MLMMI - Manitoba Swine Nutrition 2013 Survey Page 1

Transcription

1 MLMMI - Manitoba Swine Nutrition 2013 Survey Page 1

2 Table of Contents Executive Summary... 3 Objective... 4 Background...4 Methods...6 Factors Affecting Swine Feed Formulation Nutrient Bioavailability.8 2. Feed Additives Feed Ingredient Quality Safety Margins Nutrient Interaction Stage of Production Government Regulations Manure Management 14 Summary and Recommendations Acknowledgements References Appendix A -Excerpt from Table 4 from the federal Feeds Regulation, 1983 ( CFIA Table 4 )..17 Appendix B - Standardization Appendix C:Tables.19 Table C1: Standardized Feeding Phases.19 Table C2: Stages of Production for Swine Feed Related to Phosphorus.20 Table C3: Feed Phosphorus Levels Recommended by NRC..21 Table C4: NRC 1998 and2012 Recommended Phosphorus Levels. 21 Table C5: Standardized Survey Responses for Crude Protein.22 Appendix D - Detailed Survey Responses and Copy of Survey...22 MLMMI - Manitoba Swine Nutrition 2013 Survey Page 2

3 Manitoba Swine Nutrition 2013 Survey Executive Summary The Manitoba Livestock Manure Management Initiative (MLMMI) undertook this survey of Manitoba swine nutritionists in 2013 to establish a baseline of current nutrient levels in swine rations. Decreasing the levels of phosphorus (P) in pig diets reduces the level of P excreted in manure and, therefore, lessens P accumulations on farms. Establishing a baseline of current nutrient levels can be used as a starting point in understanding whether there is an opportunity to reduce P levels in Manitoba swine feed formulations. This information is important in providing a comparison of current P levels in Manitoba swine feeds to National Research Council (NRC) recommendations and Canadian Food Inspection Agency (CFIA) regulated P levels. A major driver for the survey is the full implementation in 2013 of the Livestock Manure and Mortalities Management Regulation (Province of Manitoba, 2009), which supports and legislates the management of manure as a source of P. Publications such as the U.S. Pork Center of Excellence National Swine Nutrition Guide (2010) and the National Research Council s 2012 Nutrient Requirements of Swine reflect recent advances in swine nutrition. The National Swine Nutrition Guide lists 16 factors, which affect nutrient formulation. This report deals with eight of these factors, namely: Nutrient bioavailability; Feed additives; Feed ingredient quality; Safety margins; Nutrient interactions; Stages of production; Government regulations; and Manure management. The report presents findings for each of these eight key factors, using responses from the completed surveys (a complete list of questions and responses can be found in Appendix D), along with additional, candid responses offered by respondents during the interviews. In addition, the report offers recommendations for making meaningful change. While the report does not specifically address economics, survey responses indicate that economics is a major factor in decisions made by nutritionists and producers with respect to how swine are fed. For example, while Dried Distillers Grains and Solubles (DDGS) contain high levels of P, they are nevertheless widely used because they are in large supply and relatively low in cost. Key findings of the survey were: Many nutritionists stated that CFIA Table 4 is a significant impediment to lowering P levels in the feeds they formulate. There are significant differences in the levels of P found in feeds produced by various formulators and P could be reduced in some rations before reaching minimum limitations set out in NRC and CFIA Table 4. Nutritionists recognize that there are continuous advances in the field of feed formulation and have expressed interest in learning about Standardized Total Tract Digestibility (STTD). MLMMI - Manitoba Swine Nutrition 2013 Survey Page 3

4 Recommendations coming out of this survey are: That MLMMI use the results of the survey as a platform to communicate key messages and increase understanding amongst producers, veterinarians, nutritionists and regulators of the link between nutrition and P levels in manure of all livestock.. That MLMMI recruit a swine nutrition expert to make presentations on STTD and provide resources to support nutritionists in implementing STTD. That a nutrient characteristics database be created for ingredients most commonly used by the Manitoba feed industry (particularly for ingredients that are fed more commonly in the Prairies than elsewhere like field peas, and for ingredients that often have significant variability like DDGS) to assist nutritionists to formulate for P more precisely and possibly at lower levels. Nutritionists recognize that P-enriched manure is a problem for some producers, particularly those operating in livestock intensive regions. If more efficient formulation of P in swine diets is not achieved the survival and growth of the swine and feeds industries in certain areas could be in jeopardy. Most feed companies consider this survey as a tool in helping producers address the issue of excessive P levels in manure. Some of the information in this report may appear to be repetitive. However, this only serves to emphasize the fact that manipulating P levels in swine diets interacts with many of the factors affecting nutrient formulation, and that reducing P in swine diets could significantly benefit every phase of the swine industry; from feed formulation to swine production to manure management. Objective The primary objective of this survey was to quantify the range of nutrient inclusion rates in Manitoba swine rations in order to better understand how they compare to National Research Council (NRC) and Canadian Food Inspection Agency (CFIA) Table 4 nutrients levels. An additional purpose has been to determine if opportunities exist for nutrient reduction, particularly phosphorus (P) reduction, in diets. The major drivers for the current study are: 1) commitments made during the 2009 Phosphorus Workshop held in Winnipeg; and 2) the full implementation in 2013 of phosphorus rules contained in the Livestock Manure and Mortalities Management Regulation (Province of Manitoba, 2009). Background Phosphorus (P) is one of the key mineral elements needed for skeletal development in swine. Inadequate P levels to meet physiological requirements can negatively impact animal health and development, particularly in today s fast growing swine where genetics have significantly shortened the growth cycle for pigs. However, excess P concentrations, when excreted as manure, can adversely affect land and water resources. The ongoing challenge is to strike a balance between providing essential nutrients to fully satisfy the genetic potential of swine at all growth stages, while addressing environmental issues. The problem of excess soil P is limited to certain areas of Manitoba. Soil P budgets for 78 rural municipalities (RMs) and four remote census of agriculture regions (CARs) in agro-manitoba were recently updated. In total, nine RMs were in a P surplus. Seven of these could achieve P balance by replacing synthetic P fertilizers with manure. When synthetic fertilizer was excluded from the MLMMI - Manitoba Swine Nutrition 2013 Survey Page 4

5 calculation, only two RMs had significant P surpluses due to livestock alone (Loro et. al 2013). For these parts of the province in particular, formulating livestock feeds for maximum P efficiency may be a key aspect of achieving a balance between soil P inputs and outputs. Determining P requirements of swine is a continually advancing science and recent publications use a high level of sophistication to provide P recommendations. For example, NRC 2012 has reviewed P requirements for sows and broken them down into gestation and lactation requirements and further defined these requirements with lower levels for early versus late gestation, and differing levels during lactation depending on daily weight gain of the nursing pigs. This is in contrast to an earlier understanding of the P requirement of sows published in NRC 1998 which maintains the value of 0.6% total P regardless of the stage of gestation or lactation. Canadian swine rations must comply with regulated minimum P levels as stipulated by CFIA s Feeds Regulation Table 4 (Government of Canada, 1983), which complicates balancing effective feed formulations with environmental concerns. In the absence of CFIA Table 4, the industry would formulate P based on animal needs, economics and environmental objectives. Legal requirements for feed companies to comply with outdated regulations that have not changed in more than 20 years is often cited by the industry as to why they do not formulate pig feeds with lower P levels. As a result, P is overfed in many cases relative to the animal s P requirements for optimum performance (Ramirez et al. 2012). For example, CFIA Table 4 mandates minimum P level for sows at 0.5% (Appendix A); whereas NRC 2012 indicates sow requirements are between 0.38% and 0.62%, depending on factors such as sow weight, anticipated litter size, and stage of gestation or lactation. CFIA is currently completing a review of its regulatory framework, including livestock feed regulations. 1 Economics is a key consideration in swine feed formulation since feed represents 60 to 70 per cent of the cost of production. Least-cost feed formulations may result in the use of ingredients that provide pigs with excess nutrients. For example, the ethanol industry has created a feed by-product - Dried Distiller s Grains and Solubles (DDGS)-which is a lower cost ingredient, but higher in both total P and digestible P than whole grains. While nutritionists recognize that P concentrations in rations with high amounts of DDGS can be above the CFIA regulated minimums, economics and customer demand for cheaper feeds may take precedence over lowering P concentrations. The addition of phytase to swine rations has proven to be a successful way to reduce the need for inorganic P in some swine diets. However, some nutritionists have limited confidence in using phytase to lower P concentrations. Their belief is that phytase may not always deliver as much available P as expected. For this reason, nutritionists will err on the side of caution and refrain from reducing inorganic P in their rations. Another promising tool to reducing P concentrations in feed is the Standardized Total Tract Digestibility (STTD) approach to estimating swine P requirements. The 2012 NRC STTD approach offers a more precise method of formulating P levels in feed compared to the commonly used available P method of NRC The STTD system has been successfully used in Europe where P impacts on the environment have been an issue. Further information on regulatory modernization can be accessed on the CFIA website, MLMMI - Manitoba Swine Nutrition 2013 Survey Page 5

6 Finally, conflicting information on the most appropriate dietary P levels also may be contributing to P levels that are higher than necessary. Veterinarians sometimes provide recommendations on P levels in diets that may be different than recommendations from swine nutrition experts or swine genetics companies. If swine producers experience herd health and performance issues and believe that dietary P is the potential cause, they will understandably demand increased P in rations. There are even differences of opinion among swine nutrition experts as to the lowest safe levels of P. Methods Manitoba swine feed formulators, including nutritionists and feed mill executives, were surveyed to determine how swine rations were formulated. Specific questions were asked about key aspects of formulating for P in swine rations, including questions on the following topics: Total and available P levels; Formulation tools and resources used to set P targets; The perceived efficacy of phytase to aid in P availability; Type(s) of phytase used; Amounts of phytase, inorganic P, calcium and crude protein used in formulations; Limitations to reducing P in formulations; and Safety margins used in setting P levels. In conducting the survey, care was taken to avoid biasing responses toward any particular formulation methods. Rather, every effort was made to convey to participants that the survey objective was to better understand how P formulations are currently being done in Manitoba, and, if opportunities exist within the feed industry, to improve the efficiency of P use in feed formulas. The data received from survey participants, while comprehensive, was unique to each respondent and differences in ration designs did not allow for easy analysis of the averages and ranges of nutrient content. Therefore, it was necessary to standardize results. Standardization helped to make variations in data consistent for the purpose of calculating and reporting P averages and ranges for the diets at the various stages of production. Table 1 shows the weight ranges assumed for the standardized nursery and grower/finisher phases. Specific information on the standardization process used for this survey can be found in Appendix B. Averages and ranges for data gathered in the survey can be found in Appendix C. Additional details of survey responses and a copy of the survey are presented in Appendix D. Table 1. Standardized feeding phases and assumed weight ranges for each phase. Feeding Phase Weight Range (kg) Nursery Nursery Nursery Nursery Grower Grower Finisher Finisher MLMMI - Manitoba Swine Nutrition 2013 Survey Page 6

7 Factors Affecting Swine Nutrient Formulation Animal nutrition is a complex issue with many factors coming into play. Figure 1 illustrates 16 key nutritional factors. The survey and this report address Manitoba nutritional practices with respect to eight of the factors. Each of these key factors is color-coded in the diagram, followed by key findings and applications. Although economics was not a key focus of the survey, economic considerations, nonetheless, greatly influence producers, nutritionists and feed companies in their choice of feed ingredients. Economics Feed Processing Nutrient Bioavailability Safety Margin Alternate Feedstuffs Feed Additives Gender Water Feed Ingredient Quality Health Stage of Production Nutrient Interaction Genotype & Productivity Feed Intake Government Regulations Manure Management Figure 1. Factors affecting recommended nutrient levels in swine feed Source: National Swine Nutrition Guide Preface MLMMI - Manitoba Swine Nutrition 2013 Survey Page 7

8 1. Nutrient Bioavailability Not all phosphorus (P) in plant-based feedstuffs is available to nonruminant animals and the amount of P that can be digested by pigs varies greatly by ingredient. Most of the P in grains is in the form of organic complex phytate, which is largely unavailable (indigestible) to the pig. It is more important for the nutritionist to know how much P is available rather than total P. Nutritionists rely on models to assist them in estimating available P to formulate rations. Recent advances in nutritionists understanding of a more accurate way to formulate for available P is identified as STTD in NRC Comparison of survey results to NRC 2012 is difficult due to the new STTD approach for estimating bioavailability of phosphorus used in NRC Accordingly, reference to NRC 1998 is frequently made in this report rather than to NRC2012 due to the lack of comparability of STTD methods and current practices for estimating available P. Key Findings: Various approaches are used by swine feed formulators for determining appropriate P levels in rations. All participants indicated that they based at least some rations on available P. None are formulated solely on the basis of total P. In some cases total P is used for rations, and some participants formulate P content based on digestible P. Few are using the STTD approach. There is a reasonably wide range of estimates for the available P content in major feed ingredients used by swine feed formulators in calculating rations Estimates of P availability in key ingredients were determined by nutritionists using the following sources; Feedstuffs, NRC 2012, Evapig, CVB 2007, INRA Edition, Tables of composition and nutritional value of feed materials, National swine nutritional guide, nutrition consultants, supplier specifications, laboratory analysis, research documents, enzyme companies promoting the release of P via phytase. Respondents commented that international estimates of available P in major ingredients (found in INRA, NRC, Feedstuffs, etc.) may not reflect regional conditions. Manitoba nutritionists are interested in improving their knowledge and understanding of STTD to improve diet formulations. Applications: 1. With Manitoba nutritionists expressing interest in learning about the Standardized Total Tract Digestibility model (STTD), which offers a more precise method of formulating nutrients compared to the available P method, a swine nutrition expert could be hired to make presentations on STTD, greatly benefiting the industry in Manitoba. 2. Further resources could be made available to aid nutritionists to modify their systems to the STTD model since not all feed mills have the staff and/or expertise to support a move to this new and better way of formulating feed. 3. Developing a nutrient profile of regional ingredients would provide nutritionists with improved access to ingredient testing. While this information may currently be available at the research level, it is not readily available to the feed industry. (note see Feed Ingredient Quality application #1) MLMMI - Manitoba Swine Nutrition 2013 Survey Page 8

9 4. Industry places primary importance on formulating to available P levels, whereas CFIA Table 4 expresses its regulated P levels as total P. The focus on total P in CFIA Table 4 is out of step with current industry practices. 2. Feed Additives Feed additives are included in swine rations for a variety of reasons. The focus in this survey considered additives that enhance the pigs ability to digest nutrients in feed to aid in growth. Supplemental phytase sources are commonly used to improve the digestibility of phytate phosphorus in plantbased feedstuffs. Various brands of phytase are used in Manitoba with differing units of measure for different products. Accordingly, reported usage of phytase may not be comparable between participants. Key Findings: Phytase is in broad use in Manitoba formulations. All formulators surveyed are using phytase in at least some of their diet phases, with a wide range of phytase inclusion rates being used. Low confidence in phytase efficacy among some nutritionists limits their willingness to lower P concentrations as much as may be possible. The high cost of phytase was mentioned as a limiting factor to lowering P levels. Applications: 1. The more nutritionists know about phytase, the greater the potential of managing P for maximum efficiency. 2. There may be an opportunity for phytase manufacturers to better convey information on the stability and efficacy of using phytase. 3. Feed Ingredient Quality Feed ingredient quality refers to numerous feed characteristics that, together, influence the ability of the feed to produce the desired effect on the animal. An example of feed ingredient quality affecting animal nutrition are the differences in P content of Dried Distillers Grains and Solubles (DDGS) depending on how it is produced. DDGS is a by-product of the ethanol industry, and there are considerable differences in the nutrient composition of DDGS depending on the plant producing the DDGS and even over time the same plant producing variations of DDGS if the manufacturing processes change. Due to processing, DDGS are higher in both total P and digestible P than whole grains. The higher level of available P in DDGS negates the need to use phytase in rations with elevated levels Key Findings: MLMMI - Manitoba Swine Nutrition 2013 Survey Page 9

10 Of all of the major swine feed ingredients, DDGS has the greatest variability in nutritionists estimates of available phosphorus levels. For corn DDGS the estimated range of available P content was ( %). Applications: 1. Creation of a nutrient characteristics database for ingredients most commonly used by the Manitoba feed industry could assist nutritionists to formulate for P more precisely and possibly at lower levels 2. More analysis and testing are required to accurately identify P levels in regionally available DDGS. This will need to be updated periodically, as processes in ethanol plants do change from time to time, and this can affect the available P in DDGS. 4. Safety Margins Safety margins account for variability in feeds and animals when determining levels of nutrients to allow for maintenance, growth, gestation and lactation. Safety margins are influenced by several factors, namely, animal health, compliance with minimum levels in CFIA Table 4, animal growth and productivity, variations in ingredients, and confidence in phytase efficacy. Key Findings: The majority of respondents indicated that either no safety margins were used or there were no set safety margins in place. Conflicting information on the most appropriate dietary P levels may be keeping P levels higher than necessary. These differing opinions are attributed to veterinarians, producers, swine nutrition experts, and genetics companies. The following list of survey responses attempts to capture the range of practices regarding safety margins: No surplus built in. No set margins, but typically 5%. No safety margins because P and other nutrients are included according to intake. Formulate to the average requirements on available phosphorus. Comparison to phosphorus usage practices in Europe. Recommendations in reference books. A range from 6-7% to 20% on Sow diets, 4-5% to 15% on starter diets, 4% to 10% on Finisher diets. Sow diets are fed with a safety margin of 10% and the other nursery, grower and finisher diets are close to requirements. Between.05 and 0.1 percentage point movement around total P in the diet. Applications: 1. Producers need to be better educated and informed about the consequences of overfeeding P and other nutrients. 2. Producers and nutritionists need to work together to improve understanding of what are essential ranges for P inclusion. MLMMI - Manitoba Swine Nutrition 2013 Survey Page 10

11 3. A better understanding of the stability of Phytase during feed processing is needed to enable nutritionists to formulate for lower P. 4. Manufacturers need to verify their claims as to the efficacy of phytase. 5. Nutrient Interaction s Interaction between the various components of a swine diet is one of the factors that have an impact on the bioavailability of nutrients. For example, there is a key interaction between P digestibility and calcium (Ca), since excess Ca in the diet may decrease the utilization of P. Therefore it is important that diets are formulated to provide adequate, but not excessive levels of Ca. Key Findings: Respondents indicated that many of their formulations include Monocal or Dical as inorganic P. As a percentage of the total ration, inorganic P averaged 0.4% for sow rations, 0.37% for nursery rations and 0.21% for finisher rations, with a general trend toward reduced inorganic P levels in feeder pig rations as weights increased. Some feed formulators do not add inorganic P to grower/finisher rations. Average Ca inclusion rates were 0.84% in sow rations, 0.72% in nursery rations and 0.59% in grower/finisher rations. A review of completed surveys found total Ca to total P ratios to range from 1:1 to 1.67:1. A suggested ratio of total Ca to total P for grainsoybean meal diets is 1:1 to 1.25:1 (NRC 2012). Applications: 1. Since Manitoba livestock diets often incorporate small grains (rather than solely relying on corn/soy), it would be beneficial to have small grain information on how to formulate calcium in diets to optimize P. 2. When determining calcium levels, total P levels need to be considered for optimum nutrition. A comparison of survey results to NRC recommendations suggests there may be situations where Manitoba swine diets are formulated with excess Ca. These diets should be re-evaluated to determine if Ca levels can be reduced, resulting in better utilization of P. 6. Stage of Production There are several stages of the pig s life cycle that affect feed formulation. The nutritional requirements of pregnant sows, nursing sows, weanlings and grow-finish pigs are unique. Nutritional needs will change even during the life cycles of each of these categories. For example, for nursery and grow-finish pigs, the percentage requirement for P decreases as the animal ages. Feed formulators address this through the use of phase-feeding for both nursery and finisher rations. Key Findings: MLMMI - Manitoba Swine Nutrition 2013 Survey Page 11

12 Average total P levels of sow diets (0.64 to 0.66%) are higher than the minimum allowed under CFIA Table 4 (0.5%), although the range of responses (0.48 to 0.83%) indicates some are formulating at or just below the 0.5% minimum regulated level. NRC 2012 indicates sow requirements for total P, when fed corn-soybean mealbased diets, are between 0.38% and 0.67%, depending on factors such as sow weight, anticipated litter size, and stage of gestation or lactation. The fact that the upper end of the range of responses from Manitoba formulators is above the NRC 2012 recommendations suggests an opportunity for some to reduce total P levels in sow rations. Average total P levels of nursery pig diets are only slightly higher than the 0.6 minimum allowed under CFIA Table 4, with a fairly wide range of total P levels (0.46 to 0.89%). These results indicate that some formulations are below the CFIA Table 4 requirement of 0.6%, whereas other formulations exceed CFIA Table 4 levels by a large margin. Recommendations for total P content from NRC 1998 and NRC 2012 range from 0.54% to 0.70% across the nursery feeding phases, when using corn-soybean mealbased diets, which is slightly lower than the survey averages of 0.63% to 0.71% for the four nursery feeding phases. Grower/finisher rations have the lowest total P content of any swine diets, and on average the Finisher 1 and Finisher 2 phases, which represent the largest amount of feed consumption, are below the CFIA Table 4 minimum requirement of 0.5%. The range of total P in Manitoba grower/finisher rations is from 0.30% to 0.79%, indicating that at least a few formulators have obtained CFIA clearance to reduce total P levels below the Table 4 minimum. Compared to the range of total P levels recommended by NRC 1998 and NRC 2012 for total P in corn-soybean meal-based diets across the grower/finisher phases (0.4% to 0.56%), the survey averages (0.45% to 0.57%) corresponded very closely. With respect to available P, the average available P levels targeted by Manitoba formulators are higher than the NRC 1998 recommendations for available P. For most diet phases even the lowest available P levels targeted are at least 10% above the NRC 1998 recommendations. For example, in the Grower 1 diet phase, the minimum available P level target reported in the survey was 35% higher than the NRC 1998 available P recommendation (0.31% versus 0.23%). Applications: 1. There is a possible opportunity for Manitoba feed formulators to formulate for lower P levels for most diet phases. The range of total P inclusion levels among formulators suggests that the largest opportunity for reducing total P levels may be in sow diets. However, there is also opportunity to reduce total P levels in nursery and grower/finisher rations to CFIA regulated levels as approximately 50% of responses were in excess of CFIA regulated minimum values for total P. Some formulators have obtained clearance to formulate below CFIA Table 4 values for specific customers. If the feed industry as a whole was able to formulate for total P at the lowest levels reported by formulators the potential to reduce total P in swine feeds could be large. 2. STTD was earlier identified in this report as an improvement in the way nutritionists estimate bioavailability of P and may be a tool to lower the total and MLMMI - Manitoba Swine Nutrition 2013 Survey Page 12

13 available P targets used by Manitoba formulators. STTD also offers benefits in formulating for the nutritional needs of the various phases of swine development. 7. Government Regulations Manure storage and application come under provincial regulation that governs the storage and land application of manure, whereas, minimum nutrient levels in animal feeds are prescribed federally by CFIA. The current minimum nutrient levels specified in CFIA Table 4 have been in force since While this survey and this report largely deal with conditions in Manitoba, other jurisdictions also have faced the question of how to balance economic benefits of their livestock sector and their impact on the environment through government regulation. It is recognized that Europe (especially the Netherlands) has been dealing with P issues longer than Manitoba. There is an opportunity to learn from them. Key Findings: Average total P concentrations in feed formulated for the Manitoba swine industry are close to CFIA regulated minimum levels. Eight of 11 respondents mentioned regulation or CFIA s table 4 as a limiting factor to reducing P levels in swine rations. The comment was made that regulated levels impact sow diets but not diets for other swine. For comparison, five respondents indicated that biological requirements or pig performance was a limiting factor. Most nutritionists do not see a need for CFIA Table 4 since feed formulations, technology, and markets are all dynamic, while CFIA Table 4 is static and inflexible. CFIA Table 4 regulates total P content of feed. However, current guidelines for nutritionists (e.g. NRC 1998, NRC 2012) are based on available or digestible P content of rations. Applications: 1. It is imperative that MLMMI join with regulators, the feeding industry, the swine genetics industry and most importantly hog producers in raising awareness of the limitations that CFIA Table 4 imposes on livestock formulations. CFIA Table 4 is the limitation most often cited by the feed industry in lowering P levels in swine diets. Federally regulated CFIA Table 4 is one of the factors that limit the industry s ability to comply with Manitoba s provincial goals to reduce P in animal manure. Raising awareness of the levels of P in Manitoba swine feed as determined by this study, and the connection to CFIA Table 4 as a limitation to P reductions is a crucial next step. CFIA currently is in the process of reviewing Canada s Feed Regulations 2 2 Further information on regulatory modernization can be accessed on the CFIA website, MLMMI - Manitoba Swine Nutrition 2013 Survey Page 13

14 8. Manure Management Manure can be very beneficial to soil as a source of both mineral nutrients and organic matter. A major limitation in optimizing the fertilizer value of manure for a crop is that the nitrogen (N) and P in liquid manure are seldom in balance with crop needs. If manure is applied annually to fully provide the crop s N requirements, P will build up in the soil over time, potentially to excessive levels. In areas of intensive livestock farming, where there is a limited land base, it is beneficial to minimize the level of P in liquid manure. There is no one size fits all approach to assessing nutrient balance that applies to all Manitoba farms. Each farm needs to evaluate the sources and uses of P in arriving at their P balance, and the P balance will dictate their manure management strategies. Reducing excess nutrients in livestock rations can be a cost-effective way to accomplish this. Key Findings: Participants in the Manitoba Swine Nutrition Survey are genuinely concerned about excess phosphorus in hog manure and potential ways to reduced P in swine feed. They are also interested in levels of P in the manure of other species. Applications: 1. MLMMI should use survey findings as a platform to communicate key messages and increase understanding amongst producers, veterinarians and nutritionists of the link between nutrition and P levels in manure of all livestock. In cases where P is accumulating in soil, reducing P levels in manure will require collaboration between feed formulators and producers. 2. While the process of selecting the correct ingredients to meet the nutrition needs of swine is a highly technical matter with many interactions, it is important that a strong focus is placed on industry education and awareness. Messages must be delivered in a user-friendly rather than at a technical level, reinforced through repetition, and conveyed using a variety of communication vehicles. MLMMI - Manitoba Swine Nutrition 2013 Survey Page 14

15 Summary and Recommendations This report outlines Manitoba nutritionists practices in formulating P in swine feed. Opportunities for improvements in formulating diets to P requirements have been identified throughout the report as applications. Following is a summary of some key conclusions. There is a possible opportunity for Manitoba feed formulators to formulate for lower P levels for most diet phases. Current P levels in many Manitoba swine rations are higher than CFIA Table 4 regulated minimum P levels and NRC recommended P levels. As this report has outlined, feed formulation is a complex matter influenced by such factors as economics, animal health and/or productivity considerations. The range of total P levels in Manitoba swine diets was found to be between 0.48% and 0.83% for sows, 0.46 to 0.89% for nursery pigs, and 0.36% to 0.79% for grower/finishers. With respect to available P, for most diet phases even the lowest available P levels targeted are at least 10% above the NRC 1998 recommendations. It is imperative that MLMMI join with regulators, the feeding industry, the swine genetics industry and most importantly hog producers in raising the awareness of the limitations Table 4 imposes on livestock formulations. CFIA Table 4 is the limitation most often cited by the feed industry in lowering P levels in swine diets. Since federally- regulated Table 4 limits the industry s ability to comply with Manitoba s provincial goals to reduce P in animal manure, the Province must work with the federal government to address this issue. With Manitoba nutritionists expressing interest in learning about the Standardized Total Tract Digestibility model (STTD), which offers a more precise method of formulating nutrients, a swine nutrition expert could be hired to make presentations on STTD, greatly benefiting the industry in Manitoba. Further resources could be made available to aid nutritionists to modify their systems to the STTD model since not all feed mills have the staff and/or expertise to support a move to this new and better way of formulating feed. Creation of a nutrient characteristics database for ingredients most commonly used by the Manitoba feed industry could assist nutritionists to formulate for P more precisely and possibly at lower levels. More analysis and testing are required to accurately identify P levels in regionally available DDGS. Developing a nutrient profile of regional ingredients would provide nutritionists with improved access to ingredient testing. While this information may currently be available at the research level, it is not readily available to the feed industry. (note see Feed Ingredient Quality application #1) Acknowledgements The Canada and Manitoba governments through the Growing Forward Strategic Innovation Fund- Advancing Innovation Program, a federal-provincial-territorial initiative, funded this project. Mr. Leonard Underwood played the key role of facilitating the survey and acting as the liaison with Manitoba s swine nutritionists. Virtually all Manitoba swine nutritionists and feed formulators participated in this survey and their contributions are acknowledged and greatly appreciated. ANAC Manitoba provided helpful suggestions on how to approach this project. We would also like to acknowledge the significant contributions made by Dr. Rex Newkirk, Dr. Martin Nyachoti and Dr. Mario Ramirez. MLMMI - Manitoba Swine Nutrition 2013 Survey Page 15

16 References Government of Canada Regulations Respecting the Control and Regulation of the Sale of Feeds (Feeds Regulations). viewed on August 28, Loro, P., Arzandeh, M., Brewin, D., Akinremi, W., Gyles, C., and Ige, D Estimating Soil Phosphorus Budgets for Rural Municipalities in Manitoba. Manitoba Livestock Manure Management Initiative. 33p. Province of Manitoba Livestock Manure and Mortalities Management Regulation. viewed on August 28, NRC Nutrient Requirements of Swine, 11 th ed. Natl. Acad. Press, Washington DC. NRC Nutrient Requirements of Swine, 10 th ed. Natl. Acad. Press, Washington DC. Ramirez, Dr. Mario, Young, Dr. Malachy, and Froese, Clarence Moving toward lower phosphorus levels in swine diets. Western Hog Journal Fall 2012: U.S. Pork Center of Excellence National Swine Nutrition Guide. MLMMI - Manitoba Swine Nutrition 2013 Survey Page 16

17 Appendix A Excerpt from Table 4 from the federal Feeds Regulation, 1983 ( CFIA Table 4 ) (Section 5) Range of Nutrient Guarantees for Complete Feeds1 for Use in the Exemption of Feeds from Registration FEED INTENDED FOR LIMITS CAL- CIUM (%) PHOSPHORUS (%) CHICKENS MIN. 0.6 (G) 0.4 (G) 0.7 (S) 0.5 (S,L,B) 2.75 (B) 3.25 (L) MAX. 1.2 (O) 1.5 (L,B) 6 (L,B) 1.2 (O) 2.5 (PL) TURKEYS MIN. 0.8 (O) (B) MAX. 2.5 (O) (B) SWINE MIN. 0.5 (O) 0.5 (O) 0.75 (LT,B) 0.6 (PS) 0.8 (PS) MAX. 2 2 B: Breeding G: Chickens 8-20 weeks of age; Turkeys 8 weeks to market; Swine kg body weight L: Layer chickens LT: Lactating NRS: No requirement specified O: Others PL: Prelayer chickens weeks of age PS: Turkeys 0-4 weeks of age; Swine 1-10 kg body weight S: Chickens 0-8 weeks MLMMI - Manitoba Swine Nutrition 2013 Survey Page 17

18 Appendix B - Standardization The standardization process took into account the amount of weight that a pig would gain in each area of production. During the nursery stage pigs gain approximately 21 kg and during the grow/finish stage pigs gain approximately 105 kg. These weight gains were then allocated to four nursery phases and four grow/finish phases of a standardized feeding schedule. Each phase was allocated a specific weight gain dependent upon the age/weight of the pig and the complexity of the ration. Nursery Phase 1 is typically a 2 kg gain spread. This allows for maximum gut adaptation and triggering of eating behaviour on an expensive diet. Once the piglets adapt to the solid food the step down to Phase 2 occurs. This spread is 3 kgs, though it may be as wide as 5 or as little as 2 kg. Phase 3 and Phase 4 of the nursery rations are structured around ever widening weight gains as both the cost and the digestibility of the ration decrease, as the pig is better able to digest and consume larger amounts of feed. The same holds true for the grow/finish stage. We selected 4 kgs as the starting point of the nursery stage as it allows coverage of all of the rations described by the survey participants. Following the average weight spreads we arrived at a fourphase program that ran from 4 kgs to 25 kgs. The recent movement in the industry towards heavier nursery pigs leaving the barn is reflected in this expanded endpoint. Similarly, today s heavier finisher weight is reflected in the wider weight gains we allocated to the grow/finish period, compared to what may have been standard weight ranges for feeding phases in past years (Table 1). The standardization of the weight classes resulted in overlaps in phases of the participant-provided rations and phases of the standardized ration. This overlap required that the participant-provided rations had to be adjusted to align with the standardized ration. This process was accomplished by allocating to each standardized ration phase the percentage of weight gain indicated in each portion of the participant-provided ration that overlapped. Or stated another way, we determined the total weight gain within a phase (for the standardized ration) and then calculated the percentage of that gain that overlapped with a particular phase of the participant-provided ration. In the Grower 1 phase in the example below the original weight range provided by the survey respondent was 22.5 to 40 kg and the total P concentration was 0.55%. Original weight Standardized range(kg) weight range (kg) Total P (%) Total P (%) Standardized for Grower 1 Nursery Grower (0.75*0.55)+(0.25*0.5)= Grower To determine what the P concentration for Grower 1 would be in the standardized weight classes we look at the weight gain in a particular phase. For example, the standardized weight gain for Grower 1 is 20 kg, from 25 kg to 45 kg. Of that 20 kg, the first 15 kg, or 75% can be understood to have a P concentration of 0.55% from the original Grower 1 phase, and the last 5 kg has the P concentration of 0.5% from the original Grower 2 phase. Therefore, the calculated total P concentration for Grower 1 in the standardized format would be 0.25 * * 0.5 = MLMMI - Manitoba Swine Nutrition 2013 Survey Page 18

19 Appendix C - Tables Table C1. Estimates of total P content (%) and P availability (% of ingredient comprised of available P) of key swine feed ingredients provided by survey respondents. Averages and ranges and of survey responses are presented. Total P content Available P content Average Range Average Range Corn Barley Wheat Corn DDGS Wheat DDGS Canola Meal Peas Meat & Bone Meal Monocalcium phosphate Dicalcium phosphate MLMMI - Manitoba Swine Nutrition 2013 Survey Page 19

20 Table C2. Standardized survey responses, shown as averages and ranges, for swine feed characteristics related to phosphorus for sow, nursery and grower/finisher rations. Total P (%) 1 Available P target 2 (% of ration) Assumed P availability of the ration before addition of phytase (% of ration) Estimated increase in P availability due to phytase (% increase) Phytase use, FTUs/kg of Inorganic P (% feed 3 of ration) Calcium (% of ration) Avg Range Avg Range Avg Range Avg Range Avg Range Avg Range Avg Range Sow-Gestation Sow-Lactation Nursery N N N Grower Grower Finisher Finisher Minimum total P levels in livestock feed are regulated in Canada under the Feeds Act; however, feed formulators may be able to formulate feeds with P levels below the regulated minimums if they register their formulas with CFIA or obtain customer sign-off on all formulations (including subsequent formulation changes). 2. The available P target is the desired level of available P to which diets are being formulated. 3. Caution should be used in interpreting reported values for phytase use. Manufacturers sell phytase in various units of measure (e.g. FTUs vs FYTs). 4. Standardized weight ranges for nursery and grower/finisher pigs are N1: 4-6 kg; N2: 6-9 kg; N3: 9-16 kg; N4: kg; G1: kg; G2: kg; F1: kg; F2: kg. MLMMI - Manitoba Swine Nutrition 2013 Survey Page 20

21 As seen from the responses to survey question 1, all survey respondents are formulating at least some rations on the basis of available P content. The 10 th and 11 th Revised Editions of The Nutrient Requirements of Swine (NRC 1998, 2012) offer the following recommendations (Table C3) for phosphorus levels in feed for growing pigs, fed corn-soybean meal based-diets: Table C3. Feed phosphorus levels recommended by NRC 1998 and NRC 2012 for growing pigs. NRC 1998 NRC 2012 Weight Range (kg) Total P(%) Available P(%) Weight Range (kg) Total P(%) In order to compare the NRC values with our average standardized values it is helpful to also convert the NRC numbers to the 8-phase standardized format as shown in table C4: Table C4. NRC 1998 and 2012 values for recommended phosphorus levels converted to 8-phase standardized format. NRC 1998 NRC 2012 Weight Range (kg) Total P(%) Available P(%) Weight Range (kg) Total P(%) N N N N Grower Grower Finisher Finisher The NRC 1998 recommendations for available P are lower than the average available P levels targeted by Manitoba formulators. For most diet phases even the lowest available P levels targeted by Manitoba formulators are at least 10% above the NRC 1998 recommendations, suggesting a possible opportunity to formulate for lower P levels. For example, the minimum available P level target reported in the survey for the Grower 1 diet phase (Table C2) was 35% higher than the NRC 1998 available P recommendation (Table C4) for the Grower 1 phase (0.31% versus 0.23%). Comparison of survey results to NRC 2012 is difficult due to the new STTD approach for estimating bioavailability of phosphorus used in NRC MLMMI - Manitoba Swine Nutrition 2013 Survey Page 21

22 Table C5. Standardized survey responses, shown as averages, ranges, and medians, for Crude Protein (% of ration) for sow, nursery and grower/finisher rations. Average Min Max Median Sow-Gestation Sow-Lactation Nursery N N N Grower Grower Finisher Finisher Appendix D Detailed Survey Responses and Copy of Survey The survey questions and responses are outlined in the following three pages. Question 1 - Could you comment on how you formulate for P content? i.e. to total P, to available P, to digestible P, other method The most common answer to this question was that total and available P methods are used to formulate for P in swine diets. All participants indicated that they based at least some of their rations on available P. No participants formulated solely on the basis of total P in a formulation; however, in some cases total P is used for some rations. Several participants indicated that they formulate for P content based on digestible P, or are moving toward the STTD method. There are different methods used to get the benefit of phytase in diets. Some use available P and digestible P when an enzyme is used and if an enzyme is not used then the method is total and available. MLMMI - Manitoba Swine Nutrition 2013 Survey Page 22

23 Question 2 - For the following key ingredients: What is your estimate for total P content? What is your estimate for P availability? Table D1. Estimates of total P content (%) and P availability (% of ingredient comprised of available P) of key swine feed ingredients provided by survey respondents. Averages, ranges and medians of survey responses are presented. Total P content Available P content Avg(range) Median Avg(range) Median Corn 0.26 ( ) ( ) 0.06 Barley 0.35 ( ) ( ) 0.11 Wheat 0.35 ( ) ( ) 0.17 Corn DDGS 0.79 ( ) ( ) 0.53 Wheat DDGS 0.92 ( ) ( ) 0.36 Canola Meal 1.06 ( ) ( ) 0.28 Peas 0.40 ( ) ( ) 0.15 Meat & Bone Meal 3.95 ( ) ( ) 3.50 Monocalcium phosphate ( ) ( ) Dicalcium phosphate ( ) ( ) Table D1 shows the averages, ranges and medians of the values for total P content and P availability of key swine feed ingredients used by the survey respondents. Some respondents specified that porcine meat & bone meal were used. It is interesting to see that there was a reasonably wide range of estimates used by swine feed formulators. The range of responses for total P content and P availability of dicalcium phosphate suggests that there is a range of types of dicalcium phosphate in the marketplace. An additional source of inorganic P that was mentioned was mono-dicalcium phosphate. The following excerpt from NRC 2012 (p.78) suggests that attention should be paid to the bioavailability of P in calcium phosphates: The P in inorganic P supplements also varies in bioavailability. The P in ammonium, Ca and sodium phosphates is highly available...the P in calcium phosphates may vary depending on specific form and degree of hydration... Apart from meat & bone meal and the inorganic P sources, the greatest ranges for estimates of P availability were for corn DDGS (0.24to 0.69%) and wheat DDGS (0.28 to 0.75%). Question 3 - If you formulate to available P, how do you determine these estimates of P availability in the key ingredients? Do you use a specific source or database? The responses to question 3 (in no particular order) included the following (some respondents provided multiple responses): 1. Feedstuffs 2. NRC NRC 4. Evapig 5. CVB INRA edition 7. Tables of composition and nutritional value of feed materials 8. National swine nutritional guide MLMMI - Manitoba Swine Nutrition 2013 Survey Page 23