Written by Dr T.B. Barragry PhD MSc, MVB, MRCVS, Vet Pharmacologist.
There is a growing need for a new, palatable, evidence based and effective feed additive to maximize production returns in cattle and sheep at times of stress, while also improving health, bloom, and appearance. This is all the more so with recent prohibitions on the indiscriminate usage of oral antibiotics both as prophylactic and as metaphylactic agents.
Probiotics are defined as live microorganisms that are beneficial to the host when administered in adequate amounts, and they have been widely and profitably used as additives in animal feed. Regular ingestion of probiotics as a replacement of chemical feed additives, especially as an alternative to antibiotics, benefits animal health and production. Probiotics have the ability to enhance intestinal health by stimulating the development of a healthy microbiota (predominated by beneficial bacteria), preventing enteric pathogens from colonizing the intestine, increasing digestive capacity, lowering the pH, and improving mucosal immunity. A synergy is now known to exist between bacterial probiotic strains (Bacillus Subtilis, & Enterococcus Faecium) and Yeast (Saccharomyces cerevisiae), such that the resultant mixture has a potent benefit on the health of the gut and its overall digestive function. This beneficial effect is manifested in adult animals as enhanced dry matter intake, better digestibility of nutrients, and better assimilation of end products into protein. The net result of feeding this mixture is an increase in feed efficiency, better weight gain, and optimum performance unlocking the genetic potential. The animal is not only intrinsically healthier but looks healthier too with a better coat, skin, and conformation. One such well-established feed additive is “Provita Pedigree” for cattle & sheep containing a unique formulation of yeast and probiotics.
How “Provita Pedigree” Exerts its Beneficial Gut Effects.
The Role of The Rumen
Unlike other animals such as monogastric and carnivores, Ruminant animals cannot rely on digestive enzymes to break down and digest food stuffs. The ruminant is different, insofar as much of its herbivorous diet is made up of indigestible fibres and celluloses which cannot be broken down by simple intestinal enzymatic activity. Although ruminants consume plant fibre in their regular diet, the usual enzymatic machinery for its digestion and breakdown is inadequate. For this reason, ruminants retain a large “vat” of microorganisms (the rumen) and a gut colony of microorganisms (gut microbiome) that are capable of producing enzymes to degrade plant polymers, especially in the rumen. Billions of various species of microflora including bacteria, protozoa, fungi yeasts and others inhabit the rumen to accomplish this complete digestion. The rumen, in short, is the most diverse and complex microbial system of the animal, and this dense microbial population consisting of bacteria, yeasts protozoa, fungi, and other miscellaneous microbes provides a unique system for ruminants, which allows them to utilize pastures and indigestible fibrous cellulose material and non-protein materials and convert them to volatile fatty acids, propionic acids, succinic acid, glucose and protein.
Ensuring an Optimum Rumen /Gut Microbiome with Probiotic Bacteria
Rumen microorganisms break down indigestible cellulose and other materials and render them available as nutrients for absorption and assimilation. Without this vast population of beneficial microorganisms this won’t happen and so there will be a net loss of dietary foodstuffs, nutrients glucose and energy. Thus, maintaining an adequate bacterial reservoir of the correct mix of microorganisms is necessary in the ruminant’s gut in order to maximise dietary breakdown of the indigestible dietary foodstuffs.
It follows from this, that simply pouring more food into the rumen is a waste of time and money if the rumen microbiome does not have the requisite types and populations of microorganisms. Attention to the gut microbiome comes first.
Effects of Stress on the Microbiome
It is established also that disease and stress will adversely affect the balance and functioning of the rumen microbiome. Stress causes a change in the population of good bacteria (commensals) in the gut and allows an overgrowth of other undesirable organisms. Lactic acidosis from over feeding, indigestion, anorexia, inappetence, ruminal atony, and diarrhoea can all be consequences of sub optimal ruminal microbial functioning and of a disrupted microbiome. This bacterial malfunctioning of the gut is known as “dysbiosis”.
Supplying bacterial probiotic organisms such as B Subtilis and E Faecium will not only ensure an adequate population of beneficial digestive bacteria but will also crowd out pathogens, enhance the development and flourishing of other beneficial bacterial strains, maintain a correct ruminal ph. and increase the concentrations of acetic and propionic acid which then enter the Krebs cycle for glucose production and protein deposition. Thus, probiotics in short, lubricate the engine of the body.
The Gut: -Immunity Plus Digestion
Until very recent years the rumen and gastrointestinal tract through its total complement of microorganisms, was considered to be an organ solely equipped for the digestion and absorption of nutrients. However recent research has demonstrated that in addition to digestive function, the GIT harbours the largest population of immune cells in the body. The gut in fact is the largest immune organ in the body. Therefore, there is now a general consensus that a healthy gut lead to not only to gut health but also to immune health and a less frequent incidence of outbreaks of disease. Many of the commensals of the gut (good bacteria) and especially probiotics, produce short chain fatty acids (SCFA) in the gut and these substances act as chemical messengers to upregulate the immune system of the body.
The Importance of Yeast for Ruminants.
Saccharomyces cerevisiae (yeast)
Yeast is one of the most important constituents of any useful feed additive.Mechanisms have been proposed to explain why yeast products could stimulate dry matter intake and productivity in growing and lactating cattle. Yeasts are able to grow, at least for a short period of time, in the rumen thereby directly enhancing fibre digestion and/or producing nutrients that stimulate growth of other more beneficial rumen bacteria, which do the bulk of the fibre digestion.
Yeasts also utilize nutrients, such as lactic acid which, if allowed to accumulate in the rumen could suppress bacterial growth and/or suppress DM intake by driving rumen pH down. The main purpose of yeast supplementation is to prevent and treat rumen microbial dysbiosis. This dysbiosis can routinely occur in adult animals from stress or sub clinical disease. As such it has a negative impact on digestion and daily weight gain. Added Yeast improves the rumen ecosystem by two ways: by direct production of digestive enzymes and growth stimulation, and by promoting the growth and function of beneficial microbiota. Yeasts have potential to produce metabolites, which stimulate the growth, like rumen acetogens, and to release antimicrobial compounds which inhibit potential pathogens from establishing and causing further damage.
The rumen-specific live yeast Saccharomyces cerevisiae is well documented for its ability to support rumen maturation and function in young animals. Many trials confirm the benefits of its supplementation in feeds for cattle showing, improved growth rate, and gut health. Live yeast helps to regulate rumen pH by encouraging the growth of bacteria within the rumen that counteract lactic acid, thus helping to maintain a constant rumen pH of 6.2 or above – the optimum pH to ensure effective feed digestibility and maximum nutrient absorption. Live yeast plays an important role in assisting both rumen development and rumen efficiency in young stock, as well as easing the transition on to a finishing diet, ensuring that cattle maximise feed utilisation and achieve good weight gains. Beef cattle, especially those on a final finishing diet, are often fed high energy, high starch diets, which, when fermented in the rumen, create acid and result in a lower rumen ph. If left unchecked, this decrease in rumen pH can result in ruminal acidosis, with cattle suffering from scour and sub-optimal rumen performance, both of which negatively impact on daily liveweight gain.
Potentiation of Probiotic Bacteria and Yeast (Provita Pedigree.)
Bacterial Supplements
Enterococcus Faecium and Bacillus Subtilis are two key microorganisms which maintain gut health and ensure a fully functioning rumen and gut microbiome. By supplementing these organisms, the microbiome is augmented, digestion is enhanced, pathogens are excluded, an optimum rumen ph. is maintained, and toxins are neutralised. Of primary benefit is the positive role of these bacterial organisms in the breakdown and absorption of indigestible fibres, celluloses and hemi celluloses in the ruminant diet.
Yeast
When combined with the unique benefits of yeast as in Provita Pedigree, the rumen is fine tuned to maximise and extract key nutrients from the diet, and thus increase the efficiency of digestion by enhancing the production of usable end products from the diet. Using this palatable feed additive, an increase in average daily gain is seen together with improved feed conversion efficiency, as well as improvements in skin, coat, and conformation. It is of particular benefit when fed at times of stress.