Student Case Presentation
Assessment of milk mixing consistency through Brix refractometry
| Date/Time: |
9/11/2025 #4
|
| Presenter: |
Madison Kelchen |
| Veterinary School: |
IA |
Abstract:
Calves depend on consistency at each feeding to maintain a healthy gut balance for optimal growth and survival. Calves fed a fixed rate of milk replacer have a higher average daily gain, starter intake, and feed efficiency than calves fed variable rates of milk replacer. The mode of mixing, temperature, time, and concentration are all points for potential variability in feedings. Brix refractometry is useful for immediate on-farm total solids measurement to ensure calves are receiving meals that are mixed consistently.
A preliminary study was run to determine accuracy of the Brix refractometer to account for temperature variability in both milk and environment. At each temperature, different concentrations were measured in series to see how much they varied from true total solids. Results were used in the next stage of the study with on-farm samples.
An observational study was conducted on seven dairies feeding milk replacer and three dairies feeding whole milk to calves. Immediately before feeding, farm staff collected samples from the center of the tank at every feeding. Staff recorded the date and time of collection and stored the sample in a refrigerator. For each feeding, the employee, milk temperature, and method of milk mixing were recorded. Samples were collected from each farm every five days and measured by Brix refractometry.
The preliminary study showed the most accurate reading was milk replacer at 40°F and room temperature Brix refractometer (70°F) across the three different suspensions and whole milk samples. Data showed that farms that utilized a scale for powder, a milk taxi, flow meter for water, and minimal staff variability were the most consistent. Those with a manufacturer-provided scoop, a bucket, and whisk were the least consistent. Farms that fed whole milk had more consistent feeding overall, though small variations were still observed.
