A group of broilers together at a facility.A group of broilers together at a facility.

Epithelial Integrity Is Essential as the First Line of Defense to Target BCO, Food Safety and Immunomodulation

This is Part 1 of a 4-part series.

Epithelial tissue is an animal’s first line of defense against environmental challenges. It covers all exterior and interior surfaces of the body including internal organs, blood vessels, respiratory tract and reproductive tract and serves as a physical barrier between those organs and any bacteria, viruses, fungi or other microbes that are on the outside. More than only being a physical barrier, epithelial tissue can also produce secretory components with diverse antimicrobial effects. It can also have cilia, like in the respiratory system, that remove particles and germs.  

Those epithelial tissues that require an exchange of substances between an external and internal side are especially precarious and risky, as they only have one single layer of epithelial cells. Examples include the intestine, respiratory tract, renal tubuli and endothelial capillary network. These monolayer epithelial tissues require specific care.

READ MORE: Epithelium – The First Line of Defense

Monolayer epithelial tissues are held together by tight junctions. If these tight junctions are damaged, it leads to a leaky epithelium, which allows the translocation of antigens such as bacteria, viruses or other foreign pathogens and their toxins into the body that will elicit an immune response. Stress of all types — including heat stress, stress from high stocking densities, psychological stress, metabolic stress, coccidial and/or Clostridial infections, etc. — will trigger an excessive production of free radicals and pro-inflammatory cytokines that will cause damage to the tight junctions and disrupt the integrity of the monolayer epithelial tissue.

When a bird’s epithelial tissue is weakened and bacteria or any other antigens are able to pass into the body, it can lead to diseases and systemic inflammatory reaction syndrome (SIRS) that may negatively impact growth and production. Additionally, a leaky epithelium can lead to problems such as bacterial chondronecrosis and osteomyelitis (BCO), dermatitis, septicemia and compromise food safety as the birds approach time to market.

Trace minerals like zinc, manganese and copper are critical for improving the immune response and repairing compromised epithelial tissue in a rapid and robust manner. Supplementing with inorganic sources, however, is not enough. Supplementing your poultry nutrition program with Zinpro Performance Minerals® ensures that there are nutrients available to improve the integrity of epithelial tissue, fuel the immune system as well as growth and production. This can ultimately prevent issues related to BCO and food safety and can support immunomodulation.

What Is Bacterial Chondronecrosis and Osteomyelitis (BCO)?

BCO is the most common cause of lameness in poultry around the globe, especially when working in poultry operations that do not use any antibiotics. Financial losses caused by BCO can range between 1-3% in normal conditions, or as high as 10-15% in extreme cases. As birds grow to market weight, they develop microfractures between their growth plates and the articular cartilage of the femur and tibia. If a bird’s epithelium has been compromised due to stress factors, this can allow bacteria to leak from the respiratory or gastrointestinal tract into the blood stream, eventually settling into those microfractures and leading to necrosis.

READ MORE: BCO Lameness in Chickens: The Tip of an Iceberg

This process can start at a very young age — even as embryos still inside the egg. When bacteria leaks into the bloodstream, it can either survive or be destroyed by the phagocytes (white blood cells or macrophages). It can remain there waiting for an opportunity. As the bird grows and those microfractures develop in the growth plates, the bacteria will use that opportunity to cause BCO.

Epithelial Integrity Important to Control Food-Borne Illnesses in Poultry

When epithelial integrity is weakened, this can allow potentially toxic bacteria into the bloodstream and ultimately into the surrounding muscles of the bird. Some of these bacteria are well known pathogens for humans, such as E. coli, Staph. Enterococcus and Salmonella. Birds are usually exposed to these bacteria early in life when they are establishing their normal microflora. Just like with BCO, these bacteria are waiting for an inflammatory response or stress event to damage the epithelial barrier so that they can infect the birds.

When harmful bacteria enter a bird’s bloodstream, the immune system will work to kill those bacteria, but if the bird is close to market weight, the bacteria may still be present in the fractured bones, spreading into the muscle when the bird reaches the processing facility. This is why it is important to maintain epithelial integrity to ensure that these bacteria don’t cross into the bloodstream and into the bones causing food-borne illness issues in the final product. Other problems associated with bacterial translocation are Cellulitis — epithelial disruption from scratches — and septicemia through either respiratory or digestive epithelium, which are major causes of condemnation at the processing plant.

Immunomodulation Is Key to Epithelial Integrity

When the epithelium does become compromised and a bird is facing an antigen invasion, immunomodulation is key to neutralizing those antigens and repairing the epithelium. Immunomodulation refers to an animal’s ability to self-regulate the immune system to mount a rapid and robust inflammatory response to immune challenges. But it is also about regulation, which means stopping inflammation at the right time before it becomes harmful for the organism.

Trace minerals, like zinc and manganese, are critical for the production and maintenance of epithelial tissue, as well as for producing an adequate immune response. Birds need these trace minerals not only to fuel the immune response, but they must also have sufficient levels left over to also fuel their growth and production. When it comes to this task, inorganic sources of trace minerals just aren’t enough.

Performance Trace Minerals Enhance Immune Function in Poultry

When inflammation occurs, the body’s immune system will require more nutrients to combat the challenge, leaving fewer nutrients available for performance including muscle growth. Supplementing poultry diets with zinc and manganese from Zinpro Performance Minerals can help manage inflammation by strengthening the bonds between the epithelial cells in the GI tract by maintaining the tight junctions, preventing bacteria from entering the bloodstream.

Performance trace minerals utilize a unique pathway for absorption: the amino acid transporter. They minimize the various antagonistic interactions to which other trace mineral sources are subject and, therefore, reach the intestinal lining. The efficiency of trace mineral absorption varies by amino acid, and Zinpro Performance Minerals utilize amino acid ligands that ensure effective absorption of both the amino acid and the mineral.

Zinpro Performance Minerals enter and leave circulation in a different form than ionic minerals and are excreted at a slower rate. Therefore, birds being supplemented with performance trace minerals will absorb more minerals to fuel an adequate immune response and have sufficient levels left over to maximize growth and production.

A summary of 30 studies showed an improvement in epithelial tissue strength by greater than 30% in poultry when supplemented with zinc, manganese or a combination of both from Zinpro Performance Minerals. Additionally, a summary of 23 trials showed intestinal strength was enhanced by more than 15% in poultry supplemented with zinc, manganese or a combination of both from Zinpro Performance Minerals.

To learn more about enhancing immune function and performance in your flock, contact your Zinpro representative today.

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