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. 2024 Jan 3:102:skae331.
doi: 10.1093/jas/skae331.

Intramuscular fat % in the loin of Australian pork demonstrates a stronger relationship with computed tomography lean and fat % than abattoir measures of P2 and lean

Fiona Anderson  1   2 , Maddison T Corlett  1   2 , Andrew Williams  1   2 , Graham E Gardner  1   2
Affiliations

Intramuscular fat % in the loin of Australian pork demonstrates a stronger relationship with computed tomography lean and fat % than abattoir measures of P2 and lean

Fiona Anderson et al. J Anim Sci. .

Abstract

Intramuscular fat (IMF) % is an important measure of pork eating quality, with reduced IMF % linked to the selection of pigs with low backfat P2 thickness and more muscular genotypes over several decades. This experiment tested the association of IMF % from the M. longissimus thoracis et lumborum of 345 pigs at 3 abattoirs (sites) with computed tomography (CT) determined carcass composition (% lean or fat), accredited abattoir measures of P2 backfat (mm; Hennessy Grading Probe [HGP], AutoFom III, and PorkScan Lite) and the lean % output from abattoir devices (HGP, AutoFom III, and PorkScan Plus). There was a negative relationship between carcass CT lean % with IMF % at all sites (P < 0.05), with the strength of this relationship varying between sites. The strongest relationship was demonstrated at site 1 (R2 0.30, RMSE 0.59), and across a 4 SD range in the carcass lean % at each site, resulted in a decrease in loin IMF % of 1.56, 0.44, and 0.80. There was a positive relationship of carcass CT fat % with IMF %, with similar, albeit slightly stronger relationship to IMF than with CT lean %. In contrast, only one of the 3 sites with an accredited P2 measurement device demonstrated a significant association (P < 0.05) with IMF %. This is the first time the associations of IMF % with carcass CT composition has been assessed alongside that of P2 backfat measurements from commercially deployed abattoir devices. Given P2 backfat is the key industry measure on which carcass value is determined in Australia, this experiment demonstrates the limitations that P2 has in measuring and monitoring the associations of carcass lean and fat % with IMF. Ideally, an independent measure of IMF % would allow for independent selection for lean % and IMF %; however, there is currently no commercial device that can measure pork IMF %.

Keywords: backfat; computed tomography; leanness; meat; technology; yield.

Plain language summary

Intramuscular fat (IMF) % is related to eating quality in pork; however, currently, there is no commercially available device to measure this trait. The association of IMF % with carcass composition could be used as a proxy; however, this experiment demonstrates that commercially accredited measures of P2 backfat are unable to consistently identify a relationship with IMF %. In contrast, computed tomography fat and lean % can demonstrate this relationship, which indicates that whole carcass composition is better able to provide feedback to processors and producers on IMF % and its relationship with industry practices to select for leanness.

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Conflict of interest statement

The authors declare no real or perceived conflicts of interest.

Figures

Figure 1.
Figure 1.
Relationship between loin intramuscular fat % and computed tomography lean % at site 1 (a), site 2 (b), and site 3 (c). The line represents the predicted fit and the gray-shaded region is the SE for each model, and icons represent individual observations.
Figure 2.
Figure 2.
Relationship between loin intramuscular fat % and devices predicting carcass lean %: Hennessy Grading Probe at site 1 (a), AutoFom III at site 2 (b), and PorkScan Plus at site 3 (c). The line represents the predicted fit and the gray-shaded region is the SE for each model, and icons represent individual observations.
Figure 3.
Figure 3.
Relationship between loin intramuscular fat % and P2 fat depth using: Hennessy Grading Probe at site 1 (a), AutoFom III at site 2 (b), and PorkScan Lite at site 3 (c). The line represents the predicted fit and the gray-shaded region is the SE for each model, and icons represent individual observations.
See this image and copyright information in PMC

References

    1. An, J. S., Lee J. H., Song M. H., Yun W., Oh H. J., Kim Y. J., Lee J. S., Kim H. B., and Cho J. H... 2021. Predicting body compositions of live finishing pigs based on bioelectrical impedance analysis. J. Anim. Sci. Technol. 63:332–338. doi: https://doi.org/10.5187/jast.2021.e31 - DOI - PMC - PubMed
    1. Anderson, F., Pannier L., Pethick D. W., and Gardner G. E... 2015a. Intramuscular fat in lamb muscle and the impact of selection for improved carcass lean meat yield. Animal. 9:1081–1090. doi: https://doi.org/10.1017/S1751731114002900 - DOI - PubMed
    1. Anderson, F., Williams A., Pannier L., Pethick D. W., and Gardner G. E... 2015b. Sire carcass breeding values affect body composition in lamb - 1. Effects on lean weight and its distribution within the carcass as measured by computed tomography. Meat Sci. 108:145–154. doi: https://doi.org/10.1016/j.meatsci.2015.06.002 - DOI - PubMed
    1. Anderson, F., Corlett M. T., Williams A., Sterndale S., Trezona M., and Gardner G. E... 2024. The association of P2 and lean% estimates from commercial measurement systems with computed tomography determined composition within Australian pork abattoirs. Meat Sci. 217:109612. doi: https://doi.org/10.1016/j.meatsci.2024.109612 - DOI - PubMed
    1. AUS-MEAT. 2022. AMILSC approved guidelines for experiments to accredit technologies to measure CT Lean%, Fat% and Bone% in sheep carcases. https://www.ausmeat.com.au/WebDocuments/AMILSC_Approved_Guidelines_for_t...