Meshing Feed Input and Manure Output
Jane Messenger
| Tuesday, June 11, 2002
In pork production there are inputs, and there are outputs. Swine diets are the perfect example.
Attention to detail is essential when formulating swine diets since the pig must use or excrete every nutrient. Today, manure content is being scrutinized even further with the onset of new national environmental regulations.
As part of the pending Environmental Protection Agency rules, many of you will be required to submit a Comprehensive Nutrient Management Plan. To assist with the process, USDA's Natural Resource and Conservation Service is working to help producers develop and implement CNMPs, part of which involves feed management. Alan Sutton, animal scientist at Purdue University, recently spent six months in Beltsville, Md., working with NRCS on CNMP recommendations.
"When you're talking about CNMP's, its more than just manure land application," says Sutton. "As a beginning point, you should look at the feed component and see how it can reduce potential imbalances within the operation. Then we can follow through with proper manure management programs," says Sutton.
"Our goal is to look at feed management options to help producers voluntarily reduce excess nitrogen and phosphorus in hog manure while maintaining animal health and productivity, as well as profitability of the operation," says Tom Christensen, director of NRCS' Clean Water and Animal Husbandry programs.
Maintaining profitability is, of course important, since 60 percent to 75 percent of a pork operation's overall costs is feed, points out Gretchen Hill, Michigan State University animal scientist. Reducing or stabilizing those costs can pay off with your manure management program.
"Phosphorus and nitrogen are the keys," notes Sutton. Normal feed ingredients such as protein sources don't have the right balance of amino acids, and have an influence on excretion odors. Also, we need to do all we can to minimize phosphorus excretion."
One option that's becoming more popular is to use the feed supplement phytase to reduce phosphorus output. There also are other enzymes being developed to reduce phosphorus and nitrogen excretions.
Another possibility is using genetically modified grains, which Sutton believes will be a valuable asset. "If we can develop feed ingredients that more closely meet the animal's nutritional needs, it will be easy for producers to use this in pig diets," he notes.
Sutton advises that you have feed ingredients chemically tested on a routine basis to make sure they're on target and that you're not under feeding or over feeding pigs.
Besides making adjustments to the feed, Hill points out how important it is to match nutritional feeding practices with the pigs' genetics. "It's a win-win situation on the production and environmental side in terms of reducing costs," she says. You can start with feed management standards, but you need to hone those to your specific operation to match your genetics and management style.
"Many good producers are fine-tuning rations, but many still haven't made changes to minimize excretion values," says Sutton. "Some producers may have as efficient of a feed-management program as they can get."
So, how does your feed management program measure up? Take a look at these management strategies that Sutton and NRCS came up with to reduce manure nutrient excretions and odors.
- Implement feed manage-ment techniques, such as phase feeding, split-sex feeding or processing feeds, that match the diet to the pigs' needs, while maximizing nutrient retention and reducing manure excretion.
- Formulate diets based upon available nutrients in the feed ingredients. You or your nutritionist should use the National Research Council nutrient requirements as a guide to formulate swine diets. Adjust diets based on specific genetics.
- Reduce the crude-protein level and add synthetic amino acids.
- Reduce supplemental phosphorus and add phytase to reduce phosphorus excretion.
Once you reduce the nutrient excretion from the pigs' manure, you'll benefit in a number of ways:
- It requires less land base for manure application per animal unit. This may provide you with an opportunity to balance the nutrients for your entire operation.
- You may be able to apply higher rates of manure volume per acre of land to meet agronomic rates for crop production. This may result in less labor and fuel costs for manure land application.
- Reduced nitrogen and sulfur excretion results in reduced odors.
- Lower volumes of manure production will reduce manure storage requirements and increase timing flexibility of manure land application.
"Bottom line, if we can do some things to reduce nutrient excretion and better utilize feed ingredients to be cost effective, we'll come up with some real benefits to maintain productivity," says Sutton.
"When it comes to the environment, your choice is going to be do it right or get shut down," adds Hill. "It's the way of the future."
Spelling Out Best Feed Management Practices
There are several best-management practices to consider as you adjust your feed program. Of course, these are based on economic considerations, goals of your operation and available management.
Here are some possible recommendations:
A. Diet Composition: Thoroughly evaluate diet content and reduce excessive nutrient levels. Check the ratios or relationships of different nutrients to each other. Implement a routine, chemical feed-analysis program to adjust for nutrient level changes.
B. Diet Processing: Apply stringent quality control for feed preparation or require that your feed dealer does this. Review processing techniques – pelleting, grinding, other methods – to improve nutrient availability and utilization.
C. Diet Formulation: Formulate diets based on "available nutrients" from the different feed sources. Use high-quality protein sources with superior amino acid balance or reduce protein levels and supplement with synthetic amino acids. Select feeds with high digestibility and bioavailability. Consider using specialty feeds if economical and available.
D. Animal genetics and physiology: Determine the age, sex and physiological state or role of the pig (market vs. breeding) to match its specific dietary needs. You need to match the pigs' genetic potential with the diet formulations. You also should obtain animal weight-gain data and carcass evaluations.
E. Feed management techniques: Consider implementing practices like split-sex feeding, phase feeding and installing proper feeders/feeding systems. Also important to overall performance is to decrease building gases and dust; adjust and clean feeders frequently and record feed usage.
F. Feed additives: If appropriate and economical, add phytase and fiber-degrading enzymes; add small amounts (5 percent to 10 percent) of fiber.
G. Other management techniques: Minimize feed and water waste; consider using wet/dry feeding systems; keep pigs comfortable and healthy; always supply adequate fresh water.
Source: Alan Sutton, animal scientist, Purdue University; Gary Allee, animal scientist, University of Missouri; Gretchen Hill, animal scientist, Michigan State University; Wendy Powers, animal scientist, Iowa State University.
Cutting Out Unnecessary Nutrients
How much nitrogen and phosphorus excretion can reduce your by diet manipulation? There are some potential reductions by as sited by the Natural Resource and Conservation Service and Alan Sutton, Purdue University:
- Formulating diets closer to the requirement reduces both nitrogen and phosphorus by 10 percent to 15 percent.
- Reducing protein/amino acid supplements reduces nitrogen by 20 percent to 40 percent.
- Use highly digestible feeds to reduce nitrogen by 5 percent.
- Use phytase with a reduced phosphorus supplemental diet to reduce nitrogen by 2 percent to 5 percent and phosphorus by 20 percent to 30 percent.
- Use phytase with a reduced phosphorus supplemental diet and highly-available P corn to reduce nitrogen by 2 percent to 5 percent and phosphorus by 40 percent to 50 percent.
- Use protein/carbohydrate enzymes to reduce both nitrogen and phosphorus by 5 percent.
- Use growth promotion additives to reduce both nitrogen and phosphorus by 5 percent.
- Phase-feeding program reduces nitrogen and phosphorus by 5 percent to 10 percent.
- Split-sex feeding program reduces nitrogen by 5 percent to 8 percent.
- Review feed grind/pelleting to reduce manure excretion by 20 percent to 24 percent and nitrogen excretion by 5 percent.
- Use organic or chelated minerals, which may reduce mineral (zinc, copper, selenium, manganese) excretion by about 15 percent to 50 percent
- Paylean addition can produce a 15 percent reduction in nitrogen excretion for 28 days.
Of course, the results from these practices are not additive, but the more of them that you can implement the greater your final environmental benefit.
