For the industrial production of feed, correct mixing resulting in a homogeneous feed and the avoidance of cross-contamination (carry-over of additives) from previous batches into the following feed batch contributes significantly to the quality and safety of the feed. EU legislation in the animal feed sector requires that measures are taken to avoid cross-contamination and appropriate means are available for carrying out checks in the course of manufacture. The CROSS CONTA EU-funded project aimed at comparing currently used methods and designing a new method for the measurement of homogeneity and cross-contamination in the feed industry.
Tubes containing the main compounds used in the project
Limits of the current methods
As existing methods for measuring homogeneity or cross-contamination suffer from disadvantages and do not fully meet industrial requirements, the CROSS CONTA project, funded under the 5 th Framework Programme, aimed at improving the processing quality of production plants for the manufacture of feeds by providing an efficient method for measuring homogeneity and cross-contamination.
The implementation of the method(s) developed by the CROSS CONTA project will help European companies to analyse the mixing and feed production process in order to improve the homogeneity of products and avoid cross-contamination. It will consequently improve animal production: improving homogeneity will mean that each animal receives the right amount of active substances and avoiding cross-contamination ensures that animals will not receive undesirable substances. Finally, the consumer will indirectly benefit from these improvements.
Selection of new methods
The partners led a survey to identify new tracers that could be used for the measurement of homogeneity and cross-contamination and their corresponding analytical quantification techniques. This survey allowed the selection of 7 new tracer-methods as well as 4 traditional tracer-methods representative of current European methodologies (microtracers, methylviolet, cobalt and a medicinal compound).
Laboratory production of different feed types was carried out for all the tracers at different concentrations to test recovery, sensitivity, accuracy and reproducibility. The step included both the adaptation of the analytical techniques; the production of feed samples at laboratory level and their analysis. Laboratory trials also tested the ability of the tracers to be used for granulated feed, and the behaviour of the tracers in different combination.
At the end of this laboratory step, 3 new tracer-methods were selected: three mineral elements including two rare earths. These new tracers were yttrium, ytterbium and titanium, all analysed by ICP-AES (induced coupled plasma – atomic emission spectrometry, with different preparation and mineralisation steps).
Testing and validation of the new methods
The pilot trials aiming at testing the relevance of the new tracer-methods choices for homogeneity and cross-contamination measurements and comparing them to the existing methods confirmed the selection of the 3 new tracers. Two of the new tracers, yttrium and ytterbium seemed more interesting than the third one, titanium, as their recovery levels, quantification limits and analytical reproducibility were better. One of the new tracers, yttrium, appeared particularly useful for further recommendation as it is cheaper and can be used at smaller incorporation rates than Ytterbium. However, further work needs to be done to improve the use of yttrium in mineral rich matrices such as premixes.
The partners validated at an industrial scale the choices of the selected methods and evaluated homogeneity and cross-contamination. For this, 29 industrial trials were carried out in 4 countries in some 23 different industrial plants or production lines with all tracers in different combination.
Among the traditional tracers, the results confirmed the pertinence of microtracers in almost all production controls. The results also confirmed the interest of cobalt for premix controls. The use of methylviolet is also possible on feed, and is the less costly, but the internal calibration used for the interpretation differs from all other tracers. Among the new tracers, yttrium showed the best characteristics, with comparable results with microtracers or cobalt, and being fully stable during the production process.
Upgrading the methodology
In conclusion, partners recommend (i) to use microtracers in almost all cases for feed homogeneity and cross-contamination controls, (ii) to use cobalt for premix controls, where the production lot does not have to be destroyed or further dispatched in several batches because of cobalt toxicity and (iii) to use yttrium for the control of feed that encounter high temperature, pressure or vapour treatment.
QLK5-CT-2002-01383 - Homogeneity and cross-contamination measurement in feed industry ( CROSS CONTA)
Project Co-ordinator: Dr Delphine Salvat-Brunaud
Telephone: +33 2 51 83 21 00
Address: Rue Pierre Adolphe Bobierre, BP 42301, F - 44323 Nantes Cedex3, France
REGULATION 183/2005/EC of the European Parliament and of the Council of 12 January 2005 laying down requirements for feed hygiene.
COUNCIL DIRECTIVE 95/69/EC of 22 December 1995 laying down the conditions and arrangements for approving and registering certain establishments and intermediaries operating in the animal feed sector and amending Directives 70/524/EEC, 74/63/EEC, 79/373/EEC and 82/471/EEC.