Butter is a new superfood, which means butterfat contributes more to your milk check than usual. In September, milkfat price went ahead of milk protein price for the first time since we’ve been tracking components.
As of this spring, it’s been that way ever since. This interest in butter is about the only good news we have for milk prices in 2016.
From a feeding perspective, this historical change in pricing means we need to make different choices to capture as much as we can from the milk check. Many of the protein-enhancing additives we were previously feeding are about breakeven return, given the value of protein right now.
The goal now is to improve milkfat percentage and produce more pounds of fat. Six pounds of total milk components, or more, from each cow is still our goal, but there is currently more money to be made by striving to improve milkfat yield. Simply put, milkfat and protein yield are key drivers to profitability.
Keeping the rumen healthy
The key to milkfat production is twofold: balancing nutrients in the rumen to promote production of de novo fatty acids and supplying fats that lead to the formation of preformed or long-chain fatty acids.
De novo fatty acids are short, and middle-chain fatty acids are made from the result of what goes on in the rumen. A rumen environment that minimizes wide fluctuations in rumen pH through balanced carbohydrate nutrition favors the formation of acetate and butyrate.
Acetate and butyrate are precursors to de novo milkfat. This process is good for the cow.
Feeding and management practices have a big impact on creating the right rumen environment for milkfat production. With that in mind, here are five ways you might be limiting the yield of milkfat:
1. Not enough forage NDF, effective NDF and digestible NDF
Monitoring forage neutral detergent fiber (NDF) and total ration NDF intake is the first place to start. Adequate forage NDF intake relates directly to rumen pH, and rumen pH is linked to milkfat.
Particle size of the forage neutral detergent fiber is critical. If our particles are too fine, we can induce acidosis because the feed will move through the rumen too quickly. On the other hand, particle size that is too long will lead to sorting, which means the cow won’t be eating everything designed to be in her diet.
Digestibility of NDF is very relevant but is complicated to manage. Single time-point estimates of neutral detergent fiber digestibility (NDFd) are being replaced with a “kinetic” or “curve” estimate. From this, we can calculate the end point and rate of digestion.
In the end, more data is used to predict the contribution of NDF to end products for the cow and milkfat synthesis in general. Ensure cows consume enough digestible NDF to maintain chewing and rumination. Our goal is to create a healthy rumen environment through adequate amounts of digestible forage with the right particle size that will foster de novo production of milk fatty acids.
2. Less-than-desirable cow management
In general, higher stocking density lowers de novo fatty acid synthesis. Overcrowding cows beyond a stall density of 110 percent or less than 18 inches per cow of bunk space causes slug feeding, aggressive behavior, decreased rumination and an increased risk for depressed rumen pH for extended periods.
This is especially true of first-lactation cows. All these factors impact rumen function and, consequently, de novo synthesis of milkfat.
3. Too much unsaturated fat
You must have heard or read this by now: Unsaturated fat, namely oleic acid (C18:1) and linoleic acid (C18:2), can reduce milkfat if the rumen microbes can’t biohydrogenate these fatty acids in the rumen. The reason why is that they can lead to a low rumen pH as a result of too much starch, not enough fiber, slug feeding, poor chewing and so forth.
Many feedstuffs contain C18:1 and C18:2 fats. Corn silage, soybeans, dried distillers grains, bakery waste and chocolate byproducts are examples of high-C18:2 feedstuffs. These ingredients are often essential when optimizing diet cost, but the total intake and rumen bioactivity of C18:1 and C18:2 should be looked at closely.
4. Overfeeding total ration fat
Too much total ration fat, meaning greater than 6 percent, tends to shut down de novo synthesis at the mammary gland. What happens is that you basically end up trading short-chain for long-chain fatty acids with the new effect not improving the production of milkfat.
In addition, too much ration fat can reduce feed intake and potentially lower NDF digestibility.
5. Missing out on additives
There are a couple of feed additives proven to improve milkfat:
- Buffers
- Potassium carbonate
- Methionine hydroxyl analog
Troubleshooting milkfat problems, or looking for improvements, comes down to a balancing act between the nutrients in the diet and management of the herd. Warmer weather between now and the end of summer adds another element to balance.
Carbohydrates from starch, sugar and fiber, along with management from the stall to the bunk, must be aligned to promote a favorable rumen environment and de novo fatty acid synthesis. Specific fatty acids, namely linoleic acid (C18:2), can be potent inhibitors of milkfat synthesis if not monitored.
As you open new bunkers, bags and silos, make sure to test these new feedstuffs and adjust the nutrients in the entire ration that are associated with milkfat synthesis. Keeping the rumen healthy is the first step to a healthier milk check. PD
PHOTO: Dairy cows at the feed bunk. Photo by staff.
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Christopher Canale
- Technology Manager
- Cargill Animal Nutrition
- Email Christopher Canale
