Soil Mircobial Populations, Community Compostion, and Activity Affected by Repeated Applications of Hog and Cattle Manure in Eastern Saskatchwan

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A field site near Humboldt, Saskatchewan, was annually treated with hog or cattle manure and cropped to canola, spring wheat, barley, and canola from 1997 to 2000. During each growing season, soil was analyzed for microbial populations in terms of activity and community structure, and crops were assessed for root rot and foliar diseases. Microbial activity in soils treated with cattle manure was higher than in soils treated with hog manure or urea. Similarly, nitrous oxide emissions from soil increased with increasing rates of hog and cattle manure. Potential human pathogens, including Rahnella, Serratia, Proteus, Leclercia, and Salmonella species, were identified in soils that received cattle manure, whereas pseudomonads were the dominant species in the hog-manure-treated soil. Fecal coliforms were confirmed in soils that received hog or cattle manure. However, Enterobacteriaceae populations were 10-fold higher in soils receiving cattle manure than in soils receiving the other treatments. Increasing cattle manure rates increased fecal coliform population, but there was no indication that increased hog manure rates increased fecal coliform populations. Addition of urea, hog manure, or cattle manure to the soil did not increase foliar disease in wheat, barley, and canola and had variable effects on root rot incidence in cereals.

Odor Overview

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This report focuses on building odor emissions and ways to control it, as it seems to rank high for frequency, duration and offensiveness of odor. Maintaining cleanliness throughout the building is one method to reduce odor. For new buildings, specific designs may lower emissions: flushing gutters, limited surface gutters or solid manure management systems.
One method suggests confining manure storage within the building, in a single area. The exhaust air from this area will then be put through a biofilter prior to discharge into the outdoors.
Dust particles are also odor carriers. Removing these particles from ventilation air can effectively result in reduced odor emissions. In a preliminary study, odor reductions of 50-90% were seen between the inlet and outlet of the filter when dust removal varied between 45-75%. To reduce dust, regular cleaning and maintenance is necessary, as is oil/water spraying.
Reduction in crude protein content of the diet has the ability to reduce the concentration of selected odorous compounds. It is the cost of this method that makes it more unpopular.
Different techniques have been used to control odor as the air comes out of the building. Biofilters and bioscrubbers or wetscrubbers are some of these technologies, with biofilters having the most potential.
In conclusion, if the barn is kept very clean, the manure is removed as often as possible, an efficient dust control technique is implemented and multiphase feeding programs are used, odor emissions from the building are likely to be maintained at an acceptable level. More techniques, design and methods are being researched all the time.

Effect of Micronization of Peas and Enzyme Supplementation on Nutrient Excretion and Manure Volume in Growing Pigs

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Cost of remediation of nitrogen-contaminated soils under cafo impoundments

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Manure Management Systems – Biogas Systems

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With the rise of industrial-scale hog operations come problems of foul smelling odour, ground and surface water pollution, and uncontrolled methane emissions. The creation of biogas plants has helped to address these problems. The biogas plant in Germany is capable of treating about 100,000 tons of organic waste each year and transferring it into heat and electricity. The basis behind this development is the theory behind the Renewable Energy Sources Act of the German Federal Government, which is “…to facilitate a sustainable development of energy supply in the interest of managing global warming and protecting the environment and to achieve a substantial increase in the percentage contribution made by renewable energy sources to power supply.” As far as Canada goes, we need to be concerned about surface and groundwater contamination, odour created from storage and spreading of manure, and emissions of methane and nitrous oxide as greenhouse gases. The need to find efficient and cost-effective manure management solutions are a priority. Incorporating an IWMS (Integrated Waste Management System) into a livestock operation will allow excess organic waste to be turned into resources that produce renewable energy, organic fertilizer, and reusable water. This IWMS involves wastewater treatment as well as aerobic and anaerobic digester systems. The anaerobic system holds decomposed manure under oxygen-free conditions that promote naturally growing bacteria that digest manure. Methane produced from this can be captured as an energy source. Treatment could also involve aerobic digestion that will digest manure solids into compost fertilizer to market to farmers or gardeners. Livestock producers who set up this system can receive economic benefits from organic nutrients, offset greenhouse gas emissions, and eliminate adverse environmental impact, and create a sustainable business model for future farm generations. The analysis of a plant in Lethbridge shows that an IWMS is an economically viable solution for the Canadian agriculture community.

Effect of covering pig slurry stores on the ammonia emission processes

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Nitrogen Distribution in Soils of Constructed Wetlands Treating Lagoon Wastewater

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MANAGING MANURE: New Clean Water Act Regulations Create Imperative for Livestock Producers

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Nutrients from livestock and poultry manure are key sources of water pollution. Since regulations for livestock and poultry operations under the 1972 Clean Water Act were first developed, operations in general have become more concentrated and specialized. Ever-growing numbers of livestock and poultry per farm and per acre have increased the risk of water pollution, with manure being disposed of in ways not adequately addressed in the original regulations. In 2001, the Environmental Protection
Agency (EPA) proposed new regulations that would compel operations with the largest number of animals to manage their manure according to a nutrient management plan. These regulations were signed by the
Administrator of EPA on December 15, 2002, and are expected to be implemented in 2003. The new regulations were called for in the Unified National Strategy for Animal Feeding Operations, developed jointly in 1999 by USDA’s Natural Resources Conservation Service and EPA. The Strategy outlined USDA and EPA actions to minimize water quality and public health impacts from improperly managed animal
manure. Much of the Strategy’s focus was on the largest animal feeding operations. For smaller operations, a nutrient management plan would be recommended but not required.

Variation in Feed Quality: What To Do When It Declines

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Introduction
Feed ingredients, such as barley and wheat, vary substantially in quality. If the variation in ingredient quality is ignored, the quality of finished feed may vary, resulting in changed feed intake and/or reduced growth performance. Feed ingredient quality is thus a nutritional and economic concern in the pork industry, especially the quality differences that are related to energy intake or protein deposition. Feed ingredient quality is related to its chemical composition and not to physical characteristics (bushel weight). Thus, ingredient chemical characteristics should be analyzed regularly. Analyses can be considered an investment to ensure a predictable growth performance.
Variation in ingredient quality has become increasingly important for the pork industry, because minimizing the differences between actual and calculated quality of finished feed helps to achieve a predictable performance. Diets are formulated using least-cost diet formulation, and safety margins have been included to guarantee minimum dietary nutrient levels. These margins could be reduced if ingredient quality is monitored properly. Analyses or predictions of nutrients with the greatest impact on diet cost or performance (energy, amino acids) is the most effective way to manage variation in ingredient quality, and will likely provide a high return on investment.

Variation in feed quality
Feed ingredient quality is now defined as digestible nutrient content rather than total nutrient content. Most swine nutritionists in western Canada use digestible energy (DE) and digestible amino acids to describe ingredient quality. The nutritional value of ingredients is a function of their digestible nutrient content and the pig’s voluntary feed intake (VFI).
For cereal grains, DE is the most valuable nutrient. Variations in the DE content of western Canadian wheat (range of 630 kcal/kg) and barley (range of 450 kcal/kg) can be large, due to changes in the grain’s energy digestibility. In the last decade, we have related changes in the DE content of wheat and barley to changes in their fibre or non-starch polysaccharide (NSP) content (Zijlstra et al. 1999; Fairbairn et al., 1999). Based on the relations, we have developed equations that predict the DE content for barley and wheat based on their chemical characteristics.

Prediction of wheat DE. Our best equation for the prediction of wheat DE content on a dry matter (DM) basis was based its fibre (neutral detergent fibre; NDF) and protein (CP) content:
DE (DM) = 3,584 + 38.3 x CP (DM) – 16.0 x NDF (DM) (R2 = 0.75)

Prediction of barley DE. Our best equation for the prediction of barley DE content on a DM basis was based on its fibre (acid detergent fibre; ADF) content:
DE (DM) = 3,918 – 92.8 x ADF (DM) (R2 = 0.85)

Use of prediction equations. Theoretically, prediction equations are only valid for the range of chemical characteristics used to create the equation. Some wheat samples from the 2002-harvest have a unique combination of chemical characteristics (CP and NDF) that have not been measured before. Thus, the existing equations to predict the DE content of wheat based on CP and NDF may not be valid for a large portion of the 2002-harvest. The 15 wheat samples used to create the original prediction equations (¨) have a lower CP and NDF contents than some samples from the 2002-harvest (à) (Figure 1). Thus, the existing prediction equations should be used cautiously. Barley and wheat samples from the 2002-harvest should be analysed for their chemical characteristics and DE content in grower pigs to validate and improve upon these prediction equations.

Origin of variation in DE. Barley and wheat available in western Canada vary substantially in their nutritional value. For example, the DE content of 20 barley samples ranged from 2,700 to 3,100 kcal/kg, a range that cannot be explained by the samples’ gross energy (GE) content (Figure 2). The range in wheat or barley DE content is therefore mostly due to a change in energy digestibility. A current hypothesis is that a reduction in DE content or energy digestibility is partly due to higher fibre levels. Consequently, low quality grain samples might therefore be more responsive to treatments that enhance energy digestibility.

Voluntary feed intake. Apart from ranges in DE content, a range of feed intake has been described for Australian wheat in weaned pigs (Cadogan et al. 2000) and western Canadian wheat in broiler chicks (Swift et al. 1998). A range of energy digestibility exists for western Canadian wheat (Zijlstra et al. 1999); however, the range in energy digestibility is not related to changes in feed intake in weaned pigs (Cadogan et al. 2000) or broiler chicks (Swift 1998). The existence of a range of feed intake and energy digestibility in western Canadian wheat fed to weaned pigs has not been confirmed to date. A recent study using 12 Canadian wheat varieties organized into 2 varieties in 6 wheat classes did not show a range in feed intake or growth performance for weaned pigs. However, the wheat samples included in this study did not differ much in fibre content and thus quality (Zijlstra et al. 2003).

Economic implications of ingredient quality
The economic implication of variation in feed ingredient quality was calculated for two scenarios.
Scenario 1. A change in quality will change the economic value of the ingredients. For wheat, the economic impact of a 5% change in the digestible lysine (dLYS) or DE content was calculated for grower pigs. Lysine-HCl (78% dLYS; $2.45/kg) and canola oil (8,800 kcal DE/kg; $0.89/kg) were considered as purified sources of dLYS and DE. Assuming that wheat has a mean nutritional value of 0.29% dLYS and 3,425 kcal DE/kg, a 5% difference in these nutrients will be 0.15 kg dLYS in a tonne of wheat and 171 kcal DE in a kg of wheat. The economic value of the 5% difference is per tonne of wheat is:

For dLYS: (0.15/780) * $2,450 = $0.47/tonne
For DE: (171/8,800) * $890 = $17.29/tonne

The higher economic value for the change in DE compared to digestible lysine verifies that the greatest cost-pressure with least-cost diet formulation is against dietary DE content (Zijlstra et al. 2001).

Scenario 2. If changes in energy content are ignored, pig performance may be affected. An unaccounted for reduction in dietary DE content and thus DE intake may reduce gain if feed intake is not increased, or may reduce feed efficiency if feed intake is increased to maintain the DE intake. The following estimates of costs were made for a 7% reduction in DE intake, using data from an energy intake study.

A reduction in gain of 70 grams per day results in pigs that are 8 kg lighter at slaughter after 16 weeks in the grower-finisher barn. The lower body weight at marketing would result in a loss of $10.56 per pig sold, assuming a market price of $1.50/kg and an average index of 110.

An increase in feed intake of 7%, to compensate for the reduced dietary DE content, may increase feed conversion by 0.2 kg feed per kg gain, which would increase feed costs by $2.95 per pig sold.

Change in diet formulation
Reaching a predictable performance is important to maximize net income. But to reach a predictable performance the actual diet DE content should be close to the calculated diet DE content. Thus, diet formulation must be adjusted with a decline in feed ingredient quality. Thus, low quality grains can be used effectively in swine diets, considering:

Ingredient DE content has been predicted using chemical analyses (or perhaps NIRS);

The ingredient specifications have been altered during least-cost diet formulation;

The diets have been re-formulated to ensure that the dietary DE content required for a predictable performance is met. For example, if the predicted barley DE content is lower than the average book value for barley DE, additional energy in the form of canola oil or tallow should be added to the diet to ensure that that actual dietary DE content is at the desired level.
Only then can the grower-finisher pig achieve the energy intake required to maintain protein deposition.

Value-added processing
As discussed previously, the variation in barley or wheat DE content is mostly due to a change in energy digestibility and not a change in gross energy. A decrease in energy digestibility has been linked to an increase in fibre content (Zijlstra et al. 1999; Fairbairn et al., 1999). Therefore, ingredient or diet processing techniques that increase energy digestibility might add nutritional and economic value to low quality wheat or barley. Value-added processing of low quality ingredients might include reducing particle size by grinding more finely (Oryschak et al 2002) or supplementation of fibre-degrading enzymes (Zijlstra et al. 2000).
Regular grinding results in a mean particle size of 700 to 900 microns; however, there may be merit in reducing the particle size of low quality grain to 600 microns or below. Due to the higher fibre content in low quality wheat or barley, supplementation of enzymes to digest fibre might be more beneficial in ingredients with a low or normal DE content compared to ingredients with a high DE content. The impact of value-added processing should be validated using the 2002-harvest, although some indication can be given for the expected improvement in DE content using value-added processing (Zijlstra et al. 1998),

Summary
The 2002-harvest in western Canada was poor. The amount harvested was below average and contained a large proportion of low quality grains. This manuscript focused on determining wheat and barley quality and the possible actions to take after identification of low quality grain. Possible actions include changing diet formulations and/or using value-added processing.

Implications
The quality of low quality grains, especially their DE content, may be predicted using equations based on chemical characteristics. The existing prediction equations should be used cautiously for now, and be validated using the 2002-harvest. Changing diet formulation might allow the use of low quality ingredients by introducing a larger portion of energy-providing ingredients. Value-added processing might further increase the effective use of low quality wheat or barley in swine diets, because their DE content will be increased and a lesser amount of expensive energy-providing ingredients will have to be included in the diet to meet the desired dietary DE content. Low quality wheat or barely may form a large proportion of the diet; thus, accurate prediction of their DE content is important. Further flexibility may be introduced by reducing the proportion of low quality grains in the diet and by including a number of other ingredients.

Effect of wheat sample, particle size and xylanase supplementation on energy digestibility of wheat fed to grower pigs

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The feed processing procedures grinding and enzyme supplementation were tested to reduce the existing variability in DE content of heat. Particle size reduction and xylanase enzyme supplementation increased energy digestibility of wheat and partially reduced the variation in energy digestibility.