Publisher Summary The chapter discusses the legal aspects for functional feed ingredients in the European Community (EC). Livestock production is important for the European economy. Adequate nutrition of animals is achieved by balanced diets and by the inclusion of compounds with specific functional effects. Feed additives have to undergo admission procedures that ensure efficacy and safety. In companion animals, trends can be observed towards foods with proven or assumed health benefits. Pet food is in this aspect similar to human food. Feedingstuffs that are brought onto the market with “health claims” must be admitted as feedingstuffs for particular nutritional purposes. The authorization procedure for the placing on the market of genetically modified food and feed includes feed additives consisting of, containing or produced from, genetically modified organisms (GMOs). These additives can have technological, sensory, nutritional or zootechnical impact. Specific groups are coccidiostats and histomonostats. Depending on the claim, the intended use and their chemical and physiological properties, feed additives are categorized into the following groups: (1) chemically defined substances such as preservatives, vitamins, acidity regulators, trace elements, (2) living microorganisms, (3) spores of microorganisms, (4) enzymes. Feed additives are substances, microorganisms or preparations that are added to feed or water. Feed additives are used to favorably affect the characteristics of feed, the characteristics of animal-derived products, or the color of ornamental fish and birds. Feed additives are used to fulfill the nutritional needs of animals, to reduce the negative impact of animal production on the environment, to have positive effects on animal production, performance or welfare. This is particularly accomplished by effects on the gastrointestinal microflora, by enhancement of the digestibility of feedingstuffs, or by a coccidiostatic or histomonostatic effect. The chapter discusses several regulations related to these additives.

Publisher Summary The chapter presents a discussion on intestinal fermentation, including dietary and microbial interactions. The major benefits derived from the use of antibiotics in subtherapeutic doses in animal feeding involve: disease prevention, improved feed efficiency and increased performances, especially for the young stressed animals and where management and hygiene conditions are not excellent. In pig farming, feeding antibiotics is widely practiced around weaning, the time that represents the most challenging period a pig encounters during its life in terms of infection and abundance of stressors. Although the mechanism by which antibiotics promote growth is still under heated debate, the most reliable hypothesis relates to changes in the composition of the intestinal microflora. Some antibiotic-resistant strains of Escherichia coli have evolved compensatory mutations that preclude reversion to the sensitive state, even without selective pressure. At birth, the intestinal tract of pigs is sterile and represents a good niche for rapid proliferation of environmental bacteria. Lactobacilli, streptococci, coliforms and clostridia are the main bacterial groups that can be isolated from gastric content within the first 2–3 hours of life. Along with glucose, other metabolic fuels for the small intestine are represented by the natural polyamines: putrescine, spermidine and spermine. Another category of molecules that can play a role as microbial modulators are the prebiotics, defined as “nondigestible food ingredients” that beneficially affect the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon.

The chapter presents hypotheses and facts on the quality of dietary protein digestion affecting animal performance and regulating gut bacteria growth. The complicated digestive processing of dietary proteins and their amino acids leads to the appearance in the gut of an enormous amount of possibly biologically active and nonactive peptides. Thus, in comparison with the other dietary components, proteins are puzzling and complicated, but at the same time they are indispensable components of the foodstuffs. The composition and quality of the dietary proteins are probably the main factors limiting animal growth, health and productivity. Dietary proteins in the gastrointestinal tract (GIT) cannot only be utilized by the host—they can also be used in any form (amino acids, peptides and whole proteins) as substrates for gut microbial growth. The varieties of GIT microflora present can be related to the other mechanisms and status of the host metabolism, and to the sources of nitrogen available for the GIT bacteria. To be of advantage to the host, they should be quickly digested and effectively absorbed from the gut. This is probably the reason why the intestinal capacity for digestion and absorption and for the de novo mucosal synthesis of the protein are a few times higher than the calculated theoretical requirements. The gut bacterial endopeptidases are nonspecific, and produce amino acids from dietary proteins, while the host endopeptidases located in the brush border glycocalyx are specific, producing specific peptides. The chapter also discusses the relation between cholecystokinin (CCK) receptor function and pig growth and performance.

Publisher Summary The chapter discusses the historical changes in productivity of growing farm animals and presents some examples of interactive effects between animal type and nutritional regime on animal productivity. Animal growth is then described in the aspects of nutrient partitioning, which will allow for understanding of the varying responses to nutrient intake in different animal types. Potential implications of introducing novel traits into farm animals via modification of the animal's genome on nutrient utilization are discussed. Via genetic selection, substantial improvements have been made in growth potential and carcass characteristics of farm animals. Interactions between animal genotype and nutritional regime may be better understood when animal types are characterized in aspects of nutrient partitioning. The main aspects of nutrient partitioning for growth are (1) maintenance energy and nutrient needs, (2) whole-body nutrient retention, (3) nutrient retention support costs, and (4) voluntary feed intake. In terms of nutrient retention, special consideration should be given to wholebody protein deposition and the partitioning of retained energy between whole-body protein and whole-body lipid. Quantification of the main aspects of nutrient partitioning is extremely useful for estimation of nutrient requirements, for assessing the economic impact of altering feeding strategies in commercial animal production, and for the development of effective animal breeding strategies.

Publisher Summary The chapter presents a discussion on the manipulation and characterization of the rumen ecosystem through biotechnology. Many of the biotechnological approaches originally employed in the rumen focused on direct genetic modification of microbes, in an effort to enhance processes such as cell wall digestion, toxin degradation and the balance of nutrients delivered to the ruminant small intestine. To date, the most significant contribution of biotechnology has been to define the diversity, dynamics and evolution of the ruminal ecosystem in a manner that was previously impossible using traditional culture techniques. Cloning techniques have identified myriad genes encoding a variety of unique enzyme activities, many of which may have potential applications in livestock production and industry. Novel bacteriocins and other antimicrobial agents have also been identified, and the rumen may prove to be a rich source of novel antibiotics. Gene discovery will continue to accelerate as genome sequencing of cultivated rumen bacteria continues and uncultivated genomes become available with the production of metagenome libraries. Such approaches may provide detailed knowledge of ruminal enzyme systems, the absence of which has hampered rumen scientists in solving age-old challenges such as improving the digestion of low-quality forages and the efficiency of ruminal nitrogen utilization. The microflora of the rumen is exceedingly diverse and contains representatives of all three domains, Eucarya, Archaea, and Bacteria. Ruminal fungi exhibit the most complex life cycle of all ruminal microorganisms, alternating between a motile zoospore stage and a sessile vegetative stage.

Publisher Summary The chapter presents a discussion on manipulation of the ecosystem of pigs through biotechnology. Biotechnology is providing new methods for improving the food conversion efficiency of pigs and their ability to utilize specific nutrients. Such improvements will be reflected in reduced effluent production, in some cases targeted to reduction of specific wastes such as phosphorous. Novel mapping methods for identifying genes involved in variation in food conversion efficiency will ultimately lead to identification of genes, biochemical pathways and physiological processes, amenable to manipulation by selection, transgenesis or by nonheritable approaches, such as RNA interference or use of other small molecules for controlling gene expression. Taken in conjunction with improved approaches to processing and exploiting the valuable components of effluent as well as in modifying feeds, the biotechnological approach to modifying animals promises both economic and environmental benefits for pig production. Numerous and frequently very effective post hoc methods have been developed for handling piggery effluent and minimizing environmental impact. These include effluent lagoons for trapping waste and retaining the most environmentally damaging nitrogen and phosphorous, either by assimilation into algal biomass, which sediments out in the ponds, and/or by chemical precipitation. Genetic improvement can be obtained by performance-based selection of breeding stock. Many microorganisms produce phytase, which hydrolyzes phytate.

The chapter presents a discussion on effects of antinutritional factors and mycotoxins on feed intake and on the morphology and function of the digestive system. Antinutritional factors and mycotoxins regularly occur in all the major feed raw materials including cereals, protein concentrates and forages. This chapter discusses the effects of selected antinutritional factors and mycotoxins on feed intake, gut morphology and function and nutrient utilization. Among the antinutritional factors, the compounds most likely to cause adverse effects include protease inhibitors, lectins, antigenic proteins, particular types of oligosaccharides and polysaccharides, saponins, glucosinolates, condensed tannins, nonprotein amino acids, gossypol and biogenic amines. The mycotoxins capable of reducing feed intake and causing abnormalities in gut morphology and nutrient absorption include deoxynivalenol and ergopeptine alkaloids. In the perspective of their ubiquitous distribution there is a need to assess the effects of other mycotoxins, including aflatoxins, ochratoxin A and fumonisins and also the consequences of co-contamination. Forage and root brassica crops contain a nonprotein amino acid in the form of S-methyl cysteine sulfoxide (SMCO). Rumen microbes may also act in a defensive role, but efficacy depends upon the nature of the ANFs or mycotoxins in question. Unless due recognition is apportioned to the adverse effects of antinutritional factors (ANFs) and mycotoxins, prediction models of voluntary feed intake, digestibility and nutrient utilization will continue to be of limited commercial application.

Publisher SummaryThe chapter discusses the control of intestinal diseases by dietary supplementation with antibodies. This chapter presents the most important principles of prophylactic and therapeutic, and oral application of immunoglobulins. Because of the production conditions today about 20–40% of newborn farm animals (cattle, pigs, horses, goats, sheep) exhibit failure of passive transfer (FPT). The direct consequence of this is an increased susceptibility to diseases during the first weeks of life, which necessitates the wide use of antibiotics. As a further consequence, an increasing antibiotic-resistance of diarrheal strains of bacteria has become a fact. An alternative to using antibiotic is oral application of immunoglobulin products in the periods of greatest risk that is within the first days of life and in the postweaning period. Air-dried egg yolk immunoglobulin (IgY), cow colostrum and swine serum, which can be produced on a large scale, provide the greatest chance for mass application. The most important protective role is played by specific antibodies against antigens present in the neonate's environment. The chapter discusses application of xenogenic antibodies. There are several indications for the application of cow colostrum to foals, lambs and kids, such as lack of, or low quality of maternal colostrum, mastitis, twins or multiple fetuses, and so on. Serum produced from the blood of slaughtered swine allows the large-scale production of immunoglobulins. An important problem with oral administration is proteolysis of the immunoglobulins by digestive enzymes, while another problem is caused by inactivation of antibody activity because of low pH.

Publisher Summary The chapter presents a discussion on dietary manipulation of infectious bowel disease. This chapter discusses some influences of diet on this system, and provides examples of how manipulation of the diet can help to influence colonization by certain potential enteric pathogens. Examples are drawn mainly from the problems of postweaning diarrhea in the pig, because this is an important condition that exemplifies some of the principles being explored in nutritional intervention of enteric infections. There is general agreement that diet can have an influence on intestinal disease, particularly in young animals. This chapter discusses some such dietary interactions, and particularly focuses on the problem of diarrhea in recently weaned pigs, as this condition has been extensively studied. The pathogenic bacterial species that colonize the intestinal tract, including zoonotic bacteria such as Salmonella and Campylobacter are also discussed in the chapter. Even within an animal species, such as the pig, sites of infection with different pathogens vary from the stomach (for example, Helicobacter species), small intestine (for example, Escherichia coli ) to the colon (for example, Brachyspira species). Postweaning diarrhea (PWD) is a common disease that occurs in piggeries throughout the world. Piglets usually develop a watery diarrhea, and show a rapid loss of condition, with most members of a litter being affected. The most common and significant pathogenic types associated with PWD are enterotoxigenic E. coli (ETEC). Brachyspira pilosicoli is an anaerobic spirochete that colonizes the large intestine of pigs, as well as a variety of bird species, dogs and human beings.