For these piglets, tobacco’s in and antibiotics are out
ANTIBIOTICS ARE EFFECTIVE IN fighting bacteria and the diseases they can cause. Unfortunately, they’ve been overused in society, for humans and livestock. It’s to the point where some bacteria are producing strains that can resist antibiotics’ ability to control or kill them.
In this case, the best offence is a good defense. Defend humans and livestock from microbial disease so they don’t need antibiotics to be healthy.
To that end, dozens of approaches have been created. In agriculture, one such approach is the University of Guelph’s development of naturally high immune response livestock. Their genetics dictate that they’re automatically healthier, and through their lives, are less likely to acquire the kinds of diseases that requires antibiotics.
Here’s another approach – and it involves genetically modified organisms, or GMOs.
At Guelph, genetically modified tobacco has proven successful in helping reduce potentially fatal post-weaning diarrhea in piglets.
The tobacco contains the protein FaeG, derived from a bacteria called F4 enterotoxigenic E.coli. This protein prevents nasty E. coli, the causal agent of post-weaning diarrhea, from taking hold in piglets’ small intestines.
The genetically modified tobacco is dried and fed in small amounts to
the young pigs, as a pharmaceutical feed additive.
Graduate student Victoria Seip and Profs. Robert Friendship and Vahab Farzan found that five grams a day of the tobacco (developed by Agriculture and Agri-Food Canada in its London Research and Development Centre) reduced the incidence of diarrhea in three-week-old recently weaned piglets by more than 30 per cent. Here’s why. Newborn piglets draw immunity from their mothers’ milk, against harmful E.coli and other bacteria.
But when the piglets are weaned, they no longer have such protection. It takes several weeks before they build up their own immunity.
It’s during that time they are most susceptible to the bacteria that cause diarrhea. In about half of the pig population, the cells in their small intestine naturally contain a receptor that allows those harmful bacteria to take hold there and release toxins. Diarrhea develops, and the piglets must be treated with antimicrobials or antibiotics.
That’s where the protein FaeG comes in. It competes with the harmful E.coli for receptor sites. So with many fewer places to take hold, the E. coli bacteria carry on through the intestines and are eventually excreted.
Previous research conducted by Agriculture and Agri-Food Canada showed that when embedded in dried leaves, the protein was not broken down in the digestive tract before having the opportunity to work against the pathogenic E.coli.
Seip says more work must be done before determining whether this treatment is commercially viable, but she’s enthused about results. Seip believes this plantbased product might be an alternative to antibiotics and antimicrobials that are currently added to some starter feeds for piglets, to help them stave off disease.
The challenge is to find a way to incorporate the protein into such starter feeds. In the Guelph trials, Seip and research technicians mixed the dried leaf powder with chocolate milk and bottle fed it to the 24 piglets in the study five times before they were introduced to the bacteria, to ensure the animals consistently received the proper dose.
That wouldn’t be practical in a commercial herd where most producers wean at least 150 pigs per week. If the approach is to be offered widely, it will need to be part of feed.
Others involved in this study, conducted at Agriculture and AgriFood Canada, the Arkell Research Station and the Ontario Veterinary College Isolation unit and the Animal Health Laboratory, were Drs. Rima Menassa and Josepha Delay.
This research was sponsored by the University of Guelph – Ontario Ministry of Agriculture, Food and Rural Affairs’ agreement and Swine Innovation Porc.