# Raw milk from individual teats with an optimal teat-end score has lower spore levels compared with teats with a suboptimal teat-end score

## TL;DR

Raw milk from teats with better condition has fewer spores, which may slightly improve the shelf-life of pasteurized milk.

## Contribution

This study empirically links teat-end condition to spore levels in raw milk for the first time.

## Key findings

- Teats with optimal scores had significantly lower mesophilic spore counts than those with suboptimal scores.
- The spore reduction is expected to minimally extend the shelf-life of pasteurized milk.
- Improving teat-end condition can incrementally enhance raw milk quality as part of a broader strategy.

## Abstract

Summary: Spores of sporeforming bacteria in raw milk can survive pasteurization and cause spoilage of fluid milk. To assess the previously suggested link between teat-end condition and spore levels, we determined the mesophilic spore count in a total of 102 raw milk samples obtained from an equal number of teats with optimal (score 1) and suboptimal (score 4) teat-end scores. A statistically relevant difference in mesophilic spore count was observed between the 2 groups. The observed difference is expected to result in minimal extension of pasteurized fluid milk shelf-life. Although improving teat-end condition alone may not substantially extend shelf-life, it can still contribute to incremental improvement of overall raw milk quality as part of a broader quality management strategy. Created in Canva.

Summary: Spores of sporeforming bacteria in raw milk can survive pasteurization and cause spoilage of fluid milk. To assess the previously suggested link between teat-end condition and spore levels, we determined the mesophilic spore count in a total of 102 raw milk samples obtained from an equal number of teats with optimal (score 1) and suboptimal (score 4) teat-end scores. A statistically relevant difference in mesophilic spore count was observed between the 2 groups. The observed difference is expected to result in minimal extension of pasteurized fluid milk shelf-life. Although improving teat-end condition alone may not substantially extend shelf-life, it can still contribute to incremental improvement of overall raw milk quality as part of a broader quality management strategy. Created in Canva.

•Spore levels were determined in raw milk from optimal and suboptimal teat-ends.•Spore levels were lower in raw milk obtained from teats with optimal teat-ends.•Lower spore level is expected to minimally increase the pasteurized milk shelf-life.•Teat-end condition can contribute to incremental improvement of raw milk quality.

Spore levels were determined in raw milk from optimal and suboptimal teat-ends.

Spore levels were lower in raw milk obtained from teats with optimal teat-ends.

Lower spore level is expected to minimally increase the pasteurized milk shelf-life.

Teat-end condition can contribute to incremental improvement of raw milk quality.

Udder health in dairy cows is routinely monitored (for example, through determination of SCC) to help identify and control mastitis and other infectious diseases. Another parameter used to both assess udder health and milking machine performance is the teat-end condition, typically assessed at the herd level using a 4-point scoring system. Recently, the teat-end score has been suggested as a factor associated with the levels of bacterial spores in raw milk. Spores of cold-tolerant sporeforming bacteria present in raw milk can survive pasteurization and contribute to the spoilage of fluid milk. Therefore, the objective of this study was to determine whether the condition of individual teat-ends (specifically, optimal versus suboptimal teat-end scores) affects the spore levels in raw milk obtained from these teats. A total of 102 raw milk samples were collected from 102 individual teats from cows on a single dairy farm, and tested for mesophilic spores, with 51 samples each from teats scored as either 1 (optimal) or 4 (suboptimal). A significantly lower mesophilic spore count was found in the raw milk samples collected from teats with a teat-end score of 1 compared with samples collected from teats with score of 4. The observed difference in mesophilic spore counts suggests that maintaining optimal teat-end condition through good udder health and milking machine management may help reduce spore levels in raw milk. Although the observed difference in mesophilic spore counts is expected to result in minimal improvement of fluid milk shelf-life and other quality parameters, interventions targeting teat-end status or farm management practices that aim to improve the same can still be an important incremental contributor to the overall improvement of these parameters as part of a comprehensive, multipronged approach to raw milk quality management.