• Journal of Animal Science and Technology
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• v.51 no.6
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• pp.511-520
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• 2009

The purpose of this study was to investigate effects of increased levels of eugenol, thymol and malate on pH and the concentrations of VFA, lactate and ammonia-N during in vitro ruminal incubation. One Hanwoo beef steer (741 kg) fitted with a rumen cannula was used and fed 0.5 kg/day rice straw and 10 kg/day corn-based concentrate (ratio of concentrate to rice straw = 95 : 5 on DM basis). Three different doses of thymol, eugenol and malate were used. Treatments of the experiment were as follows: Treatments of thymol were control (1g D-glucose/40ml), T1 (1g D-glucose + 40 mg thymol/40 ml), T2 (1g D-glucose + 50 mg thymol/40 ml) and T3 (1g D-glucose + 60 mg thymol/40 ml). Treatments of eugenol were control (1g D-glucose/40 ml), E1 (1g D-glucose + 55 mg eugenol/40 ml), E2 (1g D-glucose + 65 mg eugenol/40 ml) and E3 (1g D-glucose + 75 mg eugenol/40 ml). Treatments of malate were control (1g D-glucose/40ml), M1 (1g D-glucose + 25 mg malate/40ml), M2 (1g D-glucose + 50 mg malate/40 ml) and M3 (1g D-glucose + 100 mg malate/40 ml). The results of this study showed that eugenol and thymol have improved stability of the ruminal fermentation by decreasing lactic acid concentration and increasing ruminal pH. However, it inhibited the production of total VFA, acetate and propionate. Malate also improved stability of the ruminal fermentation by decreasing lactic acid concentration and increasing ruminal pH, but it had a very little effect on ruminal lactate concentrations and pH. On the other hand, malate did not decrease the concentrations of total VFA, acetate and propionate. Therefore, at the low ruminal pH expected in high-concentrate diets, thymol, eugenol, and malate are potentially useful in Hanwoo finishing diets. Further studies are necessary for determining the effectiveness of these additives on in vivo rumen fermentation and animal performance in Hanwoo finishing steers.

• Journal of Animal Science and Technology
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• v.53 no.4
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• pp.367-375
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• 2011

This study was carried out to investigate the effects of the level of cracked whole barley on daily feed intake, daily body weight gain, carcass characteristics and meat composition of finishing Hanwoo steers (feeding from 24 months to 30 months of age). The dietary treatments were consisted of five types (C; normal concentrate as a basal diet, T1; 10% addition of cracked whole barley, T2; 20% addition of cracked whole barley, T3; 30% addition of cracked whole barley, T4; 40% addition of cracked whole barley). A total 30 Hanwoo steers (588.6${\pm}$11.8kg) were allocated to 5 feeding groups. The daily feed intake and daily body weight gain were high in the order of T2 > T3 >T4 > T1 > C. The back fat thickness and longissmus muscle area were highest in C and T1, respectively (P<0.05) than other treatments. The meat yield index decreased with increased back fat thickness. The marbling score and meat quality were highest in T1 (P<0.01, 0.05, respectively), but maturity, fat color and meat color were not significantly different among treatments. The crude fat was highest in T1 (17.59%), while in T4 (7.47%) it was lowest (P<0.05). The crude protein and crude ash were not significantly different among treatments. The energy value of cracked whole barley treatments (T1, T2, T3, T4) was higher than C (P<0.05). The contents of Ca, Cu, K, Mg, Mo, Na and Zn were higher in C than the other treatments (P<0.01), but Co was higher in T2 (P<0.01). The CIE $L^*$ value of whole cracked barley treatments (T1, T2, T3, T4) was higher than C, however there were not differences among the treatments. The CIE $a^*$ value was highest in T1(P<0.05) than others. The CIE $b^*$ value was highest in C and it was decreased with increased feeding of cracked whole barley. Based on the above results, T1 treatment compared to other treatments improved the carcass quality parameters like loin muscle area, marbling score, meat quality, and CIE $L^*$ value.

• Journal of Life Science
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• v.18 no.8
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• pp.1090-1095
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• 2008

Marbling (intramuscular fat) is an important factor in determining meat quality in Korean beef market. A grain based finishing system for improving marbling leads to inefficient meat production due to an excessive fat production. Identification of intramuscular fat-specific gene might be achieved more targeted meat production through alternative genetic improvement program such as marker assisted selection (MAS). We carried out ddRT-PCR in 12 and 27 month old Hanwoo steers and detected 300 bp PCR product of the inducible cAMP early repressor (ICER) gene, showing highly gene expression in 27 months old. A 1.5 kb sequence was re-sequenced using primer designed base on the Hanwoo EST sequence. We then predicted the open reading frame (ORF) of ICER gene in ORF finder web program. Tissue distribution of ICER gene expression was analysed in eight Hanwoo tissue using realtime PCR analysis. The highest ICER gene expression showed in Small intestine followed by Longissimus dorsi. Interestingly, the ICER gene expressed 2.5 time higher in longissimus dorsi than in same muscle type, Rump. For gene expression analysis in high- and low marbled individuals, we selected 4 and 3 animal based on the muscle crude fat contents (high is 17-32%, low is 6-7% of crude fat contents). The ICER gene expression was analysed using ANOVA model. Marbling (muscle crude fat contents) was affected by ICER gene (P=0.012). Particularly, the ICER gene expression was 4 times higher in high group (n=4) than low group (n=3). Therefore, ICER gene might be a functional candidate gene related to marbling in Hanwoo.