Minerals of carcass soft tissue and bone of serially slaughtered cattle as affected by biological type and management

Abstract

SummaryMineral concentrations of soft tissue and bone were measured in carcasses from cattle slaughtered serially across a wide weight range. Seventy-four small framed Angus steers and 71 Holstein steers were selected to represent diverse mature types. Cattle were individually fed ad libitumeither a maize grain or maize silage diet, housed inside a barn or in outside pens and slaughtered over five weights within breed. After slaughter, a half-carcass was separated into soft tissue (lean and fat) and bone. Tissues were ground, freeze-dried and K, P, Ca, Mg, Na, Fe, Cu, Zn and Mn were measured. Concentrations of minerals were analysed by covariance analysis, using carcass weight as a covariate.The relationships between carcass weight and concentrations of all soft tissue minerals except Na and Zn were not affected by diet, breed or type of housing. Concentration of Na decreased with increasing carcass weight and at a slower rate in soft tissue of grain-fed cattle than in soft tissue of silage-fed cattle. Concentration of Zn increased with increased carcass weight in Angus, while in Holsteins it decreased. Soft tissue of Angus and Holsteins had similar concentrations of Fe and Mn. Holsteins had higher concentrations of the other minerals in soft tissue than Angus, possibly because they were at an earlier stage of maturity at the same carcass weight. Carcass weight had no effect on K, Ca, Fe or Cu content of soft tissue.Diet influenced concentrations of P, Ca and Na in bone and affected the relationship of bone Fe to carcass weight. Due to their later stage of maturity at the same carcass weight, Angus had less K and more Ca, Na and Zn in bone than Holsteins. Carcass weight had no influence on K, P, Mg, Na, Cu or Mn content of bone.These data provide baseline values for future studies, show that breed mature size differences in mineral concentrations of soft tissue and carcass bone may exist and that diet may influence concentration of soft tissue Na and some bone minerals.