Prevention of enteroxigenic Escherichia coli infections in pigs by dairy-based nutrition

Abstract Postweaning diarrhea (PWD) is a significant enteric disease causing considerable economic losses for the pig industry. Among several aetiological risk factors, enterotoxigenic Escherichia coli (ETEC) is considered to be a major cause. After being routinely used for several decades to control bacterial disease outbreaks in piglet, the use of antibiotics at subtherapeutic concentrations has been banned in the European Union because of the increasing prevalence of resistance to antibiotics in pigs. The removal of in-feed antibiotics from piglet diets has negative economic consequences as it dramatically increases the rate of morbidity and mortality due to ETEC as well as the use of antibiotics for therapeutic purposes. Other than subtherapeutic antibiotics, zinc oxide (ZnO) had been reported to ameliorate and/or prevent the development of PWD in piglets, but its excretion may have negative impacts on the environment. Thus, other alternatives that control ETEC infections in piglets postweaning will be of great advantage. A number of nutritional strategies have been proposed as alternative means of preventing ETEC infections, of which feeding dairy-based products to piglets could be one of such strategies. It is apparent that colostrums, milk and milk fractions such as whey and casein contain several biologically active compounds with anti-microbial and immunomodulatory properties. Recently, these dairy products and their isolated compounds such as lactoferrin and oligosaccharides have been employed as anti-infective agents against ETEC infections in iglets postweaning. The dairy by-products (e.g. whey or whey permeate) may also be fermented to further improve the anti-infective potential of the products. Overall, the anti-infective activities of dairy-based products against ETEC could be attributed to the improvement of the intestinal barrier functions, microbial ecosystem and immunity of the piglets. Keywords : Dairy-based product; Anti-microbial; Immunomodulation; Anti-infective; Enterotoxigenic Escherichia coli; Postweaning diarrhea; Pigle

The Degree of Fat Unsaturation in the Tissue and Potential Immune Response of Broiler Fed Chlorella sp.

This study was carried out to investigate the effect of Chlorella sp. administered in the diet of broilers on the degree of fat unsaturation, ratio of EPA to AA in the tissue and potential immune response of broiler. A total of 90 heads of one-day-old Ross chicks were assigned in completely randomized design by 3 dietary treatments with 6 repetitions and 5 chicks in each pen. The diets were T1: control (basal diet without enrichment with Chlorella sp.); T2: basal diet enriched with 5-g of Chlorella sp./kg feed; T3: basal diet enriched with 10-g of Chlorella sp./kg feed.  Skinless breast meat was sampled for FA determination at d-36. Chickens were vaccinated at d-6 and d-17 with live vaccine against ND to activate antibodies production, and then 2 ml of blood was collected at d-24 for IgG and IgM quantification. Administration of Chlorella sp. in broiler’s diet had no significant effect on the degree of fat unsaturation, the ratio between EPA and AA contained in the breast muscle and the concentration of IgG and IgM of broiler. In conclusion administration of Chlorella sp. from tropical marine origin in the diet of broiler has no significant effect on the degree of fat unsaturation, ratio of EPA to AA in the tissue, and potential immune response of broiler. The culture temperature in which the Chlorella sp. was cultivated may affect the FA composition of Chlorella sp. (Animal Production 12(2): 96-99 (2010)Abbreviations: AA: arachidonic acid, ALA: α-linolenic acid, EPA: eicosapentaenoic acid, FA: fatty acids, LA: linoleic acid, PGE2: Prostaglandin E2, PUFA: polyunsaturated fatty acids, SFA: saturated fatty acidKey Words: antibody, broiler, Chlorella sp., fatty acid, PUF

Fatty Acids Profile of Meat, Mucosal Siga Concentration and Production Index of Broiler as a Response to Chlorella SP. Administration in the Diet

This study was carried out to investigate the effect of different levels of Chlorella sp. in the form ofmeal administrated in the diet of broilers throughout their life upon FA profile of the breast muscle,mucosal secretory IgA (sIgA) concentration and production index (PI) of broiler. Allotted in 18 pens, thetotal of 90 Ross day old chicks were assigned in completely randomized design by 3 of dietarytreatments (T1: control (basal diet without enrichment of Chlorella sp.); T2: basal diet enriched with 5-gChlorella sp./kg feed; T3): basal diet enriched with 10-g Chlorella sp./kg feed. At d-36, skinless breastmeat was collected for FA determination. Practical standard of vaccination was performed to activateantibodies production and at d-36 gut mucosa was collected for sIgA analysis. Chlorella sp.administration had no significant effect (P>0.05) on the FA profile of breast muscle, mucosal sIgAconcentration and producton index of broiler. In conclusion, the level and ratio between n-3 to n-6polyunsaturated fatty acids (PUFA) as well as the nature of dietary PUFA source determine tissue PUFAcomposition. Beside through eicosanoid, Chlorella sp. may affect mucosal sIgA production throughcytokines mediated effect. Although Chlorella sp. administration does not improve the production indexof broiler, this treatment may produce broiler meat with lower fat content

Velocity Profiles in Slowly Sheared Bubble Rafts

Measurements of average velocity profiles in a bubble raft subjected to slow, steady-shear demonstrate the coexistence between a flowing state and a jammed state similar to that observed for three-dimensional foams and emulsions [Coussot {\it et al,}, Phys. Rev. Lett. {\bf 88}, 218301 (2002)]. For sufficiently slow shear, the flow is generated by nonlinear topological rearrangements. We report on the connection between this short-time motion of the bubbles and the long-time averages. We find that velocity profiles for individual rearrangement events fluctuate, but a smooth, average velocity is reached after averaging over only a relatively few events.Comment: typos corrected, figures revised for clarit

Efficient Reverse Transcription Using Locked Nucleic Acid Nucleotides towards the Evolution of Nuclease Resistant RNA Aptamers

Background: Modified nucleotides are increasingly being utilized in the de novo selection of aptamers for enhancing their drug-like character and abolishing the need for time consuming trial-and-error based post-selection modifications. Locked nucleic acid (LNA) is one of the most prominent and successful nucleic acid analogues because of its remarkable properties, and widely explored as building blocks in therapeutic oligonucleotides. Evolution of LNA-modified RNA aptamers requires an efficient reverse transcription method for PCR enrichment of the selected RNA aptamer candidates. Establishing this key step is a pre-requisite for performing LNA-modified RNA aptamer selection