Epidemiología de la anaplasmosis y babesiosis bovina en el valle geográfico del río Cauca

Se determinó la prevalencia de la anaplasmosis y babesiosis bovina en 12 fincas del Valle Geográfico del río Cauca. Para el análisis de los datos, las fincas se distribuyeron de acuerdo al tipo de explotación así: I Fincas de explotación lechera. II Fincas de explotación mixta (carne y leche) y Ill Fincas de ganadería de carne. Las prevalencias encontradas indican que estas enfermedades son endémicas en Ia zona. Sin embargo las prevalencias varían según el tipo de explotación y manejo de Ia finca. Por tipo de explotación las prevalencias respectivamente fueron: Para Anaplasma marginale de: I 45%, II 73%, y III 88%. Para Babesia bigemina de: 1 46,6%, II 62,5%, y III 87,4%, y para Babesia bovis (argentina) de: I 26%, II 65.4, y III 44,4%. Estos datos indican que en una zona endémica de hemoparásitos las variaciones en prevalencia están probablemente más relacionadas con factores de manejo que con factores ambientales. El factor que más contribuyó a las bajas tasas de prevalencia a nivel de finca fue el estricto control de garrapatas, to que indica que el abuso de los baños garrapaticidas en una zona endémica, puede crear situaciones epidemiológicas inestables. Se encontró una relación inversa entre las prevalencias y los problemas de hematozoarios. En las fincas lecheras La presentación de casos clínicos agudos es mayor especialmente entre las edades de 1 a 2 años. Se recomienda Ia vacunación de animales menores de un año en este tipo de explotaciones. En las fincas de carne la presentación de casos clínicos es muy esporádica. Se encontró A. marginale asociado con casos de "secadera" Se recomienda Ia investigación del papel que juegan los hemoparásitos en este síndrome.The prevalences of bovine anaplasmosis and babesiosis were determined in 12 herds in the Cauca River Valley. For analysis, herds were distributed according to production types as follows: a) Dairy herds, b) Mixed herds (dairy and beef) and c) beef herds. The prevalences found indicated that anaplasmosis and babesiosis are endemic in the area. Nevertheless the prevalences differed according to the herd type. The prevalences by respective herd types are: For Anaplasma marginale: a) 45%, b) 73% and c) 88% for Babesia bigemina: a) 46.6%, b) 62.5% and c) 87.4% and for Babesia bois (argentina): a) 26%,b) 65.47o and c) 44.47o. These data indicated that within a hernoparasitic endemic area, the variations of the prevalences are more probably related to management factors rather than enviromental factors. The factor that most contributed to the low prevalence rates was excesive tick control. This indicated that within an endemic area excesive tick control could contribute to an unstable epidemiologicat situation. An inverse relationship was found between prevalence and hemoparasitic problems. More clinical cases were reported in dairy herds, especially among animals 1 to 2 years of age. In beef herds clinical cases were sporadic. A. marginale was found to be mostly associated with "secadera" (wasting disease) cases. Investigation of the roles of the hemoparasites in this syndrome is recommended.Ganado de leche-Ganadería lech

Use of Defined Competitive Exclusion Cultures to Enhance Colonization Resistance to Enteric Pathogens

During the past several years our laboratory has conducted research towards developing defined competitive exclusion cultures that enhance colonization resistance against salmonellae in baby chicks. Previously in our laboratory it was shown that 10-day-old broiler and layer chicks that were fed diets containing 5-10% lactose provided either in the feed or in water from day-of-hatch were significantly more resistant to Salmonella typhimurium, and S. enteritidis cecal colonization than control chicks not provided a diet supplemented with lactose. Additionally, resistance against salmonellae cecal colonization was further enhanced in treatment groups provided dietary lactose in combination with an undefined mixture of anaerobic bacteria (i.e. undefined competitive exclusion culture or Nurmi culture) originally obtained from the ceca of adult broiler chickens maintained on a diet containing lactose. In order to make a defined competitive exclusion culture that was efficacious in enhancing colonization resistance against salmonellae, we cultured cecal contents obtained from adult broilers maintained on a unmedicated diet containing 5% lactose in a continuous-flow (CF) culture apparatus (i.e. chemostat), that was maintained at parameters that would best represent the cecal environment

Lighting during grow-out and Salmonella in broiler flocks

<p>Abstract</p> <p>Background</p> <p>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 <it>Salmonella </it>in broiler flocks.</p> <p>Methods</p> <p>Conventional grow-out flocks reared in the states of Alabama, Mississippi and Texas, USA in 2003 to 2006 were sampled 1 week before harvest (<it>n </it>= 58) and upon arrival for processing (<it>n </it>= 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 (<it>n </it>= 56) and post-chilling points (<it>n </it>= 54). Litter samples and drag swabs of litter were collected from the grow-out houses after bird harvest (<it>n </it>= 56). Lighting practices for these flocks were obtained with a questionnaire completed by the growers. Associations between the lighting practices and the burden of <it>Salmonella </it>in the flocks were tested while accounting for variation between the grow-out farms, their production complexes and companies.</p> <p>Results</p> <p>Longer relative duration of reduced lights during the grow-out period was associated with reduced detection of <it>Salmonella </it>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 ≥18 hours per day later in the grow-out period was associated with decreased detection of <it>Salmonella </it>on the exterior of broilers arriving for processing and in the post-harvest drag swabs of litter from the grow-out house.</p> <p>Conclusions</p> <p>The results of this field study show that lighting practices implemented during broiler rearing can impact the burden of <it>Salmonella </it>in the flock. The underlying mechanisms are likely to be interactive.</p

Aflatoxin B1 in Affecting Broiler’s Performance, Immunity, and Gastrointestinal Tract: A Review of History and Contemporary Issues

Aflatoxin B1 is a common contaminant of poultry feeds in tropical and subtropical climates. Research during the last five decades has well established the negative effects of the mycotoxin on health of poultry. However, the last ten years of relevant data have accentuated the potential of low levels of aflatoxin B1 to deteriorate broiler performance. In this regard, any attempt to establish a dose-effect relationship between aflatoxin B1 level and broiler performance is also complicated due to differences in types of broilers and length of exposure to the mycotoxin in different studies. Contrary to the prevalent notion regarding literature saturation with respect to aflatoxicosis of chicken, many areas of aflatoxicosis still need to be explored. Literature regarding effects of the mycotoxin on the gastrointestinal tract in this regard is particular scanty and non-conclusive. In addition to these issues, the metabolism of aflatoxin B1 and recently proposed hypotheses regarding biphasic effects of the mycotoxin in broilers are briefly discussed

T-2 toksin - pojavnost i toksičnost u peradi

T-2 toxin is the most toxic type A trichothecene mycotoxin. It is the secondary metabolite of the Fusarium fungi, and is common in grain and animal feed. Toxic effects have been shown both in experimental animals and in livestock. It has been implicated in several outbreaks of human mycotoxicoses. Toxic effects in poultry include inhibition of protein, DNA, and RNA synthesis, cytotoxicity, immunomodulation, cell lesions in the digestive tract, organs and skin, neural disturbances and low performance in poultry production (decreased weight gain, egg production, and hatchability). Concentrations of T-2 toxin in feed are usually low, and its immunosuppressive effects and secondary infections often make diagnosis difficult. If at the onset of the disease, a change in diet leads to health and performance improvements in animals, this may point to mycotoxin poisoning. Regular control of grain and feed samples is a valuable preventive measure, and it is accurate only if representative samples are tested. This article reviews the incidence and toxic effects of T-2 toxin in poultry.T-2 toksin je najtoksičniji predstavnik trikotecenskih mikotoksina tipa A. On je sekundarni produkt metabolizma plijesni roda Fusarium i često je prisutan u žitaricama i hrani za životinje. Štetni učinci uočeni su u eksperimentalnih životinja i životinja u uzgoju. On se povezuje s pojavom bolesti ljudi od mikotoksikoza. Učinci toksina u peradi su višestruki: inhibicija sinteze proteina, DNA i RNA, citotoksični učinak, imunomodulatorni učinak, oštećenje stanica probavnog sustava, organa i kože, živčani poremećaji te pad proizvodnih karakteristika u uzgoju peradi (slabiji prirast, pad nesivosti i valivosti). Koncentracije T-2 toksina u hrani redovito su vrlo malene, a zbog imunosupresivnog djelovanja toksina te istodobne sekundarne infekcije bolest se često teško dijagnosticira. Pri pojavi bolesti promjenom hrane može doći do poboljšanja zdravstvenog stanja, što tako|er upućuje na moguće trovanje mikotoksinima. Redovita kontrola uzoraka žitarica i hrane za životinje jedna je od preventivnih mjera, a detekcija mikotoksina u žitaricama i hrani pouzdana je samo ako se ispituje reprezentativan uzorak. U radu su opisani učestalost i toksični učinci T-2 toksina u peradi