The efficacy of a vitamin D metabolite for improving the myofibrillar tenderness of meat from cattle

The influence of a once only administration of a metabolite of vitamin D3 (HY·D®-25-hydroxy vitamin D3) on myofibrillar meat tenderness in Australian Brahman cattle was studied. Ninety-six Brahman steers of three phenotypes (Indo-Brazil, US and US/European) and with two previous hormonal growth promotant (HGP) histories (implanted or not implanted with Compudose®) were fed a standard feedlot ration for 70d. Treatment groups of 24 steers were offered daily 10g/head HY·D® (125mg 25-hydroxyvitamin D3) for 6, 4, or 2d before slaughter. One other group of 24 steers was given the basal diet without HY·D®. Feed lot performance, blood and muscle samples and carcass quality data were collected at slaughter. Calcium, magnesium, potassium, sodium, iron and Vitamin D3 metabolites were measured in plasma and longissimus dorsi muscle. Warner–Bratzler (WB) shear force (peak force, initial yield) and other objective meat quality measurements were made on the longissimus dorsi muscle of each steer after ageing for 1, 7 and 14d post-mortem at 0–2°C.