The crude protein content of your feed is critical for cattle development and growth. Amino acids from protein are required for tissue growth, healing, enzymatic activity, genetic function, energy, and critical cellular functions.
Your cattle receive their protein and all required amino acids from their feed which is why quality nutrition is the cornerstone of success for dairy cattle and beef farms.
What Is Crude Protein in Cattle Feed?
It’s important to emphasize that not all crude protein sources are equally digestible. Crude protein consists of both true protein and nonprotein nitrogen compounds, and true protein can be degradable or undegradable in the rumen. All crude protein groups have a purpose and play an essential role in animal nutrition.
Crude protein groups
- True Protein: Made of amino acids, unlike non-protein nitrogens (NPN), which lack an amino acid profile.
- Rumen degradable proteins (RDP): A type of true protein that breaks down in the rumen and becomes peptides, ammonia, and free amino acids. Microorganisms use these to grow and create microbial protein, the primary protein source for ruminants.
- Rumen undegradable protein (RUP): Also known as the bypass protein, the RUP is a type of true protein that passes through the rumen unchanged. Some are absorbed in the small intestine to meet amino acid needs, while the rest is excreted.
- Non-protein nitrogens (NPN): NPNs aren’t protein, but their nitrogen content helps rumen microbes produce microbial protein. For example, urea is an important NPN source of microbial protein, as noted by South Dakota University.
The table below shows the parental structure of crude protein groups.
| Crude Protein (CP) | ||
|---|---|---|
| Nonprotein Nitrogens (NPN) | True Protein (a.k.a. Natural Protein) | |
| Degradable Protein (RDP) | Undegradable Protein (RUP) | |
| Degradable Intake Protein | Undegradable Intake Protein | |
How to Calculate Crude Protein in Feed
To calculate crude protein, multiply the feed’s nitrogen content by 6.25. This is because proteins typically contain 16% nitrogen (1/.16 = 6.25). However the most accurate way to measure nitrogen is through lab analysis, which can also provide the exact crude protein content. Forage testing is critical for determining if your feed meets your cattle’s nutritional needs.
How Much Crude Protein Does Your Cattle Need?
Your cattle’s protein needs will depend on the type of animal (dairy or beef), breed, production stage, gestation, health, and farm goals. Pasture and forage conditions can also increase the need for supplemented protein as well. For example, if a pasture experiences heavy rainfall, nitrogen could leech from the soil, resulting in plants with reduced protein levels.
The lists below show the general crude protein requirements for different types of cattle and life stages.
Dairy cow crude protein requirements
- Pre-weaned calves: 18-24% in the calf starter feed, according to PennState University
- Weaned calves: 16% in the calf grower feed
- Lactating cows: 17-19% in early lactation, 15-17% in mid-lactation, and 13-15% in late lactation, as noted by McGill University
- Dry cows: 10-12%
Beef cow crude protein requirements
- Gestating cows: About 7.1% in the middle 1/3 of pregnancy and 7.9 in the last 1/3 of pregnancy, according to South Dakota University
- Lactating cows: 8.5-12.5%, depending on the cow weight, produced milk, and calf birth weight
Your herd’s specific needs determine the amount and type of crude protein required. Calculating the exact CP involves multiple factors. Here’s a quick example:
If your cow consumes 30 lbs of hay dry matter that contains 50% total digestible nutrients (TDN) and she requires 10% of the TDN to be rumen degradable protein (RDP), we can calculate the following:
- 50% of 30 lbs l= 15 lbs TDN
- 10% of 15 lbs = 1.5 lbs RDP per day
The feed will need a protein supplement if the hay doesn’t provide sufficient RDP.
This was just a simple example. Star Blends specialists can work with your nutritionists to determine your cattle’s specific needs.
Protein Sources for Cattle Feed
Your cows can obtain protein from forages, concentrates, and protein supplements. However, they can also obtain NPNs from sources like urea when appropriate.
Forage crude protein levels vary based on soil quality, plant maturity, and season. Here are some common forage types and their typical crude protein ranges:
- Alfalfa: 9-23%
- Corn silage: 7-9%
- Ryegrass: 8-16%
- Red clover: 12-16%
- Bermudagrass: 6-12%
- Legume hays: 15-20%
- Grass hays: 8-14%
Concentrates and protein supplements — such as corn, oats, seed meals, distillery byproducts, and urea — can provide the additional protein needed to make up for insufficient forage nutrients.
- Corn: 8-10%
- Wheat: 13-16%
- Oats: 11-13%
- Barley: 12-13%
- Rye: 12%
- Soybean meal: 47-55%
Why Quality Feed Matters For Your Cattle
Quality feed provides proper crude protein levels and other critical ingredients for your cattle’s development, productivity, and health. While vital, protein isn’t the only ingredient that can make or break the cattle feed. Even one micronutrient deficiency can negatively impact your productivity and set you back, especially if it leads to an illness in the herd.
Sourcing high-quality cattle feed ingredients and balancing them for your specific cattle needs is the most effective way to maximize your farm’s potential. Working with your nutritionist to choose the best feed for your production goals is the first step to ensure you are on the right path to meeting your goals. Star Blends can then produce customized feeds per your nutritionist’s recommendations, giving your animals precisely the nutrition they need. Contact us today to learn more about our custom feed options.
