The study was conducted with 60 Hanwoo steer calves(7 month of age, mean body weight 139㎏) for 18 months performance to examine the effect of the feeding levels of concentrates on the growth performance and fatty acid composition of adipose tissues of various locations(subcutaneous, intermuscular and intramuscular fats). The Hanwoo steer calves were randomly allotted into 3 treatments according to the feeding levels of concentrates(85, 100 and 115%), and fed concentrates of Grower(7∼12 month of age), Finisher Ⅰ(12∼16 month of age), Finisher II(17∼20 month of age) and Finisher III(21 ∼25 month of age). The feeding levels of concentrates for the cattle of 85% or 115% were decreased or increased by 15%, respectively, up to 25 month of age based on the similar body weight to the cattle of 100%. The cattle were kept in an individual pen through the experimental period and were fed rice straw ad libitum. The cattle were slaughtered at the ages of 15, 18 and 25 months, and the adipose tissues collected were subjected to analyze the fatty acid composition.
Growth of Hanwoo steers was not affected significantly by the feeding levels of concentrates, thus the lowered feed requirement was observed as the feeding levels of concentrates decreased. Overall mean dry matter intake concentrates, daily body gain and feed efficiency of Hanwoo steers up to 25month of age were 5.23㎏ , 0.75㎏ and 6.92, respectively.
Fatty acids of palmitic acid(C_(16:0)) stearic acid(C_(18:0)) and oleic acid(C_(18:1)) in the adipose tissues of three locations of Hanwoo steers were dominated. The feeding level of concentrate did not affect the fatty acid composition. Percent composition of myristic acid was lowered in the order of subcutaneous, intermuscular and intramuscular fats. Relatively lowered values of C_(16:0) in the intramuscular and C_(18:1) and unsaturated fatty acids(USFA) to saturated fatty acids(SFA) in the intermuscular fats were observed. But increased tendencies of palmitoleic acid, C_(18:1) and linoleic acid were found from the subcutaneous, intermuscular and intramuscular fats, respectively. On the other hand, percent C_(18:0) slightly decreased but the ratio of USFA to SFA tended to increase with age.
|