Towards two identification methods for breeding pigs: possibilities of a combined ear tag

The objective of this study is to develop a reliable, practical and affordable combined farm and slaughter identification for Dutch breeding pigs (sows and boars) before 1 January 2012. In consultation with representatives of pig farmers, breeding institutions, traders, slaughterhouses and governments a list of requirements for the combined ear tag has been set up. After initial interest for prototyping nine manufacturers have been visited and the requirements were discussed. Ultimately, six of the manufacturers produced a total of 13 prototypes for testing. Prototypes were subjected to a visual test and a test in two different slaughterhouses. Only four of the 13 prototypes met the established slaughterhouse criteria (loss rate <5%). These four were then tested on three pig farms. The infections, irritations and inflammation depend on husbandry conditions and the type of ear tag. The on farm loss rate of ear tag prototypes was less than 2%. The readability of the combined ear tags on the farms is not problematic. Retagging after loss was possible for one person using the existing hole but resulted in slight discomfort for the animal. During transport of the animals there were no losses. In the following slaughterhouse test no physical losses occurred. However, the functional loss rate in the slaughterhouse was above 5%. Practical implementation of the combined ear tags was studied by interviews with several stakeholders. Focus in the interviews was on the regulations, the attachment of the combined ear tags, the process of transporting pigs to the slaughterhouse, including transport, assembly and export, the need to renumber pigs, the service of the slaughterhouses for blood sampling, and the I&R in relation to the needed documentation and forms during transport. From the interviews it becomes clear that implementation in practice needs numerous reattachments and renumbering of ear tags. This leads to slight discomfort to the animals and increased labour for the farmers. This retagging has negative influence on the reliability of the data and on the guarantees of food safety. The results lead to the overall conclusion that the introduction of a combined ear tag under the current conditions is not justified as a solution to go from three to two identification procedures for breeding pigs

Benznidazole levels in blood vary with age in rats

Benznidazole (Bz) exhibits toxic side effects in animal studies and clinical use. Reductive metabolism of Bz in liver microsomes modulates the duration of its chemotherapeutic effect and its toxicity. The rate of this metabolism depends on age and is less intense in newborns and youngsters than in adults. In the present study, we determined Bz blood levels in rats of different ages that received Bz intragastrically (100 mg/kg). We developed and validated a high-pressure liquid chromatography with UV detector method for determination of Bz levels in whole blood. Bz levels were significantly higher and persisted for longer periods of time in the blood of young rats when compared to that of adult animals