Ruminants have the unique ability to degrade and ferment fiber through microbial activity. Forage is a major fiber source and can be either grown on farm or available locally at a more competitive price than concentrates. Optimizing the ration to maximize fiber digestibility helps cattle extract more energy from forage and improves feed efficiency, income-over-feed costs and, finally, farm profitability. Profitability is one of the three pillars of sustainability, which is a growing concern for both consumers and producers.

A better understanding of how fiber is degraded in the rumen helps identify the changes that can help reach this goal and make sure fiber is no longer an untapped energy source.

FEED EFFICIENCY: THE KEYSTONE OF FARM  PROFITABILITY 

Feed efficiency measures the animal’s abilty to turn feed material into food product. Improving feed effiiciency is a way to optimize the quantity of food produced per kg of feed given to the animal (whether measured in milk or meat).

Ruminants have the unique ability to release the energy from part of the fiber structure thanks to the fermentative activity of the rumen. Nutritionists can take advantage of this unique and specific function that originates in the rumen. The ruminant digestive system has the ability to degrade and ferment fiber through microbial activity. The fiber components, and the subsequent production of volatile fatty acids (VFAs), provide the majority of the energy for the ruminant. A better understanding of how fiber is degraded in the rumen helps identify the levers that can help improve feed efficiency.

In addition, improving ruminant feed efficiency also means optimizing the quantity of food produced per hectare of arable land and offers a way to more sustainably meet the demands of an increasing world population. Improving the digestibility of locally available raw materials is a key driver of income-over-reed costs for the farm manager.

FEED EFFICIENCY STARTS AT THE FIBER SOURCE 

From a fiber perspective, feed efficiency starts with forage management, from the field to the bunker. Optimal forage and fiber development starts with harvesting at the correct maturity and dry matter (DM) levels and is maintained with good storage management practices.

Producers can ensure optimal silage quality and digestibility by using a scientifically proven forage inoculant, such as MAGNIVA Forage Inoculants from Lallemand Animal Nutrition. Such forage inoculants preserve the forage’s nutritional potential, reduce DM losses and spoilage by limiting the growth of undesirable microorganisms. Taken together, this contributes to maximizing the energy available per kilogram of harvested forage (figure 1).

SILAGE FERMENTATIONS OVER TIME HOW  TO IMPROVE FIBER DIGESTIBILITY AND FEED EFFICIENCU THROUGH DIET FORMULATION? 

Ruminant nutrition ration formulation is a compromise between raw materials, forage prices and nutrient availability of each of the feed components.

As energy is coming mainly from fiber degradation, one of the solutions is to optimize the rumen function, which leads to optimal digestion of fiber from all types of ruminant diets. This can be supported by the use of scientifically documented rumen modifiers such as the specific live yeast Saccharomyces cerevisiae CNCM I-1077 (LEVUCELL SC from Lallemand Animal Nutrition).

The live yeast S. cerevisiae CNCM I-1077 acts as a real optimizer of the rumen engine. It helps boost the efficiency at which feed is transformed into energy, principally through improved degradation of fibrous material. This feed additive has a beneficial effect on microbial fiber degradation by stimulating the growth and fibrolytic activity of fiber degrading bacteria and fungi populations (figure 2). Moreover, the live yeast promotes an optimal rumen environment, with a beneficial action on rumen pH. These effects and mechanisms of action are demonstrated through more than 100 scientific publications over the 30-plus years since this strain was discovered in partnership with the INRAE in France.

As a result, the live yeast is able to improve feed efficiency by 3 to 7% under standard or stress production conditions (figure 3). This represents a valuable tool that allows for the forage portion of the diet to be maximized and gives producers and nutritionists the possibility to increase milk or meat revenue per kilogram of feed — or allows them to optimize feed cost while maintaining similar revenue. Most importantly, this improved feed efficiency does not negatively impact animal welfare and many studies have shown benefits beyond farm economics on animal welfare through improved feeding behavior, reduced Sub Acute Ruminal Acidosis (SARA) risks, etc. 

It gives producers and nutritionists the opportunity to switch from one ration to another depending on their specific situation — without compromising on feed efficiency, which supports greater flexibility and resilience.

HOW CAN NUTRITIONISTS MEASURE THE BENEFITS OF ADDING FEED ADDITIVE TO THE DIET?

Using a “precision-nutrition” tool can help nutritionists when formulating with live yeast. Lallemand Animal Nutrition has developed the “Levucell SC-submodel” with forage NDFd equations. Scientists conducted in vivo fiber digestibility assessment for a multitude of forages and feed ingredients, with and without the live yeast. These data allowed to model the live yeast’s effect in terms of increased energy value depending on the feed: +3% up to 8% depending on the ingredients and the forage characteristics (e.g., improvement obtained is higher for forages with lower intrinsic fiber degradability, Guedes, 2008) (Chaucheyras-Durand et al, 2010, Ding et al, 2014).

Thanks to this sub-model, the nutritionist can predict or model the effect that adding the feed additive to a ration will have on raw material digestibility, feed efficiency and income-over-feed cost. It contributes to precision feeding by providing different nutritional scenarios to answer farm managers’ needs (e.g., iso-cost for higher milk revenue or least cost formulations).

CONCLUSION

Improving feed efficiency while safeguarding animal welfare has always been an important objective for nutritionists. In the current context of raw material pricing, this goal continues to be a major priority.

Improving fiber degradation is one of the keys, which helps improve the environmental and economic sustainability of animal production. Getting every last nutrient out of the ration helps lessen its footprint in terms of land-use and greenhouse gas production and also helps protect the narrow margins of farm managers.