Dairy Cattle Grouping Methods (Méthode de groupage)

Brimful Capacity (Capacité à ras bord)

The term used to describe the absolute physical maximum capacity of a feed mixer, at which an adequate mix cannot be achieved.

Mixer Capacity (Capacité du mélangeur)

The maximum level to which a feed mixer can be filled while still allowing a complete and proper mix.

Single-Group Total Mixed Ration (RTM à 1 groupe)

A management strategy that simplifies feed distribution and labor management, but carries disadvantages such as higher feed costs (especially if concentrates are expensive), mixer capacity limitations, and cow overconditioning (embonpoint) in late lactation.

Herd Heterogeneity Principle

The rule indicating that the more heterogeneous a dairy herd is, the higher the number of distinct feeding groups that should be established.

Grouping by Production Level (Grouper selon le niveau de production)

The most commonly used grouping criterion in Québec for dairy cows, categorizing cows according to their daily milk production.

Three-Group Production Thresholds ($30\,\text{kg/day}$ Average)

A distribution separating cows into Group 1 ($\ge 37.5\,\text{kg}$ of milk, calculated as $30 \times 1.25$), Group 2 ($22.5\,\text{kg}\text{ to } 37.5\,\text{kg}$ of milk, calculated as $30 \times 0.75$), and Group 3 ($< 22.5\,\text{kg}$ of milk).

Two-Group Production Thresholds ($30\,\text{kg/day}$ Average)

A distribution where Group 1 consists of cows above the herd average ($\ge 30\,\text{kg}$