In-feed Antibiotics Research Articles

Impact of nursery feeding program on subsequent growth performance, carcass quality, meat quality, and physical and chemical body composition of growing-finishing pigs1

An experiment was conducted to examine the effect of the nursery feeding program on subsequent growth performance, carcass quality, meat quality, and physical and chemical body composition of growing-finishing pigs. Four dietary treatments were used in a 2 × 2 factorial arrangement of treatments based on diet complexity (Complex vs. Simple) and in-feed antibiotics (2,730 [+AB] vs. 0 [-AB] mg of chlortetracycline /kg].A total of 552 pigs, in 5 blocks, were weaned at 21 ± 2 d of age with an initial BW of 7.03 ± 0.07 kg. Each experimental block had 3 pens per treatment, with 8 pigs per pen in blocks 1 and 2, and 10 pigs per pen in the remaining 3 blocks. Nursery diets were fed in a 3-phase feeding program (Phase I, II, and III diets fed for 1, 2, and 3 wk, respectively). All pigs were fed common grower-finisher diets thereafter. Six pigs per treatment were slaughtered for chemical body composition analysis at wk 2, 8, 12, and 17 postweaning. An additional 11 pigs per treatment were slaughtered at wk 17 postweaning (approximately 115 kg BW or market weight) for analysis of carcass characteristics, chemical and physical body composition, and meat quality. During the nursery phase, ADG was lower (P < 0.05) for pigs fed the Simple diet than those fed the Complex diet (491 vs. 528 g/d). Antibiotic usage improved (P < 0.05) ADG in Phases II (408 vs. 438 g/d) and III (689 vs. 720 g/d). In Phase I and II, G:F was lower (P < 0.05) for pigs fed the Simple diet than those fed the Complex diet (0.46 vs. 0.58 and 0.75 vs. 0.78 in Phases I and II, respectively). During the grower phase, pigs previously fed -AB diets grew faster than pigs fed +AB diets (P < 0.05; 1,009 vs. 971 g/d). There were no treatment effects on overall ADG or G:F from weaning to finishing. Nursery feeding program did not affect carcass quality characteristics. However, pigs previously fed +AB diets tended (P = 0.07) to have increased LM depth. Nursery feeding program had no effect on objective or subjective meat quality measures, chemical body composition, or the weight of primal and retail carcass cuts at wk 17 postweaning, with the exception of primal belly weight. These results indicate that feeding simple nursery diets, or nursery diets without antibiotics, compromises growth performance during the nursery period but does not affect overall growth performance between weaning and market BW, carcass characteristics, and meat quality. Thus, feed costs for nursery pigs can be reduced by feeding simple diets without compromising market BW and carcass and meat quality.

Efficacy and mode of action of selected non-ionophore antibiotics and direct-fed microbials in relation to Megasphaera elsdenii NCIMB 41125 during in vitro fermentation of an acidosis-causing substrate

The efficacy of prominent in-feed antibiotics and direct-fed microbials (DFM) to prevent or mitigate ruminal acidosis and lactate accumulation, in addition to whether their presence will enhance or inhibit Megasphaera elsdenii strain NCIMB 41125 (Me) were studied in vitro. The antibiotics studied were aureomycin+sulfamethazine as AS-700 (AS), terramycin as TM-200 (TM), zinc bacitracin (ZB), flavomycin (FM) and tylosin (TS). The DFM were Bovamine (BM) which contains a propionic bacterium and a lactobacillus, Levucell (LC) which contains a strain of the yeast Saccharomyces cerevisiae and Progut (PG) which contains a hydrolysate of S. cerevisiae. The antibiotics and DFM were introduced alone or in the presence of Me to an in vitro system with fermentation vessels containing a medium that promoted rapid gas production and lactate development. Dose sizes of the antibiotics were chosen to inhibit fermentation by 10–20% or 30–40% and for DFM dose sizes were according to the manufacturers. For Me the dose size was 100µl/40ml containing 2.5×105 colony forming units per ml. Me on average reduced lactate from 20.0mM to 4.89mM, increased VFA production and shifted VFA proportions to more butyrate and valerate (respectively from 5.80 to 16.0mM/100mM and from 0.51 to 4.71mM/100mM). The antibiotics moderately reduced lactate (26.7–16.8mM), and AS, ZB and TS enhanced a VFA proportional shift towards propionate (from 22.6 to 28.7mM/100mM). In the presence of Me lactate was reduced to levels of Me alone and the ratio butyrate to propionate was reduced. None of the antibiotics inhibited the action of Me; on the contrary the interaction was additive. In contrast to the antibiotics and PG, the DFM BM and LC did not affect fermentation resulting in no response with respect to any of the variables measured. PG in the presence of Me apparently enhanced the action of Me, as noticed by an additional increase in butyrate and valerate proportions.

TURMERIC (Curcuma longa Linn.) SUPPLEMENTATION AS AN ALTERNATIVE TO ANTIBIOTICS IN POULTRY DIETS

Antibiotics have been used in non-therapeutic fashion as growth promoter for about 50 years in many parts of the world. It has been proven that supplementation of antibiotics in the diets reduces morbidity and mortality, as well as improve feed efficiency and overall growth performance of broiler chickens. However, the routine use of these antimicrobial growth promoters (AGPs) is being curtailed in view of threat to public health occurring through microflora that are developing resistance to antibiotics. This risk has driven European Union and other countries to withdraw authorization of in-feed antibiotics since 1997. Removal of AGPs resulted in substantial increase infections in poultry. As a consequence, the poultry industry needs to find alternatives to antibiotics in order to stem the effects of infection. One comparable alternative is natural sources of herbs and medicinal plants, which later known as phytobiotics. For the last 15 years, these alternatives have been increasingly claimed to increase enteric health, stimulate digestive system, and enhance growth performance. It was reported that turmeric (Curcuma longa Linn.) belongs to such class of medicinal plant and may be an alternative to antibiotics in poultry production. In this review, the responses of poultry to diets supplemented with turmeric on growth performance, egg production, health status, and carcass characteristic were briefly discussed. Keywords: Turmeric, non-antibiotic feed additive, poultry production

Effects of feeding different postbiotic metabolite combinations produced by Lactobacillus plantarum strains on egg quality and production performance, faecal parameters and plasma cholesterol in laying hens.

BackgroundProbiotics are beneficial bacteria that are able to colonize the host digestive system, increasing the natural flora and preventing colonization of pathogenic organisms and thus, securing optimal utility of the feed. However, commercial probiotic often do not meet the expected standards and the viability of the efficacy of these strains remains questionable. Another major issue has been highlighted in relation to the application of antibiotic resistant probiotics, the antibiotic resistant gene can be transferred between organisms. Recently, postbiotic metabolites produced from microbes have been extensively studied as feed additive in order to substitute in-feed antibiotics.ResultsNo significant difference (P > 0.05) was found among the treatment groups on overall feed intake, egg weight, egg mass and feed conversion efficiency. COM456 had a significant reduction (P < 0.05) in faecal pH compared to the other groups at 28 weeks of age onwards. COM456 had significant higher (P < 0.05) level of lactic acid bacteria counts from 30 weeks of age onwards, followed by COM246 and COM345 at 32 and 34 weeks of age, respectively. Significant reduction of faecal Enterobacteriaceae (P < 0.05) were observed in COM246 and COM456 from 30 weeks of age onwards. The lowest levels (P < 0.05) of plasma and egg yolk cholesterol were observed in COM456, followed by COM345 and COM246. There was no significant difference in terms of yolk weight between the treatment groups. Significant higher (P < 0.05) content of C18:3, C20:2 and C22:6 were found in treatments supplemented with metabolite combinations as compared with the control group.ConclusionsThe present study demonstrated the positive effects of metabolite combinations supplementation in laying hens. Increase in hen-day egg production was observed in all treatments supplemented with metabolite combinations. In addition, the metabolite combinations, COM456 had reduced the faecal pH and faecal Enterobacteriaceae population, improved the faecal lactic acid bacteria, reduced the plasma and yolk cholesterol and improved the faecal volatile fatty acids content. Postbiotic metabolite combinations can be used as an alternative feed additive to achieve high productivity and better animal health while reducing the use of conventional chemotherapeutic agents such as in-feed antimicrobials.

The oregano cultivar CARVA, a security for the supply of natural carvacrol

The last two decades have seen a substantial increase in the use of aromatics herbs and essential oils for animal health and nutrition (Franz et al., 2010). In relation to public awareness of the potential health risks and environmental problems caused by in-feed antibiotics, growth hormones and some synthetic pharmaceuticals, as well as in relation with trends towards more natural approaches of food production, numerous research programs were established focusing on cultivation and extraction of plants and the use of their health related compounds for feeding animals.

Effects of virginiamycin against experimentally induced necrotic enteritis in broiler chickens vaccinated or not with an attenuated coccidial vaccine

SUMMARY Necrotic enteritis (NE) is a deadly poultry disease caused by Clostridium perfringens. Infeed antibiotics such as virginiamycin (Vm) are commonly used in many countries to control NE. A ban on in-feed antibiotics usage in some European Union countries has caused an increase in the incidence of NE. In the present investigation, first, the effects of a live attenuated coccidial vaccine on the severity of experimentally induced NE in broilers and the role of Vm in prevention of disease were assessed. Second, we studied whether Vm, salinomycin (Sm), or both would help to reduce the severity of NE. The results of the first study showed that although the administration of a double dose of an attenuated coccidial vaccine led to a higher morbidity and mortality among C. perfringens-challenged birds, Vm prevented mortalities and improved the performance parameters among the vaccinated birds. In the second study, administration of Vm and Sm for 30 d were efficacious in preventing NE induced by C. perfringens which had been previously isolated from acute cases of NE in broiler farms. However, the short-term effects of in-feed Vm against NE, although evident in reducing the mortalities, were not satisfactory. This study provides further evidence that in-feed Vm benefits the poultry industry by prevention of NE.

Immune-modulatory effects of dietary Saccharomyces cerevisiae cell wall in broiler chickens inoculated with Escherichia coli lipopolysaccharide

1. An experiment was conducted to study the effect of yeast (Saccharomyces cerevisiae) cell wall (YCW) supplemented in diets of broiler chickens challenged with Escherichia coli lipopolysaccharide (LPS).2. One-day-old broiler chicks were randomly distributed into 24 cages (6 replicate cages; 8 birds/cage) and were inoculated with 0 or 1 mg/kg body weight E. coli-LPS (d 4 and 9) and 0 or 500 mg YCW/kg feed, resulting in a 2 × 2 factorial arrangement of treatments. Experimental diets did not include coccidiostats, in-feed antibiotics or enzymes.3. On d 21, the inoculation of E. coli-LPS reduced weight gain and feed intake and increased feed conversion ratio (FCR) of birds, an effect maintained until 28 d. In contrast, chickens given diets with YCW improved the FCR at both 21 and 28 d of age.4. E. coli-LPS challenge reduced the relative weight of bursa of Fabricius, except when chickens were given YCW, which resulted in an interaction. Supplementation of broiler diets with YCW exacerbated the cellular immune response as measured by the delayed cutaneous hypersensitivity response test.5. The results of this study suggested a benefit on feed efficiency when YCW was added to diets fed to broiler chickens challenged with E. coli-LPS. Part of the mode of action of YCW might be related to better maintenance of immune status in response to microbial challenge.

Effects of extracts of Humulus lupulus (hops) and Yucca schidigera applied alone or in combination with monensin on rumen fermentation and microbial populations in vitro

β-Acids in hops (Humulus lupulus) and saponins in yucca (Yucca schidigera) have been found to possess antimicrobial properties similar to that of monensin and could be an alternative to in-feed antibiotics. The effects of monensin (MON) and ethanol extracts of hops (HE) and Y. schidigera (YE) alone and in combination with MON were assessed on ruminal microbial composition and fermentation in vitro of a barley-based diet. All treatments decreased (P < 0.05) CH4 production (per unit of dry matter), microbial protein (mg), and NH3 -N accumulation. All treatments reduced (P < 0.01) the acetate:propionate (A:P) ratio and molar proportions of butyrate, but increased (P < 0.01) those of propionate, whereas those of acetate decreased (P < 0.001) with addition of MON (10 µg mL(-1)) and combined with HE or YE. Methane produced per unit of true digested dry matter decreased (P < 0.001) with all treatments except YE. Monensin reduced (P < 0.001) proportions of 16S rRNA copies of Ruminococcus flavefaciens, but increased (P < 0.01) those of Selenomonas ruminantium. Hops extract alone or combined with MON reduced (P < 0.01) proportions of R. flavefaciens but combined with MON tended (P < 0.1) to increase those of S. ruminantium. Yucca extract combined with MON increased (P < 0.01) the proportions of R. flavefaciens and S. ruminantium. All treatments except MON (2.5 µg mL(-1)) reduced (P < 0.01) the relative abundance of methanogens. Hops extract and YE altered rumen microbes and fermentation in a manner similar to MON with many responses being additive when applied in combination.

Effects of Pharmacological Concentrations of Dietary Zinc Oxide on Growth of Post-weaning Pigs: A Meta-analysis

Pharmacological dietary zinc (Zn) concentrations of 1,000 to 3,000 mg/kg diet from Zn oxide have been found to increase growth in post-weaning pigs. However, results were inconsistent among studies. A frequentist meta-analysis, in which effects were numerically described with standardized effect sizes (Hedges's g), was conducted in order to identify and quantify the responses in average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G/F) in post-weaning pigs upon dietary Zn supplementation from Zn oxide. The inability of independent continuous variables to explain significant heterogeneity obtained with fixed effect models necessitated the use of random effects models to calculate summary statistics. Dietary Zn supplementation increased (P < 0.05) ADG (mean effect size = 1.086, 95% confidence intervals = 0.905-1.266, 26 studies, 72 comparisons), ADFI (mean effect size = 0.794, 95% confidence intervals = 0.616-0.971, 25 studies, 71 comparisons), and G/F (mean effect size = 0.566, 95% confidence intervals = 0.422-0.710, 24 studies, 70 comparisons). Zinc oxide provided a feasible alternative to in-feed antibiotics to improve growth in post-weaning pigs, and its reduction in diets due to potential environmental pollution will have to be negated by alternative feed additives and management strategies in order to prevent economic losses.

Diverse and abundant antibiotic resistance genes in Chinese swine farms

Antibiotic resistance genes (ARGs) are emerging contaminants posing a potential worldwide human health risk. Intensive animal husbandry is believed to be a major contributor to the increased environmental burden of ARGs. Despite the volume of antibiotics used in China, little information is available regarding the corresponding ARGs associated with animal farms. We assessed type and concentrations of ARGs at three stages of manure processing to land disposal at three large-scale (10,000 animals per year) commercial swine farms in China. In-feed or therapeutic antibiotics used on these farms include all major classes of antibiotics except vancomycins. High-capacity quantitative PCR arrays detected 149 unique resistance genes among all of the farm samples, the top 63 ARGs being enriched 192-fold (median) up to 28,000-fold (maximum) compared with their respective antibiotic-free manure or soil controls. Antibiotics and heavy metals used as feed supplements were elevated in the manures, suggesting the potential for coselection of resistance traits. The potential for horizontal transfer of ARGs because of transposon-specific ARGs is implicated by the enrichment of transposases--the top six alleles being enriched 189-fold (median) up to 90,000-fold in manure--as well as the high correlation (r(2) = 0.96) between ARG and transposase abundance. In addition, abundance of ARGs correlated directly with antibiotic and metal concentrations, indicating their importance in selection of resistance genes. Diverse, abundant, and potentially mobile ARGs in farm samples suggest that unmonitored use of antibiotics and metals is causing the emergence and release of ARGs to the environment.

Keynote Symposium: “Tomorrow's Poultry: Sustainability and Safety” introduction and welcome

Abstract The title of the Keynote Symposium at the 2012 Poultry Science Association Meeting at the Georgia Center in Athens, Georgia, was “Tomorrow's Poultry: Sustainability and Safety.” The purpose of the symposium was to provide members and guests of the Poultry Science Association an opportunity to be updated on the recent developments in enhancing the safety of poultry foods and also to interact with an internationally recognized group of speakers who are pursuing novel strategies for increasing the safety and sustainability of US poultry production. These are very exciting times in poultry science. The poultry industry is one of the fastest growing animal food industries globally. Over the past 50 yr, through a combination of improved breeding, nutrition, management, and advances in disease control, commercial poultry industry has made monumental gains in production efficiency. Success also comes with challenges. Modern birds have weakened immune systems, increased disease susceptibility, and dependence on in-feed antibiotics. Consumers have voiced a concern about the widespread use of in-feed antimicrobials. Such concerns have led to the tremendous increase in organic poultry production in recent years. However, such antibiotic-free production systems also face bacterial disease challenges such as necrotic enteritis resulting in reduced growth rate, poor feed efficiency, and increased contamination. It is imperative that today's poultry industries be proactive in improving the safety of poultry foods. Addressing these challenges requires an increased input of knowledge about production systems and expertise to develop integrative systems that maximize animal health and product safety in a sustainable manner. Such measures include improvement of diet, use of biocontrol measures to enhance bird health, and novel processing and packaging strategies to enhance safety of food products. These measures must also be cost-effective for the continued viability of the industry. It is essential to understand these different strategies in order to successfully plan for the future of poultry production and food security in the United States. The objectives of 2012 Keynote Symposium were to provide a direct interaction and collaboration among food/feed scientists, nutritional immunologists, microbiologists, and veterinarians who are working in the areas of bird health, feed, and food safety. Such a dialogue will foster cross-fertilization of ideas and stimulate the development of innovative strategies to enhance food safety and the sustainability of US poultry food systems. To address these, the topics selected for the symposium covered a considerable spectrum of areas of emphasis in immune nutrition, gut ecology, plant-derived antimicrobials, antimicrobial peptides, processing, and packaging aspects. Health challenges from the perspective of a veterinarian related to organic production were also addressed.

Moringa olefiera: Could this be an Answer to our Need for an Alternative to Fighting Drug-Resistance and Chronic Infections?

Each year, the Center for Disease Control and Prevention (CDC) spend a substantial amount of time and resources to help fight the war on antibiotic resistance. This agency has focused a lot of its attention on education and reducing the use and unnecessary prescribing of these drugs. Over the past 25 years, the development of new antimicrobial drugs is dwindling, while the development of resistance to human or food animal therapeutic agents continue to double [1]. The use of subtherapeutic levels of antibiotics in animal feed in recent years has raised concern about the development of resistant pathogens in animals and their transfer through food to humans, and placed pressure on meat producers to eliminate the use of antibiotics in food animals. As such, there is increased interest in identifying substances that can reduce the use of in-feed sub-therapeutic antibiotics. Nutraceuticals, or natural supplement that promotes animals’ defense against infection and disease can serve as a suitable substitute for the antibiotics.

Effect of onion (&amp;lt;i&amp;gt;Allium cepa&amp;lt;/i&amp;gt; L.) as an antibiotic growth promoter substitution on performance, immune responses and serum biochemical parameters in broiler chicks

This experiment was conducted to evaluate the effect of onion (Allium cepa L.) as an antibiotic growth promoter substitute on growth performance, immune responses and serum biochemistry in broilers. A total of 192 one-d-old as hatched broiler chicks (Ross 308) were weighed and randomly allocated to four treatment groups, each with 4 replicate pens of 12 chicks. The dietary treatments consisted of the basal diet (control), antibiotic (15 mg Virginiamycin/kg), and control +10 or 30 g fresh onion bulb/kg diet. Body weights of broilers were determined at d 1, 21 and 42, feed intake was determined at the same periods, and feed conversion ratio was calculated accordingly. At 14th and 21st days blood samples were taken for measuring antibody titers against NDV and at 42nd day for biochemical analysis. At d 42, two birds per replicate were slaughtered for determination of lymphoid organ weights. Dietary supplementation of30 g/kg onion increased final body weight of broilers at 42nd d of age compared to the other treatments (P < 0.05). Birds fed30 gonion/kg in the diet had the highest feed intake than other treatments at different growth periods (P < 0.05). Dietary treatments failed to induce any significant effect on antibody titers against NDV, although the weight of lymphoid organs was significantly (P < 0.05) higher for birds fed diets supplemented with30 g/kg Onion. Broilers receiving30 g/kg onion had a significantly higher HDL and lower triglyceride concentrations compared to control groups (P < 0.05). Feeding30 g/kg onion resulted in a marked reduction in the concentration of the glucose compared to control groups (P < 0.05). The results suggested that dietary inclusion of30 g/kg onion can be applied as alternatives to in-feed antibiotics for broiler diets.

Effects of the Essential Oil Blend CRINA® Poultry in Feed on Broiler Performance and Gut Microbiology

The aim of the present study was to investigate the influence of a commercial essential oil blend (EO), CRINA® Poultry (CRP), as an alternative to in-feed antibiotic, enramycine®, on growth parameters of broilers during pre and post-challenge with Clostridium perfringens (C. perfringens). The birds received treatments from 0 to 30 days as follows: T1, positive control (+CONT): without medication or bacterial challenge; T2, negative control (-CONT): without medication but with C. perfringens challenge; T3, antibiotic with addition of enramycin with C. perfringens challenge (ENRA); and T4, with addition of CRINA® Poultry to feed with C. perfringens challenge (CRP). Overall, feed intake (FI), body weight gain (BWG) and feed conversion ratio (FCR) was not significantly different among the four treatments (P>0.05). On the other hand, EO supplementation caused some changes in the gut morphology, birds which had received CRP had longer ileal villi as compared to +CONT or ENRA groups (P<0.05). The performance of the birds which had consumed CRP was similar to all other treatments. On the other hand, the results obtained from this trail clearly showed that CRP supplementation failed to control the proliferation of C. perfringens in the intestine. The results from this study indicated that CRP under the condition of this experiment had no influence on broilers performance but it had a positive effect on gut morphology.

Alternatives to antibiotics for farm animals.

Abstract Nowadays, there is an increasing concern for the public health about the consequences from the long and increased use of antibiotics in livestock production. The use of antibiotics in animal feed as growth promoters has been completely banned by the European Union since 2006, based on their possible negative effects on human and animal health. The removal of growth promoters has led to animal performance problems and a rise in the incidence of certain animal diseases. Thus, there is an urgent need to find alternatives to antibiotics, especially in EU. Due to the modern consumers' concern about the potential development of antibiotic-resistant bacteria as well as at the same time the need to prevent economic losses of the farmers, alternatives to antibiotics has been developed to prevent the health problems and to improve the growth performance in farm animals. Owing to the full ban of antibiotic use in EU there is an urgent need to find alternatives to in-feed antibiotics. New strategies and commercial products must be developed to improve animal health and performance, based on their safety, efficacy and cost-effectiveness. The aim of this study is to summarize the beneficial effects of currently used alternatives to in-feed antibiotics, i.e. probiotics, prebiotics, organic acids, phytogenic compounds and zeolites on health and growth performance in farm animals (swine, poultry and ruminants).

Range use and pasture consumption in free-range poultry production

The recent increase in free-range meat and egg production and consumption has led to extensive investigation in this area and has revealed that the level of animal performance achieved in such systems is low compared with that achieved in conventional production systems. In Australia, this difference has been attributed either to the absence of in-feed antibiotics or to range access, which may result in exposure to detrimental climatic conditions, predators, disease, welfare challenges and nutrient dilution. Moreover, although poultry in free-range systems have ready access to outside runs, not all birds utilise them optimally. Pasture consumption results in dilution of energy and protein intake and may cause impaction and dietary electrolyte imbalance. This paper provides an overview of these issues to provide a conceptual framework for further study in this area.

Interactions of Saccharomyces cerevisiae fermentation product and in-feed antibiotic on gastrointestinal and immunological responses in piglets challenged with Escherichia coli K88+1

Interactive effects between in-feed antibiotics (PC; 0.04% chlortetracycline + 0.004% Denagard) and a Saccharomyces cerevisiae fermentation product (XPC) were investigated. Five pens of 3 pigs/pen were randomly allotted to one of six diets consisting of control (NC; no additives), XPC alone (0.2%), PC alone, or PC plus one of three levels of XPC (0.1, 0.2, or 0.4%). On day 7, all pigs were bled for baseline serum and then orally inoculated with a 6-mL dose of 2 x 10(9) cfu/mL of ciprofloxacin-resistant Escherichia coli K88(+) (ETEC). Severity of diarrhea, using fecal score (FS), was assessed on days 8, 9, and 10. On day 10, pigs were bled and 1 pig/pen was killed to obtain gastrointestinal (GIT) samples. Remaining pigs were monitored for another 4 d and then killed to obtain GIT samples. Pigs fed PC and XPC in combination of PC had a lower (P = 0.02) FS than NC. The PC pigs had lower (P = 0.02) serum interleukin-6 and XPC pigs had higher (P < 0.01) serum tumor necrosis factor-α than NC pigs. Ileal mucosal ETEC count was lower on day 10 (P = 0.04) and day 14 (P < 0.01) when additives were fed in combination. Microbiome analysis of day 10 digesta using pyrosequencing showed that pigs fed the PC with XPC had enriched (P = 0.01) Streptococcaceae family than PC fed alone. On day 10, pigs fed PC alone and in combination with XPC at a lower dose had shallower (P = 0.01) crypt depth than those fed higher doses of XPC, XPC alone, or NC. Pigs fed XPC had a thicker colon wall on day 10 (P < 0.01) compared to those fed non-XPC diets. Ileal and colonic digesta NH(3) concentration was lower (P < 0.05) for pigs fed additives-containing diets on days 10 and 14. Feeding PC or XPC reduced diarrhea and the number of ETEC attached to the ileal mucosa; however, responses suggest independent and interactive effects that might be associated with the nature of these additives.

Superbugs: the ever growing threat in our food supply

Dear Editor, Antibiotic resistance is rapidly rising. Many bacterial infections are now very difficult, and sometimes impossible, to treat. Gram negative bacteria are the pointy end of this growing problem, including very common bacteria such as E. coli. Antibiotic resistance is proportional to use. The more antibiotics used, the more resistance develops and spreads. This is both in individuals (e.g. with pneumococcus) and for populations in different countries. With many common bacteria, transmission is almost entirely human-to-human (e.g. pneumococcus, gonococcus, meningococcus). Thus, any antibiotic resistance seen in these bacteria will be almost entirely due to antibiotics used in the human sector. However with some other bacteria, the resistance seen is almost entirely due to what has occurred in the agriculture sector. Examples are non-typhoid salmonella and campylobacter. In developed countries these bacteria are almost entirely acquired from food animals (via foods). These are zoonoses, and thus almost all the antibiotic resistance is a result of what happens with antibiotic use in food animals. Vegetarians are also at risk because water, food crops and fields (via manure) can be contaminated with resistant bacteria. There is also the additional chance of cross contamination of non-meat products from meats along the food chain. There are other bacteria where the risk of acquisition from animal sources is more difficult to precisely define, but appears to be quite important. Examples are E. coli and Enterococcus. We also sometimes get surprises. Until recently Staphylococcus aureus and MRSA were thought to be almost fairly exclusive human pathogens. However, in many countries (e.g. The Netherlands and Denmark), MRSA is now found frequently in pigs and these strains infect people. Clostridium difficile is now clearly associated with food animals and people are infected with strains found in these animals. There are increasing numbers of people with community onsetC. difficile infections. Foods are a likelyway these bacterial strains were acquired. Resistant E. coli are a major concern because E. coli is the most commonbacterial pathogen causing serious infections in people. Bloodstream infection rates vary from 25–60 per 100 000 people per year.This is just the tip of the iceberg, for every such serious and life threatening bloodstream infection, there are likely to be about a hundred other infections (e.g. urinary tract infections).What is nowvery disconcerting is the increasingmulti-resistance resistanceworldwide inE. coli. Much of this resistance in E. coli (especially to third generation cephalosporins and fluoroquinolones) is related to resistance that develops in bacteria carried by food animals – especially poultry. This resistance results from the misuse of antibiotics in these animals. Worldwide each year, billions of chicken are injected with third generation cephalosporins just before or after hatching (with ceftiofur) and/or fed fluoroquinolones in their drinking water (e.g. enrofloxacin) for nearly all their lives. Antibiotics have been used for over 60 years as growth promoters. They are also used for prophylaxis (called ‘metaphylaxis’when large numbers of animals or entire herds are treated at the same time). This is in stark contrast to what happens in human medicine, where individual patient use is the norm. It effectively means that huge numbers of animals are treated continuously for most of their life with either in-feed or in-water antibiotics. It explains why over 70% of all antibiotics used in most countries are used in food animals. Some of these prophylactic antibiotics are last-line or ‘critically important’ classes of antibiotics for humans, such as the fluoroquinolones and third and fourth generation cephalosporins. While there is ongoing debate on what proportion of antibiotic resistant bacteria infecting people come from food animals, it appears to be substantial. An example of where good practice can help people with serious infections is Australia. It is the only country that has banned the use of fluoroquinolones in food animals. It is not coincidental that Australia has also one of the lowest resistance rates in campylobacter, salmonella and E. coli to fluoroquinolones in the world.

Co-administration of Bacillus subtilis RJGP16 and Lactobacillus salivarius B1 strongly enhances the intestinal mucosal immunity of piglets

Probiotics, including Bacillus spp. and Lactobacillus, are potential replacements for low dose in-feed antibiotics for pig. This study aimed to evaluate the effect of the co-administration of Bacillus subtilis RJGP16 and Lactobacillus salivarius B1 as potential probiotics to stimulate local immune responses. Thirty two newborn piglets were divided into four groups and orally administrated with different combination of probiotics (none; RJGP16; B1; RJGP16 and B1) at the age of 0, 7 and 11days. We analysed the parameters of the mucosal immunity of piglets a week after weaning. Our results showed that the gene expression of interleukin (IL)-6 in the duodenum and ileum, porcine beta-defensins (pBD)-2 in the duodenum were significantly increased (p<0.01) with co-administration of the RJGP16 and B1. Also the expression and release of TLR-2 and the number of immunoglobulin (Ig) A producing cells were increased (p<0.01). The results demonstrate that the co-administration of the two bacteria stimulate a more intense mucosal immunity than the administration of each bacterium alone.

Effects of Dietary Additives and Early Feeding on Performance, Gut Development and Immune Status of Broiler Chickens Challenged with Clostridium perfringens.

The effects of dietary additives and holding time on resistance and resilience of broiler chickens to Clostridium perfringens challenge were investigated by offering four dietary treatments. These were a negative control (basal), a positive control (Zn-bacitracin) and two dietary additives, mannanoligosaccharides (MOS), and acidifier. Two holding times included (a) immediate access to feed and water post hatch (FED) and (b) access to both feed and water 48 h post hatch (HELD). Chicks fed Zn-bacitracin had no intestinal lesions attributed to necrotic enteritis (NE), whereas chicks fed both MOS or acidifier showed signs of NE related lesions. All dietary treatments were effective in reducing the numbers of C. perfringens in the ileum post challenge. The FED chicks had heavier body weight and numerically lower mortality. The FED chicks also showed stronger immune responses to NE challenge, showing enhanced (p<0.05) proliferation of T-cells. Early feeding of the MOS supplemented diet increased (p<0.05) IL-6 production. The relative bursa weight of the FED chicks was heavier at d 21 (p<0.05). All the additives increased the relative spleen weight of the HELD chicks at d 14 (p<0.05). The FED chicks had increased villus height and reduced crypt depth, and hence an increased villus/crypt ratio, especially in the jejunum at d 14 (p<0.05). The same was true for the HELD chicks given dietary additives (p<0.05). It may be concluded that the chicks with early access to dietary additives showed enhanced immune response and gut development, under C. perfringens challenge. The findings of this study shed light on managerial and nutritional strategies that could be used to prevent NE in the broiler industry without the use of in-feed antibiotics.