The use of an optimised concentration of quercetin limits peroxidation of lipids in the meat of broiler chickens fed a diet containing flaxseed oil rich in omega-3

Ross 308 chickens were used to investigate fatty acid (FA) composition and oxidative stability of broiler chicken meat following the controlled inhibition of peroxidation in feed containing a concentrated source of omega-3 fatty acids (flaxseed oil, FLO), approximately 50% omega-3. Ninety-six one-day-old chicks were randomly allocated to four dietary treatments (n = 24/group) that included rapeseed oil (RO), flaxseed oil (FLO), RO with optimised quercetin (Q) – RO_Q, or FLO with optimised Q (FLO_Q). On day 35, breast and thigh muscles were collected in order to analyse their FA profile and malondialdehyde (MDA) levels. Dietary treatments had no effect on weight gain or feed conversion ratio in chickens. However, dietary FLO increased the deposition of α-linolenic acid in both pectoral and thigh meat (P < 0.05), and tended to decrease the ratio of omega-6/omega-3 FA in pectoral muscles (P < 0.07). Addition of an optimised concentration of Q proved to be an efficient way of limiting lipoperoxidation in breast and thigh muscles subjected to refrigeration at 2–3 °C for either 1 or 7 days. Results were consistent with the observed inhibition of peroxidation in feed mixtures and significantly correlated with MDA levels found in feed mixtures. These results provide evidence that it is possible to produce poultry meat with an improved proportion of omega-3 FA without significantly altering the performance of broiler chickens or the oxidative stability of their meat.     

Effect of chronic heat stress on gastrointestinal histology and expression of feed intake-regulatory hormones in broiler chickens

Heat stress (HS) dramatically impairs the growth performance of broiler chickens, mainly as a consequence of reduced feed intake due to the loss of appetite. This study was aimed at evaluating the alterations induced by chronic HS conditions on the morphological and morphometric features of the gastrointestinal (GI) tract and on the expression of some enteroendocrine cells (EECs) involved in the regulation of feed intake in chickens. Three hundred male chickens (Ross 308) were divided into two experimental groups and raised either in thermoneutral environment for the whole fattening period (0–41 days) (TNT group) or subjected to chronic HS conditions (30 °C for 24 h/day) from 35 to 41 days (HS group). Samples of proventriculus, duodenum, jejunum and cecum were collected from 24 broilers (12/group). Haematoxylin-eosin was used for the morphometric evaluations, while immunohistochemistry was applied for the evaluation of EECs expressing ghrelin (GHR), cholecystokinin (CCK), neuropeptide Y (NPY), glucagon-like peptide-1 (GLP-1), and serotonin (5-HT). In the proventriculus, HS reduced total wall thickness and mucous layer height (P ≤ 0.01) as well as mean diameter, circumference, and area of the compound tubular glands (P ≤ 0.001) with respect to TNT. The small intestine of HS birds was characterised by decreased villous height and total thickness (duodenum, P ≤ 0.01; jejunum, P ≤ 0.001), whereas crypt depth and width were reduced only in the jejunum (P ≤ 0.01). HS had negligible effects on the morphological aspects of the cecum. In the proventriculus, an increase in GHR and NPY EECs was observed in response to HS (P ≤ 0.001). Similarly, the small intestine villi of the HS group showed greater GLP-1 (P ≤ 0.05), 5-HT (P ≤ 0.001) and CCK (P ≤ 0.01) EECs. Moreover, the expression of 5-HT EECs was higher in the duodenal (P ≤ 0.01) and jejunal (P ≤ 0.01) crypts of HS birds, whereas GLP-1 and CCK EECs increased only in jejunal crypts (P ≤ 0.05). Finally, 5-HT EEC expression was increased in the cecum of HS group (P ≤ 0.01). In conclusion, these outcomes demonstrate that chronic HS induces morphometric alterations not only in the small intestine but also in a key organ such as the proventriculus. Furthermore, HS conditions affect the presence and distribution of EECs, suggesting that some GI peptides and biogenic amine may be implicated in the regulation of appetite and voluntary feed intake in heat-stressed broiler chickens.     

Winter density and habitat preferences of three declining granivorous farmland birds: The importance of the keeping of poultry and dairy farms

Populations of granivorous farmland birds have dramatically declined during recent decades in many European countries. Winter conditions and consequently, survival rates of farmland bird species during this critical period, are considered as one of the main causes of this negative trend. However, the importance of different habitat structures and connected food sources for successful overwintering in bird species has gained little attention so far in the Czech Republic. In this study we aimed to examine the role of habitat composition and food availability on winter distribution and abundance of three declining sedentary and granivorous bird species. During the winters 2009–2014, 149 villages in the Czech Republic were monitored for distribution and density of three farmland seed-eaters. House Sparrow was the most dominant species (88.6% of villages occupied; 4.32 ± 4.67 ind./100 m of transect), followed by Tree Sparrow (67.1% villages occupied; 1.83 ± 3.53 ind./100 m of transect) and Collared Dove (65.8% villages occupied; 0.72 ± 1.51 ind./100 m of transect). Occurrence of House and Tree Sparrow was significantly affected by the number of instances of poultry keeping. In both species, occupied villages showed a higher number of instances of poultry keeping. We did not find any such significant relationship for Collared Dove. Density of House Sparrow was significantly higher in villages with dairy farms, but we failed to find this relationship for Tree Sparrow and Collared Dove. Habitat preferences were similar for all three studied species. They positively responded to the proportion of shrubs/trees, the keeping of poultry, dairy farms and they avoided houses, arable land and grasslands. We conclude that poultry keepings and dairy farms can be important for studied species during the winter since they offer high food availability and good protection against predators. This suggestion is supported by the fact that long-term population decline has coincided with a long-term reduction in the keeping of poultry and dairy farms in the Czech Republic during the last 50 years.     

两株blaNDM-5基因介导的碳青霉烯耐药禽源大肠杆菌ST10和ST354耐药性

【背景】近年来,对碳青霉烯类抗生素耐药的肠杆科细菌的出现对公众的健康构成了严重的威胁。【目的】为了解家禽养殖中肠道菌对碳青霉烯类抗生素耐药情况,对陕西西安和浙江海宁两地的鸡和鸭养殖场粪便进行耐药菌筛选并分析。【方法】在含美罗培南的LB琼脂平板上筛选可疑菌落并利用基质辅助激光解吸电离飞行时间质谱(matrix-assisted laser desorption/ionization time of flight mass spectrometry,MALDI-TOF MS)鉴定。通过微量肉汤稀释法进行最小抑菌浓度(minimum inhibitory concentration,MIC)测定。通过Illumina HiSeq平台进行全基因组测序。使用Res Finder数据库预测获得性耐药基因。利用S1酶切后脉冲场电泳(pulsed-field gel electrophoresis,PFGE)和Southern blot杂交进行质粒和碳青霉烯类耐药基因的确认。【结果】分离出两株碳青霉烯类耐药的大肠杆菌HN1-26和XN3-1,均对头孢他啶、头孢噻呋、氨苄西林、奥格门丁、复方新诺明、磺胺异恶唑、恩诺沙星、氧氟沙星、美罗培南、四环素耐药。此外,XN3-1对氟苯尼考和大观霉素耐药。菌株HN1-26和XN3-1的多位点序列分型(multilocus sequence typing,MLST)分别为ST354和ST10。两株菌对美罗培南的MIC值均为64μg/m L,但是在含美罗培南的LB平板上,菌株HN1-26比菌株XN3-1生长得更快。两株菌都存在携带bla_(NDM-5)基因的Inc X3型质粒。两个质粒的序列完全一致,大小为46 161 bp,包含接合转移元件,能够以大肠杆菌作为受体细胞进行转移。【结论】Inc X3型质粒是转移bla_(NDM-5)基因的重要载体,在我国畜禽养殖中具有扩散风险。     

Enhancement of resistance by poultry manure and plant hormones (salicylic acid & citric acid) against tobacco mosaic virus

Virus is the most menacing factor for plant, which causes enormous economic losses in agriculture worldwide. Tobacco mosaic virus is most hazardous virus among the plants that can spread through biological and non-biological sources. TMV is ancient virus that causes huge economic losses to pepper cucumber ornamental crops and tobacco. It can be controlled by reducing the population of vector through pesticide application. However, the rapid usage of synthetic chemicals causes environmental pollution and destroys our ecosystem. Consequently, different approaches just like natural derivatives should be adopted for the environmental friendly management for TMV. This in vitro study demonstrated the potential role of natural metabolites such as poultry manure and plant extracts such as salicylic acid and citric acid for the control of TMV. Two different concentrations of poultry manure 60G and 30G were used. Poultry manure was mixed with the soil at the time of sowing. Disease severity was minimum at maximum concentration as compared to the control. Meanwhile, two different concentrations of salicylic acid and citric acid 60% and 90% were applied by foliar sprayer after three-leaf stages. Disease severity was observed after 5, 10, 15, 20, 25, and 30 days after disease inoculation. Here also maximum concentration showed the minimum disease severity and higher concentration of both animal and plants extracts were used for following experiment. Quantitative real-time PCR (RT-qPCR) results demonstrated that different plant defense-related genes such as PR1a, PAL, PR5, NPR1, PRIb, and PDF1.2 were up-regulated. Furthermore, applications of each treatment-induced systemic resistance against a wide range of pathogen including TMV and fungal pathogen Botrytis cinerea.     

Microbial challenges of poultry meat production

Food safety and shelf-life are both important microbial concerns in relation to broiler meat production. Focus is mainly placed on the absence or control of potentially pathogenic microbes such as Salmonella spp. and Campylobacter spp. but, from the commercial point of view, other spoilage bacteria also play a role as potential threats. Regarding food safety, the primary target should be the production of pathogen-free live animals, thus allowing slaughter plants to keep the processing line free of those microorganisms.Consumers believe that quality of foods from organic production is superior to foods from conventional production. The aim of the present study was to evaluate and compare the bacterial quality of chicken meat from organic and conventional production on the basis of traditional meat quality criteria. Fresh free grazing broiler carcasses were purchased directly from rural households (n = 80) and fresh retail chicken parts from conventional broiler carcasses from the local supermarkets in the region of Epirus (Poultry Producers Association. Arta) (n = 200).The samples were microbiologically tested for the presence of bacteria such as: Salmonella spp., Listeria monocytogenes, Staphylococcus aureus, Enterobacteriaceae, Escherichia coli, Campylobacter spp., and C. perfringens. Total count of aerobic mesophilic bacteria was also determined. Bacteriological tests were performed by means of standard methods of isolation and identification of individual species of bacteria according to ISO requirements. API-tests (bioMerieux) and Vitek 2 Identification System (bioMerieux) were used for biochemical determination. High levels of microbial contamination and occurrence of pathogenic bacteria at then fresh free grazing broiler carcasses reflect the poor hygienic quality of the slaughter conditions in the rural households.     

Which preventive measures against mastitis can increase the technical efficiency of dairy farms?

The aim of this paper was to explore if, and in that case how, various preventive measures against mastitis influenced the whole-farm economic outcome, measured as technical efficiency, of a sample of specialised dairy farms in Sweden. In particular, the paper aimed at analysing whether a change to preventive measures applied by fully efficient farms would be a way for inefficient farms to become fully efficient. First, technical efficiency was assessed for each farm in the sample based on farm-level accounting data and the data envelopment analysis. In a second step, the effects of preventive measures against mastitis (collected through a mail questionnaire) on technical efficiency were assessed with logistic regression. Keeping cows in a loose-housing barn, stimulating udders manually during milking, and having cows standing on clean bedding during milking were found to significantly increase the probability of a farm being fully efficient. Once the farmer considers the somatic cell count (SCC) to be too high, undertaking measures such as contacting a veterinarian, checking overall hygiene routines, and culling cows with high SCC were found to significantly increase the probability of a farm being fully efficient. Thus, these measures may be plausible targets for advisory services aimed at assisting farmers to become fully efficient, especially if they are confirmed in future studies. Several common preventive measures against mastitis, that is, choice of bedding material, frequency of cleaning stalls, pre-milking, post-milking teat disinfection, applying a milking order based on the SCC of cows, and milking high-SCC cows with a separate cluster, were found to have no statistically significant effect on farm economic outcome. However, these measures may still be valuable for non-economic goals, such as increased animal welfare, and the results imply that they can be implemented without negative impact on the economic performance of the farm.     

Failure costs associated with mastitis in smallholder dairy farms keeping Holstein Friesian × Zebu crossbreed cows

Mastitis is a costly disease and in many areas of the world, these costs have been quantified to support farmers in their decision making with regard to prevention of mastitis. Although for subsaharan circumstances estimates have been made for the costs of subclinical mastitis (SCM), farm-specific cost estimations comprising both clinical mastitis (CM) and SCM are lacking. In this paper, we quantified failure costs of both CM and SCM on 150 Ethiopian market-oriented dairy farms keeping Holstein Friesian × Zebu breed cows. Data about CM were collected by face-to-face interviews and the prevalence of SCM was estimated for each farm using the California mastitis test. All other relevant information needed to calculate the failure costs, such as the consequences of mastitis and price levels, was collected during the farm visits, except for the parameter for milk production losses due to SCM, which was based on literature estimates and subjected to sensitivity analyses. The average total failure costs of mastitis was estimated to be 4 765 Ethiopian Birr (ETB) (1 ETB = 0.0449 USD) per farm per year of which SCM contributed 54% of the costs. The average total failure costs per lactating cow per farm per year were 1 961 ETB, with a large variation between farms (range 0 to 35 084 ETB). This large variation in failure costs between farms was mainly driven by variation in incidence of CM and prevalence of SCM. Milk production losses made the largest contribution (80%), whereas culling contributed 13% to 17% to the total failure costs. In our estimates, costs of veterinary services, drugs, discarded milk and labour made a minor contribution to the total failure costs of mastitis. Relative to the income of dairy farmers in North Western Ethiopia; the total failure costs of mastitis are high. In general, Ethiopian farmers are aware of the negative consequences of CM, but creating awareness of the high costs of SCM and showing large variation between farmers may be instrumental in motivating farmers to also take preventive measures for SCM.