EB 368 Broiler Production and The Environment: 2006 College of AgriCulture And nAturAl resourCes EB 368 Broiler Production and The Environment: 2006 Bulletin coordinator: Dr. Roselina Angel, University of Maryland, [email protected] Technical editors: Dr. Roselina Angel, University of Maryland, [email protected] Dr. Wendy Powers, Iowa State University, [email protected] Contributors Dr. Roselina Angel, University of Maryland, [email protected] Dr. Todd Applegate, Purdue University, [email protected] Dr. Jennifer G. Becker, University of Maryland, [email protected] Dr. David Burnham, Aviagen, [email protected] Dr. Brooke Humphrey, University of Maryland, [email protected] George W. Malone, University of Delaware, [email protected] Dr. Mary Ann Ottinger, University of Maryland, [email protected] Dr. Tom Sims, University of Delaware, [email protected] Dr. Ken Staver, University of Maryland, [email protected] Dr. Wendy Powers, Iowa State University, [email protected] T C able of onTenTs Regulatory Issues. . . . . . . . . . . . . . . . . . . . . . . .6 Water quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Air quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Emerging/potential issues . . . . . . . . . . . . . . . . . . . . . . . .8 Dietary Modification . . . . . . . . . . . . . . . . . . . .9 Phosphorus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 Phytate phosphorus . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 Phytase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Reducing litter phosphorus through diet modifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 Protein and Amino Acids . . . . . . . . . . . . . . . . . . . . . . .12 Air Quality and Particulates . . . . . . . . . . . . . . . . . . . . .14 Micro-minerals and Heavy Metals . . . . . . . . . . . . . . . .16 Endocrine Disruptors . . . . . . . . . . . . . . . . . . . . . . . . . .18 Feed Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 Management (Animals and House) . . . . . . . .21 Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 Minimizing animal stress through management . . . . .22 Litter Management and Application . . . . . . .24 Litter management within the house and during storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 Reducing odor, particulate, and ammonia emissions from mechanically ventilated houses . . . . . . . . . . . . .26 Litter moisture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 Limiting nutrient losses from field applications of poultry litter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 The University of Maryland is equal opportunity. The University’s policies, programs, and activities are in conformance with pertinent Federal and State laws and regulations on nondiscrimination regarding race, color, religion, age, national origin, gender, sexual orientation, marital or parental status, or disability. Inquiries regarding compliance with Title VI of the Civil Rights Act of 1964, as amended; Title IX of the Educational Amendments; Section 504 of the Rehabilitation Act of 1973; and the Americans With Disabilities Act of 1990; or related legal requirements should be directed to the Director of Human Resources Management, Office of the Dean, College of Agriculture and Natural Resources, Symons Hall, College Park, MD 20742. Agronomic and Environmental Management of Broiler Litter. . . . . . . . . . . . .28 Nitrogen management . . . . . . . . . . . . . . . . . . . . . . . . .28 Phosphorus management . . . . . . . . . . . . . . . . . . . . . . .29 Trace elements in litters . . . . . . . . . . . . . . . . . . . . . . . .30 For Further Information . . . . . . . . . . . . . . . . .31 Websites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 Papers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33 Broiler Production and the Environment: 2006 I n recent years, issues related needed and excreted per pound of broiler to animal production and the produced. Work reported by Havenstein environment have been focal points et al. (1994 and 2004) shows that not for regulators and thus for producers. only are broilers heavier at an earlier age This increased emphasis on regulation (591 vs. 2,903 grams at 42 days of age for has driven changes in how we feed and male broilers that were fed their respective manage animals and will continue to do year representative diet) but also that so, possibly in an accelerated manner. broilers are more efficient in utilizing Although the technologies developed have the diet nutrients fed, which leads to provided tools for producers to meet, at much lower excreted nutrients per pound least in part, the new standards without of broiler produced to market weight. greatly affecting production costs, new Excretion calculations based on these regulations are imminent, primarily publications show that primarily through regarding air emissions that will, in all genetic potential improvements, and to probability, challenge again the producer’s a lesser extent through diet formulation ability to maintain productivity and changes, nitrogen (N) and phosphorus economic viability. This bulletin addresses (P) excretion by broiler genetic lines from current and upcoming regulations, and 1957, 1991, and 2001, that were fed their examines the tools that are available or respective year representative diets, were are being developed to meet these new approximately 40, 14, and 10 grams of N challenges. It also aims to start a discussion and 10, 4, and 2.4 grams of P excreted per on the need to look at environmental pound of broiler produced, respectively. stewardship in a holistic manner where On a percent basis, the decreases have been it is made clear that implementation 65 and 60% in N and P excretion between of different strategies will impact other 1957 and 1991 breeds. As demonstrated production cycle areas. by the decrease that occurred between 1991 and 2001 of 34 and 40% in N The poultry industry has made and P excretion per pound of broiler tremendous strides in the past 50 years produced, genetic and feed management to meet the demands of the retail and improvements appear to have accelerated food service industries for an increased in the last 15 years. These improvements supply of inexpensive and safe meat and in broiler productivity have been, in large eggs. Pressure to lower costs and increase part, responsible for the ability of the supply has led to more efficient operations, broiler industry simultaneously to increase made possible only through the use of productivity and maintain low product larger, more integrated facilities and costs, and to reduce the environmental through improvements in the broilers’ impact associated with greater production genetic potential and in animal and feed numbers. However, despite these dramatic management. In certain areas, the use of improvements, environmental concerns larger facilities, associated with higher associated with the concentrated concentrations of livestock, has given production of broilers remain a priority rise to environmental concerns and to issue today. legislative measures. It is important to keep in mind that the genetic, management, and feed formulation improvements made in the last 50 years have led to increases in productivity accompanied by large decreases in the amount of nutrients  Broiler Production and the Environment: 2006 R I face of livestock and poultry production in egulaToRy ssues the U.S. Water quality Air quality Water quality protection is addressed During the last decade there has been through the Clean Water Act. In 2002 increasing interest in how AFOs affect air the Act was revised, largely due to poor quality. This increased interest is mainly enforcement and poor compliance with due to odor nuisance from AFOs. Recently, standing policy and to advances in the EPA has initiated activity with respect incorporating impacts from large animal to air quality and AFOs. While the research feeding operations (AFOs). Perhaps the is limited, the continued rise in the most significant impact of the revision was number of people afflicted with asthma, a national shift toward applying manure irrespective of the relationship to animal to land on the basis of a P application agriculture, and the perceived notion that rate in areas with a high risk of P loss to something that smells offensive ‘can’t be water. The P Index, a risk assessment tool good for you’ will very likely propel this that, based on site characteristics, P source issue further. Producers must be kept aware properties, and P management practices, that in addition to worker safety issues, as determines the relative potential for P loss overseen by the Occupational Safety and from a field was developed in response to Health Adminisration (OSHA), concerns these concerns and is now widely used over downwind human health impacts in the U.S. to assess the risk of nonpoint will not go away anytime soon and, in P pollution of ground and surface fact, will likely draw greater attention from waters. This has had a greater impact in regulatory agencies and advocacy groups. the eastern U.S. than in other regions. Moreover, it has drawn greater attention In the Clean Air Act amendments to whole-farm flows of P with the aim of of 1990, the Environmental Protection minimizing the disparity between acres Agency (EPA) established National needed to utilize manure based on N Ambient Air Quality Standards (NAAQS) content and acres needed to utilize manure for pollutants that are applicable to based on P content. all industries. Primary standards were established to protect public health while For a large portion of the U.S., the secondary standards were established to 2002 revision of the Clean Water Act protect public welfare (e.g., decreased has resulted in few changes in standard visibility and damage to crops, animals, practices. Feedlots are applying for NPDES and buildings). Particulate matter (PM) (National Pollutant Discharge Elimination was included in the standards with System) permits. The P Index is being used PM defined as particulates with an to assess water quality risk potential but 10 aerodynamic diameter of 10 microns or because of ground slope and/or distance less. These, considered coarse particulates, from waterways, many areas, even those arise primarily from combustion processes with high soil test P, are able to continue and are addressed in large part through to apply manure based on N. Although the secondary standards because they have 1970s water quality regulations and their impacts on visibility and regional haze recent revisions have had little impact on effects. In 1997 the Clean Air Act was how animal products are produced for U.S. amended and a new criteria pollutant was consumption, the advent of air quality proposed—PM , a fine particulate with regulations for AFOs, largely undeveloped 2.5 respirable health impacts. Particles can at this point, may drastically change the 6 Broiler Production and the Environment: 2006 settle into the respiratory system, causing Response, Compensation and Liability Act asthma and bronchitis as well as potential (CERCLA) and the Emergency Planning systemic effects. Cumulative exposures and Community Right-to-Know Act to respirable dust are one of the most (EPCRA) as reportable compounds if important causes of progressive declines in emissions from a source exceed 100 lbs/ lung function. day for either NH or hydrogen sulfide. 3 Ammonia emissions have received Much attention has been paid to attention because they far exceed those of ammonia (NH ) emissions from AFOs. 3 hydrogen sulfide (40- to 50-fold) for AFOs. Besides functioning as respiratory irritants, Recent CERCLA and EPCRA violations NH emissions are related to particulate 3 by AFOs prompted the EPA to establish matter. In the atmosphere NH reacts with 3 a consent agreement that allowed the SO or NO , and forms ammonium sulfate x x animal production industry to finance and or ammonium nitrate, both of which conduct a monitoring study intended to are PM fine particles that contribute as 2.5 establish baseline emissions of both gases much as half of the total PM measured 2.5 from AFOs. in the U.S. The EPA estimates that more than 70% of the national NH emissions More recently, volatile organic 3 come from livestock operations. Steps compounds (VOCs) have been targeted to curtail NH emissions from AFOs are as concern compounds in some areas, 3 under way. In 1997, and in response specifically California, because they are to non-attainment of PM and ozone components of odor, are precursors to 10 standards, the California South Coast Air ozone formation, and because they have Quality Management District established established recommended exposure limits. local emission reduction goals for animal The Agency for Toxic Substances Disease agriculture. The district established a Registry (ATSDR), a non-regulatory federal goal of 30% reduction of volatile organic agency, has recommended, based on carbon (VOC) emissions from livestock dose response studies, exposure limits waste by 2006 and a 50% reduction of that are a function of the concentration NH emissions from dairy operations by and duration of many individual VOCs, 3 2006. The district recognized that in order as well as of hydrogen sulfide and NH . 3 to meet these ambitious goals it would The San Joaquin Valley Air Pollution be necessary for a portion of the dairy Control District of California has recently industry to relocate. established a VOC production value for the dairy industry that will be used to assess Hydrogen sulfide is both an irritant compliance status with the regional VOC and an asphyxiant that can be fatal at high standard. concentrations and has been associated with deaths (both animal and human) Odor chemistry is complex and still inside animal feeding operations, most poorly understood. Hundreds of odorous commonly as a result of manure agitation compounds, in varying proportions, combined with insufficient ventilation. interact to create a perceived odor. Odor Both Minnesota and Iowa have state perception is highly subjective depending hydrogen sulfide standards for livestock on the individual, which makes odor operations that are based on human health nuisance standards difficult to set and thus exposure conditions. It is likely that other to regulate. However, odor has generally states will apply similar standards. been considered a nuisance and there is considerable interest in determining its Both NH and hydrogen sulfide are 3 impact on human health. Some states addressed in federal regulations as part have pursued this issue through state and of the Comprehensive Environmental  Broiler Production and the Environment: 2006 local boards of health. States that have The effects of endocrine disrupting implemented some sort of odor standard compounds (EDCs) on fish and bird include North Dakota and Colorado. populations have been widely studied. Missouri requires odor control plans and Regulation of pesticides took place in has a proposed, but as yet unapproved, the 1970s and 1980s to minimize the odor standard. As a result of the complex prevalence of endocrine disruptors in the nature of odor, more recent air quality environment. Today, there is renewed activity, born out of concern for odor interest in the issue and it is likely that the nuisance, has focused on the more contributions of EDCs to the environment tangible and measurable characteristics of from animal agriculture will be scrutinized odor and specific gases. by EPA as a source that can be regulated and to which excretion standards may be applied in the future. To meet such Emerging/potential issues standards, evaluation of breeding and estrus-synchronization programs may Limited and unduplicated data be necessary. These programs would suggest that animal facilities produce particularly challenge the dairy industry. antibiotics emissions. One such report However, feeds also contain EDCs, which suggests that swine buildings exhausted, challenges all animal production facilities. in active form, approximately 30% of the While the extent to which feed EDCs affect tylosin administered. Although the data the total amount of EDCs that leave the are not duplicated, and despite broad- farm boundary is unknown, feed EDCs will scale efforts to reduce sub-therapeutic nevertheless affect all animal and poultry use of antibiotics in the animal industry, production units. in the future the implications to human health could lead to regulatory activity. Perhaps one of greatest challenges we Anthropogenic sources are reported to face now as regulators, scientists, industry contribute 6% of global greenhouse gas leaders, and producers is to determine the emissions, of which livestock contributes best ways to look at the broiler industry, 17% of the total emissions from natural and for that matter any animal industry, in and anthropogenic sources, combined. a more holistic manner. We must develop In addition to direct emissions from approaches that allow us to understand cattle, methane is produced from the better the impacts, interactions, and true anaerobic decomposition of manure or costs of the tools we research, develop, poultry litter during storage. Animal and implement in order to be viable into agriculture activities produce other the future. Viability in this context implies greenhouse gases besides methane. The sustainability. decomposition of organic matter results As developers or implementers of in nitrous oxide production. Although new technologies we tend to look for the U.S. has not signed the Kyoto treaty, answers or solutions to specific questions there is considerable interest in reducing often disregarding collateral effects unless greenhouse gas emissions. Recently there these effects are already part of our cost/ has been renewed discussion in the media benefit equation. For example, as we are regarding the U.S. decision to abstain challenged to reduce air emissions from from signing the treaty. At this time it is broiler production units we tend to look uncertain how a change in U.S. policy for one-sided solutions. Depending on our would impact animal production. areas of expertise, we look for solutions through changes in nutrition, animal management, litter amendments and/or 8 Broiler Production and the Environment: 2006 litter management, house environmental Phytate phosphorus changes, etc., with little regard for how Phytic acid (myo-inositol 1,2,3,4,5,6- each of these areas overlap and interact. hexakis dihydrogen phosphate), an organic It may be that a slight decrease in animal phosphate, is a phosphorylated cyclic density at placement may allow us, in a sugar alcohol that in mature seeds contains holistic approach either to improve or six phosphate groups. The anion form not change productivity from a broiler of phytic acid, phytate, is present in all house while decreasing litter moisture, plants, primarily in the seed portion. Roots litter nutrient content, and air emissions. contain low amounts and vegetative parts Decreasing animal density would also such as leaves are either devoid of phytate decrease input costs (diet, chicks). Data or have only trace amounts. The location that would allow us to make educated of phytate in the seeds varies according decisions about the holistic impact of to the type of plant. For example, 90% of reducing animal density requires that the phytate in corn is found in the germ we know what the correlations between portion of the kernel, while in wheat and animal density, productivity, nutrient rice most of the phytate is in the aleurone excretions/emissions, and costs are. layers of the kernel and in the outer However, the existing information base is bran. In most oilseeds and grain legumes, simply not this broad. the majority of phytate is associated with protein and is concentrated within subcellular inclusions called globoids that D M IeTaRy oDIfICaTIon are distributed throughout the kernel; however, in soybean seeds, there appears to be no specific location for phytate. Phosphorus Location within the seed makes it possible, Broiler diets consist predominantly of at least in the case of corn, to remove most plant-based ingredients. Plant ingredients of the phytate when corn is degermed. contain most (50 to 80%) of their P as part In mature seeds, phytate is present as a of a compound called phytic acid that is complex salt of calcium (Ca), magnesium generally considered to be poorly available (Mg) and potassium (K), and in some cases to monogastric animals. In most cases, in proteins and carbohydrates. order to meet the P needs of the animal, Phytate P content in grains is variable. broiler diets are formulated to contain Factors that influence this variability are inorganic sources of P primarily in the still unknown, but it is known that soil form of calcium phosphates. This results and environmental factors affect this in diets that have total concentrations content. Soil P content and productivity of P that far exceed the animal’s needs. of the grain in relation to soil P content However, if phytate P (PP) can be released will influence the amount of PP and total from the phytate molecule as inorganic P in the mature grain. Thus, because P, it can serve as a bioavailable nutrient corn is brought in from different to monogastric animals. If this P release regions, a safety margin in formulation can be achieved, there would be, in the systems is important in most broiler feed plant feedstuffs that typically make up manufacturing plants. broiler diets, adequate levels of P to meet Phytate is highly reactive and readily dietary needs and therefore the need to forms complexes with Ca, iron (Fe), Mg, supplement broiler diets with inorganic zinc (Zn), carbohydrates, and proteins. sources of P would be reduced significantly. These complexes are substantially less 9