Sarah Mikesell, editor with The Pig Site, spoke to Greg Page, global swine research manager with Trouw Nutrition, about the immunity gap and critical research to establish a good start for piglet growth that impact immunity development in piglets. Greg has spent the first 17 years of his career in poultry and fish nutrition and in the last three years has made the switch to leading Trouw’s global swine research team, which includes six researchers and 5 technicians who focus on executing the swine research portfolio at Trouw’s Swine Research Center in The Netherlands.

An immunity gap between three to eight weeks of age exists when the piglet is immune compromised and highly susceptible to disease pressure. The piglet receives some passive immunity from the sow, but that benefit is transient and subsides quickly, leaving the piglet exposed.

“There are a number of things that producers can do to minimize the immunity gap, starting with the holistic approach of a feed-farm-health concept,” he said. “We don't often talk about water quality because water often comes from a well, and we just assume that we have what we have. However, there are things that we can do to control water quality and reduce the overall pathogen load.”

Producers should also:

• Review and tighten up biosecurity measures
• Set up routine cleaning and disinfection procedures
• Minimize stress by ensuring the right climate control
• Set up measures for good water quality management
• Build a good relationship with your local veterinarian
• Develop a sound health management program
• Know what disease pressures are in your local area and set up a vaccination program for those diseases where solutions are available
• Monitor the nursery to minimize cross-contamination risks
• Feed very high-quality feed with a good sound nutritional profile that is tailored to your operation

“One of the key challenges that we have when we're talking about immunity in piglets is that they're mounting an immune response that can fundamentally change the nutrient requirements of the pig,” Page explained. “In doing this, they're diverting energy away from growing to increase their maintenance requirements. Thus, they need that extra boost of energy, and this is a new area of research, looking at what other requirements are needed beyond just energy. Do we need to alter the amino acid profile to support the production of antibodies, or do we need higher vitamin or trace minerals to support the immune response? New research does suggest amino acids like threonine, arginine and glutamine among others are more important to the immune response. So, perhaps our standard approach for the ideal protein profile needs to change in response to the health status of the herd.”

Nutritional immunology is a subdiscipline of immunology that is still developing. Page expects that several interaction effects will come up between various nutrients and how the supplementation of those nutrients is balanced through various additives or ingredients to piglet diets that will help influence the animal's response and consequently their requirements.

A critical area of active Trouw Nutrition research is looking at trying to establish a good start for piglet growth to ensure lifetime performance and the true genetic potential of modern genotypes is fully expressed.

“One thing that hasn't been investigated is the interaction between some of these different additives and their effects on the host. We supplement these additives to look from a very, very specific point of view, which is feed intake, growth and mortality, but we really don't fundamentally understand the dynamics of what that is doing to the host,” he said. “We know the digestive tract is the largest immune organ in the body, so understanding the interaction between the host, the gut, the microbiome and the immune system is an area that is developing.”

Trouw Nutrition has found that in some cases there can be too much of a good thing. Overstimulating the immune response, essentially is the same as causing a disease. The piglet is trying to mount an immune response, so it reduces growth in order to meet the needs for mounting that immune response.

“If protein and energy are key in those immune responses, they are the two single costliest nutrients to provide in a diet,” Page explained. “So, we're talking about factors that can have an impact on the cost of production - making sure that we balance the stimulation of the immune system to prevent disease while not overstimulating so that we don't end up costing too much. Overall, immunity and nutrition are really quite a complex area that we as an industry are still trying to learn about and understand.”