The purposes of this study were to compare once-calved heifers and maiden heifers, and to survey the physicochemical and eating characteristics after meat processing. Sample cattle of Japanese Shorthorn were obtained utilizing once-calved heifers (n = 3, A, B and C) and maiden heifers (n = 3, X, Y and Z) from an abattoir in Hokkaido on June 2013. Meat samples from M. semimembranosus was kept at 4℃ for 14 days postmortem, and then processed into roast beef. Physicochemical and eating characteristics of the roast beef sample were investigated. Samples from the six carcasses were supplied to 180 general consumer panels for an eating quality test. Paired comparison tests of preference were carried out using the following 9 sets; A vs X, Y and Z, B vs X, Y and Z, C vs X, Y and Z. There were no differences in all physicochemical characteristics (pH, the shear force value, sweetness, umami, bitterness and total free amino acid concentrations) between once-calved heifers and maiden heifers. The eating quality of once-calved heifer samples revealed higher eating quality scores than maiden heifer samples for almost all traits. These results suggest that meat products derived from once-calved heifer should be evaluated higher than meat from maiden heifers.
Yeso sika deer captured in the winters of 2006 and 2007 around Lake Akan in Hokkaido were transported to a deer farm, and reared for 3-10 months. Ten 2-year-old or older (adult) males were slaughtered and their carcasses were processed: 3, 3, 2, and 2 in June, July, September, and October of 2006, respectively. In 2007, three adult females were slaughtered and their carcasses were processed in each of June, July, September, October, and November (total of 15). The chemical composition and mineral contents of the loin were measured. Lipid contents of the loin from male deer were slightly lower in September and the highest in October. Regarding the mineral contents, although there was a decrease in the potassium and iron contents in September and an increase in the contents in October, there were no seasonal differences in other minerals. Lipid contents of the loin from female deer were generally high (3.9 to 7.6%), particularly in October. There were no seasonal differences in the protein contents (20.6 to 21.1%). Ash contents were significantly lower in July. The potassium contents varied depending on the season, and they were significantly lower in November. Arsenic, cadmium, and lead were not identified. There were seasonal differences in the lipid, ash, and potassium contents of the loin from adult Yeso sika deer captured and reared on a deer farm for a short period. Farmers may produce deer meat to cope with the demand by paying attention to the contents of meat as well as its productivity, including the feed efficiency, weight gain, and weight of the dressed carcass.