ENHANCING DAIRY PRODUCTION WITH POSTBIOTICS

Modern dairy production is facing a series of unprecedented challenges. Postbiotics are an emerging technology that offers a stable, quick and focused solution to help manage intestinal health in ruminants, improve performance and health and contribute to reducing their environmental footprint.

Modern livestock production is facing un- precedented  challenges  including  disease outbreaks, restrictions on antibiotic usage, environ- mental volatility, economic pressure and increasing scrutiny for sustainability and environmental foot- print. Ruminants themselves are methane producers, a gas which has a 28 times greater global warming potential than carbon dioxide, so balancing rumen health to help manage the environmental footprint is of increasing concern. Given the multitude of fac- tors that can affect livestock production, maintain- ing a healthy digestive system and good gut health is essential for ruminants to both perform efficiently and minimize their environmental impact.

RUMINANT DIGESTIVE SYSTEM

Unlike monogastric animals, the ruminant di- gestive system is designed to ferment feedstuffs via its four-chambered stomach and generate energy precursors for use. However, in the young animal (pre-ruminant) the digestive system is simpler, and the rumen, reticulum and omasum are undeveloped until the switch from milk to solid feed. This typi- cally creates a different focus for the management of intestinal health based on life stage. In the pre-ru- minant the targets include improved early immune resilience, establishing a healthy lower gut microbi- ota and preparation of the developing stomach for fermentation. In the older animal, the focus tends to be maintenance of intestinal health and rumen function for efficient nutrient use and health status. The management of ruminant intestinal health requires a multi-factorial approach using a range of tools including management, breeding, biosecurity, vaccination, nutrition and feed additives. Feed ad- ditives is a broad category and in the last few years, postbiotics have gained momentum as an additive of choice.

POSTBIOTICS – PRACTICALITY AND EFFICACY

Postbiotics are defined as ‘a preparation of inan- imate micro-organisms and/or their components that confers a health benefit on the target host’ (Swanson et al., 2020). The preparation can be me- tabolites alone or include the dead microorganisms or cellular fractions and can be based on eukaryotic, prokaryotic organisms, or both. Typical candidate microorganisms for the production of post biotics include yeast such as Saccharomyces, Bifidobacteria, lactic acid bacteria and fungi.

Postbiotics confer a number of benefits over other biotics such as pre- and postbiotics. Prebiotics are a feed source for bacteria and need to selectively stim- ulate the growth of beneficial bacteria. Probiotics need to become active in the intestinal tract and produce metabolites to exert their effect; this takes time. In the case of postbiotics, these limitations are reduced. Benefits of postbiotics include:

1. Fast acting – postbiotics already contain the ac- tive components for prebiotic and probiotic effects
2. Flexible targeting – by combining different starting microorganisms and growth conditions, the metabolite profile of the postbiotic can be tailored for more specific responses or focused on different livestock species
3. Safe – there are no live organisms in postbiotics and only recognised, safe organisms should be used for fermentation to avoid risk of toxins
4. Stable – since there are no live organisms, post- biotics have greater tolerance for different environ- mental, feed processing conditions or application routes as well as a longer shelf-life.

A fundamental step in the development of a post- biotic is the selection of the starting microorgan- ism(s). What is the metabolite profile that is needed to deliver the response required in the animal? The screening profile can then be established to identify the best candidate, and production conditions tai- lored to maximize growth and metabolite yield whilst ensuring the starting organism is safe. Care needs to be taken with inactivation and purification to ensure the metabolite profile is not adversely affected.

POSTBIOTIC COMPOSITION AND ACTIVITY

The composition of a postbiotic depends on several factors including the starting microorganism, meth- od of inactivation and purification. For example, the physical breakdown of yeast and bacteria will yield quite different cellular fractions e.g. mannan oligosac- charides and beta-glucans versus peptidoglycans (from gram positive bacteria), teichoic acids, and surface layer proteins. Positive effects of the cellular fractions on the host include immune modulation e.g. peptido- glycans from Lactobacillus salivarius acts on the IL-10 pathway to induce intestinal regulatory T-cells (Fer-nandez et al., 2011) or S-layer proteins (SLPs) from L. kefir have been shown to inhibit Salmonella invasion in Caco-2/TC-7 cell lines (Golowczyc et al., 2007).

Furthermore, while the metabolite profile from these organisms can differ, they can be broadly categorized as primary metabolites, such as amino acids, enzymes, vitamins, and organic acids, and secondary metabolites such as exopolysaccharides, alkaloids, terpenoids, peptides, and others. These secondary metabolites have a wide range of prop- erties including antioxidant, immune response reg- ulation, antimicrobial, nutritional and neural and hormonal regulation.

nu.biom – A POSTBIOTIC BUILT FOR INTESTINAL HEALTH

The nu.biom range of postbiotics (nu.ance bio- technology, Switzerland) was developed from the very beginning with a species specific, problem spe- cific approach. Proprietary microbial strains were selected and screened using a combination of ap- proaches including genomics, metabolomics and in vitro assays to determine the optimum combination of organism for the target profile, intestinal micro- bial modulation for enhanced nutrient digestion. Further refinement via in vivo assays was then un- dertaken. A 3-stage manufacturing process includ- ing liquid and solid fermentation and purification is used to produce a unique postbiotic combination for ruminant intestinal health, nu.biom BOS.

POSTBIOTICS EFFECTS

IN ADULT RUMINANT GUT HEALTH

The composition of ruminal microbiota can be influenced by bacterial postbiotics, leading to in- creases in cellulolytic bacteria with a contempora- neous increase in VFA (Izuddin et al., 2019), al- though ruminal pH is less affected. The addition of postbiotics e.g. yeast-based, can help maintain rumen microbial communication during rumen challenge, for example during periods of ruminal acidosis (Guo et al., 2024). Furthermore, reduc- tions in levels of the shiga toxin producing E. coli in rumen fluid have been demonstrated following the application of postbiotics (Aditya et al., 2022), indicating the importance of postbiotics as a tool in the One Health approach.

The inclusion of postbiotics in ruminant diets has demonstrated a number of benefits for intes- tinal health. Improved rumen structure such as increased rumen papillae allows for increased nu- trient absorption and stimulates the production of SFCA which help enhance fermentation. In the lower gut, postbiotics support a balanced microbio- ta, helping to lower Enterobacteriaceae populations and stimulate mucosal immunity. Further benefits such as upregulation of tight junction proteins to improve intestinal integrity and upregulation of an- ti-inflammatory cytokines for immune modulation have also been shown. In dehorned calves, animals fed nu.biom BOS had 15% lower dehorning would scores while their inflammatory response to E. coli and Salmonella lipopolysaccharide was significantly lower than non-supplemented animals.

Udder health can also benefit from dietary sup- plementation with postbiotics. lactobacillus-based postbiotics, for example, have been shown to evoke a localised IL-8 response in the udder in response to Streptococcus infection and significantly reduce somatic cell counts (Mathur et al., 2022). nu.biom BOS, has been shown to enrich the milk microbiota with higher levels of Lactobacilli and laboratory and field studies in lactating ruminants including cows, sheep and goats have all shown substantial reductions in somatic cell counts and improved udder health.

nu.biom BOS BOOSTS DAIRY PERFORMANCE

Milk production and quality is sensitive to intes- tinal health. Poor gut health leads to reduced ef- ficiency of nutrient use and rumen imbalance re- sulting in poor performance, increased incidence of disease and potentially mortality. Efficient nutrient digestion is important to maintain gut microbial homeostasis and avoid conditions such as acidosis, hypoglycaemia or diarrhea. In a field study of 9 Ital- ian dairy farms (average 320 cows/ farm), the sup- plementation of TMR with nu.biom BOS (6-10 g/ head/day) resulted in improved fibre digestion (Fig- ure 2). In the laboratory, supplementation of dairy

cow diets with nu.biom BOS has also been shown to significantly increase crude protein digestibility and neutral fibre digestibility (Vicente et al., 2024).

In lactating goats, nu.biom BOS supplementation resulted in significantly lower methane output per kg of milk produced (14.3 versus 11.3 g/kg, control and nu.biom BOS, respectively), coinciding with a 21% increase in ruminal propionate suggesting an effect of nu.biom BOS on the ruminal microbiota and improved efficiency (Fernández et al., 2023). Given methanogenic archaea use anywhere from 2-12% of gross dietary energy, modification of the ruminal microflora by nu.biom BOS helps to offset this potentially compromised feed efficiency.

Improved nutrient digestion was also associated with increased milk production observed across all 9 farms compared to the historical average (Figure 3).

Milk production increased from 1 to 8 litres/cow/day, with an average increase of 13.5% in a shorter interval (181 versus 195 days pre-nu.biom BOS). In a labora- tory study using 12 Friesian dairy cows, animals fed nu.biom BOS (8 and15 g/cow/day, pre calving and calving, respectively) for 105 days had significantly in- creased milk production, kg fat/day and kg protein/ day (P<0.05) versus controls (Vicente et al., 2024).

SUMMARY

Modern dairy production is facing a series of un- precedented challenges and the scenario is unlikely to change anytime soon. Producers need to rely on a toolbox of approaches to help them maximize efficien- cies and economic returns. Postbiotics are an emerging technology that offers a stable, quick and focused solu- tion to help manage intestinal health in ruminants, improve performance and health and contribute to reducing their environmental footprint. nu.biom BOS is at the forefront of this technology, using pro- prietary strains and production techniques to develop species-specific and production-specific postbiotics to address the needs for the modern dairy farmer.

About Dr. David Harrington

Dr. David Harrington is the Director of Product Management for nu.ance Biotechnology (Switzerland). He has over 25 years working in the animal health industry in the development and commercialisation of biologicals and feed additives for livestock.