Variation in carcass and meat quality traits and their relations to growth in dual purpose cattle

Carcass and meat quality traits of Norwegian (NRF) dual purpose cattle were studied, and genetic parameters between these traits and growth rate were estimated. Data were recorded on 456 NRF bulls (n = 32 sires), performance tested at test stations from 1989 to 1991. Both ANOVA and REML were utilised for h(2) estimations and gave about the same results. Carcass related heritabilities were lowest for fleshiness traits (0.05) and highest for length and fatness traits (0.55). Heritabilities for the meat quality traits ultimate pH and colour (Hunter-L*a*b) varied from 0.08 to 0.27, while h(2) for intramuscular fat % in musculus latissimus dorsi was estimated to 0.51. Unfavourable genetic correlations were found between growth rate and various carcass fleshiness traits, and between growth rate and intramuscular fat. High growth rate was associated with longer carcasses, lower dressing %, poorer fleshiness and a decreased m. l. dorsi area, combined with a decline in intramuscular fat content. The r(g) estimates between growth rate and lightness, redness and yellowness revealed that selection for daily gain will give correlated responses of lighter, but lower colour intensity meat.