Salmonella, Anitbiotics and Food Safety
A leading poultry nutrition expert discusses the current issues facing the global poultry world.
Dr. Andreas Kocher, Bio-Mos Applications manager of Alltech, is a poultry nutrition expert. His PhD dissertation was on the use of feed enzymes to improve the nutritive value of vegetable protein sources. He also worked a lot on feed additives. Originally based in Ireland, Dr. Kocher now lives and works in Australia and goes around the world not only to sell his company’s animal nutrition products but also to observe poultry trends and exchange notes with his fellow poultry experts especially on a topic which is close to his heart: salmonella and food safety.
We recently met with Dr. Kocher and discussed with him current issues affecting the global poultry industry.
What are your personal observations regarding the growth of the poultry industry in Asia?
It’s still quite a traditional industry. The stress in the environment is more challenging with the temperatures mounting. Here in the Philippines, it’s more diverse compared to say, Japan where it’s more advanced or India, where the industry is more fragmented.
What about in terms of poultry technologies?
The challenge here is how to grow birds in a way to fulfill consumer demand without losing genetic potential. We’re doing a lot of work on the biomass product. We’re doing studies on the changing microbial population, fundamental protective barriers to the intestines of the layers and their changing composition. In terms of chicken’s intestinal health, the trend is to use probiotics Another is on the organic mineral side The issue of heavy metals coming in is not an immediate . threat but it’s already in the horizon.
Let’s talk about salmonella. What facts can you tell us which you think our readers might not still probably know?
When we talk about salmonella, we distinguish two groups. Salmonella, which are a disease for the animals and we’re talking on the poultry side, salmonella polorum or colinarum they cause mortality and morbidity particularly in laying band breeding. They can colonize and be present in birds or in other animals without causing diseases, without causing effect in animal performance. But at the end of the food chain, it can become an issue on the human health side.
How does salmonella spread in birds?
They have two ways of spreading. We have a vertical transmission from the breeding hen to the day-old-chick through the egg and we have the horizontal transmission where we have the fecal material which has salmonella contaminating either the bird itself or the egg.
What is the key to the spread of salmonella then?
Strict biosecurity. There is no way around that because what we have to do is to eliminate the source. Salmonella can come in through wild birds, through rodents. There are even research studies saying that even flies carry salmonella, And it’s not the live flies that spread the salmonella to the chicken but the dead ones. The flies die and the chickens eat them and they get infected so basic insect control is part of it. You also have to control the people moving around that’s why we advise people to shower first before they enter poultry houses. We also have to control the feeds and we do this through control of raw materials, particularly meat meal which is a common source of salmonella. We also talk about heat treatment of feeds because salmonella is heat sensitive. Heating the feeds for about 85 degrees centigrade can kill salmonella. Pelleting and measures like heat shielding are also done to prevent its spread. Salmonella cannot be seen by the naked eye so we do swap sampling and analyze it in the lab. In pigs, they do antibody test.
Aside from the things you mentioned, are there any more ways that can be done to help prevent the spread of salmonella?
There are measures that we can do in the feed itself and there are steps like the use of acids which lowers the pH in the intestines of the bird and corrects the environment so it becomes less favorable for the salmonella to grow.
There are products like biomass which locks the attachment of salmonella. It prevents the entrance into the organs of the birds so you’re stopping its vertical transmission. You see, once the salmonella enters and harvests in the spleen, it goes into the oviduct. Once it’s in the egg, you have little measure to actually control it. It just lives there. It gets transferred to the birds so you prevent the attachment and entering into the body that way. On the breeding side, we’re looking at eggshell quality. If you have poor eggshell quality, it’s easier for salmonella to enter. So these are the things we can do on the feed additive side.
How does Alltech address the issue of food safety then especially in the area of salmonella control?
We’re looking at the whole chain. We’re starting in the production of our products. We undergo a very strict quality control. We have developed the Alltech Quality Control System or AQS, a combination of ISO-HACCP and different standards and on top of it, whatever level is required, we comply with that. The other thing is we’re looking at legislation in other countries-how they are applied and how we, as a company fit it within the legislation measures and bring in the issue of salmonella.
Another issue in food safety is the use of antibiotics in poultry. What’s the latest on this?
It’s a big concern. Europe has taken a precautionary approach in banning the use of antibiotics. Starting January, 2006 they can’t use any growth promoters in the feeds anymore.
What’s the danger of using antibiotics in poultry?
We have to separate the use of antibiotics in the birds and the residue in the meat. If you find residie in the meat, we have a serious problem. If you ingest the antibiotic, what it ultimately does is that it creates resistance to pathogens so if you get really sick and go to a doctor, you’re losing the ability to treat your illness. If it’s bacterial based, it’s very dangerous because low levels of antibiotics would create resistance. In high levels, you kill the bacteria. You don’t have time to build up resistance. The reason why we use antibiotics in chicken production is to control subclinical disease and they have proven that by controlling microflora, you have a growth promoting effect meaning better weight gain, better feed conversion utilization and low mortality. The danger is, when you use antibiotics in chicken meat production, it slowly builds up resistance. So you ultimately have to use high levels of antibiotics.