Additives were first developed for monogastric species. Actually, the word developed is not correct — additives have always existed for all species, but it was the ban on antibiotics, or the need to reduce their usage, for monogastrics that gave additives such a boost scientifically and commercially. From there, it was only a small step in reasoning to look for applications of the same additives for ruminant species. They are all animals, after all, and they consume — more or less — the same or similar ingredients. This is partly true, and partly misleading; something that has led to many disappointments.
Dairy cows, the ideal candidates for additives
Dairy cows attract the most interest in terms of additives because they are everywhere in the world, they consume enormous amounts of feed and they are high-yielding but sensitive (fragile) animals that require intense attention to their nutrition and health. All of the above make dairy cows the ideal candidates for additives, again looking at them both from a scientific and commercial point of view.
There are six points that must be considered by additives suppliers who want to expand their portfolio to include products for dairy cows, using existing additives not developed initially for such animals:
1. Ruminants have a fermenting vat — the rumen — before their stomach. The bacteria and other microorganisms that live there consume forages (and other feeds) and produce valuable nutrients. For example, they can consume low-cost straw and urea (within limits) and convert them to valuable energy and protein. This is an overdramatization, of course, but it is a reality that we cannot escape easily.
2. Rumen microorganisms consume, destroy or convert almost everything the animal eats. At least this is their goal, whereas sometimes we want at least some of our feed to bypass them and reach the cow directly. Nature has made it a very difficult proposition as a healthy rumen is also an efficient rumen. So, no matter what lipids you feed a cow, she will convert them to saturated ones; in contrast, a pig or chicken will deposit the same type of fats as the ones found in its feed. There are positive and negative aspects in this equation, but it is something that must be acknowledged.
3. Protected nutrients that manage to bypass the rumen obstacle are often protected so well that the animal’s digestive system cannot unblock them — at least fast or efficiently enough to offer much benefit. Perhaps this is why trials with protected nutrients are often so confusing and inconclusive. The same holds true for protected additives. So, not all protected niacin, for example, is the same. The way of protection (the brand) is also important.
4. In reality, most additives for dairy cows target (or should target) the bacteria and other microorganisms living in the rumen. As mentioned before, a healthy microbiota in the rumen is the cornerstone for a healthy animal, efficiency in nutrition, productivity and overall profitability. Bugs in the rumen can be the enemy, consuming expensive materials, or an ally, converting inexpensive ones to valuable nutrients. Helping them appears like a very good idea, and this is an area where many additives focus their efforts.
5. In monogastric species, we want to either kill, suppress or control (modify) the enteric microbiota. Thus, we have developed many additives that do exactly that — with more or less efficiency. Only a minor part is trying to either enhance or support the existing microbiota. The opposite is true for ruminants: we want to keep rumen fermentation as efficient as possible. We need to provide a helping hand to existing microbiota to do their job even better. This is currently the main focus of modern additives, and again, some succeed better than others. Seen from another perspective, a ruminant nutritionist must first feed and take care of the bugs in the cow, before the cow.
6. Protected nutrients and additives still have a place — albeit a difficult one — but only after the rumen functionality and efficiency have been secured and maximized. It is true that modern genetics have outpaced (in terms of productivity) the capacity of the rumen to supply enough nutrients. Thus, a good part of bypassing nutrients — and additives that enhance the utilization of these nutrients — can be warranted. This is where nutritionists, having fed the bugs in the rumen and having extracted the maximum possible benefits from them, must next do the balance and see what else the cow needs to fulfill her genetic potential.
All in all, being a ruminant nutritionist is a dual job: you have to be a microbiologist and a nutritionist at the same time. When trying to get any additive working for dairy cows, we must first consider whether this additive is targeting the rumen microbiota or the cow’s digestive processes beyond the rumen.
Read more: How to formulate better ruminant diets