200 Day Milk EBV for Beef Cattle

Assessing Maternal Traits

"EBVs are vitally important when considering a bull’s maternal attributes, since these cannot be assessed by eye"

Many commercial and pedigree producers are breeding their own female replacements and need to identify bulls with superior maternal attributes. An important maternal EBV is the 200-Day Milk EBV, indicating the degree to which a calf’s 200-day weight is influenced by the maternal performance of its dam – e.g. milkiness and general mothering ability.

This is calculated by considering the performance of the grand-offspring of a bull. The weights of all of his grandprogeny are influenced by his growth genes, but only those produced by his daughters are affected by his genes for milk. If the grandprogeny produced by his daughters are consistently heavier than those produced by his sons, then this is likely to be due to the superior genes for milk production and maternal behaviour passed on to his daughters and will be reflected by the EBV (see Diagram 1).

Interpretation
A bull with an EBV of +4 for 200-Day Milk is expected to produce heifer calves which will have maternal characteristics leading to their calves being 2kg heavier at 200-days than calves from heifers sired by a bull with an EBV of 0.

The other maternal traits currently produced by Signet include Longevity, Age at 1st Calving, Calving Interval and Maternal Calving Ease