Effect of thyroglobulin gene polymorphism on the intramuscular fat content in cattle examined by x-ray computed tomography and Soxhlet methods

Abstract

Abstract. Intramuscular fat content or marbling represents a valuable beef quality trait and is an important determinant of palatability due to its contribution to juiciness and flavour. Meat which has little marbling may be dry and flavourless. Higher levels of intramuscular fat have been associated with increased tenderness, juiciness and flavour of beef (Thompson 2004). Whereas this feature is highly appreciated in some markets (by example Australia, China, Korea, Japan) breeders usually try to increase intramuscular fat deposition in cattle by nutrition. However, genetic factors have been shown to affect marbling in cattle. Thyroglobulin (TG) is a glycoproteic hormone synthesised in the thyroid gland and is the precursor of triiodothyronine (T3) and thyroxine (T4) hormones which influence lipid metabolism. T3 and T4 hormones have been associated with marbling in Wagyu cattle (Mears et al. 2001). The effect of a C/T single nucleotide polymorphism in the 5'-untranslated region of TG gene has been concluded to affect intramuscular fat content in cattle (Barendse 1999). High probability of positive association between the T allele of bovine TG gene and marbling was observed by Wood et al. (2006). Thyroglobulin mainly affects the fat content of longissimus dorsi muscle (LD) (Thaller et al. 2003).

X-Ray computed tomography evaluation of intramuscular fat content in Hungarian simmental cattle

“…The CT value of intermuscular and subcutaneous fat contents are associated with negative Hounsfi eld values (-200 --20: HOLLÓ et al, 2007), but for the evaluation for intramuscular fat, positive Hounsfi eld values (-200 -+19: HOLLÓ et al, 2012, +10 -+20: FONT-I-FURNOLS et al, 2014 should also be included in the analysis. The average CT fat content of longissimus was lower (~1%) than chemical fat content similarly to previous fi ndings of ANTON et al (2013). In the present study, the highest intramuscular chemical fat level and CT fat percentage of longissimus muscle was obtained by bulls classifi ed as SEUROP fat grade 1, followed by fat grade 3, and the lowest intramuscular fat level was measured in carcasses with SEUROP fat grade 2.…”

Non-invasive methods for the determination of body and carcass composition in livestock: dual-energy X-ray absorptiometry, computed tomography, magnetic resonance imaging and ultrasound: invited review

“…Correspondingly, CT studies post mortem are also aiming to determine the salt content in the dry-cured ham, because the changing NaCl and H 2 O proportions lead to modified X-ray attenuations (Fulladosa et al , 2010 ); whereas Frisullo et al ( 2010 ) used micro-CT for the rapid estimation of intramuscular fat (IMF) in beef and for the description of the fat microstructure. Anton et al ( 2013 ) compared chemical analysis or dissection with CT in order to determine the IMF and carcass fat content of beef in a study focusing on the thyroglobulin (TG) polymorphism. They calculated correlations between IMF (% from Soxhlet analysis) and CT fat (%) in musculus longissimus dorsi , and between dissected fat (%) of the right carcass-half and CT fat (%) between the 11 th and 13 th rib joint of 0.71 and 0.96 ( P <0.001), respectively.…”

Effect of single-nucleotide polymorphisms on the breeding value of fertility and breeding value of beef in Hungarian Simmental cattle

“…At present the breeding decisions in the AHSCB are based mainly on breeding values; however, some SNPs have been demonstrated to affect intramuscular fat content and meat quality traits in the Hungarian Simmental breed as well (Anton et al, 2008(Anton et al, , 2013. Estimated breeding values (EBV) signify the level of the breeding potential of animals for specific traits.…”