Relationship between blood hemoglobin, plasma and tissue iron, muscle heme pigment, and carcass color of veal.

In 41 veal calves divided into three groups and fed different levels of dietary iron, blood hemoglobin, plasma iron, liver, spleen, and muscle iron, muscle heme pigment, and carcass muscle color at slaughter were studied. At 45 min postmortem, total carcass color was visually evaluated in the 41 carcasses. In different muscles of the carcasses the color was measured instrumentally using an invasive color measurement method at 45 min postmortem (MCDI score) and a surface color measurement method at 20 h postmortem (Minolta L*, a*, b*, and Chroma scores). Among the three groups, differences (P less than .05) in muscle iron concentrations, muscle heme pigment concentrations, and Minolta a*, b*, and Chroma scores were found. Most striking were the differences in mean iron concentrations in the longissimus thoracis muscles between Groups A (29 micrograms/g DM) and B (44 micrograms/g DM) and in the semimembranosus muscles between Groups A (31 micrograms/g DM) and C (45 micrograms/g DM). The correlations found between Minolta L*, a*, or Chroma score and the iron and heme pigment concentrations in the semimembranosus muscles were high in comparison with those found in the longissimus thoracis and rectus abdominis muscles. Compared with the plasma iron concentration, the blood hemoglobin concentration showed higher correlations with muscle iron and muscle heme pigment concentrations. It can be concluded that different iron concentrations in the milk replacer during the first 7 wk of fattening influence, to some extent, muscle iron and muscle heme pigment at slaughter. However, these differences were not measurable in the overall visual color evaluation of the carcass surface muscles.