22 November 2021 – Maintaining profitability in the face of depressed milk prices and the increasing cost of feed is one of the major challenges the modern dairy producer is facing.
In order to ensure that farms run at their most cost effective, each step of the milk production process needs to function at its most optimal to keep inefficiencies and wastage as low as possible.
Central to this system is the cow herself and, more accurately, her ability to effectively and efficiently convert feed into milk. And with local forages becoming more and more common due to sustainability ambitions, the efficiency of this milk-making process can be made more complex by these ingredients which can have varying fiber and digestibility profiles.
For Phileo by Lesaffre this can be overcome by creating the optimal rumen environment. In this Industry Perspective the company’s Head of North American Dairy Programs, Stephen Emanuele, and its Global Ruminant Manager, Valentin Nenov talks us through how the company’s yeast probiotic, Actisaf can help dairy farmers boost rumen performance to unlock efficiencies in fiber digestion, milk production, profitability, and sustainability initiatives.
[Feedinfo] You argue that rumen potential is key to profitability of a dairy farm. What are the characteristics of a good rumen environment, and why is this better for performance?
[Stephen Emanuele] Profitability of a dairy business is impacted by the amount and value of milk sold and feed efficiency as measured as energy-corrected-milk (kg)/ dry matter intake (kg). Optimizing the rumen environment, maximizes the digestion of fibre, starch, and protein. This will lead to greater microbial protein production and increased (volatile fatty acids) VFA production. The result will be efficient production of milk components and optimal milk yield influenced by lactose synthesis from glucose. When you increase the value and volume of milk produced and at the same time increase feed efficiency, dairy profitability will be increased. You cannot have efficient milk production without a good rumen environment. It will be the dairy operations that produce milk with the highest value and most efficiently that will be the most profitable.
[Feedinfo] What are the difficulties in measuring rumen function? How can tools such as milk fatty acid analysis and lactose synthesis help address this need?
[Stephen Emanuele] You cannot directly measure rumen function on a commercial dairy operation. You need to identify biomarkers that can be related to rumen function that can be measured easily on the farm. Lactose synthesis is directly related to the amount of glucose that reaches the mammary gland. Lactose synthesis measured as grams per day is correlated with milk yield. The relationship between lactose synthesis and milk yield is linear and the R2 =0.99. If you want your cows to yield 90 pounds (41kg), the cow must synthesize 2,000 grams of lactose per day. Milk fatty acid composition of milk has been linked to rumen function. The De Novo milk fatty acids, those milk fatty acids synthesized by the cow, are influenced by rumen function. Poor rumen function reduces fibre digestion, and this reduces the amount of acetate and butyrate that is produced. Acetate and butyrate are used to synthesize the De Novo milk fatty acids. When De Novo milk fatty acid synthesis is low, then milk fat percent will be low. The biomarkers identified in milk that can be easily measured that are corelated with rumen function are lactose synthesis, De Novo milk fatty acid synthesis, C16:0 milk fatty acid synthesis and double bonds per fatty acid, which is a measure of unsaturation in the milk.
[Feedinfo] Can these measurements help make decisions on-farm? How common is the use of such analyses?
[Stephen Emanuele] Yes, measuring lactose synthesis and milk fatty acid analysis can be used to help diagnose nutrition, cow comfort, management, and environmental bottlenecks on a dairy operation. These measurements can be used to fine-tune a dairy ration and help reduce ration cost. These measurements can be used to quantify the animal response to feed additives and can be used to determine which feed additives should be fed on the farm. The use of milk fatty acid analysis and the measurement of lactose synthesis on commercial dairy operations is being used by milk processors and milk cooperatives in the eastern US., eastern Canada and in the Midwest US. As more nutritional consultants understand the value of milk fatty acid testing, the use of this technology will spread farther west in the USA and Canada.
[Feedinfo] What effect does Actisaf have on the rumen environment, in terms of VFA production and fiber degradation (as well as any other effects that are relevant to this application)?
[Stephen Emanuele] Actisaf helps to create a rumen environment that increases fibre digestion and total VFA production. When Actisaf is fed at 5 grams per cow/day, acetate, propionate, and butyrate production is increased. The greatest impact is on increasing rumen pH and an increase in propionate production. Sixty percent of the glucose synthesized by the cow is made from propionate. When you increase the supply of propionate, you increase the amount of glucose synthesized by the liver. This results in more lactose synthesis by the mammary gland because lactose can only be synthesized from glucose. The amount of glucose that reaches the mammary gland influences lactose, milk fat and milk protein synthesis.
When Actisaf is fed in the dairy diet, we observe small increases in the De Novo and mixed fatty acid content of milk. We also observe an increase in milk volume from the increase in propionate production. By measuring milk fatty acid composition and lactose synthesis, we can indirectly measure the impact of Actisaf on rumen function.
[Feedinfo] Actisaf has long been used in dairy nutrition, if I’m not mistaken. In what ways does this represent an expansion of our understanding of the mode of action, or even a new application for the product?
[Valentin Nenov] Yes, you are right, Actisaf has been on the market for a long time with numerous published research papers and a long track record of success. The effect of Actisaf on acidosis prevention, fiber degradation and the increase in milk yield and quality is not new. All this is related to the mode of action of the yeast probiotic as optimizer of the rumen environment.
What is new is our deeper understanding of the effect of Actisaf on rumen efficiency to digest different types of forages in different farming conditions. In the context of sustainability, we need to improve feed efficiency of dairy cows and especially the digestibility of different local and more available forages. Compared to other farm animals, dairy cows receive a more diverse diet which can vary a lot according to forage availability, by-products used, and even climate conditions.
So, I wouldn’t say that we are necessarily looking into a new application of the product but rather a fuller understanding of its mode of action in the rumen and on gut microbiome, which will allow for more precise feeding of the yeast probiotic in different diets and conditions to improve feed efficiency. Currently we are mapping the rumen degradation of different, commonly used local forages from around the world and in what conditions Actisaf can improve it.
[Feedinfo] Why is improved fiber degradation important for improving the sustainability of farming?
[Valentin Nenov] Ruminants are unique with their digestive system allowing them to digest fibrous plant material that other animals cannot digest. Thanks to the highly dense and diverse microbiota in the rumen dairy cows can produce high quality animal protein from digesting plant fibers. As mentioned, in the context of sustainability, we are looking at feeding dairy cows with more widely available and cheaper local forages that often come with higher fiber content which limits their digestibility. Even if we look at good quality, highly digestible forages, improving fiber degradation ability of the rumen helps deliver more VFA for De Novo fatty acids synthesis and lactose production in the mammary gland, as mentioned by Dr Emanuel, which is positively related to better milk quality and more milk fat and protein. Improving fiber digestibility for ruminants is corelated with better feed efficiency which is also associated with less methane production.
So, improving rumen fiber degradability allows cows to utilize local lower quality forages to produce high quality animal protein with lower environmental impact. And considering an increasing human population and the limited availability of arable lands, ruminants may need to be fed with more fibrous forages, making rumen efficiency and fiber degradation critical to maintain good milk production.
[Feedinfo] What does the improved degradation of fiber mean for markets where forages might be of low quality and/or where feed materials are scarce or expensive?
[Valentin Nenov] Many areas in Asia and Africa, which we consider as new dairy producers, have less access to higher quality corn and alfalfa compared to North America or Europe. They are pushed to use available local forages like grass hays, mombasa grass, Bermuda grass, rice straw and so on. These local forages often have a higher fiber content (neutral detergent fiber (NDF) and acid detergent fiber (ADF)) which limits their digestibility.
Currently, at Phileo’s rumen research center, “The Farm Philo”, we are assessing the rumen degradability of those local forages in comparison to standard European forages, such as corn silage and alfalfa hay. We are also assessing the effect of yeast probiotics on the rumen microbiota and on rumen degradability of those forages. Using modern and innovative ex vivo techniques we are able to compare the real rumen degradability of various forages and the effect of different probiotics to improve it.
We found a very clear and expected correlation between NDF content in the forages and dry matter degradability in the rumen. What was more interesting is that the effect of Actisaf to improve DM degradability increases with the NDF content of the forage. In forages with lower NDF content, such as corn silage and alfalfa hay for example, Actisaf improved the DM rumen degradability by 3-4%, whereas in forages like mombasa grass and rice straw with NDF content above 60-70% rumen degradability was improved by over 6-7%. This effect of Actisaf to improve rumen degradability of forages with higher fiber content comes down to its ability to reduce rumen redox potential and create a more favourable environment for fiber degrading bacteria, which we have been able to confirm with in various previous studies.
Published in association with Phileo by Lesaffre