ISSUE FOCUS 44 FEED & ADDITIVE MAGAZINE July 2024 meet their climate targets too if we are to thrive as a cutting-edge animal nutrition business worldwide. The Volac Feed Additive business uses strategic customer partnering to provide sustainable solutions to enhance livestock production and efficiency – that also offer tangible carbon reduction benefits. One such sustainable feed additive solution represents a new way to mitigate the risk of acidosis in dairy cattle. Ruminal acidosis is typically associated with intakes of large amounts of highly fermentable, carbohydrate-rich feeds. For many years it has been considered a problem of lowered rumen pH, but a better understanding of rumen microbiology is informing new scientific thinking on its management. Dairy cows with mild clinical acidosis will be off their feed and may scour. More severe clinical signs of acidosis include decreased milk production and poor body condition score, despite adequate nutrition. Severely affected herds may experience high rates of culling or unexplained deaths. The understanding of acidosis has focused on rumen pH – with an acidotic rumen being defined as being lower than pH 5.8 for a significant amount of time during the day. Nutritionists have tried to mitigate this accumulation of acid in the rumen by feeding buffers in the cow’s diet – but this is essentially ‘putting the fire out after it has started’. Other feed additives, including yeasts, have also been used. RUMEN FERMENTATION KINETICS Nutritionists are now thinking differently – and finding novel ways to mitigate acidosis – based on new, in depth understanding of rumen fermentation kinetics. A low rumen pH is simply the product of an acidotic rumen environment. But the biological and chemical steps before the pH drop include alterations in microbial populations and the partitioning of hydrogen resulting from the breakdown of carbohydrate. The cow must get rid of this hydrogen gas. And the rumen microflora deals with it by transforming it into something else. Hydrogen accumulating in the rumen goes into ‘pools’. Biologically safe hydrogen pools include starch engulfed by rumen protozoa, bacterial glycogen formation, growth of bacteria, weak organic acids (VFAs) and methane. An unsafe pool for hydrogen in the rumen is lactic acid, which can cause acidosis. Consequently, if we focus on altering the rumen microbiome somehow, we can find productive ways of diverting rumen fermentation away from unwanted lactic acid production towards the safer hydrogen pools – and, importantly, those that don’t include methane, which represents lost energy efficiency in the diet and is not ideal environmentally. This is where novel phytogenic feed additives with antimicrobial activity, such as Volac’s new RumiBio come in. Dietary inclusion of this novel phytogenic additive can help increase desirable propionic acid production rather than lactic acid – and help change the way fermentation happens in the rumen to produce a better cow performance outcome. MITIGATING THE IMPACT OF ENDOTOXINS Mitigating the health and performance sapping impact of feed endotoxin contamination is another example where novel feed additive solutions can support improved dairy production efficiency. Endotoxins are produced by bacteria and can be found everywhere in the dairy farming environment. They are present in the food cattle eat, their normal rumen flora, the water they drink and on the surfaces they lick. In fact, wherever you find bacteria, you will likely find endotoxins. Endotoxins are incredibly diverse and form an integral part of the outer membrane of gram-negative bac-
RkJQdWJsaXNoZXIy MTUxNjkxNQ==