As the primary feeder on my family’s dairy, I have the privilege of working with our nutritionist to design and deliver accurate and healthy diets for the cows. It’s one of my favorite tasks on the farm because I enjoy the challenge and recognize the importance of accuracy.
On our dairy, the smallest ration mixed is typically for the close-up cows, and we take special care to make it as accurate as possible. Of course, the days leading up to calving can be the most nutritionally tricky for cattle as they prepare for the huge influx of energy demand while also consuming less than normal amounts of feed.
In a recent Miner Institute Farm Report, Taylor Turney, a graduate research assistant, reminded farmers of the importance of consistency in the close-up rations.
“The inconsistency of a diet becomes part of a bigger issue when there’s potential for over or underfeeding nutrients, the cost of wasting limited ingredients like forages, and the impact it may have on production,” she detailed.
Turney referenced a recent study conducted in Ontario that compared the diet fed to the diet formulated on 40 freestall dairies. The study that was published in the Journal of Dairy Science, sampled close-up diets once per month for six months, took blood samples on fresh cows and monitored production through peak lactation.
Across the board, corn silage was the primary forage source with 67.6% of farms relying on it. Straw was also common in the rations, making up as a primary or secondary source of forage on 80% of farms. Soybean meal was the most prominent concentrate used on farms.
When comparing formulated rations to those that were sampled during the study, on average, fed diets were lower in dry matter, crude protein, and copper. Crude protein averaged 12.9% as fed on farms while being formulated for an average of 14.4%.
Meanwhile, the diets provided excess acid detergent fiber, non-fibrous carbohydrates, potassium, iron, and net energy for lactation. While several of these probably raise red flags for those of us that feed cows daily, it was the non-fibrous carbohydrates that most concerned the researchers.
“In the fresh cows, for each percent increase of NFC variability in close-up diets, there was a 0.064 decrease in the liver health index,” Turney wrote. “In this study, lower variability between non-fibrous carbohydrates formulated and fed was contributed to higher liver health indexes and potential post-partum performance.”
Turney did note that researchers found formulation differences each time they visited farms with rations sometimes mirroring formulations much more nearly than the averages over time, which brings us back to that discussion on consistency. We’ve found on our farm, that having the same person feed day-to-day reduces the variability as he or she can fine-tune their loading plan.
Turney concluded her comments by reminding readers that variables like order of ingredient loading, equipment used, and cow preferences and sorting can all impact the final product.
The author is a dairy farmer in Kansas and a former associate editor at Hoard’s Dairyman. Raised on a 150-cow dairy near Valley Center, Kansas, Maggie graduated from Kansas State University with degrees in agricultural communications and animal sciences.
