2007 update of international beef genetic trend benchmarking

Summary

The Australian beef seedstock industry has had access to Best Linear Unbiased Prediction (BLUP) analysis since the mid 1980's with the first multitrait analysis run for four Hereford herds in 1986. The first Angus analysis followed soon after.
The BLUP analytical model developed by the Animal Genetics and Breeding Unit (AGBU) at the University of New England was commercialised as BREEDPLAN under the National Beef Recording Scheme by the Agricultural Business Research Institute (ABRI).
Genetic evaluations are now run for 20 breeds in Australia for up to 19 different traits. All of the weight, fertility and carcase traits are run as a multitrait analysis. A single EBV for a standardised 300 kg carcase weight is published for each of rump fat depth, rib fat depth, eye muscle area and intra-muscular fat depth with ultrasound scan EBVs used as correlated traits. Direct and maternal calving ease are calculated from a separate multitrait analysis incorporating gestation length and birth weight. Net Feed Efficiency EBVs are calculated in a separate threshold analysis utilising Insulin like Growth
Factor (IGF-1) as a correlated trait. Docility EBVs are calculated by a single trait threshold analysis
This report benchmarks the genetic trends for nine Australian breeds against the same breeds in other countries for a range of traits.
Genetic trends for some or all of the breeds were sought from the USA, Canada, United Kingdom, France, South Africa and New Zealand. While most breeds in Australia and New Zealand run joint genetic evaluations, the genetic trends for the animals born in each country are used. Individual country trends were also used for breeds which run joint analyses in the USA and Canada.
The traits chosen as indicator traits were direct calving ease, birth weight, yearling weight, scrotal size and intramuscular fat percentage. All trends supplied for breeds in other countries which were directly comparable with these five traits in Australian breeds are included in the report. Some Australian breeds do not publish EBVs for calving ease or IMF% and some breeds in the USA and Canada publish EPDs for marbling which are not directly comparable with IMF%. Comparative trends for docility and gestation length were also included for the Limousin breed.
Birth weight and yearling weight EPDs from the USA and Canada which are published in pounds were converted to equivalent EBVs expressed in kilograms by dividing by 1.1. EPDs from the USA and Canada for calving ease, scrotal size and IMF% were multiplied by two to convert them to EBVs.
All trends are expressed with a base of zero in 1996. These trends do not indicate the relative genetic level of the breeds across countries. They simply measure the genetic change for each trait since 1996.
In addition countries were compared for one Australian Index for those breeds which publish indexes in Australia. The traits included in the index calculation were direct calving ease, birth weight, 400 day weight, scrotal size, intramuscular fat and eye muscle area if available. The shortcoming of this comparison is that a breed may have different breeding objectives in different countries due to different market requirements. However it does provide a comparison of genetic trends for a group of key calving ease, growth, fertility and carcase traits.