# Milk Stability: Physicochemical and Performance Parameters in Highly Technified Holstein and Jersey Herds

## TL;DR

This study examines milk stability in Holstein and Jersey herds, finding that ionized calcium is a key factor affecting stability, with implications for dairy industry practices.

## Contribution

The study identifies ionized calcium as the main factor affecting milk stability in both Holstein and Jersey breeds under high-tech farming conditions.

## Key findings

- Milk stability was high in both Holstein and Jersey breeds (>80% v/v).
- Ionized calcium was the main factor associated with low milk stability in both breeds.
- Acidity affected Holstein milk stability but not Jersey due to higher natural acidity.

## Abstract

Low stability of milk causes losses to the farmers and dairy industry by increasing milk rejection and compromising heat treatment, respectively. The stability of milk in ethanol and its relationship with the acidity and physicochemical traits of milk from Holstein and Jersey breeds were evaluated. Titratable acidity, ethanol test, ionized calcium concentration (iCa), milk chemical composition, and the milk production, parity, and body condition score of cows were analyzed. Milk characteristics and performance parameters showed that herds were of high genetic value and were raised in high‐tech systems. Milk stability was high in the two breeds (> 80% v/v). Milk production and composition were similar in low, medium, and high stability milk in both breeds. Augments in parity, days in milk, iCa, and acidity in the Holstein breed, and total solids in Jersey increased the occurrence of less stable milk. Ionized calcium was the main factor associated with low milk stability in both breeds.

Unstable milk causes several problems in the dairy chain, increasing milk rejection in industrial plants. Holstein and Jersey herds, when kept under adequate nutritional, sanitary, and thermal comfort conditions, produce highly stable milk. Furthermore, the ionized calcium present in the milk is a variable strongly associated with milk instability in both breeds. Acidity was associated with milk instability in the Holstein herd, but in the Jersey herd, this association was not observed due to the higher natural acidity of milk.