What is the Best Protein for Calves? A Comprehensive Guide

January 12, 2026 •

3 min read

Newborn calves benefit most from milk proteins, but as they grow, they can also use plant-based options. Understanding the best protein for calves is key to ensuring their healthy development and maximizing growth.

Quick Summary

This guide covers essential protein sources for calves at different stages, highlighting the importance of milk-based proteins for newborns, the transition to plant-based sources like soybean meal, and how to select the best feed for calves.

Key Points

Milk proteins are crucial for newborns: Young calves require highly digestible milk-based proteins like whey and casein from high-quality milk replacers.
Weaned calves use plant proteins: A calf's developing rumen can effectively use plant-based proteins, including soybean meal and canola meal, after weaning.
Protein percentage changes with age: Newborns on milk replacer need 20-26% crude protein; weaned calves start on 18-20% crude protein starter, then lower it.
Digestibility is key: The quality of protein and its digestibility are critical for lean tissue growth.
Consider cost and palatability: Factors like cost and taste influence the success of a calf's feeding program.
Blends provide balanced nutrition: Mixing different protein sources, like soybean meal with canola meal, can create a complete amino acid profile.

Protein Needs of Calves

Protein is critical for muscle development, growth, and overall health in calves. The best protein source depends on the calf's age and rumen development. Newborn calves are essentially monogastric animals and need the easily digestible proteins in milk. As the rumen develops, calves can use complex proteins from plant sources.

Milk-Based Proteins: Essentials for Newborns

The best quality protein for newborns comes from milk or a high-quality milk replacer.

Whey Protein: This fast-digesting milk protein is easily absorbed. Calf milk replacers (CMRs) containing whey can effectively support calf growth. Quality whey-based formulas are highly digestible and can be as effective as casein-based options.
Casein Protein: Casein, the slow-digesting protein in milk, forms a clot in the abomasum. Studies suggest that optimal calf performance isn't solely dependent on this clotting action. Casein-based products like dried skim milk are excellent protein sources.

Plant-Based Proteins for Weaning Calves

As calves eat solid starter feeds, their rumen develops, allowing them to process plant-based proteins. Quality and palatability are key at this stage.

Soybean Meal: This is a widely used protein supplement for cattle because of its high protein content and strong amino acid profile. Calves consuming a high-protein meal (around 20%), with a good portion from soybean meal, grow faster.
Canola Meal: Canola meal is a good alternative or complement to soybean meal, providing a good balance of amino acids, especially methionine.
Distillers Grains: Dried distillers grains (DDGs), a co-product of ethanol production, offer protein, energy, and fiber. They are a cost-effective protein option, though their nutrient profile can vary.

Factors Influencing Protein Choice

When selecting protein, consider these factors:

Calf's Age: Newborns need milk-based proteins, while weaned calves benefit from plant-based options.
Digestibility: Highly digestible proteins ensure maximum nutrient absorption for faster growth.
Amino Acid Profile: A blend of sources, like soybean and canola meal, can ensure a more complete profile.
Cost and Availability: Local availability and cost-effectiveness are essential for an appropriate feed program.
Health Additives: Some feeds include additives like prebiotics to enhance gut health and nutrient absorption.

Comparison of Protein Sources


Protein Source	Typical Protein (%)	Digestibility for Calves	Cost-Effectiveness	Best For
Whey Protein	12-80% (varies by form)	High	Medium to High	Newborns/Pre-weaning (CMR)
Dried Skim Milk	30-36%	High	High	Newborns/Pre-weaning (CMR)
Soybean Meal	~48%	High (for weaned calves)	High	Weaning/Post-weaning
Canola Meal	35-38%	High (for weaned calves)	Medium	Weaning/Post-weaning
Distillers Grains	~27%	High (for weaned calves)	High	Weaning/Post-weaning

Formulating a Feeding Plan

For young, pre-weaning calves, a milk replacer containing 20-26% crude protein is recommended. As calves approach weaning, introduce a grain-based starter feed with 18-20% crude protein to stimulate rumen development. After weaning, protein can be reduced to 12-14% as the calves mature. A balanced diet should also include clean water and high-quality forage. Consulting a livestock nutritionist can help tailor a program to the farm's needs.

Conclusion

Choosing the best protein for calves depends on their age and digestive stage. Newborns require highly digestible milk proteins, such as whey and casein. As the rumen develops, calves can use cost-effective plant-based proteins such as soybean meal and canola meal. By understanding different protein sources and adjusting the diet according to age, farmers can ensure optimal growth and health. For more on feed management, consult resources from agricultural extensions, like the University of Florida's IFAS Extension on Growing Calf and Show Steer Feed Management.

Frequently Asked Questions

For newborns, the best protein is a highly digestible, milk-based protein like whey or casein, which comes from whole milk or a quality milk replacer.

Protein needs change with age. Newborns on milk replacer need 20-26% crude protein, while calves on starter feed should start with 18-20%, reducing to 12-14% as they mature.

Whey is a fast-digesting milk protein for quick absorption, while casein digests slowly. Both are effective, but recent research suggests that clotting isn't essential for optimal growth with high-quality whey formulas.

Calves can start consuming plant-based proteins, like soybean meal, once they begin eating solid starter feeds, usually around 4 to 6 weeks of age, as the rumen develops.

Yes, soybean meal is a very effective protein source for weaned calves due to its high protein content and good amino acid profile. Studies have shown it supports good growth rates.

Signs of protein deficiency include slow growth, weak muscles, and a poor coat. Monitoring weight gain and overall appearance can help assess protein intake.

Feed quality is vital. Factors like processing and ingredients affect digestibility and nutrient absorption. Low-quality whey can have reduced nutritional value.