Beef carcasses with larger eye muscle areas, lower ossification scores and improved nutrition have a lower incidence of dark cutting

Abstract

ÔØ Å ÒÙ× Ö ÔØBeef carcasses with larger eye muscle areas, lower ossification scores and improved nutrition have a lower incidence of dark cutting This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. increased pHu compliance by around 14% (P<0.001) in carcasses less than 350kg. As carcass weight increased from 150kg to 220kg, compliance increased by 13% (P<0.001) and younger cattle with lower ossification were also 7% more compliant (P<0.001). As rib fat depth increased from 0 to 20mm, pHu compliance increased by around 10% (P<0.001) yet marbling had no effect on dark cutting. Increasing musculature and growth combined with good nutrition will minimise dark cutting beef in Australia. A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT HighlightsIncreasing the musculature of beef cattle decreases dark cutting Heavier carcasses and younger cattle with lower ossification have higher ultimate pH compliance Fatter carcasses have less dark cutting reflecting better nutrition A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT2 Increasing musculature and growth combined with good nutrition of beef cattle will minimize dark cutting beef in Australia

Can potential for dark cutting be predicted by phenotype? Relationship between sex, carcass characteristics, and the incidence of dark cutting beef

“…one-half the incidence of dark cutting than those weighing less than 272 kg. Increased carcass weight may reduce the incidence of dark cutting because heavy carcasses are most likely to have increased muscle glycogen reserves (McGilchrist et al 2012), a slowed chilling rate, and a rapid decline in post-mortem pH (Cliplef et al 1989;Wulf et al 1997;Aalhus et al 2001). These results agree with previous research which found that heifer carcasses that cut dark were associated with decreased mean carcass weight (Cliplef et al 1989;Murray 1989).…”

“…McGilchrist et al (2012) reflected that increased muscularity and fatness most likely indicated improved nutrition of the cattle and increased muscle glycogen reserves; however, increased musculature in the study of Hawrysh et al (1985) was linked to increased dark cutting and was most likely indicative of rapidly growing cattle with reduced muscle energy reserves. Additionally, muscular animals with an increased proportion of fast muscle fibers (Wegner et al 2000) may be most at risk of dark cutting with acute activity such as fighting or physical combat before slaughter, which greatly lowers muscle glycogen (Lacourt and Tarrant, 1985;McGilchrist et al 2011).…”

“…Recent research by McGilchrist et al (2012) indicated that increased hot carcass weight (greater than 220 kg) was associated with decreased incidence of dark cutting. Likewise, Murray (1989) reported that beef carcasses weighing greater than 318 kg had Fig.…”

“…In Australia the incidence of dark cutting is about 10% (Meat Standards Australia (MSA) 2010), whereas in the United States of America (US) the proportion of dark cutting has increased from 1.9% in 2005 (Garcia et al 2008) to 3.2% in 2012 (Moore et al 2012). Recently, it has been indicated that improved muscling and carcass weight lowered the incidence of dark cutting (McGilchrist et al 2012), but there are contradictory reports about the effect of animal sex on the likelihood of dark cutting (Lorenzen et al 1993;Mach et al 2008). Regardless of the animal and management factors involved, that muscle glycogen is insufficient to fuel post-mortem anaerobic glycolysis and reduce carcass muscle pH is the accepted cause of dark cutting.…”

Improving beef meat colour scores at carcass grading

“…Vealers and grain-fed animals had~50% of the lighter 1B and 1C meat colour scores and older animals had the highest incidence of dark cutting (33%). Muscles from older animals are well known to exhibit darker coloured meat (Page et al 2001;Mlynek and Gulinski 2007;McGilchrist et al 2012). This reduction in lightness is most likely to be caused by an increase in myoglobin concentration and lower numbers of large 'white' fast glycolytic fibres and more 'red' slow oxidative fibres (Moon et al 2006;Mlynek and Gulinski 2007).…”