Southern Multi-breed resource population: Generation of cohorts one and two

Abstract

<p>This paper describes the generation of the first and second cohort of animals in a large 5-year breeding project being conducted across New South Wales involving five temperate beef breeds and the Brahman breed. Females were joined to 154 sires via artificial insemination and back-up matings in 2019 to generate the first cohort of calves, which were born in 2020. Calves were born and raised in mixed breed groups and will be intensively recorded head- to-head for current BREEDPLAN traits and new economically important traits. Birth d ata have been collected for Cohort One, with records available for 1,398 calves. Traits recorded at birth included birth weight, calving ease, calf fate, calf bellow and calf vigour. Traits to be collected at weaning include weaning weight, hip height, muscle score, docility (crush- side and flight speed), horn/poll phenotype and worm egg count. Relationships between calf bellow and calf vigour scores at birth and subsequent measures of behaviour and production will be assessed. Steers will be backgrounded at one of two locations before entering Tullimba feedlot and subsequently slaughtered, while females will be retained at each site to be joined naturally. Generation of Cohort Two has begun with females joined to 202 sires via artificial insemination and back-up matings in 2020, with 1,535 calves expected to be born in 2021. Data generated from the project will enhance current within -breed genetic evaluations through collection of data for traits that are currently poorly recorded, and by expanding the suite of traits available for selection.</p>