Feed contributes as one of the most important inputs (80% of costs) related to animal/poultry production systems and directly impacts profits. Feed manufacturers must take utmost care in maintaining the quality of feed.
Several factors influence feed quality:
- Quality /type of raw materials used
- Handling and storage of raw materials
- Feed mill hygiene and operations
- Moisture addition in feed etc.
Biological contaminants
Microbial contamination of feed: One of the most critical requirements for early chick feed is biosecurity because introducing early pathogen access to the naïve gut could lead to mortality, lifelong colonization, and permanent pathogen shedding. It is well established that feed can get contaminated with biological pollutants at any production stage.
Salmonella, Campylobacter, Clostridium perfringens, and Escherichia coli feed contamination are the concerns of feed safety research in poultry and other livestock. In addition to bacterial pathogens, the feed can also carry antimicrobial resistance (within bacteria in feed), devastating viruses, or mycotoxin-producing fungi.
Raw ingredients of the animal feed would never be sterile. Finished feed pelleting turns the mashed feed into dense pellets, thus decreasing dust and waste, reducing but not removing microbes from the feed. The process involves the application of steam and pressure like, for example, a basic sterilizing process in an autoclave, but to preserve nutrients intact, the duration of steam treatment is much shorter. However, conditioner temperature and retention time are set on the type of feed produced, the hygiene program of the feed mill, and logistics. Although the pelleting/cooking process is part of the disinfection process, microbiological sterilization of the material may happen and it does not necessarily reduce nor remove all the microbial load from the finished feed. Whether the remaining microbes will grow inside the feed bags depends on the transport, storage conditions, and remaining moisture. Nevertheless, a range of serious pathogens is still recovered from the finished feed.
Higher temperatures used in pelleting could damage the nutrients but still do not guarantee the feed would be pathogen-free, and the sanitation effects of pelleting at higher temperatures are lost during dust contamination while the feed bag is opened on the farm.
There are increasing incidences of salmonella contaminations in raw ingredients and finished feeds, collected from feed mills and farms. The contamination came from animal protein material such as meat meal, meat and bone meal, feather meal, blood meal, and fish meal but was not identified in rapeseed and soybean meal, and it was found in mills, farms, and feed wholesale. Feed millers need to take caution while using MBM, especially in microbial contamination. Sterilized MBM should be free of Salmonella, Clostridia, and E coli. The total bacterial count should be less than 10* 10^3 cfu/g of the sample. Controlling invisible quality parameters such as microbial degradation from bacteria and mold growth is very important.
Routine analysis of raw material/feed microbial parameters is mandatory to maintain good and consistent quality.
Chemical contaminants
It includes mycotoxins, heavy metals, pesticides, and herbicides. Mycotoxins are secondary metabolites of fungi like Aspergillus spp, Penicillium spp, Fusarium spp, etc. To date, more than 200 mold species have been discovered and 600 plus mycotoxins have been identified. Aflatoxin B1 has been one of the most toxic mycotoxins as far as animal health and performance are concerned.
Stringent regulations are implemented globally in animal production systems. More than 20 ppb in animal feed is considered high level in both poultry and dairy feeds. Moreover, the presence of a diversified fungal population in feed especially in tropical monsoon climatic conditions like India increases the incidences of multiple mycotoxins like Ochratoxins, Fumonisins, T2, etc. and can exert synergistic and additive effects on animals/birds which hamper the production and health.
Storage quality and hygiene are important. Storage structures should be clean, dry, and
well-ventilated. Equipment should be regularly cleaned, and old residues must be removed. Feed mill flushing should also be done routinely to ensure safety.
What does feed hygiene mean?
In simple terms, it means feed free of all these above-mentioned contaminants, usage of lesser antibiotics in animal production systems and thereby giving safe food to end consumers.
Measures for risk reduction in feed production
Traceability – No raw materials should be accepted from high-risk zones. Routine screening of raw materials should be mandatory.
Increased biosecurity
- Control of staff
- Control of trucks
- Control of materials
- Control of visitors
Raw materials
- Check raw material intake
- Check raw material storage
- Checking whole production line and environment
- Schedule cleaning, maintenance, and construction
- Spots of condensation
- Spots of product accumulation
Check kill step
- Reach target temperature, moisture retention time
- Stable steam conditions
- Heating mat set temperature
Routine Feed Mill Hygiene Audits and Program Implementation
- Check critical control points/hot spots
- Follow good hygiene program
Sanitization, cleaning, and disinfection are crucial in achieving feed mill hygiene.
- Cleaning and disinfection of the production line
- Empty elevator boots
- Clean the mixer
- Clean the conditioner and retentioner
- Clean the pellet mill
- Clean the cooler
- Flush the lines
- Check/clean the silos
Conclusions
As discussed, potential hazards to feed safety can be diverse. The feed producers need to ensure safe and nutritious feed to the animals thereby locking a safe feed to the food safety system. The following points can be kept in mind for achieving the same:
- Routine monitoring of the quality of raw materials
- Compliance with mycotoxin limits
- Routine cleaning, sanitization, and disinfection of feed mill lines
- Feed mill audits (HACCP)
As a part of routine quality control audits, during downtime scrapings from the hammer mill, conditioner, mixer, and cooler can be collected for microbiological tests. The risk factor can be accessed based on results mentioned in fig1. Also, multistage samples can be collected from the mixer, pellet mill, cooler, crumbler, and bagging in triplicates to perform the microbiological tests. A powerful blend of organic acids with surfactants can be used in hygiene programs to ensure safety in high-hygiene areas of the feed mill.
Broad spectrum activity of a blend of organic acids has bactericidal, virucidal, and fungicidal effects and can be an important tool in implementing the objective of feed hygiene and safety. In conclusion, the feed mill is one of the most vital blocks of poultry operations. Designing an actionable HACCP protocol and hygiene protocols for achieving standard feed quality and hygiene is important.
by Sanjeev Khanna, Envizon Biosciences
