Veal colour and other meat quality characteristics in calves fattened on maize silage and concentrate

Male Holstein (15) and female crossbred (15) calves, weaned from milk replacer at the end of experimental week 8, were fattened on a maize silage and concentrate diet (MSC). As a control 14 male Holstein calves were conventionally fattened on milk replacer only. The control calves reached the target slaughter weight of about 135 kg after 24.5 weeks and the MSC males after 28 weeks. The female MSC calves were slaughtered at the same age producing carcasses of 120 kg on average. MSC males were inferior to control calves in conformation, and MSC females showed the highest fat cover scores. Four MSC males expressed DFD (ultimate pH > 5.9 in M. longissimus dorsi (M.l.d.)) and were excluded from further Statistical analyses. The MSC calves had a significantly higher iron and pigment content in M.l.d., resulting in a darker (L*) and redder (a*) colour 24 h as well as 14 days after slaughter. Early visual judgement and instrumental measurements in the M. rectus abdominis (M.r.a.) 45 min and 24 h post mortem, using a colour scale and a Minolta Chroma-Meter, respectively, already showed significantly darker meat with increased redness for MSC calves. However, linear correlations with M.l.d. colour traits were rather low except for redness in M.r.a. 45 min p.m. and aged M.l.d. Haemoglobin concentration in blood, as assessed by a rapid method 3 d before slaughter, was overall on a relatively high level and showed no significant treatment effect and only weak or no correlation to colour traits. Apart from colour, meat quality of the MSC calves was either superior (shear force, collagen solubility, intramuscular fat, sensory tenderness, juiciness and acceptance) or equivalent (cooking loss, flavour intensity) to control. Therefore, the use of maize silage and concentrate in veal produetion seems promising, provided a pink veal colour would be accepted by trade and consumers.