This study was conducted to improve growth performance of Hanwoo heifer and to produce high quality of meat with dietary means during growing and early fattening period. Particularly, additional energy diet to relieve estrus stress was main purpose in this study. The results of in vitro rumen fermentation indicated that there was no negative effect by additional energy diet as treatments. In the feeding trial, twenty Hanwoo heifers(average 10 months age) were allocated and distributed into two treatments in randomized block design based on body weight. There were three growth stages such as growing, early fattening and late fattening periods in this feeding program, respectively. In growing stage, there were two treatments consisting of only total mixed ration(TMR) as a control and TMR with additional energy treatment. The experimental diets were fed twice a day, and water and mineral were freely accessed. In additional energy treatment, 500 g of concentrate diet was fed daily to relieve estrus stress due to obese with high energy intake. Not outstandingly differences were found across the treatments during entiretrial period. While, unexpectedly greater feed conversion ratio in treatment compared to the control was found during late fattening period. It seems that the blood cortisol decreased with addition energy supplementation compared with the control during trail period. Carcass characteristics including carcass weight, back fat thickness, marbling score, meat color, fat color, maturity and texture were not significantly different each other. Rib-eye area, however, was greater in the control compared to the treatment(p<0.05). In addition, it appears that yield index was tended to be greater in the control. In conclusion, it is suggested that additional energy supplementation to Hanwoo heifer could get a potential in improving meat quality and relieving estrus stress.

본 연구는 한우 암소비육에 있어서 고 에너지의 육성용 TMR(TDN 72.7%DM, CP 13.65%DM)을 육성기(8~12개월령) 및 비육기(13~24개월령)까지는 제한급여하고, 이후 비육 마무리기(25~32개월령)까지 자유 채식시켰을 때, 증체수준, 도체특성 및 경제성에 미치는 영향을 구명하고자 수행되었다. 공시축은 한우 암소 35두(8개월령)를 이용하여 Control구(5두), T1(10두), T2(10두) 및 T3(10두)구로 나누어 난괴법으로 배치하였다. 공시사료는 전기간 동일한 육성용 TMR을 Control구에서는 자유채식 시켰고, T1, T2, T3구에서는 각각 체중의 1.8%, 1.6% 및 1.5%로 제한하여 24개월령까지 급여하였다. 한우 암소의 체중은 비육마무리기간에서 Control구에 비해 T1, T2 및 T3 처리구가 각각 4.9%, 3.6% 및 2.5% 높은 것으로 나타났다 (p<0.05). 일일증체량은 육성기에는 Control구와 T1구가 다른 처리구에 비해 높았으며(p<0.05), 비육마무리기의 T1 처리구가 다른 처리구에 비해 높았다(p<0.05). 건물섭취량과 TDN 섭취량은 비육마무리기간에서 T1구가 가장 높았다(p<0.05). 고 에너지의 육성우용 TMR을 전 기간동안 급여함으로써 도체중과 배최장근 단면적이 일반적인 한우 암소비육 결과에 비해 현저히 증가되었다. 처리구별 도체중은 Control구에 비해 T1구가 약 11.6% 많았으며(p<0.05), 지방색과 성숙도는 Control구에서 높았다(p<0.05). 근내지방도, 육색 및 조직감은 처리구간 유의적 차이는 없었으나, 육량등급 출현율에 있어서는 Control구에서 A등급이 60%로서 다른 처리구에 비해 높았다. 육질등급에서 1++ 등급 출현율은 Control, T1, T2 및 T3구에서 각각 0%, 20%, 20% 및 0%로 나타났다. 순수익은 Control구에 비해 T1과 T2구가 각각 15% 및 13% 증가되었으나 T3구는 2% 감소한 것으로 나타났다. 결론적으로, 한우 미경산우 비육 시, 고에너지의 육성용 사료를 육성기부터 비육기(13~24개월령)까지 체중의 1.8% 수준으로 제한 급여하는 것이 전 기간 동안 자유채식시키는 것보다 도체중이나 육질등급 증가로 경제성이 향상되어 한우암소 고급육생산 프로그램 개발에 활용할 수 있을 것으로 판단된다.

본 연구는 grooming brush의 제공에 따른 한우 암소 육성우의 사양성적, 행동특성, 혈액 내 cortisol 및 혈액성상의 변화를 조사하였다. 6개월령의 암소 육성우(110.63±12.23kg) 32두를 32m2 우방에서 대조 구(non grooming brush), 처리구 1(Chevron angle type grooming brush, CHAT), 처리구 2(Straight type grooming brush, ST) 및 처리구 3(Chevron angle type and Straight type grooming brush, CHAST)으로 처리당 4두씩, 4처리 2반복으로 완전임의 배치하여, 2주간 예비시험 후 8개월간 본 시험 을 실시하였다. 시험결과 grooming brush 제공에 따른 사양성적으로 종료 시 체중과 일당증체량에서 는 대조구 대비 처리구에서 유의적(p<0.05)으로 증가하였고, 사료요구율에서는 대조구에서 가장 낮은 사양성적을 보였다(p<0.05). 행동특성 중 횡화 및 걷기시간은 대조구 대비 grooming brush를 제공한 모든 처리구에 유의적으로 높게 나타났다(p<0.05). 음수행동의 빈도는 처리구 3에서 유의적(p<0.05)으 로 증가하였다. 또한, 몸단장행동인 자기몸 핥기, brushing 행동과 투쟁행동은 대조구에서 다른 처리구 에 비해 유의적으로 증가하였다(p<0.05). 혈액성상에서 헤모글로빈수치는 처리구에서 유의적(p<0.05) 으로 높았고, 스트레스 호르몬인 cortisol 농도는 대조구에서 유의적(p<0.05)으로 높은 수치를 보였다. 따라서, grooming brush 제공에 따른 한우 육성 성적, 행동특성 그리고 혈액 내 cortisol의 변화는 집 단생활을 하는 소의 사회적인 행동에 긍정적인 영향을 미치는 것으로 볼 수 있으며, 스트레스 저감으로 인해 건강한 발육에 기여하는 것으로 나타났다.

This study was conducted to ameliorate the productive performance of Hanwoo cow using hill pasture grazing system. Twenty seven animals aged 9 were designed to divide with 3 groups which were Control (restricted concentrate and hay for 5 months), T1 (restricted concentrate and pasture grazing ad libitum for 5 months) and T2 (restricted concentrate, 30 g/head of mineral nutrients and pasture grazing ad libitum for 5 months). Average daily gains increased higher in the order of T2, Control and T1. The conception rate of Control, T1 and T2 after artificial insemination during post-grazing period were 88.9%, 100%, 100%, respectively. In conclusion, the results indicated that hill pasture grazing system might enhance not only the productive performance of Hanwoo cow but also profit for conventional feeding system.

The objective of this study was to determine the effect of different pregnancy stages on the eating and ruminating behavior of Hanwoo heifers (Bos taurus coreanae). A total of twelve Hanwoo heifers were divided into four groups depending on pregnancy stage: C: before pregnancy, 9 months old, T1: 3 months pregnant, 16 months old, T2: 6 months pregnant, 19 months old, T3: 9 months pregnant, 22 months old (3 replicates per group). Concentrate of 1% of the body weight was fed to them. Roughage was provided at ad libitum to all treatments. Our results revealed that the intake of roughage was the highest in the T3 group (at 3.68 kg) and the lowest in the C group (at 1.02 kg, p<0.05). Total intake in the order from high to low was: T3 > T2 > T1 > C (p<0.05). The rate of dry matter intake compared to body weight (DMI/BW, %) from high to low order was: T3 > T2 > T1 > C (p<0.05). Eating time, ruminating time, and chewing time were the highest in T3 group (p<0.05). Resting time was the highest in C group (p<0.05). The number of bolus and the number of total chews were significantly higher in T3 compared to those in other groups. However, ruminating time per bolus was not significantly difference among groups. The number of chews per bolus from high to low order was: C > T1 > T3 > T2 (p<0.05). The number of bolus per minute was not significantly different among groups. The number of drinking and the number of defecating were significantly higher in C and T1, respectively (p<0.05). However, the number of urinating had no effect according to pregnancy stage. Eating rate and chewing efficiency were significantly higher (p<0.05) in accordance with pregnancy stage (T3 > T2 > T1 > C). Ruminating efficiency was significantly (p<0.05) higher T1 than that in other groups.

This study was conducted to determine the growth performance and carcass characteristics of fattening Hanwoo heifers slaughtered at different ages. Twenty one Hanwoo heifers were randomly allocated to three groups (32, 36 and 40 months age), with 7 steers each, respectively. In the result, initial and final body weights were 125.6 and 651.0 kg, respectively. Average daily gain was significantly low at final stage compared with other growth stages (p<0.05). Dry matter intake was the peak at the intermediate fattening stage (p<0.05). The feed conversion ratio was significantly lower at growing stage compared to other stages (p<0.05). In yield traits, carcass weight was greater in 40 months age group compared to other groups (p<0.05). Yield index was greater in 32 months group compared to 40 months of age (p<0.05). Marbling score, meat color, fat color, texture, and maturity were not different among groups (p>0.05). However, marbling score tended to be increased in 40 months age group (5.9) compared to other groups. The appearance rate (%) of meat quality grade more than 1+ was greater at 40 months old group than other groups.

본 실험에서는 2008년부터 2010년까지 월동작물로 재배되는 청보리와 호밀에 화학비료,유기질비료 및 가축분뇨의 시용 그리고 콩과작물의 혼파재배가 작물의 생산성과 사료가치에주는 효과를 토양의 지력향상과 함께 양질의조사료를 확보하여 단위면적당 한우 사육 능력을 높일 수 있는 방법을 찾아내고자 무비구,화학비료 PK시비구, 화학비료 NPK 시비구, 유기질비료 시용구, 액상우분뇨 시용구, 액상우분뇨 시용에 헤어리벳치 혼파구 및 액상우분뇨시용에 청예완두 혼파구 등 7처리 3반복 난괴법으로 배치하여 실험이 실시되었다. 청보리의연간 건물과 가소화양분총량 (TDN) 수량은 화학비료 NPK 시비구 (각각 6.14와 3.97 ton/ha)가가장 높았으나 (p<0.05), 유기질 비료구 (각각5.24와 3.37 ton/ha), 액상우분뇨 (각각 5.53과3.63 ton/ha) 및 콩과 혼파구 (각각 5.00~5.15와3.32~3.33 ton/ha)와 유의적 차이는 나지 않았다.청보리의 TDN과 RFV는 액상우분뇨 시용에 청예완두 혼파구가 가장 높았다 (p<0.05). 청보리를 급여 시 한우 암소는 유기질비료, 액상우분뇨 혹은 액상우분뇨 시용에 두과작물 혼파구가연간 ha당 평균 2.5~2.9두를 사육할 수 있는 것으로 나타났다. 호밀의 연간 건물, 조단백질 및TDN 수량은 유기질비료, 액상우분뇨 혹은 액상우분뇨 시용에 두과작물 혼파한 구가 ha 당각각 6.69~7.13, 0.46~0.51 및 3.95~4.18 ton으로나타남으로써, 호밀을 급여할 경우 암소는 연간 ha 당 평균 3.1~3.3두 규모의 사육능력이 추정된다. 이상의 결과를 종합해 볼 때, 건물생산성만을 고려해서 화본과 작물을 단파로 재배하는 것보다는 가축의 기호성과 품질의 개선효과까지 고려하여 두과작물 등을 혼파 재배하고 가축분뇨를 시용함으로써 단위면적당 수량과 사료가치를 높일 수 있으며 한우사양 시에는 단백질공급원으로 이용되는 수입 곡류 등을 대체하는효과까지도 기대할 수 있으리라 생각된다.

This study was carried out between November 2007 and October 2008 in the experimental farm of Chunnam National University to investigate the effect of feeding of whole crop barley silage on the reproductive performance of Hanwoo heifers and cows. Two diets, rice straw or whole crop barley silage separately from concentrate were fed 11 Hanwoo heifers and 26 Hanwoo cows. In control group (=CON), heifers (n=6) and cows (n=13) were fed 7 kg (/head) rice straw and 4 kg (/head) commercial diet. In whole crop barley silage group (=WBG), heifers (n=5) and cows (n=13) were fed 8 kg (/head) whole crop barley silage and 1 kg (/head) commercial diet. 1. Conception rates for first service in CON or WBG heifers were 66.7% (4/6) and 60.0% (3/5), respectively, and the services per conception cows were 1.5±0.2 for CON and 1.4±0.2 for WBG group. 2. Days to post-partum insemination were 106.6±26.3 days for CON and 85.6±12.6 days for WBG group, and days to post-partum conception in CON or WBG were 128.4±27.1 and 96.8±16.8 days, respectively. 3. Post-partum conception rates for first service in CON or WBG were 76.9% (10/13) and 84.6% (11/13), respectively, and caving interval was 418.1±50.7 days for CON and 392.8±20.7 days for WBG group.

The objective of present study was to investigate the effect of seasons on reproductive performance of Hanwoo and Holstein heifers. Heat stress in summer or cold stress in winter stress to Hanwoo and Holstein heifers may bring reproduction failure, which would pose an important economic loss, even around Daegwallyeong region located in high mountainous area. Seasonal differences in the serum levels of LH, FSH and progesterone () in response to environmental factors (hot and cold) out of 20 pubertal Hanwoo heifers in Daegwallyeong, Gangwon Province and 20 non-lactating Holstein heifers in Chonan city of Republic of Korea at 2-3 years of age were compared. Blood samples for hormonal analysis were from jugular vein after detection of estrus repeatedly over four seasons within four-week intervals (Spring: May to June, Summer: July to August, Autumn: October to November and Winter: January to February). In Hanwoo heifer population, averages of LH and FSH concentration in spring and in summer were greater compared to those in winter (p<0.05). LH or FSH levels tended to be greater (p=0.06) in spring and less (p=0.09) in winter compared to the levels in autumn. Only in summer, cattle seemed to show lower LH or FSH secretion (p<0.05). Similar to the results in Hanwoo heifers, the serum concentrations of LH and FSH in Holstein heifers decreased further by heat stress in summer when P 4 levels were high during luteal phase. The results demonstrate significant effect of summer heat on reproduction of Hanwoo or Holstein heifers. Although parameters indicating the extent of heat stress were not measured in this study, we suggest that serum hormone levels could be considered as successful indicators of summer heat stress condition for Hanwoo and Holstein heifers even under rather cool summer climate.