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Poultry Science Mar 2016Two experiments evaluated prebiotics added to feed on the recovery of Salmonella in broilers during grow-out and processing. In Experiment 1, "seeder" chicks were...
Two experiments evaluated prebiotics added to feed on the recovery of Salmonella in broilers during grow-out and processing. In Experiment 1, "seeder" chicks were inoculated with Salmonella Typhimurium and placed with penmates. Treatments were: basal control diet, added 0.3% bamboo charcoal, 0.6% bamboo charcoal, or 0.12% Aromabiotic (medium chain fatty acids). The ceca from seeders and penmates were sampled to confirm Salmonella colonization at 3, 4, and 6 wk, and pen litter was sampled weekly. At 3 wk, charcoal fed chicks had significantly lower cecal recovery (37% lower) of Salmonella via direct plating but no differences at wk 4 or 6. At 6 wk, broilers fed Aromabiotic had no recovery of Salmonella from ceca with direct plating and significantly, 18%, lower recovery with enrichment. In Experiment 2, the treatments were: basal control diet, added 0.3% bamboo charcoal, 0.3% activated bamboo charcoal, or 0.3% pine charcoal. At placement, 2 seeders were challenged with Salmonella and commingled with penmates and ceca sampled at 1 and 2 wk, and ceca from 5 penmates/pen at 3 to 6 wk. Weekly, the pH of the crop and duodenum was measured from 1 penmate/pen and the litter surface sampled. At the end of grow-out broilers were processed. Results showed that penmates had colonized at 1 and 2 wk. Cecal Salmonella showed no differences except at 4 wk, when activated bamboo charcoal had a 18% lower recovery of Salmonella (enrichment) compared to the control (88%). Similar to Experiment 1, the recovery of Salmonella from the litter was not significantly different among treatments, however an overall decrease in recovery by 4 wk with direct plating reoccurred. The pH of the duodenum and the crop were not different among treatments. Crop pH (6.0) for all treatments were significantly higher at wk 1 compared to wk 2 to 6. Charcoals had minimal effect on Salmonella recovery in the ceca, but following defeathering, broilers fed charcoals had significantly lower Salmonella recovery from breast skin (charcoals 5+/60 compared to control 8+/20). While the addition of charcoals to broilers feed did not significantly affect Salmonella recovery during production (from litter or ceca samples) there was a lower Salmonella recovery from breast skin following scalding and defeathering.
Topics: Animal Feed; Animals; Charcoal; Crop, Avian; Diet; Duodenum; Fatty Acids; Hydrogen-Ion Concentration; Male; Pinus; Poaceae; Poultry Diseases; Prebiotics; Salmonella Infections, Animal; Salmonella typhimurium; Skin
PubMed: 26755657
DOI: 10.3382/ps/pev371 -
One Health (Amsterdam, Netherlands) Dec 2023High Pathogenicity Avian Influenza (HPAI) H5N1 outbreaks continue to wreak havoc on the global poultry industry and threaten the health of wild bird populations, with...
High Pathogenicity Avian Influenza (HPAI) H5N1 outbreaks continue to wreak havoc on the global poultry industry and threaten the health of wild bird populations, with sporadic spillover in humans and other mammals, resulting in widespread calls to vaccinate poultry. Bangladesh has been vaccinating poultry since 2012, presenting a prime opportunity to study the effects of vaccination on HPAI H5N1circulation in both poultry and wild birds. We investigated the efficacy of vaccinating commercial poultry against HPAI H5N1 along with climatic and socio-economic factors considered potential drivers of HPAI H5N1 outbreak risk in Bangladesh. Using a multivariate modeling approach, we estimated that the rate of outbreaks was 18 times higher before compared to after vaccination, with winter months having a three times higher chance of outbreaks than summer months. Variables resulting in small but significant increases in outbreak rate were relatively low ambient temperatures for the time of year, literacy rate, chicken and duck density, crop density, and presence of highways; this may be attributable to low temperatures supporting viral survival outside the host, higher literacy driving reporting rate, density of the host reservoir, and spread of the virus through increased connectivity. Despite the substantial impact of vaccination on outbreaks, we note that HPAI H5N1 is still enzootic in Bangladesh; vaccinated poultry flocks have high rates of H5N1 prevalence, and spillover to wild birds has increased. Vaccination in Bangladesh thus bears the risk of supporting "silent spread," where the vaccine only provides protection against disease and not also infection. Our findings underscore that poultry vaccination can be part of holistic HPAI mitigation strategies when accompanied by monitoring to avoid silent spread.
PubMed: 38116452
DOI: 10.1016/j.onehlt.2023.100655 -
Poultry Science Nov 2009It is generally accepted that the intestinal microbiota plays an important role in sustaining health and productivity of animals. Chlorella vulgaris, a naturally...
It is generally accepted that the intestinal microbiota plays an important role in sustaining health and productivity of animals. Chlorella vulgaris, a naturally occurring green microalga, is believed to influence performance and health, including bird reproduction and egg quality. The nutritive value of open or indoor cultured C. vulgaris depends upon the technological process used to treat the algal mass. In the present paper, it is presented and discussed how 2 differentially processed C. vulgaris powders (spray-dried: SD-CV; bullet-milled and spray-dried: BMSD-CV) affected crop and cecal microbiota in laying hens. Polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) of bacterial 16S rRNA gene fragments was applied. The diversity of the crop universal bacterial DGGE fingerprints was not affected (6.4 +/- 1.65, 5.4 +/- 1.19, and 5.5 +/- 1.35 in the control, SD-CV, and BMSD-CV, respectively). Most of the bands from the corresponding positions in the gels were closely related to Lactobacillus sp. The DGGE fingerprints of V2-V3 fragments of 16S rRNA of crop lactobacilli had lower diversity in the control hens (8.7 +/- 1.22) than in the SD-CV (9.2 +/- 1.77) and BMSD-CV (9.9 +/- 1.88); thus, feeding C. vulgaris resulted in increased lactobacilli diversity in crop. A band closely related to Lactobacillus ingluviei was present in 9 out of 12 hens in the control group but in only 1 bird in the SD-CV and in 5 out of 11 birds in the BMSD-CV, suggesting a negative effect of C. vulgaris on this lactobacillus. Feeding C. vulgaris to laying hens also resulted in increased bacterial community diversity in the ceca. No effect of the technological processing of the microalgae on the microbial diversity could be observed. The diversity of the ceca universal bacterial DGGE fingerprints was lower in the control group than in the SD-CV and BMSD-CV (5.6 +/- 1.72 vs. 9.16 +/- 2.64 and 9.31 +/- 2.41, respectively). Most of the sequences retrieved from the DGGE bands formed ceca that were closely related to Ruminococcaceae, Lachnospiraceae, and lactobacilli, giving further insight into still poorly discovered intestinal microbiota of laying hens.
Topics: Animal Feed; Animals; Cecum; Chickens; Chlorella vulgaris; Crop, Avian; Diet; Dietary Supplements; Female; Gastrointestinal Contents; Oviposition
PubMed: 19834082
DOI: 10.3382/ps.2009-00250 -
Poultry Science May 2016The non-starch polysaccharides (NSPs) in cell walls can act as a barrier for digestion of intracellular nutrients. This effect is called "cage effect." Part of the...
The non-starch polysaccharides (NSPs) in cell walls can act as a barrier for digestion of intracellular nutrients. This effect is called "cage effect." Part of the success of fibrolytic enzymes in broiler feed is assumed to be attributed to cage effect reduction. Further, changes in viscosity and potential prebiotic action should also be considered. The aim of this study was to gain insight into the relative importance of the cage effect in xylanase efficacy in broilers. Using a 2×2 factorial design, 24 pens with 30 Ross 308 male chicks were fed corn-soy based diets consisting of normal and freeze-thawed (5 d at -18°C) corn, both with and without xylanase. The freeze-thaw method was used to eliminate the cage effect, whereas a corn-based diet was used to exclude viscosity effects. Body weights (BW), feed intake (FI), and feed conversion ratio (FCR) were determined at d 13, 26, and 39. A balance study was executed at the end of the growing phase. These birds were euthanized at d 34 (non-fasted) to determine the viscosity of digesta, blood metabolites, intestinal morphology, and microbiota composition. During the finisher period, there was a significant interaction between enzyme supplementation and freeze-thawing for FCR, in which FCR was improved by freeze-thawed corn and tended to be improved by normal corn+enzyme compared with the control group. The improvement in performance (finisher period) of freeze-thawed corn and xylanase coincided with increased gut absorption of glucose (based on postprandial plasma concentrations) and increased number of Clostridiumcluster IV in the caecum, and agreed with the higher gut villus height. In addition, xylanase inclusion significantly increased the postprandial plasma glycine and triglycerides concentration, and led to elevated bacterial gene copies of butyryl CoA:acetate CoA-transferase, suggesting a prebiotic effect of xylanase addition through more than just the cage effect reduction. The applied model managed to rule out viscosity by using corn, and it was possible to isolate the cage effect by freeze-thawing the dietary corn.
Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Chickens; Diet; Dietary Supplements; Endo-1,4-beta Xylanases; Food Handling; Freezing; Male
PubMed: 26908893
DOI: 10.3382/ps/pew002 -
Poultry Science Dec 2003For evaluation of the filling and emptying of the alimentary tract, broiler breeder hens were cooped and processed over a 2-d period. Hens were fed at 0600 h on d 1 and...
For evaluation of the filling and emptying of the alimentary tract, broiler breeder hens were cooped and processed over a 2-d period. Hens were fed at 0600 h on d 1 and after access to feed for 0, 2, 4, and 6 h were placed into coops. Half of the hens from each pen were either immediately processed or were held in coops over-night and processed the following morning, d 2. The alimentary tract was excised from the carcass and then separated and weighed in three segments: the crop, proventriculus and gizzard, and intestines. Hens processed on d 1, after access to feed for only 2 h, had attained maximum intestine weight (176 g), but not until after access to feed for 6 h were peak crop weight (95 g) and peak weight for the proventriculus and gizzard (78 g) attained. Hens processed on d 2 did not differ in crop (12 to 14 g) or intestine (140 to 162 g) weight, but proventriculus and gizzard weights were significantly lower for hens not fed on d 1 prior to cooping (54 g) compared with hens fed on d 1 and cooped after 2, 4, or 6 h (62 to 63 g). However, hens processed on d 2 had proventriculus and gizzard weights that were the same as for those hens processed on d 1 and cooped at 0 h (63 g). Clearance of ingesta from the crop, proventriculus and gizzard, and intestines readily occurred while hens were held overnight without access to water.
Topics: Animal Feed; Animals; Chickens; Crop, Avian; Diet; Digestive System; Digestive System Physiological Phenomena; Female; Gizzard, Avian; Intestines; Organ Size; Proventriculus; Time Factors
PubMed: 14717561
DOI: 10.1093/ps/82.12.2000 -
Poultry Science May 1994Electrophysiological "single fiber" experiments were conducted on the vagal nerves of the domestic fowl to confirm the presence of mechanoreceptors in the crop and to...
Electrophysiological "single fiber" experiments were conducted on the vagal nerves of the domestic fowl to confirm the presence of mechanoreceptors in the crop and to study their properties. The afferent activity of the left vagus nerve was recorded in nine anaesthetized laying hens with and without the crop being artificially distended. Twenty-two units were found to respond to the crop inflation, 18 of them being slowly adapting mechanoreceptors. The discharge rate of these slowly adapting units increased as the pressure inside the crop was raised. Twelve units were localized and the responses of three units to different doses of acetylcholine, epinephrine, and norepinephrine were obtained. Mechanoreceptor discharges were enhanced when the crop was distended and during drug-induced contractions of its smooth muscle, suggesting an "in series" location within the muscle layers. Such receptors may provide the afferent limb of a reflex regulating crop motility and may be involved in the regulation of feed intake.
Topics: Acetylcholine; Afferent Pathways; Animals; Chickens; Crop, Avian; Female; Mechanoreceptors; Vagus Nerve
PubMed: 8047515
DOI: 10.3382/ps.0730744 -
Acta Veterinaria Scandinavica Jun 2010Lighting is used during conventional broiler grow-out to modify bird behaviour to reach the goals of production and improve bird welfare. The protocols for lighting...
BACKGROUND
Lighting is used during conventional broiler grow-out to modify bird behaviour to reach the goals of production and improve bird welfare. The protocols for lighting intensity vary. In a field study, we evaluated if the lighting practices impact the burden of Salmonella in broiler flocks.
METHODS
Conventional grow-out flocks reared in the states of Alabama, Mississippi and Texas, USA in 2003 to 2006 were sampled 1 week before harvest (n = 58) and upon arrival for processing (n = 56) by collecting feathered carcass rinsate, crop and one cecum from each of 30 birds, and during processing by collecting rinsate of 30 carcasses at pre-chilling (n = 56) and post-chilling points (n = 54). Litter samples and drag swabs of litter were collected from the grow-out houses after bird harvest (n = 56). Lighting practices for these flocks were obtained with a questionnaire completed by the growers. Associations between the lighting practices and the burden of Salmonella in the flocks were tested while accounting for variation between the grow-out farms, their production complexes and companies.
RESULTS
Longer relative duration of reduced lights during the grow-out period was associated with reduced detection of Salmonella on the exterior of birds 1 week before harvest and on the broiler carcasses at the post-chilling point of processing. In addition, starting reduced lights for > or = 18 hours per day later in the grow-out period was associated with decreased detection of Salmonella on the exterior of broilers arriving for processing and in the post-harvest drag swabs of litter from the grow-out house.
CONCLUSIONS
The results of this field study show that lighting practices implemented during broiler rearing can impact the burden of Salmonella in the flock. The underlying mechanisms are likely to be interactive.
Topics: Animal Husbandry; Animals; Cecum; Chickens; Crop, Avian; Lighting; Logistic Models; Poultry Diseases; Prospective Studies; Salmonella; Salmonella Infections, Animal; Surveys and Questionnaires
PubMed: 20587037
DOI: 10.1186/1751-0147-52-46 -
Poultry Science Jan 2020This study was conducted to explore the regulatory role of the target of rapamycin complex 1 (TORC1) signaling pathway in crop milk synthesis in breeding pigeons...
This study was conducted to explore the regulatory role of the target of rapamycin complex 1 (TORC1) signaling pathway in crop milk synthesis in breeding pigeons (Columba livia). Three groups of breeding pigeons in the lactation period (n = 30 pairs/group) were respectively injected with rapamycin (RAPA, a specific inhibitor of the target of rapamycin complex) at doses of 0 (vehicle, control), 0.6, or 1.2 mg/kg body weight (BW)/day via the wing vein for 7 days. The average daily feed intake (ADFI) and BW of the breeding pigeons and the BW of young squabs were respectively recorded throughout the experimental period. The breeding pigeons were sacrificed to collect their crop tissues, crop milk, and serum on the eighth day of the experiment. The results showed that neither 0.6 nor 1.2 mg/kg BW RAPA injection affected BW loss or ADFI in breeding pigeons (P > 0.05), while crop thickness and crop relative weight were significantly decreased (P < 0.05) in the 1.2 mg/kg BW rapamycin-injected group. Simultaneously, RAPA (especially at 1.2 mg/kg BW) decreased the crude protein, α-casein, α-casein, β-casein, and amino acid contents (Asp, Thr, Ser, Glu, Gly, Ala, Cys, Val, Met, Ile, Leu, Tyr, Lys, His, Arg, and Pro) of crop milk (P < 0.05) and the concentrations of albumin, total protein, and uric acid in the serum of breeding pigeons (P < 0.05). Additionally, the expression of TORC1 pathway-related proteins (TORC1, S6K1, S6, 4EBP1, and eIF4E) was downregulated in the crop tissues of breeding pigeons by 0.6 or 1.2 mg/kg BW/day RAPA injection (P < 0.05). Accordingly, the average daily gain (ADG) of young squabs declined, and the mortality rate increased significantly (P < 0.05). Together, the results showed that RAPA reduced protein and amino acid levels in the crop milk of breeding pigeons and retarded young squab growth, suggesting a crucial role of TORC1 in crop milk synthesis in breeding pigeons.
Topics: Animals; Avian Proteins; Columbidae; Crop, Avian; Dose-Response Relationship, Drug; Mechanistic Target of Rapamycin Complex 1; Milk Proteins; Random Allocation; Signal Transduction; Sirolimus
PubMed: 32416826
DOI: 10.3382/ps/pez513 -
Veterinary Research Sep 2017Plant-based transient expression is an alternative platform to produce hemagglutinin-based subunit vaccines. This production system provides not only fast and effective...
Plant-based transient expression is an alternative platform to produce hemagglutinin-based subunit vaccines. This production system provides not only fast and effective response in the context of a pandemic but also enables the supply of big volume vaccines at low cost. Crude plant extracts containing influenza hemagglutinin are considered to use as vaccine sources because of avoidance of related purification steps resulting in low cost production allowing veterinary applications. Highly immunogenic influenza hemagglutinins are urgently required to meet these pre-conditions. Here, we present a new and innovative way to generate functional H5 oligomers from avian flu hemagglutinin in planta by the specific interaction of S·Tag and S·Protein. A S·Tag was fused to H5 trimers and this construct was transiently co-expressed in planta with S·Protein-TPs which was multimerized by disulfide bonds via cysteine residues in tailpiece sequences (TP) of IgM antibody. Multimerized S·Protein-TPs serve as bridges/molecular docks to combine S·Tag-fused hemagglutinin trimers to form very large hemagglutinin H5 oligomers. H5 oligomers in the plant crude extract were highly active in hemagglutination resulting in high titers. Immunization of mice with two doses of plant crude extracts containing H5 oligomers after storage for 1 week at 4 °C caused strong immune responses and induced neutralizing specific humoral immune responses in mice. These results allow for the development of cheap influenza vaccines for veterinary application in future.
Topics: Agrobacterium; Animals; Antibodies, Neutralizing; Antibodies, Viral; Hemagglutinins; Immunity; Influenza A Virus, H5N1 Subtype; Influenza Vaccines; Male; Mice; Mice, Inbred C57BL; Orthomyxoviridae Infections; Plants, Genetically Modified; Recombinant Proteins; Nicotiana
PubMed: 28931425
DOI: 10.1186/s13567-017-0458-x -
Animal : An International Journal of... Jul 2021The provision of suitable bedding for rearing broilers is an ongoing challenge for poultry producers. The aim of the present study was to evaluate the effect of using...
The provision of suitable bedding for rearing broilers is an ongoing challenge for poultry producers. The aim of the present study was to evaluate the effect of using different types of crop residues as alternative bedding materials to wheat straw on growth performance, carcass traits, health, and welfare of broilers; moreover, the effects on the bedding and air quality were analyzed. We randomly assigned 180 1-day-old chickens (Cobb 500) across six bedding groups (three replicates of 10 birds each). Chickens in all groups were reared under similar housing conditions. Chickens of one group were reared on a wheat straw bedding (control), whereas those of the remaining five groups were reared on clover straw, cornstalk chips (CS), sugarcane top chips, chopped palm spines (CPS), and corn ear husks. Cornstalk chip and chopped palm spines were associated with the lowest (P < 0.05) ammonia concentrations compared with the remaining beddings. The mean values of bedding moisture percentage (P < 0.05), caking score, and ammonia concentrations (P < 0.05) were decreased with 6-week-old broilers reared on cornstalk chips. At 6 weeks, wheat straw, clover straw, sugarcane top chips and corn ear husks resulted in higher (P < 0.0001) BW and average daily gain compared with CS and CPS. Broilers reared on clover straw bedding showed the best FCR during 4-6 weeks of age (P < 0.01), and those kept on clover straw and sugarcane top chips exhibited the best (P < 0.01) feed conversion ratio (1.61 and 1.64, respectively) during 0-6 weeks of age. The carcass dressing yield, airborne dust concentration, bedding pH, and bacterial counts did not differ among the different bedding materials. The proportions of the drumsticks, gizzards, and abdominal fat of 6-week-old broilers were affected by bedding type (P < 0.05); but the differences among the bedding treatments were small. The mean incidence of footpad dermatitis and breast blisters was significantly less using clover straw. Broilers reared on chopped palm spine had the highest (P < 0.05) heterophil/lymphocyte ratio when compared with their counterparts. Conclusively, using clover straw or cornstalks as an alternative bedding material may be a beneficial strategy and should be highly recommended for rearing broilers.
Topics: Animal Feed; Animals; Bedding and Linens; Chickens; Gizzard, Avian; Poultry; Triticum
PubMed: 34116465
DOI: 10.1016/j.animal.2021.100260