Use Of In-feed Antibiotics Research Articles

Effects of removing in-feed antibiotics and zinc oxide on the taxonomy and functionality of the microbiota in post weaning pigs

BackgroundPost weaning diarrhoea (PWD) causes piglet morbidity and mortality at weaning and is a major driver for antimicrobial use worldwide. New regulations in the EU limit the use of in-feed antibiotics (Ab) and therapeutic zinc oxide (ZnO) to prevent PWD. New approaches to control PWD are needed, and understanding the role of the microbiota in this context is key. In this study, shotgun metagenome sequencing was used to describe the taxonomic and functional evolution of the faecal microbiota of the piglet during the first two weeks post weaning within three experimental groups, Ab, ZnO and no medication, on commercial farms using antimicrobials regularly in the post weaning period.ResultsDiversity was affected by day post weaning (dpw), treatment used and diarrhoea but not by the farm. Microbiota composition evolved towards the dominance of groups of species such as Prevotella spp. at day 14dpw. ZnO inhibited E. coli overgrowth, promoted higher abundance of the family Bacteroidaceae and decreased Megasphaera spp. Animals treated with Ab exhibited inconsistent taxonomic changes across time points, with an overall increase of Limosilactobacillus reuteri and Megasphaera elsdenii. Samples from non-medicated pigs showed virulence-related functions at 7dpw, and specific ETEC-related virulence factors were detected in all samples presenting diarrhoea. Differential microbiota functions of pigs treated with ZnO were related to sulphur and DNA metabolism, as well as mechanisms of antimicrobial and heavy metal resistance, whereas Ab treated animals exhibited functions related to antimicrobial resistance and virulence.ConclusionAb and particularly ZnO maintained a stable microbiota composition and functionality during the two weeks post weaning, by limiting E. coli overgrowth, and ultimately preventing microbiota dysbiosis. Future approaches to support piglet health should be able to reproduce this stable gut microbiota transition during the post weaning period, in order to maintain optimal gut physiological and productive conditions.

Chicken feedlot revisited: Co-dispersal of antibiotic and metal resistome under banning in-feed veterinary antibiotics

Intensive livestock farming has been implicated as a notorious hotspot for antibiotic resistance genes (ARGs) due to the excessive or inappropriate use of in-feed antibiotics over the past few decades. Since China implemented a ban on the use of antibiotics in animal feed since 2020, the dissemination of ARGs in the vicinity of feedlots has remained unclear. This study presents a case study that aims to investigate the dispersal of antibiotics and ARGs from a chicken feedlot (established in 2020) to the adjacent aquatic and soil environments. Comparing the sample collected from upstream area, the water and sediment samples from midstream and downstream areas showed an increase in total antibiotic residues and metal content (Cu and Zn) by 4.2–5.3 fold and 1.3–22.6 fold, respectively. The downstream water samples exhibited a 2.49–2.93-fold increase in the abundance of ARGs and a 1.48–1.75-fold increase in the abundance of metal resistance genes (MRGs). The results of Pearson correlation and metagenome-assembled genome revealed a tendency for the co-occurrence of ARGs and MRGs. The dissemination of ARGs and MRGs is primarily driven by tetracycline, tylosin, Cu, and, Mn, with mobile genetic elements playing a more significant role than bacterial communities. These findings shed light on the overlooked co-dispersal pattern of ARGs and MRGs in the environment surrounding feedlots, particularly in the context of banning in-feed veterinary antibiotics.

GROWTH PERFORMANCE AND GUT PROMOTING ACTIVITY OF THREE CONVENTIONAL FIBRE FEEDSTUFFS IN DIETS OF GROWING PIGS

<p><strong>Background.</strong> The increasing utilisation of fibre feedstuffs in diets of pigs nowadays calls for concerns not only on the growth but also the health status of the animals and the possibility to eradicate the use of in-feed antibiotics for pigs. <strong>Objective.</strong> To evaluate the growth performance and gut promoting activity of three fibre feedstuffs (Palm kernel cake (PKC), Brewers’ dried grain (BDG) and Wheat offal (WO)) in diets of growing pigs. <strong>Methodology</strong>. Three dietary treatments containing 40 % each of PKC, BDG and WO were randomly allotted to 24 growing crossbred (Large White x Hampshire) pigs of average initial weight of 30± 0.50 Kg in an 82 d feeding trial. <strong>Results.</strong> There was an influence (p<0.05) of sources of fibre feedstuffs for the arabinoxylan- and mannan-oligosaccharide concentrations of the dietary treatments with BDG having comparatively higher values than WO and PKC diets. The short-chain fatty acid (SCFA) concentrations and pH of gut digesta were different (p<0.05) across dietary groups with pigs fed BDG diet having higher SCFA concentration in the foregut and hindgut. In the gut flora, BDG and WO promoted the highest (p<0.05) <em>Lactobacillus</em> population in the small and large intestines respectively. There were significant (p<0.05) effects of fibre sources on the final weight, average daily gain and daily intake of pigs fed the different treatments with those fed WO diets showing superior performance over pigs fed either PKC or BDG diet. <strong>Implication. </strong>The WO diet promoted the fastest growth and better gut effects but BDG resulted in the most efficient feed to gain conversion. <strong>Conclusion.</strong> All the diets exhibited prebiotic activity, enhanced the growth of beneficial bacterial in the gut and could reduce the use of in-feed antibiotics for pigs.</p>

Potential Implication of in ovo Feeding of Phytogenics in Poultry Production.

Hatchery's goals include maximizing revenue by achieving high hatchability with day-old birds of excellent quality. The advancement of technology has benefited the poultry sector since breeding and genetics technology have increased the rates of meat maturation in developing birds in a short period of time. Excessive use of in-feed antibiotics has been shown in studies to increase the chance of resistance to human infections. Bacterial resistance and antibiotic residues in animal products raised concerns about using antibiotics as growth promoters, eventually leading to a prohibition on using in-feed antibiotics in most industrialized nations. In ovo technology is a novel method for delivering bioactive chemicals to developing avian embryos. In ovo feeding technologies may provide additional nutrients to the embryos before hatching. The introduction of bioactive compounds has the potential to assist in decreasing and eventually eliminating the problems associated with traditional antibiotic delivery in chicken production. Phytobiotics were advocated as an alternative by researchers and dietitians. So far, several studies have been conducted on the use of phytogenic feed additives in poultry and swine feeding. They have primarily demonstrated that phytobiotics possess antibacterial, antioxidant, anti-inflammatory, and growth-stimulating properties. The antioxidant effect of phytobiotics can improve the stability of animal feed and increase the quality and storage duration of animal products. In general, the existing documentation indicates that phytobiotics improve poultry performance. To effectively and efficiently use the in ovo technique in poultry production and advance research in this area, it is important to have a thorough understanding of its potential as a means of nutrient delivery during the critical stage of incubation, its effects on hatching events and posthatch performance, and the challenges associated with its use. Overall, this review suggests that in ovo feeding of phytobiotics has the potential to improve the antioxidant status and performance of chickens.

A comprehensive review on natural phenolic compounds as alternatives to in-feed antibiotics.

Intensive livestock and poultry farming in China largely relied on the use of in-feed antibiotics until July 2020. The consequences of antibiotic overuse in animal feed include accumulation in animal products and the development of bacterial antibiotic resistance, both of which threaten food safety and human health. China has now completely banned the circulation of commercial feed containing growth-promoting drug additives (except Chinese herbal medicine). Therefore, alternatives to in-feed antibiotics in animal production are greatly needed. Natural phenolic compounds (NPCs) exist widely in plants and are non-toxic, non-polluting, highly reproducible, and leave little residue. Many natural flavonoids, phenolic acids, lignans, and stilbenes have polyphenol chemical structures and exhibit great potential as alternatives to antibiotics. In this review we delineate the characteristics of plant-derived NPCs and summarize their current applications as alternatives to in-feed antibiotics, aiming to provide new strategies for antibiotic-free feeding and promote the development of more sustainable animal husbandry practices.

An insight into the commercial piglet’s microbial gut colonization: from birth towards weaning

BackgroundThe establishment of the gut microbiota can be influenced by several perinatal factors, including, most importantly, the maternal microbiota. Moreover, early-life environmental variation affects gut microbial colonization and the intestinal health of offspring throughout life. The present study aimed to explore the development of piglet gut microbiota from birth to weaning in the commercial practice and also to assess how different farm environments could condition this process. Although it is possible to find in the literature other studies with similar objectives this work probably represents one of the few studies that make a systematic evaluation of such differential factors under a real scenario. To achieve this objective, we performed two trials. In a first Trial, we selected 2 farms in which we performed an intensive sampling (5 samples /animal) to characterize the gut colonization pattern during the first days of life and to identify the time window with the greatest impact. Both farms differed in their health status and the use of antimicrobials in the piglets. In a second Trial, we selected 4 additional farms with variable rearing conditions and a distinctive use of antimicrobials in the sows with a simplified sampling pattern (2 samples/animal). Faecal samples were obtained with swabs and DNA was extracted by using the PSP® Spin Stool DNA Kit and sequencing of the 16S rRNA gene (V3-V4 region) performed by Illumina MiSeq Platform.ResultsThe present study contributes to a better understanding of microbiome development during the transition from birth to weaning in commercial conditions. Alpha diversity was strongly affected by age, with an increased richness of species through time. Beta diversity decreased after weaning, suggesting a convergent evolvement among individuals. We pinpointed the early intestinal colonizers belonging to Bacteroides, Escherichia-Shigella, Clostridium sensu stricto 1, and Fusobacterium genera. During lactation(d7-d21 of life), the higher relative abundances of Bacteroides and Lactobacillus genera were correlated with a milk-oriented microbiome. As the piglets aged and after weaning (d36 of life), increasing abundances of genera such as Prevotella, Butyricimonas, Christensenellaceae R-7 group, Dorea, Phascolarctobacterium, Rikenellaceae RC9 gut group, Subdoligranulum, and Ruminococcaceae UCG-002 were observed. These changes indicate the adaptation of the piglets to a cereal-based diet rich in oligosaccharides and starch. Our results also show that the farm can have a significant impact in such a process, evidencing the influence of different environments and rearing systems on the gut microbiota development of the young piglet. Differences between farms were more noticeable after weaning than during lactation with changes in alpha and beta biodiversity and specific taxa. The analysis of such differences suggests that piglets receiving intramuscular amoxicillin (days 2–5 of life) and being offered an acidifying rehydrating solution (Alpha farm in Trial 1) have a greater alpha diversity and more abundant Lactobacillus population. Moreover, the only farm that did not offer any rehydrating solution (Foxtrot farm in Trial 2) showed a lower alpha diversity (day 2 of life) and increased abundance of Enterobacteriaceae (both at 2 and 21 days). The use of in-feed antibiotics in the sows was also associated with structural changes in the piglets’ gut ecosystem although without changes in richness or diversity. Significant shifts could be registered in different microbial groups, particularly lower abundances of Fusobacterium in those piglets from medicated sows.ConclusionsIn conclusion, during the first weeks of life, the pig microbiota showed a relevant succession of microbial groups towards a more homogeneous and stable ecosystem better adapted to the solid dry feed. In this relevant early-age process, the rearing conditions, the farm environment, and particularly the antimicrobial use in piglets and mothers determine changes that could have a relevant impact on gut microbiota maturation. More research is needed to elucidate the relative impact of these farm-induced early life-long changes in the growing pig.

Potential effect of some essential oils on rumen methane reduction and digestibility by In Vitro incubation technique

Since excessive use of in-feed antibiotics and chemical feed supplements can potentially affect health risks and environmental problems, organic feed supplement became alternative save material. Organic material such as essential oils (EO) is potential for feed additive in the livestock industry because of their main activity as rumen manipulator. Their potential as rumen manipulators has not enough for type and doses of essential oils experiment. Therefore, the objective of this study was to evaluate 6 essential oils/EO’s (garlic/, thyme, clove, orange peel, mint, and cinnamon) with different doses (100, 200 and 300 ppm) on in vitro rumen methane reduction and in vitro digestibility using in vitro gas production technique. The experiment resulted highest level in in-vitro methane reduction potential (MRP, %) 72.83% at orange peel oils 300 ppm after 6 h incubation, while using clove oils 300 ppm had highest in vitro true digestibility of dry matter (IVTDDM) 81.41% after 30-hour incubation. Using Cinnamon oils had high value both of MRP level and IVTDDM (48.91 and 79.12 %). In Conclusion, all essential oils reduced in vitro rumen methane production at 6 h incubation compared to control at 300 ppm and there was no negative effect on In Vitro Digestibility.

The use of medicinal plants in the compound poultry feed

The experiments were carried out on 5 groups of cage housed broiler chickens of the Ross 308 cross aged from 1 to 35 days. It was found that dried chicory root, oregano, and common nettle are valuable additives in compound poultry feed. The addition of dried chicory root, oregano, and common nettle in amounts of 2 kg/t; 0.5 kg/t, and 2.0 kg/t, respectively, to broiler diets allows obtaining good livability (100%) and live bodyweight, as well as low feed conversion. In the experimental groups the dried medicinal plants were added to the feed without the use of in-feed antibiotics. It was statistically proven that the live bodyweight in broilers at the end of growing in the experimental groups was significantly in compare to control by 7.08-8.04%. This increase was accompanied by a decrease in feed conversion ratio by 10.33-10.45% due to improved digestibility and retention of dietary nutrients. With the introduction of dried medicinal plants into broiler feed, an increase in the protein content in the pectoral muscles by 1.31-1.56% and a decrease in fat content by 2.23-2.97% were found. The sensory quality of the roasted meat was good.

In-feed antibiotic use changed the behaviors of oxytetracycline, sulfamerazine, and ciprofloxacin and related antibiotic resistance genes during swine manure composting

The dynamics of oxytetracycline (OTC), sulfamerazine (SM1), ciprofloxacin (CIP) and related antibiotic resistance genes (ARGs) during swine manure composting were compared between manure collected from swine fed a diet containing these three antibiotics (TD) and manure directly spiked with these drugs (TS). The composting removal efficiency of OTC (94.9 %) and CIP (87.8 %) in the TD treatment was significantly higher than that of OTC (83.8 %, P < 0.01) and CIP (83.9 %, P < 0.05) in the TS treatment, while SM1 exhibited no significant difference (P > 0.05) between the two treatments. Composting effectively reduced the majority of ARGs in both TD and TS types of manure, especially tetracycline resistance genes (TRGs). Compared with the TS treatment, the abundance of some ARGs, such as tetG, qepA, sul1 and sul2, increased dramatically up to 309-fold in the TD treatment. The microbial composition of the composting system changed significantly during composting due to antibiotic feeding. Redundancy analysis suggested that the abundance of ARGs had a considerable impact on alterations in the physicochemical parameters (C/N, pH and temperature) and bacterial communities (Actinobacteria, Proteobacteria and Firmicutes) during the composting of swine manure.

Influence of Plant Bioactive Compounds on Intestinal Epithelial Barrier in Poultry.

Natural plant bioactive compounds (PBC) have recently been explored as feed additives to improve productivity, health and welfare of poultry following ban or restriction of in-feed antibiotic use. Depending upon the types of PBC, they possess antimicrobial, digestive enzyme secretion stimulation, antioxidant and many pharmacological properties, which are responsible for beneficial effects in poultry production. Moreover, they may also improve the intestinal barrier function and nutrient transport. In this review, the effects of different PBC on the barrier function, permeability of intestinal epithelia and their mechanism of actions are discussed, focusing on poultry feeding. Dietary PBC may regulate intestinal barrier function through several molecular mechanisms by interacting with different metabolic cascades and cellular transcription signals, which may then modulate expressions of genes and their proteins in the tight junction (e.g., claudins, occludin and junctional adhesion molecules), adherens junction (e.g., E-cadherin), other intercellular junctional proteins (e.g., zonula occludens and catenins), and regulatory proteins (e.g., kinases). Interactive effects of PBC on immunomodulation via expressions of several cytokines, chemokines, complement components, pattern recognition receptors and their transcription factors and cellular immune system, and alteration of mucin gene expressions and goblet cell abundances in the intestine may change barrier functions. The effects of PBC are not consistent among the studies depending upon the type and dose of PBC, physiological conditions and parts of the intestine in chickens. An effective concentration in diets and specific molecular mechanisms of PBC need to be elucidated to understand intestinal barrier functionality in a better way in poultry feeding.

Role of acidifiers in livestock nutrition and health: A review.

Ever since the European ban on use of in-feed antibiotics in food animals, the search for alternate antibiotic-free growth promoter is undertaken worldwide. There are few alternatives such as probiotics, pre-biotics, phytochemicals, enzymes and organic acids. Among these alternatives, the organic acids or simply acidifiers play an important role in gut health in animals. The acidifiers could be used to favourably manipulate the intestinal microbial populations and improve the immune response, hence perform an activity similar to antibiotics in food animals in countering pathogenic bacteria. Acidifiers also improve the digestibility of nutrients and increase the absorption of minerals. The incorporation of organic acids also leads to thinning of the intestinal lining which facilitates better absorption of nutrients and its efficient utilization. However, their effect will not be similar among all types of organic acids as their mechanism of activity is based on its pKa value. Moreover, there are claims about the neutralization of acids by the secretion of bicarbonates in the initial part of intestine, reactivity with metallic items in feed mills and reduced palatability due its bitter taste demands non-reactive and targeted delivery for better performance. Currently, coated salts of acidifiers are available commercially for use in food animals especially pigs and poultry. The present review highlights the role of different acidifiers in livestock nutrition with their potent applications in improving nutrient digestibility, mineral utilization, meat quality, enhancing immunity, antimicrobial effects in countering pathogenic bacteria, boosting performance and production, and thus safeguarding health of livestock animals and poultry.

58 Functional nutrition to modulate the immune response

Abstract Growing concerns about antibiotic resistance coupled with recent legislation limiting in-feed antibiotic use in livestock feed has led to a resurgence of interest in plant-based extracts, prebiotics/probiotics, and other nutraceutical compounds with immune-modulating properties. Consumer preference for functional ingredients in their own food as well as feed for their pets or livestock has created a niche for development of feed additives with bioactive properties with the potential to improve health through their ability to regulate inflammation and modulate microbial communities. For example, dietary omega-3 fatty acids have been documented to reduce inflammation through altering the fatty acid composition of immune cells, shifting immune cell function, and reducing inflammatory lipid mediator and cytokine production. Dietary probiotic supplementation allows an intimate interaction between the gut mucosa and the largest concentrated population of the host’s immune cells, the mucosal immune system. Probiotics have been shown to modulate the inflammatory response through interaction with intestinal epithelial cells, M-cells in Peyer’s patches, innate immune cells such as dendritic and other antigen-presenting cells, and increasing barrier function through increased mucus and antibody production. Other feedstuffs such as green tea components (epigallocatechin-3-gallate, EGCG) interact with neutrophils and macrophages to limit cellular migration and inflammatory molecule production to reduce inflammation. A wealth of information detailing mechanistic outcomes exists in mouse literature and human cell lines, while livestock and companion animal literature is an untapped area for future work. An emphasis on research aimed at a more molecular, mechanistic understanding of currently available feed additives will lead to the improvement of existing additives and development of new additives for use in livestock and companion animal feed.

Major cereal carbohydrates in relation to intestinal health of monogastric animals: A review.

Type, quality, and origin of cereals in diets of poultry and pigs could influence gut microbes and affect their diversity and function, thereby impacting the intestinal function of the monogastric animal. In this review, we focus on the major carbohydrates in cereals that interact directly with gut microbes and lead to the production of key metabolites such as short-chain fatty acids (SCFA), and discuss how cereal fiber impact intestinal health of poultry and pigs. An overview of how the cereals and cereals-derived carbohydrates such as beta-glucans, resistant starch, cellulose, and arabinoxylans could promote intestinal health and reduce the use of in-feed antibiotics in animal production are presented. The metabolic pathway utilized by microbes and the mechanism of action underlying the produced SCFA on intestinal health of monogastric animals is also discussed.

Effect of alpha-tocopherol acetate and ascorbic acid on performance, carcass traits, and incidence and severity of liver abscesses in feedlot cattle.

Liver abscesses (LA) in cattle negatively affect feedlot performance by decreasing ADG, feed intake, and G:F ratio. Abscessed livers are condemned and abdominal adhesions associated with LA can result in extensive carcass trimming during harvest, further compounding adverse economic impact. Given regulatory changes pertaining to the use of in-feed antibiotics in cattle production, there is growing interest in alternatives to antibiotics for LA control. The objective of this study was to evaluate the use of antioxidants, crystalline ascorbate (AOX), and alpha-tocopherol acetate, for mitigation of LA in feedlot cattle. Yearling crossbred heifers (n = 392; initial BW 481 ± 9.4 kg) were blocked by previous treatment and allocated randomly to 24 dirt-surfaced feedlot pens (10 m × 35 m) with 14 heifers/pen. Heifers were weighed, implanted with Component TE-200 implants, and placed into feeding pens. Finishing diets consisted of 60% steam-flaked corn, 30% wet corn gluten feed, 8% alfalfa, and 2% supplement (DM basis) that provided 300 mg/d monensin, and either 200 IU/d alpha-tocopherol acetate (CTL) or 2,000 IU/d alpha-tocopherol acetate plus 500 mg/d crystalline AOX. Heifers were fed once daily ad libitum for 94 d, then weighed and transported 450 km to a commercial abattoir for harvest. Hot carcass weight and incidence/severity of LA were determined the day of harvest, and carcass traits were evaluated following 36 h of refrigeration. Compared to CTL, feeding AOX tended to decrease DMI (10.66 vs. 10.31 kg/d; P = 0.08) and improve G:F (0.1204 vs. 0.1254; P = 0.12), but did not impact ADG, incidence of LA (25.6 vs. 23.5% for CTL and AOX, respectively), HCW (828.4 vs. 830.5 kg for CTL and AOX, respectively), or other carcass traits (P > 0.20). In conclusion, feeding antioxidants are not a viable alternative to decrease incidence of LA in finishing cattle.

Contribution of exogenous enzymes to potentiate the removal of antibiotic growth promoters in poultry production

Removal of prophylactic in-feed antibiotics from the diets of animals that enter the human food chain is increasing on a global basis. This removal is motivated by a range of factors including legislative compliance, consumer and retailer pressure and for ethical reasons. However, whilst this shift in approach to the rearing of production animals has benefits, there are also significant challenges for animal husbandry, disease control, nutritional optimization and food safety and security. For example, the use of in-feed antibiotics generates increases in weight gain and feed conversion ratio in the region of 4% and so, axiomatically, their removal introduces significant efficiency cost for producers. The vacuum created by the removal of in-feed antibiotics has led to a sustained body of research into alternative additives such as plant secondary metabolites, pro- and pre-biotics, acidifiers and enzymes. Whilst no single alternative to date can claim to demonstrably and consistently replace the antibiotics, many of these additives have substantial value and can form part of successful ‘anti-biotic free’ production programs. It is therefore the purpose of this review article to summarise the consequences of removal of in-feed antibiotics and to highlight the potential of feed enzymes as part of a displacement strategy.

RETRACTED ARTICLE: Antibiotic growth promoters virginiamycin and bacitracin methylene disalicylate alter the chicken intestinal metabolome

Although dietary antibiotic growth promoters have long been used to increase growth performance in commercial food animal production, the biochemical details associated with these effects remain poorly defined. A metabolomics approach was used to characterize and identify the biochemical compounds present in the intestine of broiler chickens fed a standard, unsupplemented diet or a diet supplemented with the antibiotic growth promoters, virginiamycin or bacitracin methylene disalicylate. Compared with unsupplemented controls, the levels of 218 biochemicals were altered (156 increased, 62 decreased) in chickens given the virginiamycin-supplemented diet, while 119 were altered (96 increased, 23 decreased) with the bacitracin-supplemented diet. When compared between antibiotic-supplemented groups, 79 chemicals were altered (43 increased, 36 decreased) in virginiamycin- vs. bacitracin-supplemented chickens. The changes in the levels of intestinal biochemicals provided a distinctive biochemical signature unique to each antibiotic-supplemented group. These biochemical signatures were characterized by increases in the levels of metabolites of amino acids (e.g. 5-hydroxylysine, 2-aminoadipate, 5-hydroxyindoleaceate, 7-hydroxyindole sulfate), fatty acids (e.g. oleate/vaccenate, eicosapentaenoate, 16-hydroxypalmitate, stearate), nucleosides (e.g. inosine, N6-methyladenosine), and vitamins (e.g. nicotinamide). These results provide the framework for future studies to identify natural chemical compounds to improve poultry growth performance without the use of in-feed antibiotics.

Intermittent lighting improves resilience of broilers during the peak phase of sub-clinical necrotic enteritis infection

Necrotic enteritis, either in its clinical or sub-clinical form is known to cause massive economic losses in the broiler chicken industry. Currently, the use of in-feed antibiotics as growth promoters is discouraged. Therefore, mechanisms to control NE through diet include reduction of digesta viscosity, promotion of lower pH in the gastrointestinal tract (GIT) through acidification of feed, production of short-chain fatty acids and overall stimulation of beneficial bacteria growth. Intermittent lighting programs increase feed retention in the crop and reduce pH in the foregut compartments in comparison with standard commercial lighting programs and therefore may be a valuable, yet underexploited, barrier to prevent the invasion of the GIT by pathogens. In this experiment, a 2 × 2 factorial arrangement of treatments was employed in a randomized design to investigate whether intermittent lighting would increase broiler resilience to sub-clinical necrotic enteritis. A total of 390 Cobb 500 same-hatch, mixed sex, day-old chicks were assigned to 30 floor pens to test the effect of 2 factors, namely, lighting schedule (continuous, 18L:6D vs. intermittent, 1L:3D:1L:3D:1L:3D:1L:3D:2L:6D) and a sub-clinical necrotic enteritis challenge (challenge vs. no challenge). Challenged birds had lower feed intake and weight gain and poorer feed conversion ratio (FCR; P < 0.005). Intermittent lighting reduced feed intake (P < 0.05) without compromising final body weight gain. During the peak phase of Clostridium perfringens Type A infection, the negative impact of the disease challenge on feed efficiency was lower for animals under intermittent lighting than for those under a 18L:6D schedule (2-way interaction, P < 0.005). Thus, in flocks that are raised under antibiotic-free production systems, intermittent lighting programs applied at least during the critical period for necrotic enteritis risks, i.e., d 18–24, may be a practical, non-medicated way to increase resilience of broilers to this disease.

Overview of Prebiotics and Probiotics: Focus on Performance, Gut Health and Immunity – A Review

Abstract Due to the threat and emergence of bacterial resistance against antibiotics, the use of in-feed antibiotics at therapeutic and subtherapeutic levels has been limited. Complete withdrawal of antibiotics as growth promoters (AGP) has led to poor gut health signs in chickens that include conditions like wet litter, intestinal bacteria overgrowth, poor growth performance, malabsorption and various diseases. Two of the most common alternatives to AGP are prebiotics and probiotics. Both prebiotics and probiotics have become the potential feed additives that improve the gut health, immune system and microbiota by various mechanisms of action, and enhance growth performance of chickens. The review discusses the modes of action like antibacterial, competitive exclusion (CE), and immunomodulatory properties of prebiotics and probiotics, particularly in poultry. In ovo feeding of prebiotics and probiotics with promising effect on growth performance and reduction of pathogens like Salmonella is also discussed in this review. However, it is necessary to conduct more research with prebiotics and probiotics as well as other feed additives to understand the detailed mechanisms of action and identify better alternatives for poultry production and health.

Husbandry practices and gut health outcomes in weaned piglets: Areview.

The immediate post-weaning period is one of the most stressful phases in a pig's life, and during this period, piglets are usually exposed to environmental, social and psychological stressors which have direct or indirect effects on gut health and overall growth performance. In this review, the impact of husbandry practices on gut health outcomes and performance of piglets is discussed. Husbandry practices in the swine barn generally include nutrition and management practices, maintenance of hygienic standards and disease prevention protocols, and animal welfare considerations. Poor husbandry practices could result in reduced feed intake, stress and disease conditions, and consequently affect gut health and performance in weaned piglets. Reduced feed intake is a major risk factor for impaired gut structure and function and therefore a key goal is to maximize feed intake in newly weaned piglets. In weaned piglets, crowding stress could reduce pig performance, favor the proliferation of pathogenic bacteria resulting in diarrhea, stimulate immune responses and interfere with beneficial microbial activities in the gut. Sanitation conditions in the swine barn plays an important role for optimal piglet performance, because unclean conditions reduced growth performance, shifted nutrient requirements to support the immune system and negatively affected the gut morphology in weaned piglets. Appropriate biosecurity measures need to be designed to prevent disease entry and spread within a swine operation, which in turn helps to keep all pigs and piglets healthy. Collectively, husbandry practices relating to feeding and nutrition, animal welfare, biosecurity and disease prevention are important determinants of gut health and piglet performance. Thus, it is suggested that adopting high husbandry practices is a critical piece in strategies aimed at raising pigs without the use of in-feed antibiotics.

Intermittent Feeding of Tylan Reduces Use of In-Feed Antibiotics While Still Controlling Incidence of Liver Abscesses in Finishing Steers

Intermittent Feeding of Tylan Reduces Use of In-Feed Antibiotics While Still Controlling Incidence of Liver Abscesses in Finishing Steers