The transition period receives the attention of the entire dairy industry because of the dramatic and intense changes that cows undergo. This six-week period encapsulating the time before and after calving helps determine the health and productivity of the cow throughout her lactation.
With those consequences in mind, The Ohio State University’s Kirby Krogstad detailed the balance that’s required nutritionally during this time and the risks for ruminal acidosis.
“Subacute ruminal acidosis (SARA) is highly prevalent in dairy cattle — up to 33% of dairy cattle experience SARA during their lactation. Up to 40% of pasture cattle also experience pH below 5.8,” the associate professor explained in a recent Buckeye Dairy News.
Those statistics are based on a cow maintaining a rumen pH below a threshold of 5.6 to 5.8 for an extended period of time. Acidic rumens often develop because of the interaction between these nine factors: high starch concentration in the feed, the starch source, starch processing, forage fiber content in the feed, physically effective fiber and forage particle size, supplemental buffers, level of feed intake, pasture maturity and species, and cow comfort and lying space.
These factors can be summarized as the meeting between nutrition and management on the farm. Many operations have addressed these challenges by providing a separate transition pen that allows cows easy access to feed and low stocking densities.
For those struggling with rumen acidosis, Krogstad recommended four areas of focus to improve the ability to address acidosis.
- Forage and physically effective fiber – Feeding greater levels of fiber raises rumination, chewing time, and salvia production improving rumen buffering capacity.
- Adding buffers – These products neutralize acids in the rumen to maintain a stable rumen pH.
- Cow comfort – Increased lying time improves rumination and saliva production so any measures that can be implemented to help cows rest more reduce acidosis risk.
- Bunk management – “Feed availability, uniformly mixed feed, and consistent feed delivery is also part of SARA management,” Krogstad described. The intention is to avoid slug feeding and sorting, which can escalate the risk of acidosis.
“Forage neutral detergent fiber concentrations below 17% risks reduced rumen pH and feed efficiency while forage neutral detergent fiber above 23% risks reducing feed intake and milk production,” Krogstad said.
This tightrope balancing act leaves plenty of room for farm-specific problems and solutions. When we say we can get cows off to a better start, it requires the attention of the entire dairy farm team from nutrition to feeding to overall cow management.
