Phytobiotics: an Alternative to Antibiotic Growth Promoters The use of antibiotic growth promoters (AGPs) in animal production began half a century ago, when Stokstad and Jukes added residues of chlortetracycline production to chicken feed. They were added with the objective to serve as a source of vitamin B12, but they caused a growth stimulation that was far too large to be explained only as a vitamin effect. The almost obvious cause lays in the antibiotic activity of the residues. This observation was quickly extended to other antibiotics and to other animal species, leading to widespread adoption of AGP inclusion in feeds. Antibiotics have been used for treatment and prevention of diseases, improvement of feed efficiency in conventional livestock and poultry industries. The first use of antibiotics in these industries was a way to meet the increasing demand of food as antibiotics given to pigs were estimated to save as much as 20% of feed per pound because of the weight gain. Similar results have been reported in poultry industries also. Immense and extensive use of antibiotics has created a strong selective pressure, which resulted in the survival and spread of resistant bacteria providing best example of survival for the fittest or natural selection theory of Darwin. Quick concerns have been arisen about the development of resistant pathogens associated with human and animal diseases, as well as increase in the resistance gene pool in bacteria, but all these risks were outweighed by the benefits of reduced cost to the industry. At present we are confronting a major issue of antibiotic resistance in both human and animals resulting into severe health issues. A lot of debates are going on all over the world and recently European Union and Canada has banned the use of antibiotics in the animal feed industries. In China certain antibiotics have been banned and others are under observation. In United States, also discussions are going on about the uses of antibiotics and it is expected have big measures in the nearest future. In Mexico still animal feed industries are using extensively the antibiotics, ignoring the health issues and focusing on the commercials benefits of the respective companies. But it’s not too far when the strong legal measures will be implemented in Mexico also. From personal point of view, it’s a demand of the time, to take care of the health interests of consumers and prepare ourselves to look for other alternatives of the antibiotics as growth promoters. These alternatives might have similar effects in food producing animals. Studies to find the alternatives have resulted into probiotics, prebiotics, symbiotics, enzymes, organic acids and phytobiotics. Despite of initial and then often justified distrust of these alternatives by nutritionists and veterinarians, they are becoming rightly accepted after the debates going on all over the globe about the use of the antibiotics and related health concerns. The change in European Union feed additive legislation has also contributed to create enough space for these alternatives. Among the mentioned alternatives, phytobiotics have drawn a lot of attentions because of being natural, non toxic and residue free. Phytobiotics are defined as plant-derived products added to the feed in order to improve performance of agricultural livestock. With respect to biological origin, formulation, chemical description and purity, phytobiotics comprise a very wide range of substances and four subgroups may be classified: 1) Herbs -product from flowering, non-woody and non-persistent plants 2) Botanicals -entire or processed parts of a plant, e.g., root, leaves, bark 3) Essential oils- hydro distilled extracts of volatile plant compounds and 4) Oleoresins- extracts based on non-aqueous solvents Positive effects of the phytobiotics on the growth performance and animal health have been attributed to their antimicrobial activity and immune enhancement and immune modulation properties. In diseased chicken (infected with avian mycoplasma or Eimeria tenella) it has been demonstrated that plant and their extracts could improve the growth performance, reduce the coliforms and improve both cellular and humoral immune responses of chickens. A common feature of phytobiotics is that they are a very complex mixture of bioactive components as a result exerts multiple functions in the animal body. Different studies have reported growth enhancement through the use of phytobiotics probably by synergetic effects among complex active molecules existing in the phytobiotics. However, the exact growth enhancement mechanisms of the phytobiotics in chicken are not very well understood and further investigations are required to better understand the mechanism at molecular level. Among Phytobiotics, essentials oils have drawn a lot of attention as an effective alternative to the antibiotic growth promoter and have been applied into chicken feed in Europe, USA and many Asian countries. In Mexico, till date negligible research has been conducted to see the effect of essential oils in animal feed. However the results are still controversial as some research report no essential oil effects on the performance of the bird and some demonstrate similar to or even better than an antibiotic treatment. It´s very important to mention that while comparing the effects of essential oils on chicken performance one should always keep in mind that the quality as well as the quantity of the oil determines the response. Additionally, efficacy of essential oils in feeds is affected by intrinsic and extrinsic factors such as nutritional status of animals, infection, diet composition and environment. Till now research has been conducted with the essentials oils of Ginger, Cinnamon, Capsicum, Garlic, Thyme and Oregano among others, in different parts of the world. The results are really interesting and show positive effects on the performance of the birds. As mentioned above environment plays an important role in determining the effect of the essential oils, it is highly recommendable to conduct in field study in Mexico before launching the products in the market. Conclusions Because of the increasing concerns about the use of antibiotics as growth promoters in poultry industries, the animal feed industry is in search of other alternatives with good cost benefits. The phytobiotics, especially the essential oils are opening new opportunities and possibilities as a replacement of antibiotics. But the cost is an issue which is restricting the animal feed industries to accept these products as the cost of antibiotics is cheaper than other alternatives. But if we give close look to the authorization to new antibiotics by Food and Drug Administration (FDA), in year 2008-2009 only one antibiotic was approved. FDA is also releasing new guidelines for the use of antibiotics. All these strong measures will definitely help to answer the cost issue and force the consumers to accept alternative like Phytobiotics as essentials oils. REFERENCES. 1. Cromwell, G.L. (2002) Why and how antibiotics are used in swine production. Anim. Biotechnol. 13, 7–27 2. Guo, F.C., et al. (2004c) Effects of mushroom and herb polysaccharides on cellular and humoral immune responses of Eimeria tenella-infected chickens. Poultry Science 83: 1124-1132

Chicken Anemia Virus and Immunosuppression: Impact on Marek´s Disease Vaccine ProtectionSummary Subclinical immunosuppression caused by chicken infectious anemia virus (CIAV) is an important contributing factor to Marek’s disease (MD) vaccine breaks. Infection with CIAV results in reduced T helper and cytotoxic T lymphocyte activity affecting antibody and cell-mediated immune responses. CIAV infection is controlled by the development of virus-neutralizing antibodies, which can be compromised by poorly controlled infectious bursal disease virus (IBDV) infection. MD virus (MDV), especially the very virulent (vv+) strains, is also highly immunosuppressive. When field strains of MDV infect properly vaccinated birds or reactivate from latency, memory CTL will be activated to control virus replication. These CTL are also dividing thus providing target cells for CIAV replication. In conclusion, when CIAV is actively replicating during infection with or reactivation of MDV, CTL responses are suboptimal and MDV infection is poorly controlled leading to vaccine breaks. INTRODUCTION Although MD is in general well controlled by vaccination in ovo or at one d of age, MD remains a concern for several reasons. First of all, vaccination practices are often suboptimal resulting in some vaccine breaks. Proper use of standard operating procedures at the hatchery remains essential for optimal protection and has been the topic of many presentations. The short-term financial gain by using vaccines diluted beyond the recommendations by the manufacturer results in suboptimal protection when very virulent (vv) or vv+ strains of MDV are present (4). The second reason is the continuous evolution of MDV. Over the last 100 years MDV has increased significantly in virulence (10). The first increase in virulence occurred in the mid 1950’s when the poultry industry changed from a rather extensive to a more intensive production system. Subsequent increases in virulence are, at least in part, caused by the fact that none of the vaccines prevent infection with field strains thus allowing for the development of escape mutants (1). In addition, Atkins et al. (1) suggested that the reduction in age of broilers to processing also favors an increase in virulence. Unfortunately, there are no good options to change these developments. Without vaccination, losses would be staggering in breeder and layer flocks and in many countries in broilers as well. Thorough cleaning of broiler houses after each cycle may alleviate the need to vaccinate as is the case in some countries, but this will be impractical in the USA and Mexico. A third important factor is immunosuppression especially by chicken infectious anemia virus (CIAV), which is difficult to control in commercial production systems. In this review I will briefly discuss the pathogenesis of CIAV and its impact on immune responses, MD vaccine-induced immune responses, and how CIAV can influence MD vaccine-induced immune responses. With few exceptions only references for book chapters and review papers are used for these three sections. PATHOGENESIS OF CHICKEN INFECTIOUS ANEMIA VIRUS CIAV, currently the only member of the Gyrovirinae of the Circoviridae, is characterized by its small size (±25 nm), single-stranded, circular, covalently closed, negative sense DNA genome of 2,298 nt, and very important from a practical point of view the extreme resistance of CIAV to many commercial disinfectants (7, 9). The genome codes for only three proteins: VP1 (the capsid protein), VP2 (essential for the proper folding of VP1) and VP3, which is also known as apoptin. VP3 is essential for virus replication and mutation of the start codon will prevent virus replication. VP3 is also important because it causes apoptosis of infected cells. The replication of the viral genome requires the formation of double-stranded (ds)DNA, which resembles in some respects a mini-chromosome or a bacterial plasmid. Because CIAV does not code for the necessary enzymes to generate new DNA, and thus infectious virus particles, it needs to infect dividing cells using the cellular enzymes to generate viral DNA. The dividing cells which are susceptible to infection with CIAV are the hemocytoblasts, the precursor cells for erythrocytes, heterophils and thrombocytes, in the bone marrow, thymocytes and T cells. Destruction of the hemocytoblasts by CIAV results in lower hematocrit values, decreased phagocytosis of bacteria by a lack of heterophils and thrombocytes, and increased hemorrhages. Infection of the thymocyte series results in a loss of thymocytes (thymus atrophy), T helper (Th) and cytotoxic T lymphocytes (CTL). The loss of Th lymphocytes and CTL impacts negatively the antibody and cell-mediated immune responses. Virus-neutralizing (VN) antibodies develop within six wk post infection (pi) eliminating virus replication. However, CIAV can remain present in gonads and lymphocytes probably as dsDNA fulfilling the characteristics of latency (7). Latent CIAV can be transmitted vertically and be reactivated. Infection with CIAV only causes clinical disease if infection occurs during the first one to ten d of age in maternal antibody-negative chickens. However older chickens can develop clinical disease when humoral antibody responses are severely compromised for example after infection with vv infectious bursal disease virus (IBDV). Control of vvIBDV using appropriate vaccines without causing damage to the bursa of Fabricius is therefore an important component for the control of CIAV infections. MAREK’S DISEASE VACCINE-INDUCED IMMUNITY Infection of naïve chickens with MDV causes first a lytic infection of B lymphocytes followed by a lytic infection of mostly CD4+ T cells. The lytic phase of infection can cause severe atrophy of the thymus and bursa of Fabricius resulting in immunosuppression. Latent infections are established in CD4+ T cells starting around seven d pi but infection with vv+ strains may cause permanent damage to the primary lymphoid organs and early mortality. Latency can be permanent or temporarily depending on the genetic resistance and immunocompetence of the birds and the virulence of the MDV strain. Ultimately, MDV-positive CD4+ cells may transform in which case tumors develop. To protect against MD, chickens are vaccinated in the USA at 18 d of embryonation (broilers) or directly after hatching (layers and breeders). The latter two groups of birds receive sometimes a second vaccination between 1 – 14 d of age. If a second vaccination is given, it has to be done within the first one to two d of age before chickens are exposed to field virus. Vaccination induces both innate and acquired immune responses. The former include the production of nitric oxide and interferons as well as the activation of natural killer cells which are important to reduce early MDV infections. Innate responses are short-lived, lack memory, and are therefore only important during the first 7 – 10 d pi. However, innate responses are of crucial importance for the development of acquired immunity. Antibodies play only a minor role in protective immunity because MDV infection is strictly cell-associated. In contrast to antibodies, CTL responses are a key component of vaccine-induced acquired immunity. Protective immunity is primarily antiviral reducing but not preventing replication of field virus. The importance of antitumor immunity is controversial and immune responses to tumor cells may be directed to viral antigens rather than true tumor antigens. (8). IMPACT OF CIAV INFECTION ON MAREK’S DISEASE CIAV infection in maternal antibody-positive chickens typically occurs once maternal antibodies have weaned and flocks typically seroconvert between 4 – 10 wk of age. During this time birds may also become infected with MDV field strains. CTL responses are the key component to control virus replication and memory CTL against MDV antigens will be rapidly activated and start dividing thus presenting target cells for CIAV replication. MD vaccine breaks have been linked directly or indirectly to the presence of CIAV infection in several instances (2, 3). Similarly, CIAV infection has also been implicated in infectious bronchitis breaks (5). The effect of CIAV on CTL was clearly shown by Markowski-Grimsrud and Schat (6) using reticuloendotheliosis virus (REV) as a model. Chickens hatched from antibody-positive and -negative hens were infected at four wk of age with CIAV with or without exposure to REV at the same time. At seven d pi CIAV replication was measured by quantitative (q)PCR and qRT-PCR and CTL responses to REV-transformed lymphocytes was measured by chromium release assays (CRA). In the case of maternal antibody-positive chickens, qPCR and qRT-PCR showed lack of CIAV replication and a strong CTL response to REV. Residual maternal antibodies were apparently still present at four wk of age, even while the Iddex ELISA was negative. In contrast, maternal antibody-negative chicks showed high levels of CIAV DNA and RNA, the latter indicating active virus replication. The CTL response to REV was significantly reduced in these birds. CONCLUSIONS CIAV is an important pathogen causing subclinical immunosuppression and can be an important co-factor in vaccine breaks against MD and may other diseases. Development of vaccines to protect chickens to CIAV infection early in life will be an important addition to disease control programs. REFERENCES 1. Atkins, K. E., A. F. Read, N. J. Savill, K. G. Renz, A. F. Islam, S. W. Walkden-Brown, and M. E. Woolhouse. Vaccination and reduced cohort duration can drive virulence evolution: Marek's disease virus and industrialized agriculture. Evolution 67:851-860. 2013. 2. Davidson, I., M. Kedem, H. Borochovitz, N. Kass, G. Ayali, E. Hamzani, B. Perelman, B. Smith, and S. Perk. Chicken infectious anemia virus infection in Israeli commercial flocks: virus amplification, clinical signs, performance, and antibody status. Avian Dis. 48:108–118. 2004. 3. Fehler, F., and C. Winter. CAV infection in older chickens, an apathogenic infection? In: II. International Symposium on infectious bursal disease and chicken infectious anaemia. Institut fur Geflugelkrankheiten, Justus Liebig University, Giessen, Germany, Rauischholzhausen. pp 391-394. 2001. 4. Gimeno, I. M., A. L. Cortes, E. R. Montiel, S. Lemiere, and A. K. R. Pandiri. Effect of diluting Marek's disease vaccines on the outcomes of Marek's disease virus infection when challenged with highly virulent Marek's disease viruses. Avian Dis. 55:263-272. 2011. 5. Hoerr, F. J. Clinical aspects of immunosuppression in poultry. Avian Dis. 54:2-15. 2010. 6. Markowski-Grimsrud, C. J., and K. A. Schat. Infection with chicken anaemia virus impairs the generation of pathogen-specific cytotoxic T lymphocytes. Immunology 109:283-294. 2003. 7. Schat, K. A. Chicken anemia virus. Curr. Top. Microbiol. Immunol. 331:151-184. 2009. 8. Schat, K. A., and V. Nair. Marek's disease. In: Diseases of Poultry, 13 ed. D. E. Swayne, J. R. Glisson, L. R. McDougald, J. V. Nolan, D. L. Suarez and V. Nair, eds. Wiley-Blackwell, Ames, IA. pp 515-552. 2013. 9. Schat, K. A., and V. L. van Santen. Chicken infectious anemia. In: Diseases of Poultry, 13 ed. D. E. Swayne, J. R. Glisson, L. R. McDougald, J. V. Nolan, D. L. Suarez and V. Nair, eds. Wiley-Blackwell, Ames. IA. pp 248-264 and 276-284. 2013. 10. Witter, R. L. Increased virulence of Marek's disease virus field isolates. Avian Dis. 41:149-163. 1997. This paper was presented at the 63rd Western Poultry Disease Conference and XXXIX Convención Anual ANECA, Puerto Vallarta, Jalisco, Mexico, April 2014

Development of an Acid Scrubber for Reducing Ammonia Emissions from Animal Rearing Facilities

Development of an Acid Scrubber for Reducing Ammonia Emissions from Animal Rearing Facilities Author/s : Philip A. Moore, Jr. (University of Arkansas), Rory Maguire (Virginia Tech), Mark Reiter (Virginia Tech), Jactone Ogejo (Virginia Tech),Robert Burns (University of Tennessee), Hong Li (University of Delaware) Dana Miles, USDA/ARS Michael Buser, Oklahoma State University Abstract Recent research has shown that over half of nitrogen excreted by chickens is lost into the atmosphere via ammonia volatilization before the litter is removed from poultry houses. Large quantities of particulate matter and volatile organic compounds (VOCs) are also emitted from animal rearing facilities. During the past decade we have developed and patented an acid scrubber for capturing ammonia, VOCs and dust from air exhausted from poultry and swine barns. The objectives of this project were; (1) to re-design the scrubber to improve the ammonia removal efficacy, (2) conduct full-scale testing of the scrubber under controlled conditions at various ventilation rates, (3) evaluate the cost, practicality and efficacy of various acids for scrubbing ammonia, and (4) install scrubbers on exhaust fans of poultry houses located in Virginia and Arkansas and measure the efficiency of ammonia removal from the exhaust air. The efficiency of ammonia removal by the scrubber varied from 55-95%, depending on the type of acid used, air flow rate, and the internal scrubber configuration. This technology could potentially result in the capture of a large fraction of the N lost from AFOs, while simultaneously reducing emissions of bacteria, dust, and odors, which would improve the social, economic, and environmental sustainability of poultry and swine production. Purpose The objectives of this project were; (1) to re-design our ammonia scrubber to improve the ammonia removal efficacy, (2) conduct full-scale testing of the scrubber under controlled conditions at various ventilation rates, and (3) evaluate the cost, practicality and efficacy of various acids for scrubbing ammonia. What Did We Do? During the first year of this project the main task of our team was to re-design the ammonia scrubber developed and patented by Moore (2007). A full scale prototype was constructed of wood and a series of tests were conducted to evaluate various configurations on air flow and static pressure drop in tests conducted in a machine shop. The scrubber was connected to a 48” variable speed poultry fan. Air flow was measured using a fan assessment numeration system (FANS unit). Static pressure difference was measured using a Setra 2601MS1 differential pressure sensor. The effects of slat angle, number and arrangement of slats, and thickness of cool cell material were evaluated. Following the initial testing a fiberglass mold was made and six scrubbers were constructed. One of these was used to evaluate the effectiveness of water, strong acids, acid salts, and a neutral salt on scrubbing ammonia. Anhydrous ammonia was metered out into a distribution system located within the fan at a sufficient rate to result in 25 ppm NH3 in the plenum between the fan and the dust scrubber. Evaluations of each acid were made with the variable speed fan set at 60 and 40 Hz, which corresponded to air flows of approximately 8,000 and 5,000 cfm, respectively. A stainless steel star sampler was used to take air samples from the plenum and from the air exhausted from the scrubber. Ammonia concentrations were measured using a photoaccustic multigas analyzer (Innova 1412). All personal involved in this testing wore respirators equipped with NH3 cartridges. Three 2-hour trials were conducted with solutions of the following acids at both 40 and 60 Hz: alum, aluminum chloride, ferric sulfate, ferric chloride, sodium bisulfate, sulfuric acid, hydrochloric acid, phosphoric acid, and nitric acid. The effects of water and calcium chloride were also evaluated. For these trials the amount of each acid added was equivalent to 2 liters of concentrated sulfuric acid. In addition to measuring inflow and outflow ammonia levels, the mass accumulation of ammonia in both the dust and acid scrubber reservoirs was determined by analyzing the contents for ammonium using an auto-analyzer. Twenty ml aliquots of the scrubber solution were taken at times 0, 1 and 2 hours for ammonia and pH measurements. These data were used to validate that the difference in inlet and outlet ammonia were, in fact, due to accumulation of NH3 in the scrubber. Notes were also taken on each chemical’s ease of use and potential for problems. For example, some dry acids did not readily dissolve and some strong acids, like sulfuric acid, had very strong exothermic reactions. Salts of aluminum and iron become aluminum and iron hydroxides at high pH which have the potential to clog cool cell material. Another performance issue that was monitored was the loss of fine droplets (mist) from the scrubber. When dealing with high air volumes and small droplet sizes, there is a potential for mist to exit the system, resulting in not only the loss of N, but of the acid used to scrub NH3. In order to measure mist loss, five 12.5 cm Whatman 42 filters were attached on a wire cage on the exhaust of the scrubber. These filters were placed in a 50 ml centrifuge tub at the end of each trial and shaken with 25 ml of DDI water, which was analyzed for ammonium, along with sulfate, chloride, nitrate, or phosphate, depending on the acid used. What Have We Learned? Early on in this research we learned that two scrubbers (a dust scrubber and an acid scrubber) were needed rather than one. If the dust isn’t removed from the exhaust air of poultry houses, then a large amount of the acid will be wasted neutralizing the dust. We found that the relationship between slat angle and pressure drop was exponential and the angle that would maximize particle collisions on a wet surface while minimizing pressure drop was 45o. We also found that as the number of rows of slats increased the effect on pressure drop was linear. The final configuration chosen was eight rows of slats in the dust scrubber and three rows of slats in the chemical scrubber, followed by one or two 6” thick layers of cool cell material. The pressure drop using this configuration was about 0.1” of water at 5,000 cfm and 0.3” of water at 8,000 cfm. All of the acids scrubbed ammonium from air, whereas water and calcium chloride only worked for a very short period of time. The iron (Fe) and aluminum (Al) compounds tended to work a little better than the other acid salts or the strong acids. We believe this is due to Fe and Al compounds coating the cool cell material. Although no difference was observed in the static pressure during these short tests, we believe Al and Fe hydroxides would eventually form and may clog the cool cells. Due to the inherit danger in dealing with strong acids, we concluded that an acid salt that did not contain Al and Fe, such as sodium bisulfate, would be used for our research in the future. This product is sold under the tradename PLT for a poultry litter treatment and is readily available to poultry growers. Future Plans Four NH3 scrubbers will be attached to sidewall fans of a commercial broiler house located in Madison County, Arkansas. The efficacy of these scrubbers for reducing ammonia, volatile organic compounds (VOCs), and particulate matter will be evaluated. We will also measure the amount of sodium bisulfate, water and electricity used by the scrubbers, as well as the mass of nitrogen captured. A cost-benefit analysis will be performed based on this data. Data on the efficacy to scrub ammonia will also be conducted on farms in DE, VA, and PA. Acknowledgements This research was funding by USDA/ARS and by grants from USDA/NRCS and the National Wildlife Foundation. The authors would like to thank the hard work and great ideas supplied by Scott Becton and Jerry Martin, without which this scrubber could not have been built.

Treating Poultry Litter with Aluminum Sulfate (Alum)

Treating Poultry Litter with Aluminum Sulfate (Alum) Published on: 07/30/2012 Rating: Author : Philip Moore (USDA- ARS) Definition: Aluminum sulfate (alum) is added to poultry litter in the poultry house to reduce ammonia volatilization. Purpose: Over half of the nitrogen excreted by chickens is lost to the atmosphere as ammonia before the litter is removed from poultry houses. Research has shown that alum additions to poultry litter greatly reduces ammonia emissions. Lower ammonia levels in poultry houses due to alum additions result in heavier birds, better feed conversion and lower mortality. Alum additions to poultry litter also precipitates phosphorus into a form which is not water soluble. This greatly reduces phosphorus runoff from fields fertilized with poultry litter, as well as phosphorus leaching. Alum additions also reduce the number of pathogens in litter. How Does This Practice Work: Alum should be applied to poultry litter at a rate equivalent to 5-1 0% by weight (alum/manure). For typical broiler operations growing six week old birds, this is equivalent to adding 0.1 to 0.2 lbs alum per bird or 1 -2 tons of alum per house per flock if 20,000 birds are in each house. The reduction in ammonia emissions is due to the acid produced when alum is added to the litter. This acid converts ammonia to ammonium; which is not subject to volatilization. The reduction in litter pH also causes pathogen numbers to decrease. Aluminum from alum reacts with phosphorus to form an insoluble aluminum phosphate compound that is far less susceptible to runoff or leaching. Where This Practice Applies and Its Limitations: This practice applies to all poultry operations that have dry litter (broiler, breeder and turkey houses). There are no known limitations of this practice. Effectiveness: Alum additions result in less nitrogen being lost due to ammonia volatilization. Ammonia fluxes from alum-treated litter have been shown to be 70% lower than normal litter (Moore et al., 2000). This results in a higher nitrogen content of the litter, which boosts crop yields. Lower ammonia levels in the rearing facilities also improve poultry production and make the environment safer for agricultural workers. Reducing atmospheric ammonia emissions will also result in less air pollution, such as fine particulate matter (ammonia is a precursor to fine particulate matter), acid precipitation, and atmospheric nitrogen deposition. Treating poultry litter with alum is also one of the most effective methods of reducing phosphorus runoff from fields fertilized with litter. Alum applications to poultry litter have been shown to reduce phosphorus runoff by 87% from small plots (Shreve et al., 1 995) and by 75% from small watersheds (Moore and Edwards, 2007). The long-term effects of applying alumtreated litter to land have indicated that this practice is sustainable (Moore and Edwards, 2005; 2007). Soluble phosphorus levels in soils fertilized with alum-treated litter are significantly lower than that in soils fertilized with normal litter. Hence, there is less phosphorus leaching with alum-treated litter (Moore and Edwards, 2007). Longterm studies conducted by Moore and Edwards (2005) showed that exchangeable aluminum levels in soils fertilized with normal and alum-treated litter are low (less than 1 mg Al/kg soil) and are not significantly different, whereas plots fertilized with the same amount of nitrogen from ammonium nitrate have very high exchangeable aluminum (up to 1 00 mg Al/kg soil). Moore and Edwards (2005) also showed that tall fescue yields from long-term studies were highest with alum-treated litter, followed by normal litter and lowest with ammonium nitrate. Cost of Establishing and Putting Practice in Place: Treating poultry litter with alum is a cost effective best management practice, due to the economic returns from improved poultry production and reduced energy costs. Alum costs about $250/ton. As mentioned earlier two tons of alum should be applied to a typical broiler house after each flock. Moore et al. (2000) showed that the economic returns from this practice were $308 for the grower and $632 for the integrator (company), for a combined return of $940. This is almost twice the cost ($500) to treat the house, resulting in a benefit/cost ratio approaching 2. Operation and Maintenance: Alum is normally applied between each flock of birds. Dry alum can be applied with a number of different spreaders, such as de-caking machines, fertilizer spreaders, manure spreaders or drop spreaders. Applicators should always wear goggles for eye protection and a dust mask to avoid breathing alum dust. Gloves should also be worn to prevent skin irritation. To insure the chickens do not consume the granules of alum, it is best to till the product into the litter. This can be done with a litter de-caker or with any other device that physically mixes the alum into the litter. Liquid alum is normally only applied by a certified professional applicator. There are two types of liquid alum - normal liquid alum (48.5% alum) and acid alum (36.5% alum). Acid alum is preferred in situations where the litter is very dry, since it activates quickly. To add the equivalent of one ton of dry alum, 370 gallons of liquid alum or 51 2 gallons of acid alum is needed. References: Moore, P.A., Jr., S. Watkins, D.C. Carmen, and P.B. DeLaune. 2004 Treating poultry litter with alum. University ofArkansas Cooperative Extension Fact Sheet (FSA8003-PD-1 -04N). Moore, P.A., Jr, T.C. Daniel and D.R. Edwards. 2000. Reducing phosphorus runoff and inhibiting ammonia loss from poultry manure with aluminum sulfate. J. Environ. Qual. 29:37-49. Moore, P.A, Jr., and D.R. Edwards. 2005. Long-term effects of poultry litter, alum-treated litter, and ammonium nitrate on aluminum availability in soils. J. Environ. Qual. 34:21 04-2111 . Moore, P.A, Jr., and D.R. Edwards. 2007. Long-term effects of poultry litter, alum-treated litter, and ammonium nitrate on phosphorus availability in soils. J. Environ. Qual. 36:1 63-1 74. Shreve, B.R., P.A. Moore, T.C. Daniel, D.R. Edwards and D.M. Miller. 1 995. Reduction of phosphorus runoff from field-applied poultry litter using chemical amendments. J. Environ. Qual. 24:1 06-111 .

Treating Poultry Litter with Aluminum Sulfate (Alum)

Treating Poultry Litter with Aluminum Sulfate (Alum) Published on: 07/30/2012 Rating: Author : Philip Moore (USDA- ARS) Definition: Aluminum sulfate (alum) is added to poultry litter in the poultry house to reduce ammonia volatilization. Purpose: Over half of the nitrogen excreted by chickens is lost to the atmosphere as ammonia before the litter is removed from poultry houses. Research has shown that alum additions to poultry litter greatly reduces ammonia emissions. Lower ammonia levels in poultry houses due to alum additions result in heavier birds, better feed conversion and lower mortality. Alum additions to poultry litter also precipitates phosphorus into a form which is not water soluble. This greatly reduces phosphorus runoff from fields fertilized with poultry litter, as well as phosphorus leaching. Alum additions also reduce the number of pathogens in litter. How Does This Practice Work: Alum should be applied to poultry litter at a rate equivalent to 5-1 0% by weight (alum/manure). For typical broiler operations growing six week old birds, this is equivalent to adding 0.1 to 0.2 lbs alum per bird or 1 -2 tons of alum per house per flock if 20,000 birds are in each house. The reduction in ammonia emissions is due to the acid produced when alum is added to the litter. This acid converts ammonia to ammonium; which is not subject to volatilization. The reduction in litter pH also causes pathogen numbers to decrease. Aluminum from alum reacts with phosphorus to form an insoluble aluminum phosphate compound that is far less susceptible to runoff or leaching. Where This Practice Applies and Its Limitations: This practice applies to all poultry operations that have dry litter (broiler, breeder and turkey houses). There are no known limitations of this practice. Effectiveness: Alum additions result in less nitrogen being lost due to ammonia volatilization. Ammonia fluxes from alum-treated litter have been shown to be 70% lower than normal litter (Moore et al., 2000). This results in a higher nitrogen content of the litter, which boosts crop yields. Lower ammonia levels in the rearing facilities also improve poultry production and make the environment safer for agricultural workers. Reducing atmospheric ammonia emissions will also result in less air pollution, such as fine particulate matter (ammonia is a precursor to fine particulate matter), acid precipitation, and atmospheric nitrogen deposition. Treating poultry litter with alum is also one of the most effective methods of reducing phosphorus runoff from fields fertilized with litter. Alum applications to poultry litter have been shown to reduce phosphorus runoff by 87% from small plots (Shreve et al., 1 995) and by 75% from small watersheds (Moore and Edwards, 2007). The long-term effects of applying alumtreated litter to land have indicated that this practice is sustainable (Moore and Edwards, 2005; 2007). Soluble phosphorus levels in soils fertilized with alum-treated litter are significantly lower than that in soils fertilized with normal litter. Hence, there is less phosphorus leaching with alum-treated litter (Moore and Edwards, 2007). Longterm studies conducted by Moore and Edwards (2005) showed that exchangeable aluminum levels in soils fertilized with normal and alum-treated litter are low (less than 1 mg Al/kg soil) and are not significantly different, whereas plots fertilized with the same amount of nitrogen from ammonium nitrate have very high exchangeable aluminum (up to 1 00 mg Al/kg soil). Moore and Edwards (2005) also showed that tall fescue yields from long-term studies were highest with alum-treated litter, followed by normal litter and lowest with ammonium nitrate. Cost of Establishing and Putting Practice in Place: Treating poultry litter with alum is a cost effective best management practice, due to the economic returns from improved poultry production and reduced energy costs. Alum costs about $250/ton. As mentioned earlier two tons of alum should be applied to a typical broiler house after each flock. Moore et al. (2000) showed that the economic returns from this practice were $308 for the grower and $632 for the integrator (company), for a combined return of $940. This is almost twice the cost ($500) to treat the house, resulting in a benefit/cost ratio approaching 2. Operation and Maintenance: Alum is normally applied between each flock of birds. Dry alum can be applied with a number of different spreaders, such as de-caking machines, fertilizer spreaders, manure spreaders or drop spreaders. Applicators should always wear goggles for eye protection and a dust mask to avoid breathing alum dust. Gloves should also be worn to prevent skin irritation. To insure the chickens do not consume the granules of alum, it is best to till the product into the litter. This can be done with a litter de-caker or with any other device that physically mixes the alum into the litter. Liquid alum is normally only applied by a certified professional applicator. There are two types of liquid alum - normal liquid alum (48.5% alum) and acid alum (36.5% alum). Acid alum is preferred in situations where the litter is very dry, since it activates quickly. To add the equivalent of one ton of dry alum, 370 gallons of liquid alum or 51 2 gallons of acid alum is needed. References: Moore, P.A., Jr., S. Watkins, D.C. Carmen, and P.B. DeLaune. 2004 Treating poultry litter with alum. University ofArkansas Cooperative Extension Fact Sheet (FSA8003-PD-1 -04N). Moore, P.A., Jr, T.C. Daniel and D.R. Edwards. 2000. Reducing phosphorus runoff and inhibiting ammonia loss from poultry manure with aluminum sulfate. J. Environ. Qual. 29:37-49. Moore, P.A, Jr., and D.R. Edwards. 2005. Long-term effects of poultry litter, alum-treated litter, and ammonium nitrate on aluminum availability in soils. J. Environ. Qual. 34:21 04-2111 . Moore, P.A, Jr., and D.R. Edwards. 2007. Long-term effects of poultry litter, alum-treated litter, and ammonium nitrate on phosphorus availability in soils. J. Environ. Qual. 36:1 63-1 74. Shreve, B.R., P.A. Moore, T.C. Daniel, D.R. Edwards and D.M. Miller. 1 995. Reduction of phosphorus runoff from field-applied poultry litter using chemical amendments. J. Environ. Qual. 24:1 06-111 .

Ascites (Water Belly) in Broiler Chickens during Winter Season

Ascites (or water belly) is a condition of fast growing broiler chickens in which the excess amount of ascitic fluid accumulated in the abdominal cavity. It has become major concern to the poultry industry around the world. This condition is extremely common in high altitude & more particularly during winter / cooler season.

Ascites is associated with inadequate supply of oxygen, poor ventilation and respiratory disease complex aetiology. Morbidity is usually 1-5%, mortality 1-2% but can be up-to 30% at high altitude.

During winter season broilers are fed high energy diets to meet their nutritional demands. Since fast growing broilers have high basal metabolic rate (BMR), to metabolize high energy diet, their body needs of oxygen multipliers. There is high demand of blood through heart & lungs for proper body function due to high BMR & high energy diet.

This physiological demand increase pulmonary arterial pressure (hypertension). Bird lungs have very little ability to expand and the blood capillaries in the lungs are not able to handle increased blood flow or blood pressure. The result is an increased pressure in the liver with leakage of blood fluids, without the red blood cells, into the body cavity forming ascites or water belly.

Following may be the cause of ascites (water belly):

Today´s broilers grow much faster, eating less feed. The growth of the heart and lungs has not increased in size proportional to the increase in body weight and breast meat yield. The rapid growth of the bird means more oxygen demand, requiring more work out of the heart and lungs.
Anything that limits oxygen uptake from the lungs is going to cause the heart to work harder. Diseases of the lungs and poor ventilation may be involved. Major cause of Oxygen deficiency :
a) Presence of ammonia in the poultry house. Birds are unable to get adequate oxygen as they inhale air full of ammonia so blood is deprived of oxygen supply.

b) The dust particle in the air of poultry shed are inhaled by the birds and while exhaling they settle in various part of air sacs, specially thoracic air sac where air stays for longer period which leads difficulty for birds to breath hence deficiency of oxygen in the blood.

c) Presence of high carbon dioxide level in the shed either due to overcrowding, poor ventilation, blocking fresh & cold air during winter with curtains or due to lack of proper exhaust fans results deficiency of oxygen in the blood of bird.

Excess levels of sodium in the water or salt in feed leads to increased blood pressure in the lungs. Many feed millers still use fish meal high levels of sodium. Levels of sodium over 400 ppm could cause problems in broilers.
High altitudes have long been known to cause heart failure and ascites.
Chilling is a common cause in small flocks. It causes an increased blood flow through the lungs.
Signs of ascites:

High rate of panting is often observed in ascitic birds even the absence of apparent heat stress.
Gurgling sound often accompany as they often just sit with panting.
Birds which are ascitic may show sign of Cyanosis (a blue discolouration of skin) especially around comb & wattles.
Ascitic birds tire out easy and often die on their bellies.
Most death begins at about 3 weeks of age.
If their belly is opened, a cup or more of fluid or jellied material will pour out.
Lungs of ascitic bird may often appear pale or greyish. Lungs are extremely congested & oedematous.
Liver enlargement is often seen.
Thickening of right side myocardium & dilation of the ventricle are very common.
Microscopic finding - increased cartilage nodules in lung.
Sometimes birds die from the effects of too much blood and fluid in their lungs before there is any significant amount of fluid in the body cavity.
Identification:

To differentiate from broiler "Sudden Death Syndrome" and "Bacterial Endocarditis", a cardiac specimen (Troponon T) can be measured in blood.

How to minimize ascites (water belly)?

Keep air quality fresh by moving air regularly and efficiently. In the colder months, it is better to add heat and keep the air moving than to shut down vents or reduce airflow in an effort to conserve heat.
Treat litter by "Liiteron" to reduce ammonia production. Litter treatment is important to reduce incidence of water belly.
Restricting feed, feeding a mash diet, or using a less energy and protein diet.
Checking sodium level of water, if sodium level is high then consider using an alternate source of water that is better quality for the first 3 - 4 weeks.
Replace fish meals with other readymade source like amino acid arginine, if it is being used as Sodium level more than 400 ppm could be problem for broiler.
Careful attention to brooding temperature is also critical for minimizing water belly.
Prevent respiratory disease conditions.
Select breeds which are not genetically susceptible to this condition.
The objective should be to minimize progression leading from pulmonary hypertension to terminal ascitis or water belly condition for availing better profit during winter season. Best Management Practice is only answer to reduce problem of Ascites (Water belly) and insure better ROI.

Author : Ganesh Kumar Dahal (Guybro)

Poultry Production Without Antimicrobials

A healthy intestine is vital for good health and production in poultry, according to Dr Richard Bailey, poultry health scientist with Aviagen.
Speaking on the importance of the intestinal microbiota for chicken health at the joint session of the British Society of Animal Production and the UK Branch of the World's Poultry Science Association earlier this year, Dr Bailey said that one of the key aims of producing animals for the food chain is to obtain good growth rates and performance through feed conversion efficiency while maintaining optimal animal health. To achieve this, a healthy gut is essential, he said.
Optimal intestinal health is heavily reliant upon the acquisition and maintenance of a balanced intestinal microbiota, which has become one of the key topics in the European poultry industry.Microorganisms reside in all known habitats, therefore, animals have had to evolve in a world full of bacteria, viruses, fungi and protozoa. Part of the evolutionary process has resulted in symbiotic relationships between an animal and its microbial residents.
The intestinal microbiota of an animal is a complex population of microbes dominated by a large bacterial community. The composition of this community is highly dynamic with spatial shifts in population along each region of the intestinal tract in relation to the change in conditions of each section.With total bacterial cells numbers outnumbering the host's own cell number by a ratio of 10 to one, it is not surprising that the intestinal microbiota plays a vital part in the health and well-being of all animals, Dr Bailey said.
Many mechanisms have been identified by which the microbiota promotes host health. It has been found that the intestinal microbiota aids digestion, protects against pathogens, produces nutrients and plays a role in the development and maturation of the immune system.With the advent of culture-independent DNA technologies, our knowledge of the composition of the intestinal microbiota has improved greatly, explained Dr Bailey. Using these techniques, it has been suggested that the intestinal microbiota of the chicken comprises around 640 species of bacteria from 150 different genera. The increased application of molecular methods has revealed that culture-based methods had vastly underestimated the complex community of bacteria within an animal's microbiota.
It has been demonstrated that the composition of the intestinal microbiota is affected by factors such as sex, age, dietary intake and health status of the host. The exact relationship between the host and its resident microbiota is still an active area of research and it is becoming ever more apparent that the intestinal microbiota is highly influential in terms of host health and immunity. Culture-independent techniques combined with '-omics' technologies have allowed microbiologists to learn more about the relationship between the host and its resident microbiota.
There is a delicate balance between the host, intestinal microbiota, the intestinal environment and diet, continued Dr Bailey. If there is an imbalance in the relationship, the composition of the intestinal microbiota may alter. The shift in microbial populations can have a negative effect on the host, leading to poor growth and impaired performance. This is seen in cases of dysbacteriosis.
Dysbacteriosis is a digestive condition of poultry and has been broadly described as an overgrowth of the intestinal microbiota – especially members of the Bacteriodetes, Clostridium spp. and E. coli – which can lead to non-specific enteritis. Onset is usually between 20 and 30 days of age and it is thought to be triggered by changes in diet, poor management and overcrowding. The condition rarely causes clinical signs but it can adversely affect bird performance.
Typically, dysbacteriosis is treated using antimicrobial therapy. However, with increasing pressure on veterinarians and poultry producers in many countries to reduce antibiotic use, there is a need to find alternatives to promote good intestinal health and prevent intestinal upsets.The management of intestinal health without antimicrobials is a wide area of research. The use of a probiotic supplement is a popular approach, said Dr Bailey. Probiotics have been found to boost enteric health by inhibiting the growth and/or attachment of less favourable bacteria in the intestinal tract or by modulating the composition of the intestinal microbiota towards a more favourable community.
Intestinal bacteria derive most of their energy from the host's diet so poultry feed composition has a major influence on bacterial populations and it is possible to modulate the microbiota by altering the diet and including specific components, such as essential oils, oligosaccharides (in the form of prebiotics), enzymes and specific carbohydrate sources.
Deciding on the best approach is not easy as results from intervention studies can vary. The key to the maintenance of intestinal health is to understand how the intestinal microbiota changes at key points in the bird's life and how to prepare the bird for these changes.
The combination of practical field experience from poultry producers and veterinarians with laboratory research into the relationships between the host and its microbiota is likely to reveal further ways by which enteric health can be improved in future.
Summing up, Dr Bailey said that intestinal health is vital for good overall health and performance in poultry, as in other animals. Disruption of the resident bacteria can have detrimental effects, leading to digestive upsets and a loss in performance. However, he said, there is a mounting body of evidence indicating that the intestinal microbiota can be successfully modulated by the use of probiotics, when the appropriate product is administered correctly and at the appropriate time.
Research into alternatives to antimicrobials remains an important area of study. A number of research groups from across the globe have demonstrated in laboratory trials that there is a place for products such as probiotics in helping to control gut pathogens, thus reducing the need for antimicrobials. They also have potential to help establish a healthy gut microbial population early in the chick's life and potentially prevent intestinal imbalances as the result of common stressful events, such as feed change, vaccination or thinning, added Dr Bailey.
Source :www.thepoultrysite.com/articles/2144/poultry-production-without-antimicrobial