Autumn Calving Index £ACI

The Autumn Calving Index (£ACI) is suitable for autumn block-calving herds and reflects the costs of feeding for winter milk production and the higher milk price per litre received at that time of year.

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It favours a greater weight of milk than £SCI but has less emphasis on fat health and protein percentages. £ACI has a slightly greater emphasis on female fertility than £PLI, which is for year-round-calving herds.

£ACI is an across-breed index, which means you can use it to compare bulls of different breeds.

Search for a bull by name or herdbook number

Autumn block calving breeding index reports

The £ACI:

  • Promotes milk quality, with more weight on volume than the £SCI
  • Places strong emphasis on fertility
  • Selects for reduced maintenance cost
  • Improves udder and leg health
  • Places strong emphasis on longevity
  • Promotes easier calving
  • Improves functional type – Feet and Legs and Udders

The £ACI value represents the additional profit a high £ACI bull is expected to return from each of its milking daughters over her lifetime compared with an average bull of zero £ACI.

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

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

  1. Select bulls with a higher £ACI 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

Related content

Profitable lifetime index £PLI

Spring calving index £SCI

Dairy breeding and genetics homepage

Bull and cow genetic reports explained and a glossary of terms