Some reports of slight savings
Cost of P Excretion It takes 3 times more land to spread hog manure on when you base the recommendation on P instead of N Potential BIG cost in the future
Low Phytate Corn “Gene Jockeys” and plant breeders have developed corn varieties with very low levels of phytate P. Commercially available in a year or two
Distiller’s Dried Grains from SD & MN Research on DDG from SD & MN ethanol plants shows that P is 60% more available from their products Tremendous opportunity for gestating sows and finishing pigs Low in lysine
Balance on Available P Do when using other feedstuffs than corn and soybean meal Add less inorganic P (cheaper) Less P excretion
Improving Feed Efficiency Anything that improves feed efficiency will decrease feed in the dust or the amount of feed ending up in the manure, thereby reducing the nutrient load in the manure and the substrate for odor production.
Conclusions Environmental issues will continue to be important in the livestock industry. By utilizing certain nutrition schemes and management tools we can theoretically lower our inputs and outputs of N and P. We all need to do our job in protecting the environment.