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.     

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.     

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.     

Characterization and partial purification of proteinases from the highly alkaline midgut of the humivorous larvae of Pachnoda ephippiata (Coleoptera: Scarabaeidae)

Proteinases in the humus-feeding larva of Pachnoda ephippiata were partially purified and characterized. Proteinase activity from the midgut was alkali-stable and its pH optimum for activity was about pH 12. Nine proteolytic bands were visible on zymogram gels containing gelatin; one band of 19 kDa was dominant. P. ephippiata mainly employed serine proteinases for digestive proteolysis. The combination of strong midgut alkalinity and midgut proteinases with pronounced alkali stability, a high proteolytic activity on model humic acids, and a large tolerance to high humic acid concentrations would enable the P. ephippiata to gain nutrients from soil by digesting the proteinaceous component of soil humic substances.     

The diet and food preferences of Onychiurus procampatus (Collembola) from upland grassland soils

Specimens of Onychiurus procampatus (Collembola) observed grazing on fungal mycelia were collected from the surface soil of three differently manged upland grasslands. A general trend of an increasing proportion of Collembola with a full gut was found along a gradient of reduced sheep management intensity, which was correlated with increased fungal biomass. In the laboratory, this collembolan showed a consistent order of preference for the mycelium of seven common fungal species isolated from the field sites.     

Survival and feeding activity of Protaphorura armata in different composts

Effects of compost products, enriched or not-enriched with a strain of the mycoparasitic fungus Trichoderma atroviride, on the survival of the collembolan Protaphorura armata and the viability of fungal conidia after the transit through the springtail gut were investigated. The effect of compost enriched with Ca-Lignosulphonate (Ca-Ls), a low cost by-product of the acid sulphite pulping process, with lignin-like structure, on P. armata was also evaluated. All compost products enriched or not with the mycoparasitic fungus or Ca-Ls did not affect P. armata survival. No statistical differences were found in animal survival for different types of product or in enriched and not-enriched products. In addition to adults, live juveniles were also observed in all compost products. The gut content of animals, collected at the end of the survival test from compost enriched with T. atroviride, was examined under the light microscope, and in a few cases observations revealed the presence of some T. atroviride conidia. Subsequent tests carried out to study the viability of conidia after the transit through the springtail gut showed that colonies of the fungus developed from all faecal pellets produced by adult and juveniles specimens of P. armata previously fed on conidia of T. atroviride. These results suggest compatibility between Collembola and Trichoderma or Ca-Ls in the composts.     

Dental chews positively shift the oral microbiota of adult dogs

Microbiota plays a prominent role in periodontal disease, but the canine oral microbiota and how dental chews may affect these populations have been poorly studied. We aimed to determine the differences in oral microbiota of adult dogs consuming dental chews compared with control dogs consuming only a diet. Twelve adult female beagle dogs (mean age = 5.31 ± 1.08 yr) were used in a replicated 4 × 4 Latin square design consisting of 28-d periods. Treatments (n = 12/group) included: diet only (CT); diet + Bones & Chews Dental Treats (BC; Chewy, Inc., Dania Beach, FL); diet + Dr. Lyon’s Grain-Free Dental Treats (DL; Dr. Lyon’s, LLC, Dania Beach, FL); and diet + Greenies Dental Treats (GR; Mars Petcare US, Franklin, TN). Each day, one chew was provided 4 h after mealtime. On day 27, breath samples were analyzed for total volatile sulfur compound concentrations using a Halimeter. On day 0 of each period, teeth were cleaned by a veterinary dentist blinded to treatments. Teeth were scored for plaque, calculus, and gingivitis by the same veterinary dentist on day 28 of each period. After scoring, salivary (SAL), subgingival (SUB), and supragingival (SUP) samples were collected for microbiota analysis using Illumina MiSeq. All data were analyzed using SAS (version 9.4) using the Mixed Models procedure, with P < 0.05 considered significant. All dogs consuming chews had lower calculus coverage and thickness, pocket depth and bleeding, plaque thickness, and halitosis compared with CT. In all sites of collection, CT dogs had a higher relative abundance of one or more potentially pathogenic bacteria (Porphyromonas, Anaerovorax, Desulfomicrobium, Tannerella, and Treponema) and lower relative abundance of one or more genera associated with oral health (Neisseria, Corynebacterium, Capnocytophaga, Actinomyces, Lautropia, Bergeyella, and Moraxella) than those fed chews. DL reduced Porphyromonas in SUP and SUB samples. DL and GR reduced Treponema in SUP samples. DL increased Corynebacterium in all sites of collection. BC increased Corynebacterium in SAL samples. DL and GR increased Neisseria in SAL samples. DL increased Actinomyces in the SUB sample. GR increased Actinomyces in SAL samples. Our results suggest that the dental chews tested in this study may aid in reducing periodontal disease risk in dogs by beneficially shifting the microbiota inhabiting plaque and saliva of a dog’s oral cavity. These shifts occurred over a short period of time and were correlated with improved oral health scores.     

鸡肠道免疫的研究进展

鸡肠道相关淋巴组织是粘膜相关淋巴组织的主要组成部分 ,是防止肠道病原感染的第一道防线。其中的肠道上皮、上皮间淋巴细胞、粘膜固有层淋巴组织在肠道免疫功能的调节方面起着重要的作用。本文就鸡肠道免疫研究进展做一综述。     

小麦麸水平对生长鸡消化道结构的影响

试验观察小麦麸水平对蛋鸡(0—4周)消化道结构的影响。试验采用去皮去胚玉米、淀粉及提纯大豆蛋白为主的半纯合饲粮,分别含有0(对照)、8、16、24、32和40%小麦麸,饲粮能量水平和蛋白质含量基本相同,用玉米油补充小麦麸降低的饲粮能量。试验结果表明对照组的采食量明显低于5个试验组(P<0.01),由此而导致较低的体重(P<0.01)。小麦麸水平超过8%,就足以使肌胃重量明显增加(P<0.01),小麦麸水平为32—40%,增加的程度更大些。致使小肠重量及长度增加的最低小麦麸水平分别为24%(P<0.01)和8%(P<0.01),盲肠重量及长度明显增加的最低小麦麸水平分别为16%(P<0.01)和8%(P<0.01)。小麦麸水平超过32%导致直肠重及长度明显增加(P<0.01)。小肠厚度在8～16%小麦麸水平时降低(P<0.01),超过24%,其厚度恢复至对照水平,盲肠厚度增加的最低小麦麸水平为16%(P<0.01),直肠厚度在小麦麸水平超过16%有增加的趋势,统计差异不显著。嗉囊及腺胃重和食道长、重及厚度不受小麦麸的影响。