Parameters for BREEEDPLAN
Parameters for BREEEDPLAN - Beef CRC - Beef Genetic Technologies
| Genetic evaluation systems such as BREEDPLAN are underpinned by parameters such as estimates of heritabilites and genetic correlations between a range of economically important traits. Beef CRC will deliver a large number of new parameters as well as new traits for inclusion in BREEDPLAN. Genetic and phenotypic parameters for use in genetic evaluation schemes will be developed for the following traits: • Age at puberty and post-partum re-conception in tropically adapted cattle • Beef tenderness and associated carcase and beef quality traits when assessed in carcases that have been hung by the Achilles tendon or tender-stretched • Relationships between commercial steer traits and reproductive and adaptive performance in their femail half-sibs • Growth and carcase and beef quality when steers have been grown at fast or slow rates post-weaning • Male indicator traits to improve female reproductive performance • Early predictors of lifetime reproductive performance • Predictors of maternal productivity |
| Trial Marker-Assisted EBVs for Tenderness (EBVM) |
| Genetic parameters for traits associated with beef tenderness (shear force, MQ4 score, flight time, meat colour) and markers for tenderness were estimated and included in a new method to calculate EBVM in BREEDPLAN for industry use in mid-2008. The new method will be adapted for use for additional traits (e.g. feed efficiency, carcase and meat quality, female reproduction) as soon as prediction equations accounting for sufficient variation for those traits become available. |
| CRCIII Female Reproductive Traits |
| Genetic parameters for traits and indicator traits (e.g. age at puberty, post-partum re-conception interval, lifetime reproductive performance and early-life indicators of lifetime female reproductive performance) in northern Australian herds and the associations between those traits and steer traits (growth, feed efficiency and carcase and beef quality attributes) will be estimated and included in BREEDPLAN. Industry use: Estimates of genetic parameters (heritabilities, genetic correlations etc) are essential to underpin genetic evaluation schemes such as BREEDPLAN. Most industry practitioners of genetic improvement would not even be aware of these estimates, as they use only the BREEDPLAN EBVs and accuracies calculated from the parameters. The main users of such parameters are therefore the developers and commercialisers of BREEDPLAN (AGBU and ABRI), though the parameters will also be used by other researchers (e.g. the CRC’s phenotypic prediction project which use the parameters in their model development). Economic benefit: Reproduction rate is a critical profit driver in cattle breeding herds. Suboptimal reproduction rates in northern Australian Bos indicus derived herds represent the major inefficiency of production in Australian beef herds. CRC economic analyses show the gross margin of beef cattle production in Queensland alone could increase (direct benefit to producers) by $28 m annually by increasing branding rates by 5% in first- and second-calf heifers and 1% in mature cows. The impact of changed body composition on reproduction in breeding herds due to selection to improve steer traits also impacts on total herd profitability and productivity. |
| CRCIII Maternal Efficiency Traits |
| Genetic parameters for traits and indicator traits such as conception and weaning rates and days-to calving in first and second-calf heifers and their associations with body composition and feed efficiency in southern Australian breeding herds will be estimated and included in BREEDPLAN. Industry use: Estimates of genetic parameters (heritabilities, genetic correlations etc) are required to underpin BREEDPLAN, though most genetic improvement practitioners would not be aware of the estimates, as they simply use the BREEDPLAN EBVs and accuracies calculated from the parameters. The main users of the parameters are therefore the developers and commercialisers of BREEDPLAN, though the parameters are also used by other researchers (e.g. the CRC’s phenotypic prediction project uses the parameters in their model development). Economic benefit: Reproduction rate is a critical profit driver in cattle breeding herds. Associations between feed efficiency and maternal performance are also important particularly in temperate areas of Australia where land costs are higher and supplementary feeding is more commonly practiced. The impact of changed body composition on reproduction in breeding herds due to selection to improve steer traits also impacts on total herd profitability and productivity. |
| Male Indicator Traits to Improve Reproduction |
| Identification of male indicator traits for industry use depends on results of data analyses to commence after data collection is complete. Early life predictors of fertility in the male will greatly improve the efficiency of selection of sires for reproductive performance. There are genetic and economic advantages in identifying new traits in sires used for breeding purposes to indirectly improve the fertility of both female and male relatives. Genetic parameters for such traits will be estimated and included in BREEDPLAN for northern Australian herds. Industry use: Estimates of genetic parameters (heritabilities, genetic correlations etc) are essential for BREEDPLAN, though most genetic improvement practitioners would use only the EBVs and accuracies calculated from the parameters. The main users of such parameters for male indicator traits will be the developers and commercialisers of BREEDPLAN (AGBU and ABRI). Economic benefit: Identifying early life predictors of a bull’s fertility will reduce the number of bulls required for breeding throughout northern Australia by up to 50%. Identifying new traits related to fertility of a bull’s progeny will provide new opportunities to increase rates of genetic improvement for all traits and significantly increase the impact of using genetically superior bulls in commercial herds in northern Australia. |
