Composite String Sampling for Dairy Farms: A Smarter, More Accurate Way to Monitor Milk Quality and Udder Health

Composite string sampling is an innovative method that enables dairy farmers to collect representative milk samples from groups of cows over multiple milkings. Unlike grab or dipper samples, this approach provides a more refined picture of milk quality and udder health by capturing variations that occur across time and between animal groups.

At QualiTru, we believe smarter sampling means better decisions. Composite string sampling—made possible through our aseptic, inline sampling systems—gives producers the data they need to improve hygiene, identify milk quality problems sooner, and streamline mastitis management protocols.

Why Use Composite String Sampling on Your Dairy?

Traditional milk quality and mastitis monitoring programs rely on individual cow samples or bulk tank samples for data collection. Both have limitations:

• Individual cow samples are accurate but highly labor-intensive and costly.
• Bulk tank samples are easy to collect but the comingled milk dilutes the signal, making it hard to pinpoint problems in specific groups or locations.

Composite string sampling bridges this gap, offering the following benefits:

1. Monitor Raw Milk Quality More Precisely

String sampling collects milk from groups of cows over multiple milkings into a single, aseptic container. This method allows for:

• Reliable Standard Plate Count (SPC) and Somatic Cell Count (SCC) testing results
• Consistent detection of fluctuations in milk fat and protein levels
• Early identification of trends that may impact raw milk quality

2. Improve Dairy Farm Sanitation Monitoring

String sampling can help detect and pinpoint elevated levels of bacterial contaminants, such as coliforms and psychrotrophic spoilage organisms, that may indicate hygiene or milking equipment issues. By identifying increases in contaminating organisms along the process flow, producers can pinpoint sources of contamination more easily and take corrective actions more quickly.

3. Strengthen Mastitis Detection and Udder Health Programs

By reducing the dilution effect seen in bulk tank samples, string sampling may improve the detection of contagious mastitis pathogens. When string samples are taken from milk lines serving specific milking strings, the data may:

• Narrow the search for infected cows by identifying affected groups
• Reduce labor and testing costs compared to whole-herd testing
• Support more targeted mastitis control interventions

This group-based insight helps farmers manage udder health more effectively while saving time and resources.

How It Works

Using QualiTru’s inline aseptic sampling systems, producers can collect representative string samples directly from existing milk lines without introducing contaminants. Sample collection is simple, sterile, and proven effective. Our systems integrate easily with existing milking equipment and work with peristaltic pumps to gather precise volumes over time.

Milk coming out of the receiver represents the commingled milk of the group of cows (string) currently being milked in the milking parlor. Samples should be collected at the receiver at least once for each string. The TruDraw® Sterile Single Sampler is ideal when a small sample is required. However, the best method to collect the sample consistently throughout milking is by using a TruMotion™ 2 liter Collection Bag and Watson-Marlow peristaltic pump (or equivalent QualiTru peristaltic pump offering).

Key Benefits of Composite String Sampling

• Accurate and more precise SPC and SCC data
• Increased sensitivity of mastitic bacteria detection
• More precise monitoring of environmental hygiene
• Streamlined nutrition management based on milk components
• Reduced labor costs vs. individual cow sampling
• Strong compliance with the Pasteurized Milk Ordinance (PMO) and quality programs

Start Sampling Smarter

Composite string sampling gives you the data you need to stay ahead of problems before they affect your milk check. With better visibility into milk quality and udder health, you can make proactive decisions that enhance productivity, reduce losses, and support long-term herd health.