A Nutritional Update for Strauss Milk Replacers

The recent publication of new national dairy calf nutrition standards has prompted us at Strauss Feeds to do some updating of our own.

In 2021, the National Academies of Science, Engineering and Medicine (NASEM) published the eighth edition of Nutrient Requirements for Dairy Cattle. These new guidelines replaced the previous set of nutrition standards issued by the National Research Council in 2001.

The new NASEM guidelines were developed by a team of dairy and animal science researchers from across the country who performed an exhaustive search of data from studies conducted over the past 20 years. A specialized subcommittee of calf experts developed specific guidelines for preweaned dairy calves.

Many of the recommendations in the previous NRC 2001 guidelines for calves were extrapolated from data on older, ruminating heifers. In other words, they used heifer data, and scaled it down for smaller animals. The NASEM committee recognized that young, pre-ruminating dairy calves have very different digestive systems and nutritional needs, and built their guidelines accordingly.

At Strauss Feeds, we have confidence in the NASEM guidelines, and have reconfigured the contents of our standard vitamin and trace mineral (VTM) premix formulation accordingly. The changes include:

• Adjusting mineral levels to match the NASEM guidelines. Compared to our previous VTM premix, this has resulted in a slight increase in magnesium, iodine, manganese, and zinc, while slightly lowering calcium, phosphorus, and iron. Selenium remains at its previous level.

• Dropping copper levels by half, from 10 parts per million (ppm) to 5 ppm. This change is based on recent, research-based evidence that pre-ruminating calves absorb 5 times more copper from their diets than ruminating calves do. Lowering the levels thus helps avoid copper build-up in the liver and potential copper toxicity in calves.

• Leaving B-complex vitamins “as is.” The NASEM calf committee concluded no adjustments in B-complex vitamins were tested in calves to indicate any changes would be more beneficial compared to the NRC 2001 standards.

Each of these vitamins and trace minerals are important for calf nutrition in their own right, and  often have an interaction with each other. For example, zinc is important for supporting immunity, yet too much zinc can interfere with the absorption of iron and copper. So, it’s a delicate balance to ensure that we include enough – but not too much – of each ingredient.

“Strauss Feeds is one of the few, if not the only, U.S. milk replacer manufacturers that can assay trace minerals in-house. ”

Another important change we have made is switching from inorganic to organic micro mineral sources. Inorganic minerals, often formulated with sulfates, are stored by the animal – usually in the liver – if they are not needed. Over time, this can lead to a build-up of stored minerals that may impair liver function and sometimes reach toxic levels.

There is a growing body of knowledge about the importance of liver function throughout the lifetime of a dairy cow, especially in the transition from calving into lactation. We now understand the critical importance of protecting the liver and keeping it “clean.”

Our new, organic minerals are formulated with chelated minerals instead of proteinates or inorganic sources. Based on a number of scientific papers in recent years, chelates are much more researched than proteinates, and are more bio-available to the animal. All of the copper, iron, zinc and manganese in our milk replacer is coming from chelated sources, and 100% of our selenium is in the form of selenomethionine, an organic selenium source. These minerals have been proven to be more easily absorbed in the small intestine, and utilized more efficiently in calves’ systemic pathways. And, if they are not needed, the calf simply excretes them, so they do not build up in the liver.

We also take great care at Strauss Feeds to ensure that every batch and bag of our milk replacer contains the same levels of our meticulously crafted VTM package. Building this formulation “on paper,” is one thing, but getting it to every calf is quite another.

Our own in-house team of laboratory specialists performs assays on the trace minerals for each batch of VTM premix for consistency before it is added to the milk replacer. Strauss Feeds is one of the few, if not the only, U.S. milk replacer manufacturers that can assay trace minerals in-house. Then, our manufacturing processes are continuously monitored and routinely audited to ensure the ingredients are evenly distributed.

You can have confidence that your calves are receiving optimal nutrition with Strauss milk replacer, based on both the best science and hands-on implementation.

Recent Posts