A challenge for the pig sector is to find substitutes for antibiotics that promote gut health and productivity while competing financially with the latter, says Bent Borg Jensen, senior researcher in the Department of Animal Science at Denmark’s Aarhus University.
The academic spoke at the international congress for livestock science, EAAP 2014, in Copenhagen last month in terms of new feeding and management strategies to counter the problems associated with modern pig production, such as diarrhea and ulcers.
“While there have been a great deal on research trials carried out on the impact of pre and probiotics on the gut microbiota of pigs, the results have generally been inconsistent. Some studies have shown zero effect while others the contrary,” he told feednavigator.com.
One of the clear limitations for the pig sector in terms of using pre and probiotics in feed is their current price, said Jensen.
“They have not tended to be used at high dosage levels in pig trials due to the high costs that would be incurred as a result, hence perhaps the variance in outcomes seen.
We have found the beneficial effect from the use of such microorganisms in pig diets is only really seen when they are used daily and in large quantities due the composition of that species’ gut microflora along with the fibrous nature of a pig’s diet,” he added.
Jensen said his team has seen good results from using probiotics for one week in pigs prior to the slaughter stage to alleviate the problem of boar taint but, at current price levels, such an approach is not viable for the sector.
“But pre and probiotics might be more cost effective when used in weaning diets, due to the much lower quantities of feed required at that life stage,” said the researcher.
Jensen said there are indicators that the bacillus strain of probiotics is beneficial for pigs but “we need more strain and dosage specific data to confirm its immune strengthening abilities.”
An alternative approach to antibiotics in terms of promoting health and growth in pigs is going down the route of extra zinc or copper supplementation, he said, but the problem with such feed additives is that the surplus heavy metals end up in the manure, and risk polluting the environment.
If the right doses and types of organic acids can be determined they too could also have a positive impact on the performance of pigs, while low-protein diets with added essential amino acids might also be a beneficial feed combination for the sector, said Jensen.
But for the pig industry to make informed choices on some of these novel gut health promoters, he said more information is needed on the complex interactions that occur between the immune system, the intestinal bacteria and the metabolism of pigs.
Jensen also notes the constraints placed on earlier research methodology in terms of sampling and microbiological culture.
“Today, we have at our disposal new generation molecular biological tools for the cultivation of bacteria that, compared to the older techniques, allow for much more sampling and, in turn, detailed understanding of the effect of pre and probiotics on gut microflora.
The next 10 years should bring new insights that will lead to the development of new types of feed, which combined with feed additives and feed processing, will change the composition of gut bacteria so that the animal's immune system will be strengthened and its health and productivity boosted,” said the pig health specialist.