Published online by Cambridge University Press: 02 September 2010
Ways of conducting a progeny test for growth of carcass characters are discussed with reference to statistical efficiency. An intensive system (375 kg slaughter weight) is compared with a semi-intensive system (475 kg slaughter weight) and the use of intermediate results as predictors of the final outcome is discussed.
The crossbred progeny of 32 Hereford bulls (1043 calves) were admitted to a Progeny Testing Centre at 2-month intervals at 2 weeks of age over a period of 2 years, and divided between the two feeding regimes. Growth and carcass characters were measured, including taste panel assessments.
The semi-intensive system was found to have a higher power of discrimination between progeny groups, and tended to rank the bulls i n a different order from the intensive system. Truncation of the test at various intervals introduced an element of risk into the formation of the final judgement and showed little advantage as a predictor.