Time to Think Beyond Protein to Amino Acid Balancing

Time to Think Beyond Protein to Amino Acid Balancing

Today, most milk replacers for calves are formulated and scrutinized based only on crude protein (CP) content, a number that doesn’t give us any real measure of the true building blocks the calves need: the amino acids.

Provimi research has shown that by balancing for amino acid requirements we can allow for more ADG at a lower concentration of CP in the milk replacer. he first trials that Provimi published were in conventional 20 and 22% CP milk replacer feeding programs.  In those studies, calf weight gain supported by a 22% CP milk replacer without added amino acids was achieved in calves fed a 20% CP milk replacer with added amino acids.  These studies illustrated that supplemental amino acids increased ADG by approximately 10% in conventional feeding programs (20% CP, 20% fat milk replacer fed at 1 pound of powder daily).  Similar results were observed with higher planes of nutrition when calves fed a 24% CP milk replacer with supplemental amino acids at 1.5 pounds of powder grew at similar rates to calves fed a 28% CP milk replacer without supplemental amino acids.  In this trial, supplemental amino acids increased ADG by over 15%.

Provimi amino acid concentration recommendations have also been validated in expert-reviewed research from other laboratories.  A study from China confirmed that the relative proportions of lysine, methionine, and threonine outlined in our published research was appropriate for calves fed milk replacers where 50% of the protein was supplied by soy protein concentrate.  Additionally, New Zealand researchers found calves fed whole milk (4.4% fat, 3.5% protein) supplemented with our recommended levels of amino acids reached 200 pounds of body weight days sooner than calves fed milk without supplemental amino acids.  This experiment also followed heifers through their first lactation and observed that heifers supplemented with amino acids in whole milk produced 1,275 pounds more fat-corrected milk than heifers not supplemented with amino acids.

“Almost twenty years ago Provimi began calf research to understand how amino acid formulation fits into dairy calf nutrition,” says Tana Dennis, PhD, calf & heifer specialist with Provimi. “We have been formulating our milk replacers based on the trials we conducted in calves fed milk replacer and starter from approximately 2 days of age through weaning at 4 to 6 weeks of age.  

Good for the Cow, Better for the Calf

 “The newborn calf is the most efficient animal on the farm with respect to utilizing protein, but the right building blocks need to be provided,” states Dennis, PhD. “If we are just providing a high protein diet, and not ensuring the amino acids are balanced, we risk much of the protein being wasted.” 

Many dairy farmers understand the pitfalls of overfeeding protein to their cows, and the production loss that can occur when the lactating cow has to divert energy from milk production to excrete excess nitrogen. What they might not know is that it’s much more taxing on a young calf’s system to excrete the excess nitrogen than it is on the cows, because they do not have a fully developed rumen to help recycle it.

“Most calf raisers care about doing what’s best for their calves so they tend to feed them more milk replacer than is necessary, without realizing that there is a potential downside to overfeeding protein,” explains Dennis. “The best thing they can really do is provide their young calves the precise nutrition they need, and that means ensuring they receive the right sequence of amino acids, something they might not be getting today.”

Know Your Milk Replacer

While there are a lot of milk replacers on the market that don’t balance for amino acids, there are some that do, so the next time you purchase your milk replacer be sure to ask questions that go beyond the CP level.

Article was published in Progressive Dairyman, August 2017.

Tags: Calf Nutrition