French feed institute focuses on feed hygiene issues

Tecaliman, the French feed institute, focused its annual symposium on three relevant subjects: an enquiry about cross contamination in French feed plants since 1999, the impact of pelleting on enterobacteria and manufacturing practices for medicated feeds. Fabrice Putier, Tecaliman's director, deems this year's meeting a success with more than 150 attendants.

The analysis of feed plant performances regarding homogeneity and cross-contamination since 1999 enables the technical centre to compare those results with other European countries to give a firm benchmark and to give each feed plant the opportunity to compare its performance with the French feed plant average.

Historical data

"We kept every result from 1999 to 2005," said Putier. "Even those which had been improved through correctives measures afterward. So we collected nearly 1,200 results about homogeneity and more than 900 for cross contamination. For the last year of our study, those represented around 82 percent of all French production."

Homogeneity is traced through the relative standard deviation (variation coefficient); more than half the results are below 5 percent and 85 percent are below 10 percent. The evolution of the median, which shows a real improvement over the years, goes from 7.1 in 1999 with a small amount of data to 4.1 in 2005, a significant decrease. The industry may find it difficult to go much lower on a global basis. So the target of 5 percent, as included in the good manufacturing practice (GMP) guide, is really accurate as well as the maximum of 85 percent under 10 percent.

Improvement in cross contamination issues is evident through historical data. The median of the collection of tracer in the immediate batch after its incorporation went from 5.7 in 1999 to 2.9 in 2005. And the collection of it in the second batch after its incorporation had nearly been cut in half between those two years from 1.2 to 0.7. Also to be noted: the extreme values disappeared through the years and the French feed plants have become more and more similar in their ability to avoid cross-contamination. The French feed plants are, for the most part, well above the target set in the GMP guide. "The profession has really secured the sanitary operation of its production by mastering its mixing and limiting cross contamination," summarised Putier.

Tracking bacteria

Its progress has also been noticeable in the bacteriological field, as Sandy Rouchouse, Tecaliman engineer, shared in her presentation. Tecaliman was leader of a huge study focused on the impact of pelleting on enterobacteria. "We've been working under the European regulation 2160/2003 that deals with zoonoses. We were focused on the demonstration of the quality of the pelleting process upon the bacteriological quality of feeds and on the proposal of the minimum conditions to clean the feeds," said Rouchouse. Eighty-four trials had been conducted on 11 feed plants to validate the target temperature/time tables on four types of feeds for pig, chicken, laying hen and turkey.

For the first time, Tecaliman used a statistical method at the pilot level which enabled them to decrease the number of trials without sacrificing statistical representation. For pig feed, and to a lesser extent for turkey, the passage through the pellet mill channel is really pivotal. The enterobacteria population is decreased 3 log with an 87 C at the exit of the pellet mill. Tecaliman had been able to produce tables between the residence time in the channel and the temperature at the entrance on the machine. The feed plant trials showed that the conditioning temperature is really key to assure a good decrease of enterobacteria at the pellet mill exit. Each type of feed had its own table. "We showed that our tables are really accurate on the formulations we had. Of course, for each formulation the feed manufacturer must test it precisely on its own process. We also showed the importance of a bacteriological diagnosis and management of the entire plant. You must also still take care of the beginning of the batches when the necessary temperatures are not yet reached," concluded Sandy Rouchouse.