Organic Meat Production and Processing

Steven C. Ricke, Ellen J. Van Loo, Michael G. Johnson, Corliss A. O'Bryan, Steven C. Ricke, Ellen J. Van Loo, Michael G. Johnson, Corliss A. O'Bryan

• Publisher: Wiley-Blackwell
• Year: 2012
• Print ISBN: 9780813821269
• eBook ISBN: 9781118229231
• Edition: 1
• Topic: Technik & Maschinenbau
• Subtopic: Lebensmittelwissenschaft

Organic Meat Production and Processing describes the challenges of production, processing and food safety of organic meat. The editors and international collection of authors explore the trends in organic meats and how the meat industry is impacted. Commencing with chapters on the economics, market and regulatory aspects of organic meats, coverage then extends to management issues for organically raised and processed meat animals. Processing, sensory and human health aspects are covered in detail, as are the incidences of foodborne pathogens in organic beef, swine, poultry and other organic meat species. The book concludes by describing pre-harvest control measures for assuring the safety of organic meats.

Organic Meat Production and Processing serves as a unique resource for fully understanding the current and potential issues associated with organic meats.

Section V

Preharvest Control Measures for Assuring the Safety of Organic Meats

20 Probiotics as Pathogen Control Agents for Organic Meat Production

Gregory R. Siragusa and Steven C. Ricke

Abstract: Probiotics, also referred to as competitive exclusion cultures or direct-fed microbials, consist of either single microorganism or groups of microorganisms that when administered to a host animal are capable of eliciting an identifiable beneficial response in the recipient host. Beneficial responses include limiting food-borne or disease-causing pathogen colonization and/or infection, as well as a myriad of host performance indicators such as improved or more efficient growth and better health. Although probiotics have been examined for most food animal species, it is still unclear which mechanisms are employed by these cultures. Both host and microbial factors are involved in an interactive fashion between the commensal bacteria and the corresponding host animal. As more sophisticated molecular tools are applied to the gastrointestinal tract microbiota, a much more precise and detailed picture will emerge without doubt. Once more is known about the gut microbiome, it should be possible to develop more consistent and effective probiotic cultures.

Keywords: probiotics; competitive exclusion; antibiotic growth promoters; poultry; ruminants; swine; microbiome; direct-fed microbials; company-specific inoculant

20.1 INTRODUCTION

Drug-free and organic poultry production within the United States is a relatively small sector compared to conventionally reared production (USDA-ERS, 2010), but antibiotic-free production is increasing in volume (O’Bryan et al., 2008). From 1997 to 2008, total poultry numbers (broilers, layers, and turkeys) certified in the United States Department of Agriculture (USDA) organic program increased from 798,250 to 15,518,075 (USDA-ERS, 2010). Growing pressure from the regulatory and public health sectors as well as consumer groups is providing a motive for the industry to consider alternative pathogen control interventions for production on a wider scale within the traditionally conventional production sector of the food animal industry.

Although a variety of biological agents have been suggested and in some cases experimentally applied to food animal production systems, much remains to be determined regarding practicality and commercialization (Nisbet, 2002; Joerger, 2003; Berghman et al., 2005; Ricke et al., 2005; Sirsat et al., 2009). Among the available biologicals, probiotics and competitive exclusion cultures have been fairly extensively examined for their potential abilities to limit colonization of food-borne pathogens in the gastrointestinal (GI) tract. Mechanistically, probiotic or competitive exclusion cultures serve more as a GI tract microflora barrier that “competitively excludes” or prevents colonization of the respective food-borne pathogen. The purpose of this chapter is to highlight administration of probiotics as an alternative biological intervention for pathogen control in food animal production to decrease reliance on antibiotic growth promoters (AGPs) or conventional antibiotics.

20.2 ANTIBIOTICS IN FOOD ANIMAL PRODUCTION

While antimicrobial resistant (AR) bacteria and their association to both human disease and AGPs usage in agriculture is a contentiously debated issue, there is little question of the adverse impacts on poultry production efficiency arising from withdrawal of AGPs. For example, since original work published by Jukes and Williams (1953), poultry production has clearly been more consistently efficient and highly reliable with the routine usage of AGPs of various classes. While estimates for nontherapeutic antibiotic usage in the US poultry industry varies (Jones & Ricke, 2003), the impact of feeding low levels of antibiotics has been proven to select for resistant bacterial pathogens and many examples have been published on the incidence of specific antibiotic resistance expression among poultry associated zoonotic pathogens from antibiotic-fed poultry (Butaye et al., 2003; Emborg et al., 2003; Ashayerizadeh et al., 2009; Young et al., 2009). Challenges to the routine usage of AGPs in poultry production is strongly driven by the development and increased incidence of AR human pathogenic bacteria, as well as a basic understanding of the propagation of antibiotic-resistant bacteria (Aminov & Mackie, 2007). While the scientific evidence for reducing AGP usage is relatively consistent, the economic case for AGP usage has been analyzed for its high cost to producers with questionable return (Graham et al., 2007). Not all interpretations of the data support a ban on AGPs (Phillips et al., 2004).

Poultry welfare and disease incidence are reported to be negatively impacted from AGP withdrawal. In production terms, poultry disease levels rise, mortalities increase, feed conversion worsens, and final weights decrease significantly. From a microbiological viewpoint, AGP withdrawal presents conditions favorable to clostridial overgrowth and subsequent necrotic enteritis, avian pathogenic Escherichia coli (APEC) proliferation, and resulting clinical or subclinical disease. The ever-present challenge from Eimeria spp. coccidiosis, which is considered to precede onset of clostridial disease, becomes even more critical to bird health (Williams, 2005).

Within the European Union, AGPs are banned from usage in livestock production. The so-called “Danish Experiment,” whereby a complete ban of AGPs was mandated, has led to an industry which is able to meet production demands albeit at a greater food cost to the consumer (Aarestrup et al., 2008). From a worldwide poultry production viewpoint, countries that ultimately export their poultry meat must also consider and adhere to the food laws of the importing country and produce meat for final delivery within that standard.

Another consequence of subtherapeutic antibiotic withdrawal from poultry production is that there appears to be an increased rate of carriage of some food-borne bacterial pathogens including Campylobacter while the case for Salmonella is less clear (Ashayerizadeh et al., 2009; Bokkers et al., 2009; Young et al., 2009). Increased governmental and public health sector oversight and standards for lower levels of these pathogens will elevate the rising rate of zoonotic pathogens to an even greater level of importance for the producer, whether conventional or AGP free.

The food animal sector should continue to strive for producing meat that is reduced in zoonotic pathogen carriage, efficiently produced, enhances animal welfare, and does not deposit high levels of antibiotics in the environment to select for AR bacteria. On a more practical level, veterinarians, nutritionists, and production managers would benefit by having a set of alternative interventions that offer different advantages specific for their operations over time. A case in point is the usage of alternative feed ingredients such as dried or wet distillers grains (DDGS) that is steadily rising as a result of the current bioethanol industry; however, the impact of these ingredients have been shown to adversely affect microbial profiles of livestock by predisposing cattle to higher carriage rates of enterohemorrhagic E. coli (Wells et al., 2009). Conversely, in broilers, the impact of DDGS on the general microbial levels was not observed, but it remains to be shown whether such alternate feed ingredients impact levels of pathogenic subtypes of APEC or type A Clostridium perfringens (Loar et al., 2010). In the future, use of new and varied feedstuffs available to both the conventional, drug-free, and organic poultry producers will require pathogen control interventions that are effective within a variety of changing feed compositions.

20.3 DEVELOPMENT OF PROBIOTICS

Probiotics or direct-fed microbials (DFM) are live bacterial cultures which when administered to the host animal impart a beneficial influence on the host in some detectable manner. The majority of the focus for probiotic and DFM application in food animals has been on their potential ability to limit food-borne pathogen colonization in the GI tract. Only recently have other benefits to the host animal become a focus of extensive research (Yan et al., 2011). Development and application of probiotics in feeds and food production has been extensively reviewed. Bernardeau and Vernoux (2009) differentiated probiotic use into the era of 1950–1993 and post-1993. This chronological division was derived from a consideration of regulatory status and oversight, safety, and product efficacy and claims. Although probiotic and DFM cultures have historically garnered interest as a potential means to improve overall host animal or human health via introduction of bacteria identified as beneficial to the host, considerable uncertainty persists on how best to achieve success (Klaenhammer, 2000; Saarela et al., 2000). Part of the problem rests with a lack of understanding and appreciation of just how complex the GI tract microflora truly is in most farm production animals.

The classic approach to probiotic or DFM administration to animals has been to introduce bacterial cultures to relatively young animals such as day-old chicks where the gut microflora has yet to develop and the GI tract remains relatively unoccupied. Early successes with undefined culture mixtures proved that this concept would be effective against food-borne pathogen invaders such as Salmonella (Nurmi & Ratala, 1973). Subsequent efforts to refine this approach proved to be more inconsistent and less predictable, primarily due to minimal attempts to identify or at least characterize the bacteria in these mixtures administered to the animal. This in turn led to efforts to use more defined cultures where the microorganisms that made up the probiotic culture were identified and administration could be more consistent for potential large-scale commercial production.

However, not knowing the fate of the probiotic culture once administered to the animal is problematic for any attempt to standardize for potential commercialization. Consequently, development of defined probiotic cultures where all bacteria were characterized became the preferred research direction for potential commercialization (Nisbet, 2002). As these cultures were developed, it became apparent that better methods were needed not only for identification of the probiotic microorganisms but elucidation of their metabolic role in the GI tract (Ricke & Pillai, 1999; Vaughan et al., 2000). Consequently, molecular techniques such as denatured gradient gel electrophores...

Table of contents

• Cover
• Series
• Title Page
• Copyright
• IFT Press Series
• List of Contributors
• Section I: Economics, Market, and Regulatory Issues
• Section II: Management Issues for Organically Raised and Processed Meat Animals
• Section III: Processing, Sensory, and Human Health Aspects of Organic Meats
• Section IV: The Current Food Safety Status of Organic Meats
• Section V: Preharvest Control Measures for Assuring the Safety of Organic Meats
• Index