Feed additives, extracts, plants tested as alternatives to antimicrobials

SASKATOON — Antibiotics have been used effectively in the livestock industry for 50 years but resistance problems and consumer backlash have researchers looking for alternatives.

“They were very effective in animal health and were one less thing we as nutritionists had to worry about,” said Brett Lumpkins of the Southern Poultry Research Centre at Athens, Georgia. He spoke at the recent western nutrition conference held in Saskatoon.

“What we need to understand is that when we deal with an anti-biotic-free production, we need to take into account the whole gamut. There are several aspects we have to consider in order to get that beneficial bacteria into the gut and get the most health benefits for the birds,” he said.

The European Union banned antibiotics in feed for sub-therapeutic use in 2006, although antibiotic use actually went up through veterinary prescription.

Companies are looking to adjust to consumer preferences for lower antibiotic use in livestock production, while still maintaining bird health.

Alternative treatments for poultry start at birth.

The chick undergoes a dramatic change in diet after it hatches and proper nutrition is required to jumpstart intestinal development.

Some diet ingredients can help but others may hinder it. Products like enzymatic soybean protein and brewer’s yeast can benefit gut bacteria and help with better nutrient absorption.

Some of these products can also help the beneficial bacteria outcompete harmful bugs.

A product like butyric acid, a short chain fatty acid with antimicrobial properties, changes the pH of the gut and helps get rid of non-beneficial bacteria. However, it smells like vomit so ways to inhibit the odour are needed.

Ongoing research into phytoceuticals, plant-based treatments, may provide some answers.

Research into essential oils such as oregano and thyme show weight gain improvements and are marketed as a flavouring additive to stimulate appetite.

“They do no harm. The basis of them is a defence mechanism,” Lumpkins said.

Vaccinations continue to be important. There is no residue in the meat when vaccines are used in the early stages of life.

Natural products like oregano do not interfere with the vaccine’s efficacy and may actually support them in the fight against problems like coccidiosis.

Prebiotics can help maintain gut bacteria and are most useful if they are fed from birth to slaughter.

Other products called saponins, which include things like the yucca plant or Quillaja, have been shown to produce less ammonia, improve intestinal structures and provide better nutrient absorption

Reduced antibiotic use for pigs is also under study, said John Pluske of the School of Veterinary and Life Sciences at Murdoch University in Australia.

The period after weaning is a delicate time in which the pigs require protection.

“Some sort of protection is still needed whether it is in an anti-biotic-free or antibiotic-reduced environment. It depends on the circumstances.”

An Australian study fed aspirin to eliminate inflammation after weaning and researchers noted improved growth rates and better feed conversion.

However, the effects were less dramatic when it was tried on farms.

Belgium and Denmark may provide some of the answers to how producers can reduce antimicrobial use through different management practices, said Pluske.

Those changes may include dietary additives, such as yeast extracts, which have been shown in some studies to help with growth and some disease prevention.

Protein levels in the diet are also being researched. Studies have looked at an antimicrobial compound in a high and low protein diet and how they work together. High protein diets without antimicrobial compounds result in more diarrhea in young pigs. However, a high protein diet with added compounds showed pigs reached market weight sooner.

Some studies have shown a re-duction in diarrhea by including rice in the diet after weaning.

Antibiotic-free production is possible, but a case study from Iowa showed there are tradeoffs, said Pluske. Antibiotic-free pigs grew slower and more died. Production costs were $11 more per pig in the antibiotic-free vegetarian diet.

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