Beef market in Korea has become confronted with many difficulties by imported beef. We realize that differentiation of beef quality with imported beef is the best way to give competitiveness to Hanwoo. Feeding technology is very important in Hanwoo to produce high quality beef as well as genetic background of the individual. The current study was conducted to determine the effects of vitamin A on the carcass traits and on meat quality of Hanwoo beef as a basic study to manipulate vitamin A contents in feeds to produce high quality beef.
The experiment Ⅰ was conducted to investigate the effect of dietary types on feed intake, body weight gain and carcass characteristics in Hanwoo steers. A total of thirty Hanwoo steers, averaging 445kg body weight, were equally allotted to three groups of commercial formula feed, TMR and the mixture feed (additional 2.5 kg/d formula feed to TMR) by randomized block design. Steers were fed restrictively for formula feed including rice straw, but fed ad libitum for TMR and the mixture feed. Steers could access to water and mineral block freely. The results obtained were as follows.
Daily body gain of steers fed TMR was the greatest among treatments, and was usually maintained 0.80 kg per day during the whole experimental period. Total body gain in the formula feed was greater by 12.03kg and 11.23 kg compared to the TMR and the mixture, respectively.
For meat quantity grade, the percentage of grade A was 20%, 40% and 10% for the formula feed, the TMR and the mixture, respectively.
For meat quality grade, the percentage of grade 1 was 60%(the formula feed), 70%(TMR) and 100%(the mixture), respectively.
In economical analysis, feed cost in the formula feed was increased by 16% and 11% compared to the TMR and the mixture, respectively. However, net income in the TMR and the mixture compared to the formula feed was increased by 10% and 20%, respectively.
Feeding the mixture feed to Hanwoo steers resulted in higher profits by improvement of meat quality.
As results, although feed cost in the mixture was increased by increasing feed intake, however net income was greatly increased due to the improvement of performance and meat quality.
In experiment Ⅱ, Ninety heads of Hanwoo steer (mean age of 30 month) were used to correct blood from jugular vein and carcass data. Blood metabolites and hormones were analyzed and evaluated the correlation coefficients.
Mean retinol concentration in blood of Hanwoo steers in the finish fattening phase was 43.65㎍/㎗.
Overall, there were negative correlations between blood retinol concentration and marbling score and meat quality grade in Hanwoo steers. From the results obtained in the current study, we concluded that it might be possible to from produce high quality beef by manipulating retinol contents in Hanwoo feeds. Further detailed studies, however, are necessary to determine retinol contents in feeds, vitamin A feeding level, and vitamin A feeding periods.