Are probiotics important for chickens?

It is said that we have 10 times more bacterial cells on and within us—our microbiota—than the number of cells in our body. Ten times! Trillions of bacterial microorganisms! However, they only make up 1–3 % of our body weight. This underscores the power of these mighty microscopic microbes. Moreover, much of this microbial biomass resides in the gut. Although the numbers of bacteria vary with the species, one truth remains; the majority of an animal’s microbiota lives in the intestinal tract. 

More than 900 bacterial species inhabit the gut—a microbiota indeed! Moreover, this internal microbiota has an important function in an animal. This can include the digestion of food, breakdown of toxins, modulation of the immune system, exclusion of pathogens, and the support of intestinal health. 

The microbiota is not a static entity. It is influenced by several factors both internal (such as age and genetics) and external (such as the environment, diet, and stressors). Moreover, an unbalanced microbiota can have significant effects on the animal such as increased susceptibility to disease, poor growth, and decreased productivity. The good news is that we can positively influence and balance the gut microbiota for the animal’s benefit with the use of probiotics.

Literally translated as meaning “for life,” a probiotic is a live microorganism that is intended to have health benefits when consumed in adequate amounts. Often, bacteria and other microorganisms are believed to be harmful, but many are beneficial.

Probiotics have a variety of effects in the body. Different probiotics work in diverse ways. Depending on the species of microorganism and application, several benefits are expected from probiotic supplementation. For instance: the maintenance of a healthy intestinal community of microorganisms; the modulation of immunological activity; the production of beneficial substances; increased digestion; support of intestinal health; and the reduction and prevention of colonization by potential pathogens to name a few.

These functions are accomplished through several mechanisms. Competition for attachment sites and nutrients by probiotics reduces their availability for pathogenic microbes. Some specific probiotic-produced substances can inhibit pathogens and keep numbers of harmful bacteria low. Immunomodulation and enhancement of gut barrier function are other important functions of probiotics. Simply stated, probiotics help maintain a healthy balance in the gut to promote proper health, performance, and defend against intestinal disorders.

A variety of microbial species have been used as probiotics in animals including Bacillus, Enterococcus, Lactobacillus, Pediococcus, and yeast strains belonging to Saccharomyces cerevisiae. In general, these form three major classifications: spore forming bacteria such as Bacillus, lactic acid producing bacteria such as Lactobacillus, and live yeasts. Commercially available products may contain a single or multiple different probiotic species depending on the end use and desired result.

However, some special probiotics have the best of both worlds. For instance, Bacillus coagulans DSM 32016 combines the benefits of spore forming and lactic acid producing bacteria. As such, B. coagulans DSM 32016 leverages the different mechanisms of action to modulate the microbiota for the benefit of the animal. Moreover, the spore-forming B. coagulans DSM 32016 is heat stable and a great candidate for pelleted feed.

In chickens, there are several factors that can exert influence on the composition of the intestinal microbiota including age, breed, and sex of the bird. However, the elements that, perhaps, have the most influence on the microbiota in chickens are feed source, feed processing, and environment. The basal diet used in poultry production (soy-free vs soy-based, pelleted vs mash) can shift the microbiota and yield significant production gains. 

Environmental factors such as the ambient temperature, litter quality, and maternal interaction likely play a role in the development of the intestinal microbiota. At hatch, chicks are exposed to bacteria from the surface of the eggshell that is covered in bacteria from the breeder hen and the hatching cabinet. The initial contact impacts the future immunity and intestinal health, ultimately directing the development of the gut-associated immune system.

In some regions, litter is reused between broiler flocks, which positively affects the microbiota if the litter is properly primed with beneficial bacteria. Moreover, environmental differences between conventionally raised poultry and pasture flock birds may also be a distinguishing influence on the intestinal microbiota.

Probiotics are often fed to poultry and have been proven consistently enhance performance enhancers. Furthermore, they demonstrate positive influences on intestinal morphology, microbial populations, nutrient absorption, intestinal barrier function and immune response, and antioxidative capacity. The measure of how well probiotic supplementation on a poultry farm performs is often measured by feed intake, body weight gain, and feed conversion rate. Improvements in bird health and welfare are measured through reduced frequencies of morbidity and mortality during certain critical phases of production, such as dietary stress (e.g., change of diet) and health stresses (e.g., animal density).

The chicken’s intestinal tract plays a significant role in the success in health and growth during the production phase and the microbial communities in the gut are essential for host nutrition and peak performance. Probiotics play a vital part in this role. 

Chickens supplemented with probiotics have been shown to have improved intestinal barrier function and morphology. For instance, probiotic feeding has also been shown to increase absorptive surface area of the small intestine thereby improving nutrient absorption and performance. Probiotics modulate the intestinal immune system and can help protect against common intestinal pathogens such as Salmonella, Clostridium, E. coli and other harmful bacteria. Furthermore, they improve intestinal integrity and barrier function in challenged birds. 

Poultry seem particularly sensitive to temperature-associated environmental challenges. Indeed, it has been suggested that modern poultry produce more body heat due to their greater metabolic activity. Dietary probiotic supplementation has been shown to be beneficial in broiler chickens undergoing heat stress by improving intestinal morphology and barrier function resulting in improved meat quality. In laying hens, probiotic supplementation can lessen the adverse impact of heat on the egg production rate, average daily feed intake, and egg weight.

In chick hatching operations, probiotic supplementation can be beneficial by compensating for the lack of contact with grown chickens, which would typically establish a gut microbiota—early administration of probiotics can improve gut microbial profiles. Probiotics fed to laying hens have resulted in improved feed efficiency reflected as significant improvements in egg weight and eggshell quality as well as decreased rates of damaged eggs.

In general, probiotic supplementation improves the meat quality of production broilers. This has been attributed to better intestinal health and increased nutrient digestion and absorption from improved nutrient availability. Supplementation of free-range and pasture-raised flock diets with probiotics has the potential to not only improve production and organoleptic quality of poultry and poultry products, but also to reduce the environmental burden of rearing poultry. Overall, probiotic supplementation can improve bird health and welfare and lead to reduced production cost and environmental impacts.

Probiotics have the best results on health and performance when fed throughout the entire rearing or production period. However, there are several occasions in which a probiotic is indicated. Day-old chicks from a hatchery should have probiotics supplemented to them as early as possible. Birds that have been treated with an antibiotic would benefit from probiotic feeding. Birds should be supplemented with additional dosages of probiotics during times of stress such as changes in temperature, environment, feed, and water. 

Many probiotic strains of bacteria exist, and, like other feed ingredients, it is important to select the right product for your birds’ needs. There is no simple answer for this as this can be individual for each farm and situation. Furthermore, there are microbe-specific differences that impact the selection of a suitable probiotic depending on the intended purpose. For instance, Bacillus species are known for their heat stability and digestive enzyme production as well as improvements in feed conversion improvements whereas lactic acid-producing bacteria quickly colonize the intestine of young animals.  

However, it is also important to select the correct subspecies of microbe. For example, not all strains of Bacillus have beneficial effects. Careful selection and screening of the different strains is key to finding a successful solution! Biochem has more than 30 years of experience with probiotics, and we rely on these many years of knowledge to help you select appropriate probiotic for your needs. Contact one of our experts to learn more about the probiotic solutions we offer.