Influence of β-glucanase-producing Lactobacillus strains on intestinal characteristics and feed passage rate of broiler chickens

Alleviation of negative effect of heat stress through supplementations of cinnamon (Cinnamomum zeylanicum) and turmeric (Curcuma longa L) powders in diets of broiler chickens

This study was designed to assess the effect of cinnamon powder (CNP) and turmeric powder (TP) on growth performance, antioxidant status, liver function, meat quality and lactate dehydrogenase activity of broiler chickens under heat stress conditions. A total of 200, one day old as-hatched broiler chickens (ROSS 308) were randomly allotted into five treatments with four replicates (n = 10). Treatment groups were control (C): fed basal diet; T1: 0.5% CNP; T2: 1.0% CNP; T3: 0.5% TP and T4: 1.0% TP. Results indicated that body weight gain, feed intake and feed conversion ratio were improved significantly (p < 0.05) in treatments fed CNP and TP. Serum malondialdehyde and lactate dehydrogenase activity were decreased (p < 0.05) while blood superoxide dismutase, catalase and glutathione peroxidase activity were increased (p < 0.05) in treatments fed CNP and TP. Addition of CNP and TP decreased (p < 0.05) serum aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase activity. Treatments fed CNP and TP resulted increased (p < 0.05) breast and thigh meat monounsaturated fatty acid, polyunsaturated fatty acid, linoleic acid, oleic acid and water holding capacity while decreased (p < 0.05) saturated fatty acid and cook loss. In conclusion CNP and TP possess advantageous effect on growth performance, antioxidant status, liver function, meat quality and lactate dehydrogenase activity.

Using cinnamon (Cinnamomum zeylanicum) and turmeric (Curcuma longa L) powders as an antibiotic growth promoter substitutions in broiler chicken's diets

In the current study supplementations of cinnamon (Cinnamomum zeylanicum) powder (CNP) and turmeric (Curcuma longa L) powder (TP) as an antibiotic growth promoter substitutions on growth performance, intestinal microbiota and hematological profile of broiler chickens have been investigated. A total of 240, one day old as-hatched broiler chickens (ROSS 308) were randomly assigned into five treatments with four replicates per treatment and 10 chickens per replicate. Treatment groups were C: control (fed basal diet); CNP1: 0.5% CNP; CNP2: 1.0% CNP; TP1: 0.5% TP; TP2: 1.0% TP and 500 mg oxytetracycline (OTC)/kg of diet. Body weight gain (BWG), feed intake, and feed conversion ratio (FCR) were improved (p < 0.05) by CNP and TP while OTC improved BWG and FCR. Ileal and cecal Lactobacillus and total aerobes were significantly improved while coliforms and Escherichia coli were decreased by CNP, TP, and OTC. The percentage of packed cell volume (%PCV), hemoglobin (Hb), red blood cell (RBC) count, and white blood cell (WBC) count was increased by CNP and TP while OTC decreased %PCV, Hb, RBC, and increased WBC count. In conclusion, the results showed that OTC can be safely replaced by CNP and TP at 1.0% dose rate in broiler chicken's diets.

Juvenile growth, thermotolerance and gut histomorphology of broiler chickens fed Curcuma longa under hot-humid environments

Background

This study was conducted to assess the juvenile development, thermotolerance, and intestinal morphology of broiler chickens fed Curcuma longa in a hot-humid environment.

Methods

In a Completely Randomized Design, 240 broiler chicks were randomly assigned to four nutritional treatments of baseline diets supplemented with 0 (CN), 4 (FG), 8 (EG), and 12 g (TT) of turmeric powder/Kg of feed, with four replicates of fifteen birds each. Data on feed consumption and body weights were evaluated weekly during the juvenile growth phase. The physiological indicators of the birds were assessed on day 56 of their lives. The birds were subjected to thermal challenge and data were collected on their physiological traits. Eight birds were randomly selected, euthanized and dissected in each treatment, and 2 cm segments of duodenum, jejunum, and ileum were sampled for villi width, villi height, crypt depth, and the villi height: crypt depth ratio measurements.

Results

It was revealed that the weight gain of the birds in EG was significantly greater (p < 0.05) than that of CN birds. The birds in TT, FG, and CN had comparable but smaller duodenal villi than those in EG. The ileal crypt depth in EG chickens was smaller than in CN but comparable to the other treatment groups. In the duodenum, the villi to crypt depth ratio was in the order EG > TT > FG > CN.

Conclusions

To conclude, dietary supplementation of Curcuma longa powder, notably the 8 g/kg diet improved the antioxidant status, thermotolerance, and nutrient absorption by improving intestinal morphology in broiler chickens in a hot-humid environment.

Physiological parameter values for physiologically based pharmacokinetic models in food-producing animals. Part II: Chicken and turkey

Physiologically based pharmacokinetic (PBPK) models are growing in popularity due to human food safety concerns and for estimating drug residue distribution and estimating withdrawal intervals for veterinary products originating from livestock species. This paper focuses on the physiological and anatomical data, including cardiac output, organ weight, and blood flow values, needed for PBPK modeling applications for avian species commonly consumed in the poultry market. Experimental and field studies from 1940 to 2019 for broiler chickens (1-70 days old, 40 g - 3.2 kg), laying hens (4-15 months old, 1.1-2.0 kg), and turkeys (1 day-14 months old, 60 g -12.7 kg) were searched systematically using PubMed, Google Scholar, ProQuest, and ScienceDirect for data collection in 2019 and 2020. Relevant data were extracted from the literature with mean and standard deviation (SD) being calculated and compiled in tables of relative organ weights (% of body weight) and relative blood flows (% of cardiac output). Trends of organ or tissue weight growth during different life stages were calculated when sufficient data were available. These compiled data sets facilitate future PBPK model development and applications, especially in estimating chemical residue concentrations in edible tissues to calculate food safety withdrawal intervals for poultry.

Clostridium perfringens as Foodborne Pathogen in Broiler Production: Pathophysiology and Potential Strategies for Controlling Necrotic Enteritis

Clostridium perfringens (Cp.) is the cause of human foodborne desease. Meat and poultry products are identified as the main source of infection for humans. Cp. can be found in poultry litter, feces, soil, dust, and healthy birds' intestinal contents. Cp. strains are known to secrete over 20 identified toxins and enzymes that could potentially be the principal virulence factors, capable of degrading mucin, affecting enterocytes, and the small intestine epithelium, involved in necrotic enteritis (NE) pathophysiology, also leading to immunological responses, microbiota modification and anatomical changes. Different environmental and dietary factors can determine the colonization of this microorganism. It has been observed that the incidence of Cp-associated to NE in broilers has increased in countries that have stopped using antibiotic growth promoters. Since the banning of such antibiotic growth promoters, several strategies for Cp. control have been proposed, including dietary modifications, probiotics, prebiotics, synbiotics, phytogenics, organic acids, and vaccines. However, there are aspects of the pathology that still need to be clarified to establish better actions to control and prevention. This paper reviews the current knowledge about Cp. as foodborne pathogen, the pathophysiology of NE, and recent findings on potential strategies for its control.

An open source physiologically based kinetic model for the chicken (Gallus gallus domesticus): Calibration and validation for the prediction residues in tissues and eggs

Xenobiotics from anthropogenic and natural origin enter animal feed and human food as regulated compounds, environmental contaminants or as part of components of the diet. After dietary exposure, a chemical is absorbed and distributed systematically to a range of organs and tissues, metabolised, and excreted. Physiologically based kinetic (PBK) models have been developed to estimate internal concentrations from external doses. In this study, a generic multi-compartment PBK model was developed for chicken. The PBK model was implemented for seven compounds (with log K_ow range -1.37-6.2) to quantitatively link external dose and internal dose for risk assessment of chemicals. Global sensitivity analysis was performed for a hydrophilic and a lipophilic compound to identify the most sensitive parameters in the PBK model. Model predictions were compared to measured data according to dataset-specific exposure scenarios. Globally, 71% of the model predictions were within a 3-fold change of the measured data for chicken and only 7% of the PBK predictions were outside a 10-fold change. While most model input parameters still rely on in vivo experiments, in vitro data were also used as model input to predict internal concentration of the coccidiostat monensin. Future developments of generic PBK models in chicken and other species of relevance to animal health risk assessment are discussed.

Dietary multi-enzyme complex improves In Vitro nutrient digestibility and hind gut microbial fermentation of pigs

This study was conducted in two stages to investigate the potential of multi-enzyme supplementation on the nutrient digestibility, growth performance, and gut microbial composition of pigs. In stage 1, effects of multi-enzyme complex (xylanase, α-amylase, β-glucanase, and protease) supplementation on the ileal and total tract dry matter (DM) digestibility of feed-stuffs were investigated with in vitro two-stage and three-stage enzyme incubation methods. A wide range of feed ingredients, namely, corn meal, wheat meal, soybean meal, fish meal, Oriental herbal extract, Italian rye-grass (IRG) and peanut hull were used as substrates. Supplementation of the multi-enzyme complex increased (P < 0.05) the digestibility of the Oriental herbal extract and corn meal. In stage 2, in vivo animal studies were performed to further investigate the effects of the dietary multi-enzyme complex on the nutrient utilization, growth performance, and fecal microbial composition of pigs. A total of 36 weaned pigs were fed corn- and soybean meal-based diets without (control) and with the multi-enzyme complex (treatment) for 6 weeks. Fecal samples were collected from 12 pigs to analyze the microbial communities by using DNA sequencing and bioinformatics tools. Multi-enzyme supplementation had no effect on apparent digestibility of nutrients and growth performance of pigs compared to control. Taxonomic analysis of the fecal samples indicated that the bacteria in both control and treatment samples predominantly belonged to Firmicutes and Bacteroidetes. In addition, the proportion of the phylum Firmicutes was slightly higher in the treatment group. At the genus level, the abundance of Treponema and Barnesiella increased in the treatment group; whereas the numbers ofthe genera including Prevotella, Butyricicoccus, Ruminococcus and Succinivibrio decreased in the treatment group. These results suggest that multi-enzyme supplementation with basal diets have the potential to improve nutrient digestibility and modify microbial communities in the hind-gut of pigs.

Improved growth performance due to hypertrophied intestinal absorptive epithelial cells by heat-killed Lactobacillus sakei HS-1 in broiler chickens1

This study investigated the effect of heat-killed Lactobacillus sakei HS-1 (HK LS HS-1) on the growth performance and intestinal histology of broilers through 2 feeding trials. In trial 1, 48 male broilers were separated into 3 groups: 1) basal diet (1 to 21 d, including antibiotics; 21 to 49 d, not including antibiotics) supplemented with 0 bacterial cells of HK LS HS-1/g (control); 2) 106 bacterial cells were used; and 3) 108 bacterial cells were used. Trial 2 was carried out in a tropical area of Thailand, where 50 7-d-old male broilers were separated into 2 groups: 1) basal diet (control group); and 2) basal diet supplemented with 107 bacterial cells of HK LS HS-1/g. In trial 1, compared with the control, BW gain (linear; P = 0.019) and G:F (linear; P = 0.032) linearly increase with increasing HK LS HS-1 supplementation. In addition, 3 males died in the control group, while none died in the experimental group. In trial 2, growth performance was not significantly different between the groups. Observation of the gross anatomical visceral organs and intestinal histological parameters showed no difference among the groups. However, the weight of the ileum, total small intestine, gizzard, and ceca decreased, while the height of the ileal villus increased with increasing HK LS HS-1 supplementation (P < 0.05). On the duodenal villus apical surface, protuberated cells, cells without microvilli, recently exfoliated regions on villus tips, and deeper cells at the sites of these recently exfoliated cells were more frequently observed in the experimental groups compared to the control; therefore, the duodenal epithelial cells of the experimental groups were hypertrophied by rapid cell turnover. On the ileal villus apical surface, morphological changes (i.e., cell shedding) were not observed, but protuberated cells were observed; thus, the ileal epithelial cells of the experimental groups were hypertrophied by prolonging the detention period of cells on the villus tip without shedding into the intestinal lumen. The results indicate that HK LS HS-1 improves the growth performance of broilers due to the presences of hypertrophied intestinal absorptive epithelial cells on the villus apical surface, which induce enhanced durability against environmental stress.

Comparing two techniques for viscosity measurements in poultry feedstuffs: does it render similar conclusions?

Viscosity of intestinal contents is known to affect digestion and absorption of nutrients. In most poultry studies, intestinal viscosity has been measured only after complete removal of solid particles by centrifugation. Centrifugation may however remove particles that contribute to viscosity, hence giving rise to an underestimation of viscosity. Two viscosity measurement techniques, one including a centrifugation step (Brookfield) and the other without (Haake), were compared in-vitro to assess whether both techniques result in similar conclusions regarding viscosity in feedstuffs. Two sets of feedstuff preparations were used. The first set was prepared with different combinations of milled feedstuffs in order to have a wide range of viscosity: 100% corn, 25% corn + 75% wheat, 100% wheat, 90% wheat + 10% rye, all mixed with distilled water. In the second set, barley was incubated with different beta-glucanases, and soybean and sunflower meal were incubated with different pectinases, again all mixed with distilled water. Viscosity was assessed using both techniques (Haake and Brookfield equipments) at six different time points. To evaluate the extent of agreement between the two methods, the Lin's concordance correlation coefficient (CCC) was assessed using the percentage of increase in viscosity within each method, based on pairwise feedstuffs comparison (first set), or relative to the feedstuff without enzyme (second set). The rate of the agreement between the two methods was substantial for the first set of feedstuffs (66%) and for the barley diets incubated with beta-glucanases (69%), whereas the CCC score for the soybean meal diets was very poor (2%) and fair for the sunflower meal diets, incubated with pectinases (32%). The lack of agreement for the latter can be explained by the limited variation in viscosity in these low-viscous mixtures. Although the two techniques are considerably different (e.g., with or without preceding particle removal), they seem to render similar conclusions when applied to poultry feedstuffs to identify distinct differences under the tested circumstances.

Comparative effect of thymol or its glucose conjugate, thymol-β-D-glucopyranoside, on Campylobacter in avian gut contents

Campylobacter jejuni is an important human food-borne pathogen that can contaminate meat and poultry during processing. Consequently, strategies are sought to reduce the carriage of C. jejuni in food animals before they arrive at the abattoir. Thymol is a natural product that reduces survivability of Campylobacter in vitro, but its rapid absorption from the proximal alimentary tract limits its bactericidal efficacy in vivo. Thymol-β-D-glucopyranoside is more resistant to absorption than free thymol, but its administration to chickens has not been reported. In the present studies, 1 mM thymol-β-D-glucopyranoside was shown to exhibit near equal anti-Campylobacter activity as 1 mM thymol when incubated anaerobically in avian crop or cecal contents in vitro, resulting in reductions of 1.10-2.32 log10 colony forming units mL(-1) in C. jejuni concentrations after 24 h incubation. In a follow-up live animal study, oral administration of thymol-β-D-glucopyranoside, but not free thymol, significantly lowered (>10-fold) recovery of Campylobacter from the crop of market-aged broilers when compared to placebo-treated controls (n = 6 broilers/treatment). Neither thymol-β-D-glucopyranoside nor thymol affected recovery of Campylobacter from cecal contents of the treated broilers. These results indicate that rapid absorption or passage of free thymol from the crop precluded its anti-Campylobacter activity at this site and throughout the entire gastrointestinal tract. Conversely, lower recovery of Campylobacter from the crop of birds treated with thymol-β-D-glucopyranoside indicates this conjugate was retained and able to be hydrolyzed to biologically active free thymol at this site as intended, yet was not sufficiently protected to allow passage of efficacious amounts of the intact glycoside to the lower gut. Nevertheless, these results warrant further research to see if higher doses or encapsulation of thymol-β-D-glucopyranoside or similar glycosides may yield an efficacious additive to reduce carriage of Campylobacter as well as other pathogens throughout the avian gut.

Enzymatic polishing of cereal grains for improved nutrient retainment

Consumer acceptance of food products is largely driven by the dietary and functional quality of their ingredients. Though whole cereal grains are well known for bioactive components, scientists are facing dire need for better technologies to prevent the nutritional losses incurred through the conventional food processing technologies. Application of enzyme for depolymerisation of carbohydrates present in bran layer of grain is becoming an efficient method for phenolic mobilization and dietary fiber solubilisation. The present article emphasizes deep insights about the application of enzyme as an alternative technology for cereal grain processing to improve the product quality while forbidding the nutritional losses in an eco-friendly manner.

Microbiota intestinal e desempenho de frangos alimentados com rações elaboradas com sorgo ou milheto e complexo enzimático

Avaliou-se a suplementação enzimática em rações contendo milheto ou sorgo sobre a microbiota intestinal e o desempenho de frangos. Foram alojados 420 pintos - ensaio de microbiota - e 1.200 pintos - ensaio de desempenho -, submetidos aos tratamentos com sorgo ou milheto suplementados ou não com complexo enzimático. O delineamento utilizado foi inteiramente ao acaso, com sete repetições de 15 aves cada, para o ensaio de microbiota, e em blocos ao acaso, com cinco repetições e 60 aves por parcela para desempenho. Foram realizadas pesquisas de bactérias Gram-negativas e contagem do número total de microrganismos aeróbios do intestino delgado. A suplementação enzimática não afetou a microbiota intestinal de frangos aos 14 e 28 dias de idade. Houve efeito da suplementação enzimática nas dietas com sorgo para conversão alimentar na fase pré-inicial. Nas dietas com milheto, a suplementação melhorou o ganho de peso no período de um a 35 dias de idade. No período total de criação, de um a 42 dias, não foi observado efeito da suplementação para milheto ou sorgo. Conclui-se que a utilização da suplementação de enzimas em rações com sorgo ou milheto pode melhorar os resultados de desempenho, dependendo da fase de crescimento de frangos de corte.

Dietary probiotic inclusion level modulates intestinal mucin composition and mucosal morphology in broilers

The aim of this study was to investigate the effect of dietary probiotic inclusion level on mucin composition (monosaccharide ratio), mucosal morphometry, mucus layer staining intensity, and mucus layer thickness along the broiler intestinal tract. One-day-old male Cobb broilers were administered maize-soybean meal basal (BD) diets for 42 d and depending on the feed additive used, broilers were allocated into the following 5 experimental treatments: control C (BD, no additive), treatment P1 (10(8) colony forming units of probiotic/kg of BD), treatment P2 (10(9) cfu of probiotic/kg of BD), treatment P3 (10(10) cfu of probiotic/kg of BD), and treatment A (2.5 mg avilamycin/kg of BD). Intestinal samples from duodenum, ileum, and cecum of 14- and 42-d-old broilers were collected and analyzed. Mannose (Man) decreased linearly with increasing probiotic level in duodenum (P=0.015) and ileum (P=0.042) of 14-d-old broilers. N-Acetyl-glucosamine and galactose decreased linearly (P=0.012 and P=0.001, respectively), while fucose increased linearly (P<0.001) with increasing probiotic feed inclusion level in 42-d-old broiler cecum, with treatment A not differing from treatment C (P≥0.05). Cecal villus height and crypt depth increased linearly (P=0.016 and P=0.003, respectively) with probiotic inclusion level, with treatment A having higher (P≤0.05) values only from treatment C. Mucus layer thickness increased linearly with probiotic inclusion level in duodenum at 14 d and 42 d (P=0.007 and P=0.030, respectively). Finally, mucus layer staining intensity was influenced (P<0.001) by villus fragment (i.e., tip, midsection, and base) but not from the treatment, age, and intestinal segment examined. As a conclusion, this study provides evidence that probiotic inclusion level affects intestinal mucin monosaccharide composition, mucus layer thickness, and intestinal morphology in broilers.

Effects of exogenous enzymes in corn-based and Canadian pearl millet-based diets with reduced soybean meal on growth performance, intestinal nutrient digestibility, villus development, and selected microbial populations in broiler chickens

An experiment was conducted to compare a commercial corn-soybean meal diet with a pearl millet diet containing less soybean meal (-27%), alone or in combination with exogenous enzymes, on growth performance, jejunal villus development, ileal CP, and AA digestibility, and cecal microbial populations in broilers. One hundred sixty 1-d-old male Ross 508 broilers (5/cage) were randomly allocated to one of the following dietary treatments: 1) a standard corn-soybean meal control diet (CTL); 2) a pearl millet-soybean meal diet (PM); 3) CTL + exogenous enzymes (CE); and 4) PM + exogenous enzymes (PE) with 8 replicate cages/treatment. The PM and PE diets contained less soybean meal because of greater CP and AA contents of pearl millet. All diets were isonitrogenous and isocaloric. Body weight and feed intake were recorded weekly over 35 d. At d 21 and 35, 8 broilers per treatment were euthanized for sample collection and analyses. Gain-to-feed was greater (P < 0.01) for pearl millet- than corn-based diets. Apparent ileal digestibility (AID) of CP and most AA was similar between corn-based and pearl millet-based diets, and enzyme supplementation improved AID of CP (P < 0.01) and most AA at both d 21 and 35. However, for AID of some AA at d 21, the response to enzyme supplementation was less pronounced in broilers fed pearl millet-based diets than those fed corn-based diets (grain × enzyme, P ≤ 0.05). The villus was longer (P < 0.01) in broilers fed PM and PE than CTL and CE at d 35. Similarly, at d 35, lactobacilli loads were greater (P < 0.01) in broilers fed PM and PE than CTL and CE. It is concluded that, in comparison with corn, broiler diets formulated with pearl millet require less soybean meal and can be used to improve growth performance traits, intestinal lactobacilli populations, and villus development, whereas enzyme supplementation increases AID of CP and AA.

BOARD-INVITED REVIEW: opportunities and challenges in using exogenous enzymes to improve nonruminant animal production

Diets fed to nonruminant animals are composed mainly of feed ingredients of plant origin. A variety of antinutritional factors such as phytin, nonstarch polysaccharides, and protease inhibitors may be present in these feed ingredients, which could limit nutrients that may be utilized by animals fed such diets. The primary nutrient utilization-limiting effect of phytin arises from the binding of 6 phosphate groups, thus making the P unavailable to the animal. The negative charges allow for formation of insoluble phytin-metal complexes with many divalent cations. Furthermore, phytin and protein can form binary complexes through electrostatic links of its charged phosphate groups with either the free amino group on AA on proteins or via formation of ternary complexes of phytin, Ca(2+), and protein. The form and extent of de novo formation of binary and ternary complexes of phytin and protein are likely to be important variables that influence the effectiveness of nutrient hydrolysis in plant-based diets. Nonstarch polysacharides reduce effective energy and nutrient utilization by nonruminant animals because of a lack of the enzymes needed for breaking down the complex cell wall structure that encapsulate other nutrients. Enzymes are used in nonruminant animal production to promote growth and efficiency of nutrient utilization and reduce nutrient excretion. The enzymes used include those that target phytin and nonstarch polysaccharides. Phytase improves growth and enhances P utilization, but positive effects on other nutrients are not always observed. Nonstarch polysaccharide-hydrolyzing enzymes are less consistent in their effects on growth and nutrient utilization, although they show promise and it is imperative to closely match both types and amounts of nonstarch polysaccharides with appropriate enzyme for beneficial effects. When used together with phytase, nonstarch polysaccharide-hydrolyzing enzymes may increase the accessibility of phytase to phytin encapsulated in cell walls. The future of enzymes in nonruminant animal production is promising and will likely include an understanding of the role of enzyme supplementation in promoting health as well as how enzymes may modulate gene functions. This review is an attempt to summarize current thinking in this area, provide some clarity in nomenclature and mechanisms, and suggest opportunities for expanded exploitation of this unique biotechnology.

Evolving enzyme technology: impact on commercial poultry nutrition

The use of exogenous enzymes to improve the nutritional value of poultry diets is a relatively new concept. The technology is rapidly evolving, with new enzymes, enzyme combinations, and novel applications being developed as rapidly as regulatory restrictions will allow. Most researchers in the field of poultry nutrition would consider phytase to be the last significant leap forward in terms of enzyme use in the animal feed industry. However, there is a great deal of ongoing research into the next generation of enzymes with a focus on ingredient quality, predictability of response via least-square models, improvements in food safety, effect of bird age, effect of various side activities and enzyme dose, maximisation of net income and reduction in environmental pollution. It is the purpose of the present review article to summarise the current research in the area of feed enzymes for poultry and to speculate on future applications of enzymes and new enzyme technologies that may be of value to the industry in the coming years.