c Land Needs K-State

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1 Diet Impacts Nutrient Excretion and dagronomi c Land Needs Dr. Joel DeRouchey Extension Livestock Nutrition and Environmental Specialist Department of Animal Sciences and Industry

2 Inputs Our Ultimate Goal Bl Balance of fi inputs & managed outputs Feed Animals Irrigation Water Fertilizer Legume N Crops Losses or Soil Storage Manure Farm Boundary Managed Outputs Meat & Milk Crops Manure

3 Inputs Our Ultimate Goal Bl Balance of fi inputs & managed outputs Feed Animals Irrigation Water Fertilizer Legume N Crops Losses or Soil Storage Manure Farm Boundary Managed Outputs Meat & Milk Crops Manure

4 Diet Formulat ion Emphasis Producers and nutritionist i ts continually work to minimize feed cost / lb of gain Historically there has been more concern with too little (deficient) than too much nutrients in the diet Monocalcuim phosphate - $250 vs $1,000 / ton Soybean meal - $180 vs $300 per ton

5 Dietary P in Feedlot Diets ) % diet P (DM supplement byproduct corn roughage.35 85% corn 85% corn + supplement byproduct byproduct + supplement NRC, 1996 requirement Recent UNL data

6 Ethanol Indus stry Influence Ethanol co-products have reduced feed costs in many locations throughout the United States Utilizing ethanol co-products in ruminant rations increases dietary protein (nitrogen) and phosphorus The unintended consequence is: Increasing land requiremen nts for manure application Environmental concerns for both water and air quality

7 Whole Farm Nu utrient Balance The ability to develop nutrient balance for a livestock operation is imp portant for maintaining a long-term production system, and for compliance with current and future environmental regulations.

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9 How does diet im mpact excretion? Excretion calculated as: - = Feed Nutrient t Nutrient Intake Excretion Nutrient Retention by Animal or Animal Products

10 Diets referenced from May et al., % WDGS 21.4 lb 14.0% 2.24% 0.28% 0.48 lb 0.06 lb 30% WDGS 21.4 lb 16.9% 2.70% 0.50% 0.58 lb 0.11 lb MWPS worksheet Form 7;

11 0% WDGS lb/d lb lb Beef 30% WDGS lb/d MWPS worksheet Form 7; lb lb

12 Class Example Swine Manure 0% WDGS 350 d 350*( ) 350*( ) = 137 lb/yr = 12.3 lb/yr 12.3 * 2.3 = 28 lb/yr 30% WDGS 350 d 350*( ) 350*( ) 29.8 * 2.3 = 172 lb/yr = 29.8 lb/yr = 69 lb/yr MWPS worksheet Form 7;

13 Dietary phosphorus intake on excretion P excretio on (g/d d) Y = x x ; r 2 = P intake (g/d) Meyer and Trenkle, Iowa State

14 Nutrient Balance of a Commercial Feedlot A commercial feedlot in South-Central Kansas with a capacity of approximately 35,000 cattle was used from November 2005 to May Within the feedlot, 8 adjoin ing pens were used for data collection. Data included daily head co ount, BW weight, ration ID, and amount of feed delivered. All pens were cleaned uniformly at the beginning g and conclusion of the experiment with weights of removed manure recorded by pen. DeRouchey et al., 2007

15 Feedlot Nitrogen Nutrient Balance 1 Item, N intake, g/hd/d N retained, g/hd/d N excreted,,g/hd/d N harvested manure, g/hd/d N lost, g/hd/d Mean SD N lost, % of excreted Represents 8 pens in a 35,000 capacity feedlot from November 2005 through May 2006 in south-central Kansas. 2 Referenced value from Kissinger et al. (2007). DeRouchey et al., 2007

16 Feedlot Phosphorus Nutrient Balance 1 Item, P intake, g/hd/d P retained, g/hd/d P excreted, g/hd/d P harvested manure, g/hd/d P lost, g/hd/d Mean SD b P lost, % of excreted Represents 8 pens in a 35,000 capacity feedlot from November 2005 through May 2006 in south-central Kansas. 2 Referenced value from Kissinger et al. (2007). DeRouchey et al., 2007

17 Summary of Feedlot Nutrient Balance Phosphorus and Nitrogen retention of feedlot cattle were 19.7% and 13.3% of the feed nutrients fed to feedlot cattle, respectively. Significant amounts of nutrient excretion relative to nutrient intake levels occur in feedlot cattle.

18 Land requirements for solid manure application based diet composition 1,000 hd feedlot (2,3 81 hd / yr fed) 147 feeding period; occupied 350 d / yr 780-1,300 lb BW 3.5 ADG and 6.0 F/G Fed either 0 or 30% WDGS 0.28% or 0.50% dietary P, respectively 90% of the P excreted was recovered Continuous corn (175 bu)

19 Land requirement for corn-based diet Cattle fed corn based diet will excrete approximately 28 lb of P 2 O 5 per space 28 * 0.90 (recovered) = 25 lb P 2O 5 per space 25 lb * 1,000 spaces = 25,000 lb P 2 O 5 / yr 1 acre 175 bu corn = 58 lb P 2 O 5 / yr 25,000 / 58 = 431 acres required to balance excretion with crop uptake (assumes 100% P 2 O 5 available for crop use)

20 Land requirement for corn-based diet Approximately 1,300 ton ns of scraped manure will be collected from 1, 000 feedlot spaces Practically 15 tons per acre (equal to one load) is minimum amount thatt should be spread 19 lb P 2 O 5 per ton of manure 1,300 tons / 15 tons per load = 87 acres required each year to spread manure onto crop ground

21 Land requirement for corn-based diet Agronomic basis = 431acres Only spread 3.1 tons per acre (not practical) 58 lb P 2 O 5 required / 19 lb P 2 O 5 per ton Practical spreading basis = 87 acres 15 ton per load * 19 lb 285 lb P 2 O 5 per acre applied Enough P 2 O 5 for 5.4 ye ears P 2 O 5 per ton

22 Land requirement for corn-based diet Bottom line acres is needed to balance excretion and plant uptake in this scenario Not all fields receive manure each year Need to supplement manure application with commercial N fertilizer r per soil tests and nitrogen crediting

23 Land requiremen nt for 30% WDGS Cattle fed 30% WDGS will excrete approximately 69 lb of P 2 O 5 / space 69 * 0.90 (recovered) = 62 lb P 2O 5 per space 62 lb * 1,000 spaces = 62,000 lb P 2 O 5 per yr 1 acre 175 bu corn = 58 lb P 2 O 5 per yr 62,000 / 58 = 1,069 acres required to balance excretion with crop uptake (assumes 100% P 2 O 5 available for crop use)

24 Land requiremen nt for 30% WDGS Approximately 1,300 ton ns of scraped manure will be collected from 1, 000 feedlot spaces Practically 15 tons per acre (equal to one load) is minimum amount thatt should be spread 48 lb P 2 O 5 per ton of manure 1,300 tons / 15 tons per load = 87 acres required each year to spread manure onto crop ground

25 Land requiremen nt for 30% WDGS Agronomic basis = 1,0 069 acres Only spread 1.2 tons per acre (not practical) 58 lb P 2 O 5 required / 48 lb P 2 O 5 per ton Practical spreading basis = 87 acres 15 ton per load * 48 lb 720 lb P 2 O 5 per acre applied Enough P 2 O 5 for 12.4 years P 2 O 5 per ton

26 Land requiremen nt for 30% WDGS Bottom line.. 1,069 acres is needed d to balance excretion and plant uptake in this scenario Not all fields receive manure each year Need to supplement manure application with commercial N fertilizer r per soil tests and nitrogen crediting

27 Balancing Manu ure Applications Balancing field phosphoruss levels is important to long term manure application Liquid vs solid manure application Designated fields not to excessively build liquid application fields with solid manure applications Fertilizer cost savings Avoiding excessive application when acres are available Is over application of manure really that bad? How much and how often has it occurred previously? What is the soil P test? What is the soil loss risk? P Index rating? Use of high nutrient uptake crops

28 What are altern native options? Greater transportation of manure Is it economical to haul manure further? Manure export Are your neighbors comfortable with manure use? Do your neighbors unde rstand the value of manure? Can you add economic value to manure by feeding high phosphorus p containing ingredients?

29 Inputs Our Ultimate Goal Bl Balance of fi inputs & managed outputs Feed Animals Irrigation Water Fertilizer Legume N Crops Losses or Soil Storage Manure Farm Boundary Managed Outputs Meat & Milk Crops Manure

30 Diet Impacts Nutrient Excretion and dagronomi c Land Needs Dr. Joel DeRouchey Extension Livestock Nutrition and Environmental Specialist Department of Animal Sciences and Industry