Preslaughter Management and Dark-Cutting in the Carcasses of Young Bulls

Abstract

One hundred-and-twelve yearling bulls were penned together for at least 3 mo in groups of 7 or 21. They were then shipped 150 km to an abattoir in groups of either 7 or 21, and were either regrouped or not regrouped before shipment. They were held overnight at the abattoir before slaughter. A further seven yearling bulls were shipped and held individually before slaughter. After slaughter, muscle color was appraised by Federal graders. Load size had no significant effect on the incidence of dark-cutting, but regrouping had a dramatic effect (73 vs. 2% dark cutters, P < 0.01). There were no dark cutters among the bulls shipped individually. It is concluded that agonistic encounters among regrouped bulls was a far more important cause of dark-cutting than either load size or exposure to an alien environment.

Factors affecting beef palatability — farmgate to chilled carcass

“…Mixing probably elicits the most detrimental effect on glycogen loss and should be avoided at all costs (Grandin 1993). Agonistic behaviour is particularly prevalent when young bulls are mixed and this would account for the extremely high prevalence of dark cutting (about 50%) in 2 studies highlighted in Table 1 (Price and Tennessen 1981;Warriss 1984). Unfortunately, there is very little available data involving mixed consignments of steers or heifers.…”

Social Stress and Dominance Among Group Members After Mixing Beef Cows

“…L'origine de la race a influ6 (P<0,01) (Kelley 1980;Moberg 1987) which may lead to production losses such as lowered reproductive rates, increased mastitis, decreased body weight gain and pathological conditions such as shipping fever. The physiological and behavioral changes associated with dark-cutting beef (Price and Tennessen 1981) and buller-rider syndrome (Irwin et al 1919), which are influenced by mixing, may also be considered to be consequences of social stress.…”

Effects of Transport and Electrolyte Supplementation on Ion Concentrations, Carcass Yield and Quality in Bulls

“…From an economic perspective. marketing factors are important since they can impair meat quality and increase carcass loss (Price and Tennessen 1981;Phillips et al 1985; Jones et al 1988;Shorthose and Wythes 1988). Furthermore, there is a growing concern that animal welfare in the preslaughter environment may be degraded (Fraser 1979;Kilgour 1988 Jones et al 1988).…”