Beat Lower Milk Prices By Boosting Protein Content

By Ron Johnson, Dairy Editor
Thursday, January 31, 2008 11:49 AM CST

Milk prices are probably going to be lower this year. But there are ways to raise the price you get for your farm’s milk.

One way is to increase the milk’s protein content. University of Illinois-Extension Dairy Specialist Mike Hutjens talked about “Building on Milk Protein” during the recent Illinois Dairy Days.

“As milk prices decline from record high prices in the summer of 2007 and the potential loss of income from discontinued use of rBST, dairy managers will look for other sources to maintain income and profitability,” Hutjens said.

Since the protein in milk is worth more than twice as much as the fat in milk, raising the protein content can keep income up. Another way to maintain income is to lower the ration’s protein costs while keeping milk production at the same level.

Hutjens began by explaining the relationship between fat test and protein test.

“Understanding the relationship between milk fat test and true milk protein test can uncover milk component opportunities,” he said. “If your true milk protein test to milk fat test is below 0.75, look for reasons this ratio is too wide.”

Hutjens noted that for five common dairy breeds, the protein test of their milk is normally 75 percent or more of the fat test. Here’s an example:

A Holstein dairy cow has a normal milk fat test of 3.66 percent. Meanwhile, her normal milk protein test is 2.99 percent. That makes for a ratio between the two of 0.82, meaning her protein test is 82 percent of her fat test. And this 82 percent is, of course, higher that the 75 percent threshold.

A Jersey, meanwhile, has a normal milk fat test of 4.57 percent and a protein test of 3.54. That makes her normal fat: protein ratio 77 percent.

For a Guernsey the normal milk fat test is 4.42 percent and the normal protein test is 3.3 percent. Here the normal fat: protein ratio is 75 percent.

A Brown Swiss has a normal milk fat test at 3.95 percent, while her protein test is 3.25 percent. Those numbers mean her normal fat: protein ratio should be 82 percent.

And for an Ayrshire, the normal milk fat test stands at 3.86 percent while the protein test is 3.13 percent. These numbers work out to a normal fat: protein ratio of 81 percent.

If a farm’s milk fat: protein ratio is too “wide” n or below 75 percent n use records to try to figure out why, Hutjens suggested. Look at groups of cows, lactation numbers, days in milk and milk yield.

The idea is to get cows to use the protein in their feed more efficiently. “By improving nitrogen capture from feed to milk and tissue, protein efficiency can be increase to over 30 percent of the dietary protein consumed,” Hutjens said.

The amount of protein in milk, along with milk production itself, can fall if a cow’s rumen does not have enough ammonia in it, he explained. If there’s not enough ammonia in the rumen, microbes in the rumen do not produce enough amino acids. That leads to the loss of milk production and a lower protein test.

Hutjens recommended doing these five things if milk protein levels are low:

* Look at the ration summary to see what the percentage of crude protein is. It should be 16.5 to 17 percent. Rumen degradable protein (RDP) should be 65 percent of the crude protein. And rumen undegradable protein (RUP) should be 35 percent of the total crude protein. Last, soluble protein should equal 33 percent of the total crude protein. If any of those numbers are too low, milk protein can suffer.

- Check the amount of starch in the ration. This should be 22 to 26 percent of the ration dry matter.

- See what the level of sugar in the ration is. This should be 4 to 6 percent of the total dry matter.

- Compare the true milk protein test to the milk fat test. Evaluate ratios below 75 percent.

- Look at the cows’ manure. If it’s stiff or firm, that could be a sign of a nitrogen shortage in the ration.

Amino acids

It can also help to correct the ration’s amino acids balance. Doing this can result in two to five pounds more milk per cow, Hutjens said.

It can also boost the milk protein percentage by 0.1 to 0.2 percent. And balancing for amino acids can raise the milk fat level by 0.1 to 0.3 percent.

Attaining the correct balance of amino acids can improve feed efficiency, too, Hutjens pointed out. It’s not uncommon to see feed efficiency improve by 0.08 percent. That can translate into additional profits of 15 to 20 cents per cow per day.

That’s an extra $45.75 to $61 of profit per cow over a 305-day lactation. For a 50 cow-herd, it adds up to $2,287 to $3,050 a year.

Getting the ration’s amino balance right can manifest itself in other positive ways, though they can be harder to measure. Hutjens mentioned fewer metabolic disorders like fatty liver syndrome, along with an increase in fertility because of lower blood urea nitrogen (BUN).

Protein sources

Yes, protein prices have risen, thanks mainly to increases in the cost of corn and soybeans, Hutjens said. But he observed that some protein ingredients are still economical.

A recent analysis that valued corn at $3.50 a bushel and 44 percent soybean meal at $300 a ton, showed that blood meal is economical if it’s priced under $885 per ton. For brewers’ grains containing 30 percent dry matter, the break-even price is $77 a ton. For canola meal at 36 percent crude protein it’s $220 a ton.

Corn distillers’ grain is a good buy at $289 a ton or less, while corn gluten feed is affordable at $144 a ton or less. Fuzzy cottonseed has a break-even price of $249 a ton or lower, while cottonseed meal containing 41 crude protein has a break-even value of $343 a ton.

For fish meal, the break-even price is $800 a ton, and for linseed meal it’s $251 a ton. Some dairy farmers have access to pork meat-and-bone-meal, Hutjens noted. That meal is worth up to $774 a ton.

Meanwhile, raw soybeans are worth $231 per ton, but if they’re roasted and contain 55 percent rumen undegradable protein their value rises to $467 a ton. Sunflower meal, at 35 percent protein, is worth a maximum of $210 a ton, where corn costs $3.50 a bushel soybean meal costs $300 a ton.

Milk urea nitrogen

Hutjens went on to talk about milk urea nitrogen, or MUN. Looking at the amount of urea nitrogen in a cow’s milk can provide an accurate reflection of how much nitrogen that cow is absorbing but not using for growth or to make milk.

Most of this nitrogen comes from feed. When a cow eats too much protein, she excretes the excess nitrogen in her milk and urine.

Scientists have discovered a direct relationship between MUN and the amount of nitrogen a cow excretes. This MUN test can show when a cow is wasting protein and excreting excessive nitrogen. It can also tell whether or not she is not consuming enough nitrogen, and therefore not enough protein.

“Herds will have different optimal MUN levels, depending on feeding and milking relationships, feeding systems and cow eating patterns and frequencies,” Hutjens explained.

Testing individual cows and whole herds can establish a baseline MUN level. From there, increases or reductions in MUN can be tracked and analyzed.

“Normal” levels of urea nitrogen in milk range from seven to 16, Hutjens noted. Hutjens advised looking for answers if MUN drops or rises more than two or three points below the baseline.

He also recommended calculating bulk tank MUN averages each week. Doing so will get rid of any day-to-day variation.

Don’t be alarmed if you get conflicting reports on your herd’s MUN numbers.

“DHI and milk plant MUN values will vary due to machine standards and sampling differences. DHI processing centers may provide MUN group averages by lactation number, days in milk, and milk production,” he said. “Pennsylvania workers recommend a minimum of eight to 10 cows per group to calculate an ‘unbiased’ or ‘true’ group MUN value.”

Underfeeding and overfeeding protein are not the only things that can affect the MUN number.

Hutjens said, “Heat stress can contribute to an increase in MUN values by two to three units, due to rumen and blood flow changes. That means MUN can be used to monitor the impact of heat abatement improvements.”

A MUN evaluation can also reveal whether a cow is suffering from subacute rumen acidosis (SARA). When a cow has subacute rumen acidosis, there’s less microbial growth in her rumen. Less microbial growth means excess ammonia is not being captured, but is instead being excreted in the cow’s milk and urine.

A MUN test can also reveal cows that are using more energy than they are consuming early in their lactations. This “negative energy balance” results in cows using amino acids from their body tissue as a source of energy.

Feed and MUN

If a herd’s MUN content falls, it might be due to the corn silage. Processed corn silage, with no whole kernels or partial kernels, can make the starch in the silage more available in the rumen, Hutjens explained. That can lower MUN.

On the other hand, “New-crop corn silage will have lower levels of fermentable carbohydrates (meaning less starch is available), raising MUN,” he continued. “Michigan workers recommend three months of storage (for corn silage) before feeding, to optimize starch availability in the rumen.”

MUN can also rise if cows eat lush pastures. And, it can climb if they eat legume-grass silage that’s wet or high in crude protein.

“Grinding or processing grain finer increases the rate of fermentation in the rumen and increases ammonia capture by rumen microbes, lowering MUN,” Hutjens added. “Shifting to less-degraded protein sources, such as heat-treated soybeans instead of raw soybeans, can lower MUN values.”

Comments »

Comment on this story

Comments will be approved within 48 hours

Name:

Email: (optional)

Comments:

Image Verification: (Case sensitive)