한우 육성 및 비육기 영양수준이 발육 , 사료이용성 및 도체 조성에 미치는 영향 = Effect of Feeding Level During Growing and Fattening Period on Daily Gain , Feed Efficiency and Carcass Composition of Korean Native Bulls

다국어 초록 (Multilingual Abstract)

To evaluate the effect of feeding level on daily gain, feed efficiency and carcass composition, high (H: DCP and TDN was supplied for 1.1㎏ daily gain × 1.1) and low (L: DCP and TDN was supplied for 0.6㎏ daily gain × 1.1) level nutrient were fed to each 12 heads of Korean native bulls (KNB) for the 1st period (body weight from about 120㎏ to 300㎏), and thereafter during 2nd period 12 heads were devided into two groups and fed with H and L-feeding level until animals weighted about 500㎏. 1. Daily gain was significantly increased (P$lt;0.05) and the feeding period was significantly decreased when fed with H level. Shifting feeding level (H→L or L→H) did not affect the daily gain during whole period although there was a trend that H level during 1st period was more efficient than L level. 2. Dry matter intake was higher with H level than with L level. 3. DCP efficiency was better when fed with L level. The efficiency of L→H level was lower than that of H→L level during whole period but was better than that of H→H level during the early phase of 2nd period. 4. TDN efficiency was not influenced by the feeding level. However, TDN efficiency of H group was slightly better than that of L group during the 1st period. 5. Dressing percentage was significantly increased when fed with H level during the 2nd period. Fat content was significantly increased when fed with H→H level, while there was no significant differences among H→L, L→H, L→L feeding levels. There was no significant differences in retailed cuts between the feeding levels. 6. Carcass price was higher and feed cost was lower when fed with L level during the 2nd period. The monthly income per head was higher when fed with H level during the 1st period, although there was no big differences between H→H and L→H feeding level.