The quest for a balanced digestive microflora and the potential benefits of probiotic yeast to achieve it, has been garnering much attention in the swine industry as more producers move away from the use of antibiotics as growth promoters. These issues were the drivers behind a technical meeting on pig production late last year hosted by Lallemand Animal Nutrition and ISPAIA, the French Institute for Animal Production and Agro Industry.
Focusing on the nutrition and health issues surrounding farrowing the event focused on the importance of a balanced digestive microflora and the unique potentials of probiotic yeast Saccharomyces boulardii, which has been researched and developed for over 50 years primarily due to human applications. About 150 international professionals of pig production and animal health and nutrition gathered for the event, generating great opportunities to challenge existing concepts and suggest creative solutions to pig production practices worldwide, according to Lallemand.
Modern production challenges
Pig producers in both the United States and in countries worldwide face a host of challenges, from increased sow prolificacy to changing formulations due to decreased use or banning of antibiotic growth promotants. Some of the most profound challenges regarding the latter have come in the countries of Europe, with one of the biggest being the European Union ban on antibiotic growth promoters. But U.S. producers face many of the same or similar challenges as their European counterparts.
As Ken Mellits, professor of virology at the University of Nottingham, explained in a presentation about piglet neonatal diarrhea, increased litter size and heterogeneity have led to higher peri-natal mortality rates. Mellits described a recent emergence of Clostridium difficile associated diarrheas. He said it can be linked to decreased piglet sizes at birth, but also has been influenced by the withdrawal of antibiotics as growth promoters and changes in the piglets' diet. These factors induce modifications of the gut microflora, increasing piglet sensitivity to the pathogen.
Research has shown that longer farrowing processes also lead to decreased colostrum quality for the last piglets born. It appears that in recent years, the importance of colostrum quality has been largely overlooked. In a presentation about sow behavior during peripartum and colostrum quality, Dr. Nicolas Devillers, from Agriculture and Agri-Food Canada, analyzed the various factors determining colostrum quantity and quality, in particular its antibody content. He underscored the negative impact of sow behavior, environment, and litter size heterogeneity on colostrum intake and quality.
Farm-level production practices were also examined at the conference by Guy-Pierre Martineau, Toulouse Veterinary School. In a presentation about functional pathologies, Martineau pointed out the impact of antibiotic therapies on the appearance of functional diarrheas in piglets due again to possible modifications of the gut microflora.
The role of stress on sow health was also discussed at the conference. Beyond sow behavior, the influence of stress can be found in its impacts on the sow's digestive health. Until now, little was known about the sow's gut transit.
But in an original study on that very issue, presented by Antoine Grannec, from La Coop Fédérée (Québec), it was shown that a sow's transfer to the farrowing room prior to farrowing halted the digestive transit. Researcher Dr. Nicola Walker, of the BRI laboratory in Montreal (Lallemand/Institut Rosell), who studied the sow's faecal microflora populations with genetic analysis methods, showed that the stress generated by farrowing had a direct influence on the sow's microflora populations.
All this indicates there are a number of immense challenges to a healthy gut environment in the pig. Feeding yeast address many of them. One such example is Saccharomyces boulardii, which has been largely used in humans since the 1950s, in particular for the prevention of antibiotic-associated diarrheas, but is now being applied to animals. The research concerning this probiotic and its modes of action in the gut are well described (over 150 scientific publications) and so in a unique twist of modern research, for once pig medicine benefits from experiences in human medicine.
Jacques Goulet, of Laval University, in Quebec, exposed the probiotic concept and in particular, the use of S. boulardii yeast, in a world dominated by bacteria (other probiotics used in man and animal are bacterial). Contrary to bacteria, this yeast is not affected by antibiotics, hence its potential in antibiotic-associated diarrhea, where most antibiotics have a deleterious effect on the gut-friendly bacteria. The yeast is able to prevent intestinal infections caused by various pathogens, such as E. coli, C. difficile or Salmonella.
Safeguarding gut mucosa
Other studies have shown S. boulardii's ability to stimulate the production of IgA, the antibody specialized in safeguarding the gut mucosa. In vitro research also showed that the yeast promotes gut wall development and maturation. In Grannec's original study of digestive transit dynamic, it was shown that sow gut health around farrowing was more normal' with the live yeast. The impact of stress was reduced. In a new, on-going study, he is now looking at further characterizing the effects of S. boulardii on the digestive process in sows, as well as feed efficacy, milk quality and the sow's reproductive functions.
Preliminary results showed that the probiotic effect was linked to the diet composition. Finally, if some of the effects of S. boulardii are well-described, in particular those linked to its human applications, this could be only the tip of the iceberg as far as potential for meeting the challenges of modern pig production.
Equilibrium, whether of the gut microflora or the outside environment of the animal, will continue to be key in addressing the needs of today's sow.
New technologies, such as DNA fingerprinting and other powerful genetic analysis tools, hold a lot of promise for understanding the world inside the gut. These technologies have proven successful in studying the rumen microflora, giving a better understanding of ruminant microflora populations, their functions and the influence of various factors.
As the industry begins to apply these same tools to monogastrics, the face of pig nutrition is bound to change, with more interest drawn not only to nutrition and the interaction of the feed components with the microflora, but also to the animal's environment, stress factors and behavior. In this context, the ability of yeast to restore and maintain the sow's digestive balance, offering protection against pathogens or the effects of stress, while improving feed efficacy, offers great potential for pig production.