The incidence of dark cutting in southern Australian beef production systems fluctuates between months

Abstract

Dark cutting is detrimental to meat quality and therefore is the major cause of carcass downgrades under the Meat Standards Australia grading system. This study quantified the variation between months in the incidence of dark cutting, in southern Australia. Four years of Meat Standards Australia grading data, from nine individual beef processors in Western Australia, South Australia, Victoria and Tasmania, was utilised for the analysis. The dataset contained 42 162 slaughter groups, of 10 or more grass-fed cattle, which allowed for the percentage of dark cutters per slaughter group to be analysed. The interaction between month, year and state was significant (P < 0.001). The lowest risk of dark cutting for South Australia and Western Australia was in October (1.53% ± 0.75 and 6.96% ± 0.76) and November in Tasmania and Victoria (7.34% ± 0.9 and 5.27% ± 0.81) potentially when feed availability and quality is highest. The incidence of dark cutting was highest for all states during the period from February to June. Lower pasture availability and quality in combination with higher levels of stress due to extreme high or low temperatures during this time could all contribute to the higher incidences. The findings of this study show that procurement and management decisions made by cattle buyers, producers and processors need to change throughout the year to help mitigate the incidence of dark cutting carcasses and reduce financial loss.

The Impact of Heat Load on Cattle

“…Dark cutting is generally attributed to low muscle glycogen stores at slaughter, which is predominantly a function of glycogenesis [143]. Muscle glycogen depletion has been associated with numerous factors including, but not limited, to nutritional status, particularly in grazing systems [144,145], water supply and quality [143], animal temperament [145,146], sex [145,146], climatic conditions and climatic variability [147], and hormone growth promotants, however, this may be confounded by sex [148]. Furthermore, periods of heat load are associated with a decrease in feed intake [40,50,55,149].…”

Abattoir Factors Influencing the Incidence of Dark Cutting in Australian Grain-Fed Beef

“…The condition is generally attributed to low muscle glycogen stores at slaughter [ 5 ], which is either a function of insufficient glycogenesis on farm [ 6 ] or too much glycogenolysis during the pre-slaughter period due exercise or stress. Muscle glycogen concentration at slaughter has been associated with numerous factors including, but not limited to, nutritional status [ 4 , 7 , 8 ], water supply and quality [ 6 ], animal temperament [ 9 , 10 ], gender and climatic conditions [ 8 ].…”

Preslaughter factors affecting mobility, blood parameters, bruising, and muscle pH of finished beef cattle in the United States

“…Other studies have documented numerous other factors associated with dark cutting. For example, time of the year ( Kreikemeier et al., 1998 ; McGilchrist et al., 2014 ); duration of transport ( Gallo et al., 2003 ; Chulayo and Muchenje, 2017 ; Burns et al., 2019 ), and animal-related factors ( Scanga et al., 1998 ) are just a few that have been reported previously. Identifying a single preslaughter factor associated with this defect is challenging, mainly because numerous and compounding intrinsic and extrinsic factors contribute to its occurrence.…”