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. 2021 Jan 25;5(1):txab011.
doi: 10.1093/tas/txab011. eCollection 2021 Jan.

Comparison of two live-animal ultrasound systems for genetic evaluation of carcass traits in Angus cattle

C J Duff  1 , J H J van der Werf  2 , P F Parnell  1 , S A Clark  2
Affiliations

Comparison of two live-animal ultrasound systems for genetic evaluation of carcass traits in Angus cattle

C J Duff et al. Transl Anim Sci. .

Abstract

The improvement of carcass traits is an important breeding objective in beef cattle breeding programs. The most common way of selecting for improvement in carcass traits is via indirect selection using ultrasound scanning of selection candidates which are submitted to genetic evaluation programs. Two systems used to analyze ultrasound images to predict carcass traits are the Pie Medical Esaote Aquila (PIE) and Central Ultrasound Processing (CUP). This study compared the ability of the two systems to predict carcass traits for genetic evaluation in Australian Angus cattle. Genetic and phenotypic parameters were estimated using data from 1,648 Angus steers which were ultrasound scanned twice with both systems, first at feedlot entry and then following 100 d in the feedlot. The traits interpreted from ultrasound scanning included eye muscle area (EMA), rib fat (RIB) rump fat (RUMP), and intramuscular fat (IMF). Abattoir carcass data were collected on all steers following the full feedlot feeding period of 285 d. For all ultrasound scan traits, CUP resulted in higher phenotypic and genetic variances compared to the PIE. For IMF, CUP had higher heritability at feedlot intake (0.51 for CUP compared to 0.37 for PIE) and after 100 d feeding (0.54 for CUP compared to 0.45 PIE). CUP predicted IMF also tended to have stronger correlations with the breeding objective traits of carcass IMF and marbling traits, both genetically (ranging from 0.59 to 0.75 for CUP compared to 0.45-0.63 for PIE) and phenotypically (ranging from 0.27 to 0.43 for CUP compared to 0.19-0.28 for PIE). Ultrasound scan EMA was the only group of traits in which the heritabilities were higher for PIE (0.52 for PIE compared to 0.40 for CUP at feedlot intake and 0.46 for PIE compared to 0.43 for CUP at 100 d of feeding), however with similar relationships to the breeding objective carcass EMA observed. For subcutaneous fat traits of ultrasound RIB and RUMP, the heritabilites and genetic correlations to the related carcass traits were similar, with the exception being the higher heritability observed for CUP predicted RUMP at feedlot intake at 0.52 compared to 0.38 for PIE. The results from this study indicates that the CUP system, compared to PIE, provides an advantage for genetic evaluation of carcass traits in Angus cattle, particularly for the IMF and associated marbling traits.

Keywords: Angus; beef cattle; carcass; genetic parameters; phenotypic parameters ultrasound.

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Figures

Figure 1.
Figure 1.
Distribution of ultrasound scan intramuscular fat (IMF) steer phenotypes for the PIE (top) and CUP (bottom) systems at 100 d feeding.
See this image and copyright information in PMC

References

    1. AUS-MEAT. 2020. Handbook of Australian Beef Processing, Version 7.Murarrie, QLD:AUS-MEAT Ltd. Available from https://www.ausmeat.com.au/WebDocuments/Producer_HAP_Beef_Small.pdf [accessed January 6, 2021].
    1. Börner, V., Johnston D. J., and Graser H. U.. . 2013. Genetic relationships between live animal scan traits and carcass traits of Australian Angus bulls and heifers. Anim. Prod. Sci. 53: 1075–1082. doi:10.1071/AN12435 - DOI
    1. Duff, C., van der Werf J. H. J., and Clark S. A.. . 2018. Comparison of two live-animal ultrasound systems to predict carcass intramuscular fat and marbling in Australian Angus cattle. In: Proceedings of the 11th World Congress on Genetics Applied to Livestock Production No. Electronic Poster Session.Auckland, New Zealand. p. 262. http://www.wcgalp.org/system/files/proceedings/2018/comparison-two-live-... [accessed February 29, 2020].
    1. Duff, C., van der Werf J. H J., and Clark S. A.. . 2019. Should Angus breeders live-animal ultrasound scan for intramuscular fat in the genomics era? Proc. Assoc. Adv. Anim. Breed. Genet. 23: 496–499. http://www.aaabg.org/aaabghome/AAABG23papers/122Duff23496.pdf [accessed March 1, 2020].
    1. Gilmour, A. R., Gogel B. J., Cullis B. R., and Thompson R.. . 2009. ASReml user guide release 3.0. Hemel Hempstead, UK: VSN Int. Ltd.

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