Effects of Antimicrobial peptides on egg production,egg quality and caecal microbiota of hens during the late laying period

This study was conducted to determine the effects of diet supplementation of laying hens with antimicrobial peptides (AMP) on egg production, egg quality and caecal microbiota. A total of 360 Hy‐Line Brown laying hens (72 weeks old) were divided into three groups with four replicates of 30 birds each. The laying hens were fed with the basal diet (Control), the basal diet + 50 mg/kg AMP (group 1) and the basal diet + 100 mg/kg AMP (group 2). The experiment lasted for 45 d. Eggs were collected daily and caecal samples were collected at the end of the experiment. The results showed that AMP supplementation caused a significantly increased laying rate and decreased feed/egg ratio (p ＜ .05). Meanwhile, a distinctive difference in cecal microbiota was observed between AMP and control groups and the average values of microbial diversity and richness were lower in the AMP group than in the control group. At the phylum level, the relative abundance of Verrucomicrobia and Cyanobacteria were lower in the AMP group than in the control group. In conclusion, the results indicated that dietary supplementation with AMP can improve egg production and affect the cecal microbial community membership and structure of hens during late laying period.     

Dietary fiber and chicken microbiome interaction: Where will it lead to?

The last few decades have been marked by a rapid genetic improvement in chicken growth rates. The modern-day chicken is more efficient in converting feed into muscle mass than their predecessors. This enhanced efficiency emanates from better nutrient digestion, absorption, and metabolism. The gut has therefore become a research focus especially after the ban on the use of antibiotics as growth promoters (AGP) in poultry. In pursuance of better gut health in the post-AGP era, many different strategies are being continuously sought and tested. The gut is inhabited by more than 900 bacterial species along with fungi and archaea, and they play an important role to maintain a conducive milieu for the host. A beneficial shift in the microbial ecosystem of the chicken can be promoted by many dietary and non-dietary interventions, however, diet is ranked as one of the most important and potent regulators of gut microbiota composition. Therefore, the constituents of the diet warrant special attention in the modulation of the gut ecosystem. Among dietary constituents, fiber possesses a significant ability to modulate the microbiota. In this review, we will highlight the importance of fiber in poultry nutrition and will also discuss the effects of fiber on gut microbiota and its resultant ramifications on the liver and brain.     

Opportunities of prebiotics for the intestinal health of monogastric animals

The goal of prebiotic applications from different sources is to improve the gut ecosystem where the host and microbiota can benefit from prebiotics. It has already been recognized that prebiotics have potential roles in the gut ecosystem because gut microbiota ferment complex dietary macronutrients and carry out a broad range of functions in the host body, such as the production of nutrients and vitamins, protection against pathogens, and maintenance of immune system balance. The gut ecosystem is very crucial and can be affected by numerous factors consisting of dietary constituents and commensal bacteria. This review focuses on recent scientific evidence, confirming a beneficial effect of prebiotics on animal health, particularly in terms of protection against pathogenic bacteria and increasing the number of beneficial bacteria that may improve epithelial cell barrier functions. It has also been reviewed that modification of the gut ecosystem through the utilization of prebiotics significantly affects the intestinal health of animals. However, the identification and characterization of novel potential prebiotics remain a topical issue and elucidation of the metagenomics relationship between gut microbiota alteration and prebiotic substances is necessary for future prebiotic studies.     

助产对奶牛产后子宫菌群的影响

在奶牛养殖业中,难产是奶牛临床上的常发病,助产是处理难产的常用手段。助产的发生会导致母牛受胎率降低、冻精使用量增加、空怀时间增加和首次配种时间后移等繁殖问题。本研究从细菌学角度分析助产对奶牛产后子宫菌群的影响,以期为提高牧场受胎率提供数据参考。在宁夏地区某大型奶牛场,以助产和非助产奶牛为研究对象,在产后45 d进行子宫灌洗,采集灌洗液样本共7份。通过细菌分离培养、16S rRNA测序等方法分离细菌。结果共分离出10个细菌属,12种细菌,其中,非助产奶牛子宫冲洗液中分离出链霉菌属、链球菌属、肠杆菌属、葡萄球菌属、气球菌属5个属的细菌;助产奶牛子宫冲洗液分离出志贺菌属、不动杆菌属、假单胞菌属、棒状杆菌属、芽胞杆菌属、气球菌属、肠杆菌属、葡萄球菌属、链球菌属等9个属的细菌。本研究的结果表明,助产和非助产奶牛子宫菌群差异显著,助产导致子宫内菌群多样性增加。     

Essential oil and aromatic plants as feed additives in non-ruminant nutrition: a review

This paper summarizes the current knowledge regarding the possible modes of action and nutritional factors involved in the use of essential oils (EOs) for swine and poultry. EOs have recently attracted increased interest as feed additives to be fed to swine and poultry, possibly replacing the use of antibiotic growth promoters which have been prohibited in the European Union since 2006. In general, EOs enhance the production of digestive secretions and nutrient absorption, reduce pathogenic stress in the gut, exert antioxidant properties and reinforce the animal’s immune status, which help to explain the enhanced performance observed in swine and poultry. However, the mechanisms involved in causing this growth promotion are far from being elucidated, since data on the complex gut ecosystem, gut function, in vivo oxidative status and immune system are still lacking. In addition, limited information is available regarding the interaction between EOs and feed ingredients or other feed additives (especially pro- or prebiotics and organic acids). This knowledge may help feed formulators to better utilize EOs when they formulate diets for poultry and swine.     

Effects of alkaline protease on the production performance,egg quality,and cecal microbiota of hens during late laying period

This study investigated the effects of diet supplementation with alkaline protease (AKP) on the production performance, egg quality, and cecal microbiota of laying hens. A total of 720 Hy-Line Brown laying hens (60 weeks old) were divided into four groups with six replicates of 30 birds each. No AKP was added to the control diet, and the hens in the other three groups (Groups 1, 2, and 3) were fed the basal diet supplemented with AKP preparations at 3, 6, and 9 u/g of diet, respectively. Results showed that AKP supplementation significantly decreased the feed/egg ratio (p < 0.05). Compared with that of the control group, the eggshell strength of Group 1 was significantly increased (p < 0.05), and the egg yolk weight of Groups 1 and 3 was significantly increased (p < 0.05). Distinctive difference in cecal microbiota was observed between AKP and control groups, and the average values of microbial diversity was lower in the AKP group than in the control group. The relative abundance of Bacteroidetes and Firmicutes at the phylum level, Rikenellaceae, Lachnospiraceae, Lactobacillaceae, Erysipelotrichaceae, and Christensenellaceae at the family level, and Rikenellaceae_RC9_gut_Group, Lactobacillus, Romboutsia, Lachnoclostridium, and Blautia at the genus level in the AKP group changed significantly compared with that in the control group (p<0.05).     

Current ocular microbiome investigations limit reproducibility and reliability: Critical review and opportunities

Enthusiasm for research describing microbial communities using next‐generation sequencing (NGS) has outpaced efforts to standardize methodology. Without consistency in the way research is carried out in this field, the comparison of data between studies is near impossible and the utility of results remains limited. This holds true for bacterial microbiome research of the ocular surface, and other sites, in both humans and animals. In addition, the ocular surface remains under‐explored when compared to other mucosal sites. Low bacterial biomass samples from the ocular surface lead to further technical challenges. Taken together, two major problems were identified: (1) Normalization of the workflow in studies utilizing NGS to investigate the ocular surface bacteriome is necessary in order to propel the field forward and improve research impact through cross‐study comparisons. (2) Current microbiome profiling technology was developed for high bacterial biomass samples (such as feces or soil), posing a challenge for analyses of samples with low bacterial load such as the ocular surface. This article reviews the challenges and limitations currently facing ocular microbiome research and provides recommendations for minimum reporting standards for veterinary ophthalmologists and clinician scientists to limit inter‐study variation, improve reproducibility, and ultimately render results from these studies more impactful. The move toward normalization of methodology will expedite and maximize the potential for microbiome research to translate into meaningful discovery and tangible clinical applications.     

Dose–response and functional role of whey permeate as a source of lactose and milk oligosaccharides on intestinal health and growth of nursery pigs

Two experiments were conducted to evaluate dose–response and supplemental effects of whey permeate on growth performance and intestinal health of nursery pigs. In experiment (exp.) 1, 1,080 pigs weaned at 6.24 kg body weight (BW) were allotted to five treatments (eight pens/treatment) with increasing levels of whey permeate in three phases (from 10% to 30%, 3% to 23%, and 0% to 9% for phase 1, 2, and 3, respectively) fed until 11 kg BW and then fed a common phase 4 diet (0% whey permeate) until 25 kg BW in a 48-d feeding trial. Feed intake and BW were measured at the end of each phase. In exp. 2, 1,200 nursery pigs at 7.50 kg BW were allotted to six treatments (10 pens/treatment) with increasing levels of whey permeate from 0% to 18.75% fed until 11 kg BW. Feed intake and BW were measured during 11 d. Six pigs per treatment (1 per pens) were euthanized to collect the jejunum to evaluate tumor necrosis factor-alpha, interleukin-8 (IL-8), transforming growth factor-beta 1, mucin 2, histomorphology, digestive enzyme activity, crypt cell proliferation rate, and jejunal mucosa-associated microbiota. Data were analyzed using contrasts in the MIXED procedure and a broken-line analysis using the NLIN procedure of SAS. In exp. 1, increasing whey permeate had a quadratic effect (P < 0.05) on feed efficiency (G:F; maximum: 1.35 at 18.3%) in phase 1. Increasing whey permeate linearly increased (P < 0.05) average daily gain (ADG; 292 to 327 g/d) and G:F (0.96 to 1.04) of pigs in phase 2. In exp. 2, increasing whey permeate linearly increased (P < 0.05) ADG (349 to 414 g/d) and G:F (0.78 to 0.85) and linearly increased (P < 0.05) crypt cell proliferation rate (27.8% to 37.0%). The breakpoint from a broken-line analysis was obtained at 13.6% whey permeate for maximal G:F. Increasing whey permeate tended to change IL-8 (quadratic, P = 0.052; maximum: 223 pg/mg at 10.9%), to decrease Firmicutes:Bacteroidetes (P = 0.073, 1.59 to 1.13), to increase (P = 0.089) Bifidobacteriaceae (0.73% to 1.11%), and to decrease Enterobacteriaceae (P = 0.091, 1.04% to 0.52%) and Streptococcaceae (P = 0.094, 1.50% to 0.71%) in the jejunal mucosa. In conclusion, dietary inclusion of whey permeate increased the growth of nursery pigs from 7 to 11 kg BW. Pigs grew most efficiently with 13.6% whey permeate. Improvement in growth performance is partly attributed to stimulating intestinal immune response and enterocyte proliferation with positive changes in jejunal mucosa-associated microbiota in nursery pigs.     

Bacillus amyloliquefaciens CECT 5940 improves performance and gut function in broilers fed different levels of protein and/or under necrotic enteritis challenge

Two studies were conducted to investigate the effect of Bacillus amyloliquefaciens CECT 5940 (BA) as a probiotic on growth performance, amino acid digestibility and bacteria population in broiler chickens under a subclinical necrotic enteritis (NE) challenge and/or fed diets with different levels of crude protein (CP). Both studies consisted of a 2 × 2 factorial arrangement of treatments with 480 Ross 308 mix-sexed broiler chickens. In study 1, treatments included 1) NE challenge (+/−), and 2) BA (1.0 × 10⁶ CFU/g of feed) supplementation (+/−). In study 2, all birds were under NE challenge, and treatments were 1) CP level (Standard/Reduced [2% less than standard]) and 2) BA (1.0 × 10⁶ CFU/g of feed) supplementation (+/−). After inducing NE infection, blood samples were taken on d 16 for uric acid evaluation, and cecal samples were collected for bacterial enumeration. In both studies, ileal digesta was collected on d 35 for nutrient digestibility evaluation. In study 1, the NE challenge reduced body weight gain (BWG), supressed feed conversion ratio (FCR) and serum uric acid levels (P < 0.001). Supplementation of BA increased BWG (P < 0.001) and reduced FCR (P = 0.043) across dietary treatments, regardless of challenge. Bacillus (P = 0.030) and Ruminococcus (P = 0.029) genomic DNA copy numbers and concentration of butyrate (P = 0.017) were higher in birds fed the diets supplemented with BA. In study 2, reduced protein (RCP) diets decreased BWG (P = 0.010) and uric acid levels in serum (P < 0.001). Supplementation of BA improved BWG (P = 0.001) and FCR (P = 0.005) and increased Ruminococcus numbers (P = 0.018) and butyrate concentration (P = 0.033) in the ceca, regardless of dietary CP level. Further, addition of BA reduced Clostridium perfringens numbers only in birds fed with RCP diets (P = 0.039). At d 35, BA supplemented diets showed higher apparent ileal digestibility of cystine (P = 0.013), valine (P = 0.020), and lysine (P = 0.014). In conclusion, this study suggests positive effects of BA supplementation in broiler diets via modulating gut microflora and improving nutrient uptake.     

草鱼肠道内分泌细胞中肽激素的免疫组织化学定位

通过过氧化物酶抗过氧化物酶(PAP)免疫组织化学染色方法,用10种哺乳动物激素培育出的抗血清对三尾草鱼肠道中免疫活性内分泌细胞进行了鉴别。与其中6种抗血清起反应的分别是:胃泌素、胰高血糖素样免疫反应物、抑胃肽、亮氨酸脑啡肽,P物质和牛胰多肽免疫活性内分泌细胞。其它4种抗血清在三尾草鱼肠道中没有发现免疫活性反应。草鱼肠道中各种免疫活性内分泌细胞的形态,大多数为开放型,少数为封闭型或兼有两种类型的特点。对6种免疫活性内分泌细胞的分布特点及其在肠道各段的密度进行了比较和讨论。