As food safety and consumer awareness increases, feed hygiene has become an integral part of poultry and livestock operations – ensuring that the feed given to the animals is clean and safe. Raw materials and feed can be contaminated by pathogens that can lead to risks on health of animals and economic losses.
Sanitation is critical in poultry production to maintain the better health of the flock and prevent pathogenic organisms in human food. A well-managed sanitation program helps to reduce the incidence of disease and improve the overall production of meat and eggs. It comes with its own set of challenges from both growth of pathogenic bacteria on the farm and possible contamination in feed.
As food safety and consumer awareness increases, feed hygiene has become an integral part of poultry and livestock operations – ensuring that the feed given to the animals is clean and safe. Raw materials and feed can be contaminated by pathogens that can lead to risks on health of animals and economic losses. Aside from that, the contamination in feed and ingredients is a potential risk of food safety for consumers, whereas Salmonella is the leading cause of gastrointestinal disease and is commonly found in poultry production.
There have been several studies of Salmonella association in feed and food. As early as 1976, McKenzie and Bains found significant correlation of Salmonella contamination in feed ingredients with broiler meats while Shirota et al., in 2001 found that there was correlation on frequency of serotypes of Salmonella in feed and eggs. In some studies, Salmonella isolates from feed were recovered in the slaughterhouse, meat processing plant and in raw processed meat like chicken nuggets and strips.
The question is: why we are seeing microbial contamination in feed? Interestingly, a survey by Jones and Richardson in 2004 of three (3) feed mills in the US illustrate that Salmonella and Enterobacteria can be found in major feed ingredients like corn and soybean meal. Other feed ingredients like wheat and wheat middlings can have risk of Enterobacteria contamination. Wood et al., suggests that Enterobacteriaceae contamination can be an indicator of feed hygiene due to recognized association between the risk of Salmonella and degree of Enterobacteria contamination.
In Europe, Regulation (EC) 183/2005 laying down requirements for feed hygiene aims to ensure customer protection throughout the food chain, starting from feed production up to feeding of food-producing animals. In 2018, China published its final version of Hygienic Standard for Feeds GB 13078, which includes total number of molds, bacteria and Salmonella as parameters for feed and feed ingredients exported to the said country. Since microbial quality of raw materials can be contaminated by disease-causing pathogens, what are the things a feed producer can do?
WAYS TO MANAGE MICROBIAL CONTAMINATION
In managing contamination, producers should start with monitoring the quality of incoming ingredients in terms of microbial contamination like Salmonella, Enterobacteria, E. coli and molds. Eventually, major ingredients and their suppliers can be assessed on risk of contamination. Partnership with suppliers of good quality ingredients will help in managing contamination.
Since there is always risk of contamination as new batches of ingredients go inside the feed mill, review of cleaning practices and their frequency is integral in managing contamination. Special emphasis should be taken care of on “hot spots,” or areas where contamination tends to build up as days progress. In machines like mixers, conditioners and coolers, regular cleaning frequency is necessary to reduce spread of contamination. It is also important to control dust accumulation in all areas of feed mill as it can be a vector of pathogenic bacteria and spread inside the mill.
In most cases, use of feed additives with antibacterial properties like organic acids will help reduce the risk of contamination – especially for mash and young animals. For decades, acetic and citric acids have been added to food as preservatives and to inactivate foodborne pathogens. In feed and ingredients, organic acids like formic (Figure 1), propionic and blends of acids are known to be effective in a commercial scale in inhibiting growth of bacteria and molds. Thus, adding organic acids or blends of acids during cleaning or flushing of mixers may inhibit growth of pathogens in the equipment and production line. Study from Stonerock 2007 shows the inhibition capacity of an acid blend of formic and propionic acid at different dose level (Table 2). With 0.12% inclusion rate in vitro, it has already 5 log reduction against Salmonella enteritidis.
In maintaining feed hygiene, checks and balances are also needed. Regular feed hygiene audits will help monitor the progress of company’s objective for food and feed safety. In general, feed hygiene audits will assist the people involved in production to inform them on which areas need urgent cleaning and improvement such as buildup of molds and bacteria at the end of the conditioner machine and re-contamination after pelleting the feed. These audits will also minimize cross-contamination from dirty areas of warehouses to clean depot of finished feeds by using different sets of cleaning tools. Feed hygiene audits can be instrumental in deepening the employees’ understanding in feed safety and an avenue for training on “dos and don’ts” in feed sanitation.
Feed hygiene will always be vital in establishing control and improving the operational standards of feed business to manage contamination and traceability. By partnering with a global company like ADM, feed producers can gain confidence that their feed production is safe, clean and efficient.