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The Ages of Sires and Dams of Registered Hereford Cattle⁽¹⁾

Iowa State College

Abstract

The progeny test is one of the most accurate means of determining the breeding value of an individual. A beef bull's breeding worth can be fairly well estimated by the time his first season's calves are a year old. Since bulls are usually at least one year old before being used to any great extent, they will be around three years of age or older before reliable progeny tests of them show their true breeding worth.

How old are the bulls in use today? Are most of them old enough to have had their breeding value tested or are they mostly young bulls which have been selected by pedigree and individual merit and which probably will be discarded before their breeding value is known?

To answer this question a random sample of 500 bulls and 500 cows was taken from the Hereford registrations of 1930. The ages of the parents at the time the service was made were then calculated. This gave the ages of 1000 sires and 1000 dams at the time they were bred to produce these registered calves.

⁽¹⁾ (Journal Paper No. B12 of the Iowa Agricultural Experiment Station).