Management of nutrition and gut health is essential in achieving clean eggshells. Feed stuff selection in particular is vital. For instance, it is crucial producers are aware of any anti-nutritional factors, toxins or contaminants contained in feed that can lead to nutritional imbalances, intestinal diseases and reduced overall bird health.
1. Fiber management
The amount and type of fiber in feed impacts proper gut performance. For example, soluble fiber is difficult to digest due to its high NSP (Non-starch polysaccharides) content. NSPs can increase gut viscosity and hold a large amount of water, leading to dirty eggs, and other issues. Barley, rye, wheat or triticale all have higher levels of NSPs than sorghum or corn. Supplementing the fiber with high NSPs with enzymes (β-glucanases and xylanases) improves the nutrient value of diets and helps overcome issues. Insoluble fiber also has proven benefits as it has an abrasive effect in the gut, enhancing nutrient digestion and improving gut health. Fibrous ingredients with a high-water absorbing capacity should therefore be incorporated into the feed.
2. Performance impacted by particle size
Flocks benefit from being fed with larger, coarse particles as they develop larger and more muscular gizzards and longer intestinal tracts. The increased retention time also stimulates pH drop, which has a bactericidal effect. Larger feed particles have a longer transit time through the gut, which improves the length of microvilli and increases the absorptive surface area in the intestine, and thereby positively affects digestibility and nutrient absorption.
3. Protein intake must be controlled
Producers must take care with protein levels too. Any excess leads to increased nitrogen excretion which negatively impacts bird health and the environment. The portion of amino acids and non-amino acid nitrogen not digested in the digestive tract acts as a substrate for microbes that can generate toxins. This material can insult the ileum, causing overgrowth of pathogenic bacteria, imbalance in the gut ecosystem, gut irritation, dysbacteriosis and in some cases subclinical necrotic enteritis.
Determining BA (Biogenic Amines) in feed ingredients, such as fish meal or animal byproducts, helps to evaluate the quality and degree of spoilage of the material before the production of feeds. In addition, it is important to make the association between the BA content and the bacterial load in the feed.
4. Probiotics can help
Beneficial bacteria must be part of the gut environment. Probiotics have proved to be an easy way to positively influence populations in the intestine. Probiotics are live micro-organisms which can alter the dynamics of the gut microflora and thus, improve animal performance and health through the combination of different mechanisms of actions.
Not only is the gut the major organ for nutrient digestion and absorption, it also works as the first protective mechanism to exogenous pathogens. When the gut function is impacted by pathogens, there is not only an immunological response but also a change in passage rate, digestion, mucin secretion, and an increase in turnover rates of the intestinal epithelium.
Reduced feed intake results in a higher maintenance requirement, with diversion of nutrients to bolster the immune system. Energy and nutrients expended to mount a strong enough immune response to defeat disease, because of a disturbed microbial ecosystem, reduce absorption and digestion of nutrients (increased FCR), overstimulating the immune system and therefore triggering enteritis and noticeable performance losses.
The dirty eggs issue is multifaceted. However, to a large extent the problem can be ameliorated by using low-NSP grains or NSP enzyme supplementation in the diet; increasing the use of insoluble fiber; using low protein feeds with correctly balanced amino acid profile and restricting the use of animal by products to minimize the risk of high content of biogenic amines. Finally, the addition of probiotics can balance the gut environment excluding pathogens and bringing balance to the most important organ in the hen to support and enhance productivity and the best egg quality.
Carlos de la Cruz, Global Expert Egg Production, Evonik Health and Nutrition GmbH