by Deborah Jeanne Sergeant
Real-time data helps any business stay more nimble in its operation. Analyzing milk on-farm can help dairy producers make more informed decisions about feeding and herd management with nearly real-time precision. Heather Dann, Ph.D. of The William H. Miner Institute presented “Milk Analysis and the On-farm Use for Management Decisions” as a webinar recently.
Dann referenced a study that monitored 430 farms for 15 months, infrared technology helped researchers measure milk fatty acid metrics.
“Milk fat and protein increased when de novo fatty acids in milk increased,” Dann said. “It occurred for both Holstein and Jersey herds.”
The testing facilities included Sterns County & Zumbrota, MN, DHIA Labs, Cornell University, Miner Institute, Texas Federal Milk Market Lab, St. Albans Co-op, AgriMark Co-op and Cayuga Marketing Co-op.
Dann said milk fat composition, the most variable component of milk, is 98 percent triglycerides.
“There are more than 400 unique fatty acids in milk,” Dann said. “About 20 fatty acids make up the majority, broadly grouped into three sub-categories.”
De novo fatty acids are made in the mammary gland and are influence by rumen fermentation and function. Preformed fatty acids come from fat in the diet and body fat mobilization. Mixed origin fatty acids come both from the diet and are made in the mammary gland.
“In addition to these three fatty acid groups, we also have another metric, unsaturation or double bond,” Dann said.
Dann said the milk fatty acid profiles provide insight into the performance and health of the cow and, overall, the herd.
“They reflect the diet and dietary changes, management environment, and physiological state of the cow, such as risk of milk fat depression, energy balance and stage of lactation,” Dann said.
Research conducted in 2014 and 2015 indicate that herds with high de novo fatty acids give milk that is higher in true protein (3.5 percent, versus 3.16 percent in 2014 and 3.19 percent versus 3.10 percent in 2015).
“De novo fatty acids reflect rumen function, especially fiber fermentation,” Dann said. “Acetate and butyrate are building blocks.”
She added, “Rumen conditions that enhance microbial fermentation stimulate microbial protein production and increase milk protein content.”
The proportion of de novo fatty acids indicate to dairy producers key factors in cow care.
Dann said more physically effective fiber — greater than 21 percent — and less ether extract —under 3.5 percent were the factors most related to high de novo fatty acid content.
“These findings fit with controlled research about what dietary factors affect milk fat,” Dann said.
In addition, high de novo herds tend to be five times more likely to delivery feed twice daily in free stall and 11 times more likely to delivery feed five times daily in tie stalls.
“This emphasizes the importance of feed arability for our cows,” Dan said.
Herd density also plays an important role. High novo herds tend to be 10 times more likely to provide more than 18 feet in bunk space per cow and five times more likely to stock stalls at less than 110 percent.
“We need to get the diet and the ‘dining experience’ right,” Dann said. “We must focus on diet formulation and management environment. Milk fatty acid metric gives us another tool to tell how well we’re doing in these areas.”
She believes the information should be used to offer a herd “snapshot” for troubleshooting health issues, evaluating changes over the course of time, assist in better understanding the natural variation and place into correct context the season and stage of lactation as it affects production.
She said farms can set goals and use the metrics to help them stay on track better — and tweak management when production falls short of the goals.
“Fatty acid metrics help implement a change,” Dann said.
She warned that other factors can play a role in milk fat depression. Risk factors can include diet, including fermentable carbohydrates, fats, feed additives, yeast and mold; cow and environmental factors, such as genetics, parity, days in milk, season, time budget/behavior, stocking density, and feeding strategy.
Changes in milk fat are often subtle, especially if diet is involved, so tracking long-term variations can help farmers more accurately monitor shifts before their herd health suffers.
Dann has become so enthusiastic about sampling at the bulk tank that she said, “I can’t wait until we can sample on farm with each milking. In the meantime, using pen, group or string sampling can help. One of the reasons I encourage folks to do this is when they’re trouble shooting a herd.”
The webinar was hosted by The Miner Institute, Cornell University, St. Albans Co-op Creamery and Agricultural Modeling and Training Systems, LLC.