Spring Calving Index (£SCI)

The Spring Calving Index (£SCI) is an across-breed genetic ranking index developed to breed cows that produce lower volumes of milk of a higher quality. It’s specifically for spring block-calving herds, which rely heavily on grazed grass and calve in a tight (12 weeks or less) block.

This index is expressed as a financial value and represents the additional profit a high £SCI bull is expected to return from each of its milking daughters over her lifetime compared with an average bull of zero £SCI.

Both the £SCI and £ACI Indexes emphasise important genetic areas are maintained or improved, e.g. fertility (calving interval and non-return rate), somatic cell count (SCC) and milk solids. While increased emphasis on the maintenance cost by reducing cow liveweight will give the daughters of high £SCI bulls improved efficiency suited to a spring-calving, grazing-based system.

As an across-breed index, you can use it to compare bulls of different breeds.

The £SCI:

• Promotes milk quality rather than volume
• Places strong emphasis on fertility
• Selects for reduced maintenance cost
• Improves udder and leg health
• Places strong emphasis on longevity
• Promotes easier calving
• Protects functional type
• Feet and Legs and Udders

The pie chart below shows the breakdown of the individual weightings of traits in the £SCI.

The figure below shows the relative gain of traits within the £SCI index.

* Trait reversed for presentation purposes.

Four simple steps when selecting the right bulls for your breeding programme:

1. Select £SCI bulls with a higher value than your best cow
2. Select fitness traits to maintain your strengths and address herd weaknesses (Fertility, Lifespan etc)
3. Match type to suit your herd
4. Selected calving ease for maiden heifers

The below table shows the average phenotypic values for females used to calculate the base for the £SCI index.