ResearchPad - poultry https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Meta-analysis of the correlation between dietary copper supply and broiler performance]]> https://www.researchpad.co/article/elastic_article_15740 To conduct a meta-analysis assessing the correlation between dietary copper supply and broiler performanceMethodsStudies that were published prior to January 2019 and reported the dietary copper supply and broiler growth performance were identified using search functions in the Web of Science, Springer, Elsevier, Science Direct, and Taylor & Francis Online databases; the Journal of Dairy Research; and China National Knowledge Infrastructure (CNKI). We performed stratified analyses on the possible sources of bias, including differences in the study locations and years of publication. The publication bias was assessed with Egger’s test method.ResultsA total of 12 randomized controlled trial (RCT) studies were eligible for inclusion. The pooled WMDs of the ADG, ADFI and FCR were -0.166 (95% CI: -1.587 to 1.254), -0.844 (95% CI: -1.536 to -0.152) and -0.029 (95% CI: -0.057 to 0.000), respectively. In the Israeli and Indian studies, the ADG and ADFI data in the experimental group were higher than those in the control group; however, in America, a relatively high FCR value was found in the experimental group compared to that in the control group. The analysis of the study period showed that for the 1980s and 2010s, the ADG and ADFI of the experimental group were lower than those of the control group, while, in the 1990s and 2010s, the FCR of the experimental group were lower than those of the control group. The observed values were adjusted for study effects, and a model was used to obtain the copper supplementation under the optimal production performance. The results showed that the adjusted average daily gain (ADG), average daily feed intake (ADFI), and feed to gain ratio (FCR) presented a quadratic relationship with Cu supplementation (P<0.05). The maximum value of ADG (31.84 g/d) is reached when Cu is added at amount of 158 mg/kg, and the minimum value of FCR (1.53) is reached when Cu is added at amount of 217 mg/kg. No significant publication bias existed in the studies (Egger's test: P value were 0.81, 0.71 and 0.14).ConclusionFrom this study, it can be concluded that the traditional copper addition is no longer suitable for modern broiler breeding; the higher copper content may be beneficial for the production performance of broilers. ]]> <![CDATA[Development of plasma and whole blood taurine reference ranges and identification of dietary features associated with taurine deficiency and dilated cardiomyopathy in golden retrievers: A prospective, observational study]]> https://www.researchpad.co/article/elastic_article_14758 A surge in Food and Drug Administration (FDA) consumer complaints identified concerns that legume-rich, grain-free diets were associated with nutritionally-mediated dilated cardiomyopathy (DCM). Golden retrievers represent the most reported breed affected by this condition and previous studies documented the disease is responsive to dietary change and taurine supplementation. Although dietary findings across cases are compelling, prospective studies with control groups are lacking. The role of diet in developing taurine deficiency and echocardiographic changes consistent with DCM in healthy dogs is unknown.ObjectivesWe hypothesized that golden retrievers eating non-traditional diets are at a higher risk of having taurine deficiency and nutritionally-mediated DCM compared with those eating traditional commercial diets. We aimed to compare taurine concentrations and echocardiographic indices of systolic function between golden retrievers in each diet group and elucidate associations between diet and these variables. Additionally, we aimed to generate breed-specific reference intervals for whole blood and plasma taurine concentrations.Animals86 golden retrievers.MethodsGolden retrievers eating traditional or non-traditional diets were evaluated and diet history, taurine concentrations and echocardiographic data were collected. Dietary features, taurine concentrations and echocardiographic findings were compared between diet groups. Relative risks were calculated for the likelihood of echocardiographic abnormalities and taurine deficiency in each diet group. Breed-specific reference intervals were constructed for taurine concentrations in dogs from the traditional diet group.ResultsGolden retrievers eating non-traditional diets had significantly lower taurine concentrations and more frequent systolic dysfunction. Breed specific reference intervals are higher than previously reported across breeds.ConclusionsNon-traditional diets, which were typically grain-free and contained legumes in this study, were significantly associated with and have increased relative risk for the identification of taurine deficiency and echocardiographic abnormalities consistent with nutritionally-mediated DCM. These findings were identifiable in the absence of clinical signs and support the findings of multiple previous studies and the ongoing FDA investigation. ]]> <![CDATA[Identification of potential vulnerable points and paths of contamination in the Dutch broiler meat trade network]]> https://www.researchpad.co/article/elastic_article_14703 The poultry meat supply chain is complex and therefore vulnerable to many potential contaminations that may occur. To ensure a safe product for the consumer, an efficient traceability system is required that enables a quick and efficient identification of the potential sources of contamination and proper implementation of mitigation actions. In this study, we explored the use of graph theory to construct a food supply chain network for the broiler meat supply chain in the Netherlands and tested it as a traceability system. To build the graph, we first identified the main actors in the supply chain such as broiler breeder farms, broiler farms, slaughterhouses, processors, and retailers. The capacity data of each supply chain actor, represented by its production or trade volumes, were gathered from various sources. The trade relationships between the supply chain actors were collected and the missing relationships were estimated using the gravity model. Once the network was modeled, we computed degree centrality and betweenness centrality to identify critical nodes in the network. In addition, we computed trade density to get insight into the complexity of sub-networks. We identified the critical nodes at each stage of the Dutch broiler meat supply chain and verified our results with a domain expert of the Dutch poultry industry and literature. The results showed that processors with own slaughtering facility were the most critical points in the broiler meat supply chain.

]]>
<![CDATA[SPOP promotes ubiquitination and degradation of MyD88 to suppress the innate immune response]]> https://www.researchpad.co/article/elastic_article_14645 MyD88 is a central adaptor that mediates initiation of the innate immune response and production of the proinflammatory cytokines that restrain pathogens and activate adaptive immunity. Although MyD88 is crucial for a host to prevent pathogenic infection, misregulation of its abundance might lead to autoimmune diseases. Thus, degradation of MyD88 is a key canonical mechanism for terminating cytokine production. Here, we characterized a novel E3 ligase, SPOP, that targets MyD88 for degradation. ChSPOP attenuated IL-1β production through K48-linked polyubiquitination and degradation of chMyD88, and thus impaired immune responses. Spop deficient mice showed more susceptibility to infection by Salmonella typhimurium. These findings demonstrate that SPOP is a negative regulator of MyD88-dependent pathway activation triggered by LPS and Salmonella typhimurium, which helps the host to maintain immune homeostasis.

]]>
<![CDATA[Molecular epidemiology, genetic diversity and antimicrobial resistance of <i>Staphylococcus aureus</i> isolated from chicken and pig carcasses, and carcass handlers]]> https://www.researchpad.co/article/elastic_article_14574 The epidemiology of Staphylococcus aureus in food animals, associated products, and their zoonotic potential in Nigeria are poorly understood. This study aimed to provide data on the prevalence, genetic characteristics and antimicrobial resistance of S. aureus isolated from chicken and pig carcasses, and persons in contact with the carcasses at slaughterhouses in Nigeria. Surface swabs were collected randomly from 600 chicken and 600 pig carcasses. Nasal swabs were collected from 45 workers in chicken slaughterhouses and 45 pig slaughterhouse workers. S. aureus isolates were analyzed by spa typing. They were also examined for presence of the Panton-Valentine Leucocidin (PVL) and mecA genes, as well as for antimicrobial resistance phenotype. Overall, 53 S. aureus isolates were recovered (28 from chicken carcasses, 17 from pig carcasses, 5 from chicken carcass handlers and 3 from pig carcass handlers). Among the isolates, 19 (35.8%) were PVL-positive and 12 (22.6%) carried the mecA gene. The 53 isolates belonged to 19 spa types. The Based Upon Repeat Pattern (BURP) algorithm separated the isolates into 2 spa-clonal complexes (spa-CC) and 9 singletons including 2 novel spa types (t18345 and t18346). The clonal complexes (CC) detected were CC1, CC5, CC8, CC15, CC88 and CC152. CC15-related isolates represented by spa type t084 (32.1%) and CC5 represented by spa type t311 (35.3%) predominated among isolates from chicken carcasses/ handlers, and pig carcasses/ handlers, respectively. Multidrug resistance exhibited by all the CC except CC8, was observed among isolates from chicken carcasses (64.3%), pig carcasses (41.2%), handlers of chicken meat (40.0%) and handlers of pork (33.3%). All the CC showed varying degrees of resistance to tetracycline while CC15 and CC5 exhibited the highest resistance to sulphamethoxazole/trimethoprim and erythromycin, respectively. The predominant antimicrobial resistance pattern observed was penicillin-tetracycline-sulphamethoxazole/trimethoprim (PEN-TET-SXT). In conclusion, food animals processed in Enugu State in Southeast Nigeria are potential vehicles for transmission of PVL-positive multiple-drug resistant S. aureus and methicillin-resistant S. aureus from farm to slaughterhouse and potentially to the human population. Public health intervention programs at pre- and post-slaughter stages should be considered in Nigerian slaughterhouses.

]]>
<![CDATA[Assessment of the genomic prediction accuracy for feed efficiency traits in meat-type chickens]]> https://www.researchpad.co/article/5989db51ab0ee8fa60bdc4ab

Feed represents the major cost of chicken production. Selection for improving feed utilization is a feasible way to reduce feed cost and greenhouse gas emissions. The objectives of this study were to investigate the efficiency of genomic prediction for feed conversion ratio (FCR), residual feed intake (RFI), average daily gain (ADG) and average daily feed intake (ADFI) and to assess the impact of selection for feed efficiency traits FCR and RFI on eviscerating percentage (EP), breast muscle percentage (BMP) and leg muscle percentage (LMP) in meat-type chickens. Genomic prediction was assessed using a 4-fold cross-validation for two validation scenarios. The first scenario was a random family sampling validation (CVF), and the second scenario was a random individual sampling validation (CVR). Variance components were estimated based on the genomic relationship built with single nucleotide polymorphism markers. Genomic estimated breeding values (GEBV) were predicted using a genomic best linear unbiased prediction model. The accuracies of GEBV were evaluated in two ways: the correlation between GEBV and corrected phenotypic value divided by the square root of heritability, i.e., the correlation-based accuracy, and model-based theoretical accuracy. Breeding values were also predicted using a conventional pedigree-based best linear unbiased prediction model in order to compare accuracies of genomic and conventional predictions. The heritability estimates of FCR and RFI were 0.29 and 0.50, respectively. The heritability estimates of ADG, ADFI, EP, BMP and LMP ranged from 0.34 to 0.53. In the CVF scenario, the correlation-based accuracy and the theoretical accuracy of genomic prediction for FCR were slightly higher than those for RFI. The correlation-based accuracies for FCR, RFI, ADG and ADFI were 0.360, 0.284, 0.574 and 0.520, respectively, and the model-based theoretical accuracies were 0.420, 0.414, 0.401 and 0.382, respectively. In the CVR scenario, the correlation-based accuracy and the theoretical accuracy of genomic prediction for FCR was lower than RFI, which was different from the CVF scenario. The correlation-based accuracies for FCR, RFI, ADG and ADFI were 0.449, 0.593, 0.581 and 0.627, respectively, and the model-based theoretical accuracies were 0.577, 0.629, 0.631 and 0.638, respectively. The accuracies of genomic predictions were 0.371 and 0.322 higher than the conventional pedigree-based predictions for the CVF and CVR scenarios, respectively. The genetic correlations of FCR with EP, BMP and LMP were -0.427, -0.156 and -0.338, respectively. The correlations between RFI and the three carcass traits were -0.320, -0.404 and -0.353, respectively. These results indicate that RFI and FCR have a moderate accuracy of genomic prediction. Improving RFI and FCR could be favourable for EP, BMP and LMP. Compared with FCR, which can be improved by selection for ADG in typical meat-type chicken breeding programs, selection for RFI could lead to extra improvement in feed efficiency.

]]>
<![CDATA[Effectiveness of Live Poultry Market Interventions on Human Infection with Avian Influenza A(H7N9) Virus, China ]]> https://www.researchpad.co/article/N117bb014-c2b9-42ea-b03e-d0eedee29880

Various interventions for live poultry markets (LPMs) have emerged to control outbreaks of avian influenza A(H7N9) virus in mainland China since March 2013. We assessed the effectiveness of various LPM interventions in reducing transmission of H7N9 virus across 5 annual waves during 2013–2018, especially in the final wave. With the exception of waves 1 and 4, various LPM interventions reduced daily incidence rates significantly across waves. Four LPM interventions led to a mean reduction of 34%–98% in the daily number of infections in wave 5. Of these, permanent closure provided the most effective reduction in human infection with H7N9 virus, followed by long-period, short-period, and recursive closures in wave 5. The effectiveness of various LPM interventions changed with the type of intervention across epidemics. Permanent LPM closure should be considered to maintain sufficient effectiveness of interventions and prevent the recurrence of H7N9 epidemics.

]]>
<![CDATA[Porcine Deltacoronavirus Infection and Transmission in Poultry, United States1]]> https://www.researchpad.co/article/N310e7684-0ad7-4fff-9a6d-fec488c31cf9

Coronaviruses cause respiratory and gastrointestinal diseases in diverse host species. Deltacoronaviruses (DCoVs) have been identified in various songbird species and in leopard cats in China. In 2009, porcine deltacoronavirus (PDCoV) was detected in fecal samples from pigs in Asia, but its etiologic role was not identified until 2014, when it caused major diarrhea outbreaks in swine in the United States. Studies have shown that PDCoV uses a conserved region of the aminopeptidase N protein to infect cell lines derived from multiple species, including humans, pigs, and chickens. Because PDCoV is a potential zoonotic pathogen, investigations of its prevalence in humans and its contribution to human disease continue. We report experimental PDCoV infection and subsequent transmission among poultry. In PDCoV-inoculated chicks and turkey poults, we observed diarrhea, persistent viral RNA titers from cloacal and tracheal samples, PDCoV-specific serum IgY antibody responses, and antigen-positive cells from intestines.

]]>
<![CDATA[MLST-based genetic relatedness of Campylobacter jejuni isolated from chickens and humans in Poland]]> https://www.researchpad.co/article/N2eb0d267-f054-40f4-b445-0c8d9725ee43

Campylobacter jejuni infection is one of the most frequently reported foodborne bacterial diseases worldwide. The main transmission route of these microorganisms to humans is consumption of contaminated food, especially of chicken origin. The aim of this study was to analyze the genetic relatedness of C. jejuni from chicken sources (feces, carcasses, and meat) and from humans with diarrhea as well as to subtype the isolates to gain better insight into their population structure present in Poland. C. jejuni were genotyped using multilocus sequence typing (MLST) and sequence types (STs) were assigned in the MLST database. Among 602 isolates tested, a total of 121 different STs, including 70 (57.9%) unique to the isolates' origin, and 32 STs that were not present in the MLST database were identified. The most prevalent STs were ST464 and ST257, with 58 (9.6%) and 52 (8.6%) C. jejuni isolates, respectively. Isolates with some STs (464, 6411, 257, 50) were shown to be common in chickens, whereas others (e.g. ST21 and ST572) were more often identified among human C. jejuni. It was shown that of 47 human sequence types, 26 STs (106 isolates), 23 STs (102 isolates), and 29 STs (100 isolates) were also identified in chicken feces, meat, and carcasses, respectively. These results, together with the high and similar proportional similarity indexes (PSI) calculated for C. jejuni isolated from patients and chickens, may suggest that human campylobacteriosis was associated with contaminated chicken meat or meat products or other kinds of food cross-contaminated with campylobacters of chicken origin. The frequency of various sequence types identified in the present study generally reflects of the prevalence of STs in other countries which may suggest that C. jejuni with some STs have a global distribution, while other genotypes may be more restricted to certain countries.

]]>
<![CDATA[Diversity of A(H5N1) clade 2.3.2.1c avian influenza viruses with evidence of reassortment in Cambodia, 2014-2016]]> https://www.researchpad.co/article/Nf51e501a-7d3b-493b-bbd9-bf4dbc27c932

In Cambodia, highly pathogenic avian influenza A(H5N1) subtype viruses circulate endemically causing poultry outbreaks and zoonotic human cases. To investigate the genomic diversity and development of endemicity of the predominantly circulating clade 2.3.2.1c A(H5N1) viruses, we characterised 68 AIVs detected in poultry, the environment and from a single human A(H5N1) case from January 2014 to December 2016. Full genomes were generated for 42 A(H5N1) viruses. Phylogenetic analysis shows that five clade 2.3.2.1c genotypes, designated KH1 to KH5, were circulating in Cambodia during this period. The genotypes arose through multiple reassortment events with the neuraminidase (NA) and internal genes belonging to H5N1 clade 2.3.2.1a, clade 2.3.2.1b or A(H9N2) lineages. Phylogenies suggest that the Cambodian AIVs were derived from viruses circulating between Cambodian and Vietnamese poultry. Molecular analyses show that these viruses contained the hemagglutinin (HA) gene substitutions D94N, S133A, S155N, T156A, T188I and K189R known to increase binding to the human-type α2,6-linked sialic acid receptors. Two A(H5N1) viruses displayed the M2 gene S31N or A30T substitutions indicative of adamantane resistance, however, susceptibility testing towards neuraminidase inhibitors (oseltamivir, zanamivir, lananmivir and peramivir) of a subset of thirty clade 2.3.2.1c viruses showed susceptibility to all four drugs. This study shows that A(H5N1) viruses continue to reassort with other A(H5N1) and A(H9N2) viruses that are endemic in the region, highlighting the risk of introduction and emergence of novel A(H5N1) genotypes in Cambodia.

]]>
<![CDATA[The evolution and genetic diversity of avian influenza A(H9N2) viruses in Cambodia, 2015 – 2016]]> https://www.researchpad.co/article/Ncf402c92-86f9-4684-b431-03c7c64bd7da

Low pathogenic A(H9N2) subtype avian influenza viruses (AIVs) were originally detected in Cambodian poultry in 2013, and now circulate endemically. We sequenced and characterised 64 A(H9N2) AIVs detected in Cambodian poultry (chickens and ducks) from January 2015 to May 2016. All A(H9) viruses collected in 2015 and 2016 belonged to a new BJ/94-like h9-4.2.5 sub-lineage that emerged in the region during or after 2013, and was distinct to previously detected Cambodian viruses. Overall, there was a reduction of genetic diversity of H9N2 since 2013, however two genotypes were detected in circulation, P and V, with extensive reassortment between the viruses. Phylogenetic analysis showed a close relationship between A(H9N2) AIVs detected in Cambodian and Vietnamese poultry, highlighting cross-border trade/movement of live, domestic poultry between the countries. Wild birds may also play a role in A(H9N2) transmission in the region. Some genes of the Cambodian isolates frequently clustered with zoonotic A(H7N9), A(H9N2) and A(H10N8) viruses, suggesting a common ecology. Molecular analysis showed 100% of viruses contained the hemagglutinin (HA) Q226L substitution, which favours mammalian receptor type binding. All viruses were susceptible to the neuraminidase inhibitor antivirals; however, 41% contained the matrix (M2) S31N substitution associated with resistance to adamantanes. Overall, Cambodian A(H9N2) viruses possessed factors known to increase zoonotic potential, and therefore their evolution should be continually monitored.

]]>
<![CDATA[Effect of arabinoxylo-oligosaccharides and arabinoxylans on net energy and nutrient utilization in broilers]]> https://www.researchpad.co/article/5ca11391d5eed0c484570dd0

Arabinoxylo-oligosaccharides (AXOS) are hydrolytic degradation products of arabinoxylans (AX) that can be fermented by the gut microbiota, thus potentially displaying prebiotic properties. This study examined the effects of AX and AXOS on net energy (NE) and nutrient utilization in broilers. Ross 308 broilers (n = 90, 30 birds per treatment) were fed wheat-soybean diets supplemented with pure AX, AXOS produced by exposing the AX to xylanase in vitro (AXOS), or AX with xylanase (AX + E) from d 10 to 21. Performance parameters were measured from d 10 to 21. On d 15, 10 birds per treatment were allocated to closed-circuit net energy chambers to assess the impact of AX and AXOS on dietary energy utilization, through assessment of both metabolisable energy (ME) and NE. Ileal and caecal digesta samples were collected on d 21 to determine the effect of AX and AXOS on ileal and total tract dry matter digestibility, ileal digestible energy, digesta pH, short chain fatty acids (SCFA) and microbiota concentration. Feed conversion ratio was numerically the lowest in birds fed the diet supplemented with AXOS, which is 1.26 compared to 1.37 and 1.30 for AX and AX + E, respectively. Ileal dry matter digestibility was higher in birds fed AXOS than those fed AX (P = 0.047). Ileal digestible energy and total tract dry matter digestibility were higher in birds fed AXOS than those fed AX or AX + E (P = 0.004 and P = 0.001, respectively). Birds fed AXOS had higher ME intake (P = 0.049) and nitrogen retention (P = 0.001) and a strong trend of higher NE (P = 0.056), NE intake (P = 0.057) and retained energy (P = 0.054) compared to those fed AX. Ileal total SCFA, lactic and formic acid concentrations were higher in birds fed AXOS than those fed AX (P = 0.011, P = 0.012 and P = 0.023, respectively). Birds fed AXOS or AX + E had higher caecal total SCFA, acetic, butyric and isovaleric acid concentrations compared to those fed AX (P = 0.001, P = 0.004, P = 0.016 and P = 0.008, respectively), and caecal propionic acid concentration was higher in birds fed AX + E than those fed AX (P = 0.050). Ileal and caecal microbiota concentrations were numerically higher and pH was lower in birds fed AXOS and AX + E than those fed AX. Results from this study indicate that feeding AXOS directly is more efficient than AXOS generation in the gastrointestinal tract, and suggest that AXOS has a potential to be an efficacious prebiotic in broiler diets.

]]>
<![CDATA[Performance effects of feed-borne Fusarium mycotoxins on broiler chickens: Influences of timing and duration of exposure]]> https://www.researchpad.co/article/5ca1138fd5eed0c484570da2

In commercial practice, broiler chickens may be exposed to Fusarium mycotoxins either during specific growth stages or throughout the entire production cycle. A 34-day feeding trial was conducted to identify sensitive periods for mycotoxin effects during the growth cycle of broiler chickens. A total of 420 newly-hatched Ross 308 male broilers were randomly assigned to 60 cages with 7 birds/cage. Sources of clean wheat (<0.5 mg/kg deoxynivalenol [DON]) and Fusarium-contaminated wheat (11.4 mg/kg DON) were used to formulate the starter diets (0.41 and 6.62 mg/kg DON) provided from 1 to 21 d of age and the grower diets (0.54 and 7.90 mg/kg DON) provided from 22 to 34 d. Control and DON diets were provided to broilers according to treatments (control, DON 1 to 14 d, DON 15 to 21 d, DON 22 to 34 d and DON 1 to 34 d). Birds were monitored daily for morbidity or mortality. Broiler growth performance (body weight, average daily gain, average daily feed intake and feed to gain ratio) was measured weekly. Segments of duodenum, jejunum and ileum were collected at 21 and 34 d and morphometric parameters (villus height, crypt depth, villus width, muscularis thickness and villi:crypt ratio) were measured. Birds fed the DON starter diet during the first 14 d did not exhibit any changes in growth performance; however, growth performance was suppressed in birds fed DON-contaminated diets during the grower period (22 to 34 d). At 34 d, birds that received the DON grower diet (DON 22 to 34 d and DON 1 to 34 d) were lighter (1,433 vs. 1,695 g) than birds fed the control diet. Feed to gain ratio was higher in birds fed the DON grower diet from 22 to 28 d (1.77 vs. 1.56) and 28 to 34 d (2.24 vs. 1.85) compared with corresponding controls. These results suggest that providing older broiler chicks (22 to 34 d) feed contaminated with Fusarium mycotoxins (specifically DON) may result in production losses. Histopathological analysis of the ileum region revealed that birds provided the DON diets throughout the entire trial (1 to 34 d) had shorter villi (506 vs. 680 μm) and shallower crypt (85 vs. 115 μm) than control birds. Taken together, these results indicate that DON-induced growth suppression may be a result of adverse effects on intestinal morphology during later growth phases of broilers.

]]>
<![CDATA[On growth performance, nutrient digestibility, blood T lymphocyte subsets, and cardiac antioxidant status of broilers]]> https://www.researchpad.co/article/5ca11379d5eed0c484570bcd

Different lipid sources differ in the fatty acid profiles and differently affect growth performance as well as immune function of broilers. The influences of different dietary lipid sources on growth performance, nutrient digestibility, blood T lymphocyte population, and cardiac antioxidant status were investigated of broilers. A total of 360 one-day-old male broilers (BW = 44 ± 3 g) were randomized into 3 treatment groups, consisting of 6 replicates with 20 birds in each group. Broilers received standard diets supplemented with 5% (wt/wt) of lard (LD, as a control diet), sesame oil (SO), or flaxseed oil (FO). Broilers in both SO and FO treatment groups had lower (P < 0.05) feed conversion ratios from 22 to 42 d and during the overall phase compared to those in LD treatment group. Meanwhile, the apparent total tract nutrient digestibility of crude fat in SO and FO treatment groups was higher than that in LD treatment group. Both FO and SO treatments decreased (P < 0.05) abdominal fat percentage compared to LD treatment. Total triglycerides and total cholesterol in chicken blood were decreased (P < 0.05) by SO and FO treatments compared to LD treatment. Feeding broilers with FO and SO led to a decrease (P < 0.05) in blood CD4+ T lymphocyte count and in CD4+:CD8+ ratio compared to LD treatment. Sesame oil and FO treatments increased cardiac glutathione peroxidase (P < 0.05) compared to LD treatment. It is concluded that addition of 5% SO and FO to the standard corn-soybean meal diet improved feed efficiency, increased the activities of cardiac glutathione peroxidase, and affected the T lymphocytes ratio of fast growing broilers.

]]>
<![CDATA[Growth performance, gastrointestinal weight, microbial metabolites and apparent retention of components in broiler chickens fed up to 11% rice bran in a corn-soybean meal diet without or with a multi-enzyme supplement]]> https://www.researchpad.co/article/5ca1137bd5eed0c484570bf1

We investigated the effects of adding up to 11% rice bran (RB) in corn-soybean meal diets fed to broiler chickens without or with a multi-enzyme supplement (MES). The MES supplied xylanase, β-glucanase, invertase, protease, cellulase, α-amylase and mannanase with targeted activity of 2,500, 300, 700, 10,000, 1,200, 24,000, and 20 U/kg of feed, respectively. The study used a two-phase feeding program (starter, d 0 to 24; finisher, d 25 to 35) with RB added at 5% and 11%, respectively creating 4 diets in each phase. Diets were iso-caloric and iso-nitrogenous and contained phytase (500 FTU/kg) and TiO2 as a digestibility marker. Three hundred and sixty d-old male Ross 708 broiler chicks were placed in cages based on BW (15 birds/cage) and allocated to 4 diets (n = 6). Birds had free access to feed and water. Body weight and feed intake were recorded. Excreta samples were collected 3 d prior to the end of each phase for apparent retention (AR) of components. Samples of birds were sacrificed on d 24 and 35 for gut weight and ceca digesta for organic acid content. There was no interaction (P > 0.10) between RB and MES on BWG and FCR in starter or finisher phase. In finisher phase, birds fed MES had better BWG (961 versus 858 g) and FCR (1.69 versus 1.86) than birds fed non-MES diets (P < 0.01). Feeding RB reduced (P = 0.02) BWG in finisher phase resulting in lower d 35 BW. Birds fed RB had higher (P ≤ 0.01) gizzard weight on d 24 and 35 than non-RB birds. An interaction (P ≤ 0.01) between RB and MES on concentrations of propionic and iso-butyric acids in ceca digesta showed that MES reduced these acids in non-RB diet. The AR of gross energy was higher (P < 0.02) for MES versus non-MES birds in starter and finisher phases. In conclusion, independently, RB increased gizzard weight and reduced final BW whereas MES improved growth and energy utilization.

]]>
<![CDATA[Productive performance, egg quality, hematological parameters and serum chemistry of laying hens fed diets supplemented with certain fat-soluble vitamins, individually or combined, during summer season]]> https://www.researchpad.co/article/5ca1137ed5eed0c484570c27

This present study aimed to determine the efficacy of supplementing layer diets with vitamin A (0, 8,000 and 16,000 IU/kg diet) and vitamin E (0, 250 and 500 mg/kg diet) either individually or in combination on egg production and quality, and blood hematology and chemistry of birds reared under summer conditions. A total of 135 Bovans Brown laying hens were distributed to 9 treatment groups with 5 replicates of 3 hens/pen in a 3 × 3 factorial design. A significant improvement in feed conversion ratio (FCR) was observed as supplementary vitamin A or E increased (P ≤ 0.01). Hens fed diets supplemented with 16,000 IU vitamin A plus 500 mg vitamin E/kg diet had the best FCR among all groups. Egg quality traits were not significantly affected by the interaction of vitamin A and vitamin E levels. There was a significant increase in monocytes (P ≤ 0.01) and a decrease in basophils counts (P ≤ 0.05) in response to vitamin E. Significant decreases were observed in packed cell volume (PCV), thyroxine (T4), alanine transferase (ALT), albumin, total cholesterol and total lipids ( (P ≤ 0.05 or P ≤ 0.01) P ≤ 0.01) , and increases were observed in serum concentrations of globulin (P ≤ 0.05) and calcium (P ≤ 0.01) due to vitamin A. The combination of 0 IU vitamin A and 500 mg vitamin E/kg diet had the highest values of PCV (40.09%) and hemoglobin (Hb) (10.33 mg/100 mL) among all groups. Vitamin E raised serum values of total protein, total cholesterol and total lipids (P ≤ 0.05 or P ≤ 0.01). Feed intake, FCR, PCV, Hb, lymphocytes, monocytes, eosinophils, T4, ALT and total protein were significantly affected by the interaction of vitamins A and E (P ≤ 0.05 or P ≤ 0.01). The interaction of vitamins A and E was only significant with respect to serum total protein (P ≤ 0.05). It can be concluded that layer diets supplemented with vitamins A and E had good results in alleviating the harmful impacts of high ambient temperature. The combination of 16,000 IU vitamin A and 500 mg vitamin E per kilogram diet is preferable for obtaining better production of laying hens reared under hot summer conditions.

]]>
<![CDATA[Broiler gut microbiota and expressions of gut barrier genes affected by cereal type and phytogenic inclusion]]> https://www.researchpad.co/article/5ca1137dd5eed0c484570c00

The present study assessed the effects of cereal type and the inclusion level of a phytogenic feed additive (PFA) on broiler ileal and cecal gut microbiota composition, volatile fatty acids (VFA) and gene expression of toll like receptors (TLR), tight junction proteins, mucin 2 (MUC2) and secretory immunoglobulin A (sIgA). Depending on cereal type (i.e. maize or wheat) and PFA inclusion level (i.e. 0, 100 and 150 mg/kg diet), 450 one-day-old male broilers were allocated in 6 treatments according to a 2 × 3 factorial arrangement with 5 replicates of 15 broilers each, for 42 d. Significant interactions (P ≤ 0.05) between cereal type and PFA were shown for cecal digesta Bacteroides and Clostridium cluster XIVa, ileal digesta propionic and branched VFA, ileal sIgA gene expression, as well as cecal digesta branched and other VFA molar ratios. Cereal type affected the cecal microbiota composition. In particular, wheat-fed broilers had higher levels of mucosa-associated Lactobacillus (PCT = 0.007) and digesta Bifidobacterium (PCT < 0.001), as well as lower levels of total bacteria (PCT = 0.004) and Clostridia clusters I, IV and XIVa (PCT ≤ 0.05), compared with maize-fed ones. In addition, cereal type gave differences in fermentation intensity (PCT = 0.021) and in certain individual VFA molar ratios. Wheat-fed broilers had higher (P ≤ 0.05) ileal zonula occluden 2 (ZO-2) and lower ileal and cecal TLR2 and sIgA levels, compared with maize-fed broilers. On the other hand, PFA inclusion at 150 mg/kg had a stimulating effect on microbial fermentation at ileum and a retarding effect in ceca with additional variable VFA molar patterns. In addition, PFA inclusion at 100 mg/kg increased the ileal mucosa expression of claudin 5 (CLDN5) (PPFA = 0.023) and MUC2 (PPFA = 0.001) genes, and at 150 mg/kg decreased cecal TLR2 (PPFA = 0.022) gene expression compared with the un-supplemented controls. In conclusion, cereal type and PFA affected in combination and independently broiler gut microbiota composition and metabolic activity as well as the expression of critical gut barrier genes including TLR2. Further exploitation of these properties in cases of stressor challenges is warranted.

]]>
<![CDATA[Influence of dietary carbohydrases, individually or in combination with phytase or an acidifier, on performance, gut morphology and microbial population in broiler chickens fed a wheat-based diet]]> https://www.researchpad.co/article/5ca11384d5eed0c484570ccc

The objective of this study was to examine the effects of dietary carbohydrases (xylanase and β-glucanase; XG), individually or in combination with phytase or acidifier on the growth performance, carcass attributes, intestinal microbial counts and morphology in broiler chickens fed a wheat-based diet. A total of 240 one-day-old male broiler chicks were randomly allocated into 4 treatment groups with 6 replicates of 10 birds each. The dietary treatments included a basal diet, the basal diet with an enzyme complex containing XG, XG plus a microbial phytase (XG + P) and XG plus acidifier (XG + A). The results indicated that feed conversion ratio (FCR) was improved in broiler chickens which received XG + A during the entire production period (1 to 35 d) of the trial (P < 0.05). The broiler chickens fed XG + P had lower feed intake compared with the control group at 29 to 35 d of age. The experimental treatments had no effect on the body weight gain of broiler chickens. In carcass traits, except for spleen (P < 0.05), the dietary treatments had no effects on the carcass characteristics of broiler chickens. The birds which received diets supplemented with XG and XG + A had a lower weight of the spleen compare with the control. Addition of XG in combination with phytase (XG + P) resulted in a decrease in ileal enumeration of Escherichia coli at 35 d of age (P < 0.05). However, dietary treatments did not alter the population of ileal Lactobacilli in broiler chickens. Supplementing carbohydrases with phytase and acidifier (XG + P and XG + A) significantly increased the intestinal villus length at 35 d of age (P < 0.05). In conclusion, the present study demonstrated that supplementation of the wheat-based diet with a combination with carbohydrases and acidifier (XG + A) improves FCR in broiler chickens. Furthermore, combinations of carbohydrases with phytase (XG + P) and with acidifier (XG + A) decrease the E. coli counts and increase the villus length in broiler chickens.

]]>
<![CDATA[PDIP38/PolDIP2 controls the DNA damage tolerance pathways by increasing the relative usage of translesion DNA synthesis over template switching]]> https://www.researchpad.co/article/5c897795d5eed0c4847d30a7

Replicative DNA polymerases are frequently stalled at damaged template strands. Stalled replication forks are restored by the DNA damage tolerance (DDT) pathways, error-prone translesion DNA synthesis (TLS) to cope with excessive DNA damage, and error-free template switching (TS) by homologous DNA recombination. PDIP38 (Pol-delta interacting protein of 38 kDa), also called Pol δ-interacting protein 2 (PolDIP2), physically associates with TLS DNA polymerases, polymerase η (Polη), Polλ, and PrimPol, and activates them in vitro. It remains unclear whether PDIP38 promotes TLS in vivo, since no method allows for measuring individual TLS events in mammalian cells. We disrupted the PDIP38 gene, generating PDIP38-/- cells from the chicken DT40 and human TK6 B cell lines. These PDIP38-/- cells did not show a significant sensitivity to either UV or H2O2, a phenotype not seen in any TLS-polymerase-deficient DT40 or TK6 mutants. DT40 provides a unique opportunity of examining individual TLS and TS events by the nucleotide sequence analysis of the immunoglobulin variable (Ig V) gene as the cells continuously diversify Ig V by TLS (non-templated Ig V hypermutation) and TS (Ig gene conversion) during in vitro culture. PDIP38-/- cells showed a shift in Ig V diversification from TLS to TS. We measured the relative usage of TLS and TS in TK6 cells at a chemically synthesized UV damage (CPD) integrated into genomic DNA. The loss of PDIP38 also caused an increase in the relative usage of TS. The number of UV-induced sister chromatid exchanges, TS events associated with crossover, was increased a few times in PDIP38-/- human and chicken cells. Collectively, the loss of PDIP38 consistently causes a shift in DDT from TLS to TS without enhancing cellular sensitivity to DNA damage. We propose that PDIP38 controls the relative usage of TLS and TS increasing usage of TLS without changing the overall capability of DDT.

]]>
<![CDATA[Contact with adult hen affects development of caecal microbiota in newly hatched chicks]]> https://www.researchpad.co/article/5c8977aad5eed0c4847d32a0

Chickens in commercial production are hatched in a clean hatchery environment in the absence of any contact with adult hens. However, Gallus gallus evolved to be hatched in a nest in contact with an adult hen which may act as a donor of gut microbiota. In this study, we therefore addressed the issue of microbiota development in newly hatched chickens with or without contact with an adult hen. We found that a mere 24-hour-long contact between a hen and newly hatched chickens was long enough for transfer of hen gut microbiota to chickens. Hens were efficient donors of Bacteroidetes and Actinobacteria. However, except for genus Faecalibacterium and bacterial species belonging to class Negativicutes, hens did not act as an important source of Gram-positive Firmicutes. Though common to the chicken intestinal tract, Lactobacilli and isolates from families Erysipelotrichaceae, Lachnospiraceae and Ruminococcaceae therefore originated from environmental sources instead of from the hens. These observation may have considerable consequences for the evidence-based design of the new generation of probiotics for poultry.

]]>