한우 암소의 번식형질은 생산성과 직결되는 핵심 경제형질로서 개량의 중요성이 크다. 본 연구는 혈통 정보와 유전체 정보를 통합하는 single-step genome-wide association study (ssGWAS)를 적용하여 한우 암소 번식형질과 연관된 유전체 영역을 탐색하고 기능적 후보 유전자를 제시하고자 하였다. 분석에는 초산우의 초산일령과 경산우의 임신기간, 공태일수, 분만간격, 수태당 종부횟수의 표현형 자료가 활용되었으며, 총 809두의 초산우 와 789두의 경산우가 포함되었다. ssGWAS 결과 대부분의 SNP 표지인자는 전체 상가적 유전분산의 1% 미만을 설명하였으나 일부 염색체에서 뚜렷한 피크가 관찰되었다. 이에 전체 상가적 유전분산의 1% 이상을 설명하는 SNP 윈도우를 선별한 후 물리적 위치가 인접한 윈도우를 병합하여 peak interval로 정의하였고, 각 peak 내에서 변이 설명 비율이 최대인 SNP를 lead SNP로 지정하였다. 이후 후보 유전자 탐색 및 기능 주석 분석을 수행하였고, CattleQTLdb를 활용하여 기존 보고된 번식형질 관련 QTL/association 영역과의 중복 여부를 확인하였다. 기능 풍부도 분석에서 는 자궁·태반 조직 재형성과 관련된 proteolysis 조절 기작과, 정자 기능 및 수정능력과 연관된 기능 항목이 확인되어 번식 과정의 주요 생물학적 경로를 시사하였다. 또한 기존 보고와 중복되지 않는 신규 후보 QTL 영역을 다수 검출하여 번식형질의 유전적 기반에 대한 추가 단서를 제공하였다. 본 연구 결과는 한우 암소 번식 형질과 관련된 유전체 영역 및 유전자 기능적 근거를 제시함으로써, 향후 암소의 유전체 선발 및 번식 능력 개량을 위한 기초 자료로 활용될 수 있을 것이다.

Integrated crop–livestock farming systems improve the self-sufficient feed ratio, and provide environmental benefits for agro-ecosystems. This study was conducted to evaluate the crop-livestock recycling indicators of Korean Hanwoo farms. 55 Korean beef farms were classified into five types. Organic Hanwoo farms were insufficient the area of forage crop cultivation required for Hanwoo certification in Korea, with forage crop sufficiency index of 49.6%. The forage self sufficiency index of grazing eco-farms was 108.5%, and self-certified (PGS) and conventional livestock farms was only 24.5 and 25.6%, respectively. The forage self sufficiency index was 60.4, 52.9, and 111.9% for Hanwoo + grassland crop, Hanwoo + forage crop + rice, and Hanwoo + grassland combined farms, respectively. Livestock density was 10.3 LSU (livestock units)/ha for organic Korean cattle farms, which was lower than 25.6 LSU/ha for conventional farms. In addition, the livestock density of grassland eco-farms was the lowest at 3.4 LSU/ha. Livestock density was 12.2 LSU/ha in the southern region, which was lower than in the central-northern region. In conclusion, forage crop sufficiency and livestock density are considered valid indicators for assessing the level of crop-livestock integrated agriculture.

This study was conducted to elucidate the effects of feeding betaine or monosodium glutamate on the growth and carcass performance of Hanwoo steers according to the fattening stage under high-temperature stress. Farms in an area where THI was 78 or higher for more than 100 days were selected, and 30 head in the early fattening stage (14-15 months of age), 30 head in the mid-fattening stage (16-18 months of age), and 30 head in the late fattening stage (24-25 months of age) were tested, and 10 head were assigned to each treatment group. The experimental group was divided into control, T1 with 96% of the amino acid compound additive and 4% betaine, and T2 with the amino acid complex additive and 4% monosodium glutamate. 50 g per head were fed every morning for a total of 5 months from May 1, 2022 to September 30. In this study, there was no effect of betaine and monosodium glutamate on the growth and rectal temperature of Hanwoo steers at each fattening stage, but monosodium glutamate had a positive effect on the increase in rib eye area and decrease in back fat thickness in steers in the late fattening stage (P<0.05). Therefore, the results of this study indicate that monosodium glutamate did not have a direct effect on the growth of fattening Hanwoo steers, but it is thought to have a positive effect on the rib eye area and back fat thickness through protein metabolism and muscle development.

This study was conducted to investigate the effects of supplementation of direct-fed microbials (DFMs) during the growing and finishing periods on growth performance and carcass characteristics in Hanwoo steers. DFMs were administered only during the first 3 months after arrival and the final 3 months before slaughter, and the feeding trial lasted for 740 days. During the growing phase, the treatment group showed a significantly higher average daily gain (ADG) of 0.89 kg compared to 0.80 kg in the control group (p<0.05). No significant differences were found between groups during the fattening phase. In the finishing phase, ADG was significantly higher in the treatment group (0.59 kg vs. 0.53 kg; p<0.05), although concentrate intake increased by 6.17% without statistical significance. At the end of the entire feeding period, the treatment group had a higher final body weight (803.05 kg vs. 763.51 kg), and overall ADG was significantly greater (p<0.05). For carcass traits, cold carcass weight was significantly higher in the treatment group (p<0.05), while no significant differences were observed in backfat thickness, loin eye area, or marbling score. However, the proportion of carcasses graded 1++ was higher in the treatment group (50.0%) than in the control group (30.0%). In conclusion, supplementation of direct-fed microbials during the growing and finishing periods improved average daily gain and increased the proportion of carcasses with higher quality grades in Hanwoo steers.

This study evaluated the effects of the cells alive system (CAS) freezing method and different thawing methods (refrigeration and running water) on the quality of aged Hanwoo shoulder clods. Thawing time was significantly influenced by the thawing method, with running water thawing taking 3 h and refrigeration thawing exceeding 20 h. CAS freezing yielded significantly higher lightness (L*) values during running water thawing than it did during general freezing (p<0.05), likely owing to reduced water loss. CAS-frozen meat exhibited lower volatile basic nitrogen levels and thawing loss (2.05%–2.11%) compared with that of general frozen meat (3.17% –3.79%), indicating superior freshness and reduced quality deterioration (p<0.05). Among the textural properties, springiness was highest in frozen and running water-thawed CAS meat (10.5 mm). In contrast, general freezing combined with refrigeration thawing caused the greatest quality degradation, as reflected by the lowest pH (5.45) and water holding capacity (86.36%), and highest cooking loss (32.98%). These results suggest that CAS freezing combined with running water thawing minimizes changes in quality and enhances springiness, making it an optimal approach for the production of high-quality aged meat.

Alfalfa hay varieties have been developed and cultivated in Korea to enhance the self-sufficiency rate of domestic roughage. The objective of this study was to compare the effects of feeding domestic and imported alfalfa on the growth performance and economic feasibility of Hanwoo bulls. This study was conducted using eight Hanwoo bulls, aged 6 to 7 months, during their growing period. Hanwoo bulls were divided into two groups: one group fed imported alfalfa and the other group fed domestic alfalfa. Dry matter intake, weight gain, and blood metabolites were analyzed for two months of the growing stage. There was no significant difference between the two groups in dry matter intake and body weight. However, the price of domestic alfalfa is lower than that of imported alfalfa, so feeding domestic alfalfa is expected to have a positive effect on reducing production costs. Further study is needed to compare not only the growth performance but also carcass characteristics after slaughter by feeding domestic alfalfa to Hanwoo for a longer period during their growing stage.

We investigated the variations in the total bacterial counts (TBC) and coliform counts in a variety of Korean Hanwoo beef cuts (strip loin, rump, flank, shank, chuck and loin) stored at different temperatures after wrapping or vacuum packaging. TBC and coliform counts in all the cuts increased with an increase in the storage period. The initial microbial at baseline was higher in the chuck cut (2.0 log CFU/cm2) than in the other cuts (1.1~1.3 log CFU/cm2). Compared to wrapping, vacuum packaging effectively delayed spoilage. TBC exceeded 6 log CFU/cm2 at 2 and 4oC in 21 and 11 days for wrapped meats and in 50 and 32 days for vacuum-packaged meats, respectively. Regardless of the initial microbial count, the TBC of wrapped meats stored at 10 and 15oC exceeded 6 log CFU/cm2 in 4 and 3 days respectively, whereas that of the vacuumpackaged meats exceeded this level at these temperatures 6 and 5 days, respectively. Chuck cuts, with relatively high initial microbial levels, reached the spoilage point more quickly than other cuts under the same conditions. To sum up, vacuum packaging followed by storage and distribution at 2oC is the most effective approach for extending shelf life and maintaining quality.

This study was conducted to estimate the effects of the forage process on rumen fermentation characteristics and greenhouse gas emissions of rye. Rye was grown at the Taeyoung Livestock farm and harvested at the heading stage. The harvested rye (5 kg) was sub-sampled for fresh forage, hay, and silage in triplicates. The sub-sampled rye was freeze-dried or air-dried for fresh forage or rye hay, respectively. For rye silage, the sub-sampled rye forage was ensiled into a 10 L mini bucket silo and stored for 90 days. For 72 h rumen incubation, each forage (0.3 g) was placed into the incubation bottle with the rumen mixture (30 mL) in quadruplicates. After the incubation, total gas was measured and sub-sampled for CO2 and CH4 analyses, and the bottle content was centrifuged for in vitro digestibilities of dry matter (IVDMD) and neutral detergent fiber (IVNDFD), and rumen fermentation characteristics. Silage had higher crude protein, crude ash, and acid detergent fiber concentrations than fresh forage and hay but lower non-fiber carbohydrates and relative feed value (p<0.05). And, silage had higher lactic acid bacteria than the other forages but lower pH (p<0.05). After 72 h incubation in the rumen, fresh forage had higher IVDMD and butyrate content than the other forages (p<0.05). However, silage had higher rumen pH and propionate content than the other forages but lower A:P ratio (p<0.05). Regarding greenhouse gases, silage had lowest total gas (mL/g DMD and NDFD) and CH4 (mL/g DMD and NDFD) emissions, while fresh forage had lowest CO2 (mL/g DMD) emission (p<0.05). Therefore, this study concluded that the ensiling process of rye can effectively mitigate greenhouse gas emissions of Hanwoo.

This study analyzed the correlation between carcass traits of Hanwoo steers and feeding methods (concentrate feed and total mixed ration for ruminants). The results indicated that in the feeding system using concentrate feed, the variation in carcass weight and marbling score among individual animals within farms tended to affect the average carcass sale price, with both showing negative effects (p=0.057, p=0.053). The standardized regression coefficients were used to compare the influence of each variable, revealing that the coefficients for carcass weight variation and marbling score variation were –0.38 and –0.30, respectively, indicating a greater influence of carcass weight variation. Therefore, reducing the variations in carcass weight and marbling score among steers in farms using concentrate feed is likely to increase the average carcass sale price. In the case of farms using total mixed ration (TMR) for ruminants, the variation in marbling score among individual animals significantly affected the average carcass sale price, showing a negative effect (p=0.002). Thus, reducing the variation in marbling score among steers in TMR farms is likely to increase the average carcass sale price. In summary, the coefficient of variation of marbling score was found to have a significant impact on the average carcass sale price of the farm. In farms using concentrate feed, the variations in both carcass weight and marbling score tended to affect the average carcass sale price (0.05<p<0.1). Meanwhile, in farms using TMR, the variation in marbling score had a significant impact. In conclusion, the coefficient of variation for marbling score in carcass performance was found to have the most significant impact on the average carcass sale price for both feeding types (concentrate and TMR diets). Furthermore, reducing the variation along with carcass weight of Hanwoo steers on concentrate feed may be a way to increase farm income.

The study aimed to investigate the impact of varying levels of neutral detergent-soluble fiber (NDSF) in Hanwoo growing cattle diets on rumen fermentation and methane (CH4) emissions. An in vitro rumen fermentation experiment utilized feeds with different NDSF levels, incorporating ingredients such as corn grain, soybean meal, soybean hulls, palm kernel meal, beet pulp and timothy hay. The NDSF contents in the diets were 9.02% (T1), 10.09% (T2), 12.42% (T3) and 14.63% (T4). In vitro dry matter digestibility (IVDMD) at 48 h was 7.4% higher for T4 compared to T1 (p<0.05). Total gas production at 48 h was 6.6% higher for T4 than T1 (p<0.05). CH4 production significantly decreased at 9 h and 12 h for T1 and T2 (p<0.05). At 48 h, CH4 production was 5.6% higher for T4 compared to T1 and 6.7% higher compared to T2 (p<0.05). At 12 h ans 24 h, the ammonia nitrogen concentration of T4 was approximately 33.1% and 40.4% lower, respectively, compared to T1 (p<0.05). The acetate to propionate ratio at 48 h was approximately 18.8% higher for T4 than T1 (p<0.05). From 9 h to 48 h, the proportions of butyrate and valerate were significantly higher for T4 (p<0.05). At 48 h, the dominant phylum in T4's rumen microbial community was Candidatus Thermoplasmatota Methanomassiliicoccus, an Archaea. Therefore, this study confirmed that increasing the NDSF content in growing Hanwoo cattle diets up to 12.42% increases IVDMD without increasing CH4 emissions, which is expected to positively impact Hanwoo productivity.

This study was conducted to examine the microbiological quality indicators (total bacterial count and coliform count) and physicochemical quality indicators (pH, redness, volatile basic nitrogen [VBN] content) of meat according to various storage temperatures (20~15oC) and packaging methods (wrap, vacuum). Based on these results, we proposed a safe consumption period. Redness, pH, and VBN content were not considered appropriate for setting the expiration date, as the redness and pH of the meat after spoilage were better than the standard values for both vacuum and wrap packaging (p<0.05). Additionally, the VBN content at 2 and 4oC increased slightly (fresh level) until the initial time of spoilage (1.0×106 colony-forming unit [CFU]/cm2) and then increased rapidly thereafter. Therefore, the results were not consistent with microbial spoilage. When the decay point was evaluated based on the presence of microorganisms, vacuum packaging extended the storage period approximately 2.5-fold when compared with wrap packaging, and the meat could be stored at 2 or 4oC for 40 or 23 days, respectively. Therefore, to evaluate meat quality, microbial indicators should be considered first. The microbiological standards proposed in this study can be used for safety management during the distribution of meat. However, to ensure meat safety, additional investigations of appropriate indicators of freshness must be conducted.

This study aimed to investigate the effects of amino acid complex additives, such as protected vitamin C (VC) or detoxified sulfur (DS), on the growth and metabolism of Hanwoo cattle under high-temperature conditions. Accordingly, farms in Temperature-Humidity Index (THI) regions ranging from 78 to 89 for over 100 days were selected. The experimental groups were control, T1 (lysine + methionine + VC, 50 g/head/day), and T2 (lysine + methionine + DS, 50 g/head/day) with 70, 77, and 71 animals each. The range of the THI for 115 days was 78-89, and this occurred in most of the experiment days. The results showed that there was no significant difference in rectal temperature among the groups. The body weight increased to 786.4 and 809.0kg in the T1 and T2 groups, respectively, compared to the control group (p<0.05). Linoleic acid showed a high result of 2.01% in the T1 group compared to the control group (p<0.05). Unsaturated fatty acids were higher at 55.70 and 56.54% in the T1 and T2 groups, respectively, compared to the control group (p<0.05), and the omega 6/3 ratio was reduced to 20.10% (p<0.05). These findings indicate that T1 has a positive impact on growth, meat quality, and fatty acid composition compared to the control group. In conclusion, amino acid complex with VC improved the body weight of Hanwoo steers and the unsaturated fatty acids and essential amino acids of their meat; however, further research is needed to clarify this impact on carcass performance.

γ-aminobutyric acid (GABA) is a natural stress-reducing substance and is actively used as a human health supplement. However, minimal research has been conducted on its use in cattle. This study was conducted to evaluate the effects of GABA on the growth performance, complete blood count, blood metabolites, and carcass characteristics of fattening Hanwoo steers. Twenty-one fattening steers were randomly assigned to one of three treatments: control (basal diet: concentrate feed + rice straw), T1 (basal diet + GABA supplement at 0.8% of feed/head/day), and T2 (basal diet + GABA supplement at 1.6% of feed/head/day). Feed intake and conversion ratio did not differ among the treatments. However, the average daily gain during the early fattening period increased linearly to 0.80 kg, 0.86 kg, and 0.92 kg in the control, T1, and T2 groups (p<0.05). Plasma γ-glutamyl transferase (37.5, 58.2, 42.8 U/ℓ) and creatinine (1.32, 1.34, 1.49 ㎎/㎗) levels in the GABA supplement group were increased compared to those in the control group. The carcass weight (422.7, 427.1, 454.1 kg), rib eye area (86.67, 92.57, 91.14 cm2), and marbling score (3.67, 4.29, 4.14) were numerically higher in the GABA supplement group than in the control group. Thus, GABA supplementation positively affected the average daily gain and carcass characteristics of Hanwoo steers. However, the effect of the GABA supplement level of GABA was small, and further research using rumen-protected coating technology on GABA is necessary.

한우에게 급여하는 사료 내 에너지원의 종류에 따라 반추위 미생물의 아미노산 조성에 차이가 있는지를 조사하고자 본 연구를 수행하였다. 국내 한우 비육우 사육에 주로 이용되는 에너지원 사료인 옥수수(T1), 생미강(T2), 소맥(T3) 그리고 소맥피(T4)로 반추위 환경과 유사한 연속식 배양기를 이용하여 72시간까지 배양을 진행하였다. 배양이 진행되는 동안 6시간 간격으로 배양액의 발효 성상을 확인하였으며 pH, NH3-N이 일정하게 유지되는 것을 확인하였으며, 배양 종료 시점인 72시간대에 미생물체 단백질 합성량(MPS), 미생물의 아미노산 조성 및 미생물 균총 변화를 분석하였다. 배양액의 pH는 모든 처리구에서 배양 기간동안 5.5~7.0을 유지하였다. Total VFA 농도는 T1이 23.13 mM으로 가장 낮았고, T4가 29.93 mM으로 가장 높았다(p<0.05). A (acetate) :P (propionate) 비율은 T1이 1.48로 가장 낮았으며, T4가 2.81로 가장 높게 나타났다 (p<0.05). Butyrate는 T1이 2.37 mM으로 가장 낮았으며, T2, T3 그리고 T4는 4.37~4.58 mM으로 차이가 없었다(p<0.05). MPS는 T2 (332.5 mg/L)와 T3 (320.2 mg/L)가 높았고 T1 (137.5 mg/L)와 T4 (154.2 mg/L)로 낮게 나타났다(p<0.05). DGGE band 분석결과 모든 처리구는 57.5 % 이하의 유사도가 나타났다. 미생물의 총 아미노산 함량은 T1 (31.59 %)과 T3 (31.33 %)가 가장 높았으며, T2 (20.09 %)가 가장 낮았다 (p<0.05). 이는 급여된 사료 내 총 아미노산 함량과 반대되는 결과로 나타났다. 따라서, 본 연구에서 한우 급여 에너지원 사료에 따른 반추위 내 미생물 발효 특성과 미생물체 단백질 합성량이 미생물 군집에 영향을 미치며 이에 따라 미생물의 총 아미노산 함량에 영향을 미친다는 것을 확인하였다.

본 연구는 국내의 한우 개량에 있어서 정확한 혈통 정보가 중요해짐에 따라 고밀도 Single Nucleotide Polymorphism (SNP) chip의 SNP 정보들을 활용한 친자 확인으로 혈통 정보의 신뢰도 향상에 기여하고자 실시하였다. 이미 혈통 정보가 확인되고 Microsatellite (MS) 유전자형으로 친자 여부가 확인된 14개의 가계, 318두로 친자 확인 분석을 하였다. Call rate 100%인 마커들을 활용한 친자 확인 분석 결과, 9두가 모 부정, 19두가 완전 부정으로 총 28두가 부정으로 판정되었고, 이는 부모의 SNP 정보에서 나올 수 있는 조합과 다른 자식의 유전자형이 확인되었다. 이후, 친자 확인 정확도 향상을 위해 call rate와 minor allele frequency (MAF)를 기준으로 SNP 마커 수를 증가시켜 분석하였으나 부정으로 판정되는 개체들이 추가적으로 발생하였고, 이는 SNP 정보의 결측치 증가 및 자식의 유전자형 변이로 인한 것으로 판단된다. 따라서 고밀도 SNP chip을 활용한 친자 확인 분석에는 보다 신중한 접근이 필요하며, 본 연구 결과는 고밀도 SNP 정보를 이용한 친자 확인 연구에 있어서 기초자료로 활용될 수 있을 것으로 사료된다.

This study was designed to evaluate the objective meat qualities of Hanwoo longissimus lumborum muscle after a period of long-term storage (40 days) in which conditions similar to those under which the meat would be stored for export to the Hong Kong beef market were simulated. Twelve LL muscles were sampled from animals slaughtered the previous day at a commercial beef export abattoir and assigned to one of three groups. Each group was subjected to a different packaging condition; Shrink film packed (SFP), vacuum packed (VP), or modified atmosphere packed (MAP)(O2/60%, CO2/40%). Objective meat qualities were assessed at day 1, 7, 21 and 40 of storage. Different Packaging conditions had no noticeable influence on cooking loss significantly. However, the moisture content in both the SFP and MAP groups tended to decline in a linear manner with storage periods throughout the 40 days period. Drip loss of MAP (5.68%) group was much higher in the SFP (3.18%) and VP (2.64%) groups at storage day 40. Redness (CIE a*) of meat color responded in a significant and completely different manner to each packaging method. Redness significantly (p<0.05) and continuously increased 17.51 at day 1 to 20.41 at day 40 in VP group, while MAP linearly dropped and ultimately reached 10.6 after 40 days of aging (p<0.05), at which point the meat had a brown color. Tests of Warner-Bratzler shear force (WBSF) indicated that the tenderness levels of the ready-for-export Hanwoo LL muscles were acceptable 7 days postmortem in the SFP and VP groups, however there was no significant difference between each group. Our gathered data suggests that the packaging method selected for export determines how well the objective qualities of the beef hold up, and indicate that VP is likely the most reliable method.

쇠고기 이력추적제는 소 개체마다 이력번호를 부여하여 수입쇠고기가 한우고기로 둔갑하는 사례를 막고, 소비자 에게 구입한 한우고기의 세부 이력 정보들을 제공하는 데 도움을 준다. 이번 연구는 2021년-2022년 서울지역 대형 축산물판매업소에서 유통되는 한우고기 344건에서 DNA 동일성 검사를 실시하여 이력번호 등 주요 표시정보들의 진위를 판별하였다. 그 결과 45건(13.1%)에서 이력번호가 불일치한 것으로 확인되었다. 불일치율은 2021년(14.7%) 에 비해 2022년(11.3%) 감소하였고, 도심서북권 20.7%, 동 북권 14.4%, 서남권 및 동남권 10.2% 순으로, 북부권 (16.9%)이 남부권(10.2%)에 비해 높게 나타났다. 또한 6개 브랜드 중 B사 및 D사는 이력관리가 양호한 반면, E사 및 A사는 이력관리가 취약한 것으로 확인되었고, 통계적 으로 유의한 결과 차이를 보였다(P<0.001). 이력번호 불일 치 시료의 실제 이력번호는 업소 내 입(출)고 거래내역 자 료를 근거로 조사하였고, 그 결과 실제 이력번호 확인율 은 53.9%에 불과하였으나, 확인된 범위 내에서 시료의 표 시정보 진위 판별 결과, 거짓 표시는 이력번호 13.1%, 성 별 2.9%, 도축장명 2.2%, 등급 1.6% 순으로 나타났고, 품종 (한우) 거짓 표시는 없었다. 거짓 표시 축산물의 유통 차 단을 위해 표시정보의 신속한 진위 판별이 중요하므로 업 소 내 이력번호가 기재된 날짜별 부분육 소분할 작업내역 작성을 의무화하는 법적 근거 마련이 필요하다. 본 연구 결과는 투명한 축산물 유통 거래 질서 정착을 위한 이력 관리 방향 설정에 참고자료로 활용하고자 한다.

본 연구에서는 미생물 첨가에 따라 거세한우 비육우 분의 이화 학적 특성, 미생물 성상, 가스발생량 및 퇴비 부숙도에 미치는 영 향을 규명하고자 수행하였다. 이상의 결과를 종합하면, 4주 후,미생물 첨가구에서 수분, 유기물, 총질소 함량 및 pH가 낮았으며, 나머지 이화학적 특성에서는 차이가 나타나지 않았다. 유산균과 효모균 수는 증가하였으며, 대장균 수는 감소하였다. 12주 후, 미 생물 첨가구에서 유산균과 고초균 수는 높았으나, 수분, 효모 및 대장균 수는 낮게 낮았다. 하지만 암모니아, 황화수소 발생량과 퇴비 부숙도는 미생물 첨가에 의한 효과가 나타나지 않았다. 따라 서, 거세한우 분에 미생물을 첨가하면 유익균은 증가하고, 병원성 미생물은 감소하여, 비육우의 생산성은 증진될 것으로 사료되지 만, 가스 발생량 및 퇴비 부숙도에 대한 추가적인 연구는 지속적 으로 수행되어야 할 것으로 사료된다.

반추위 미생물체 단백질의 아미노산 조성이 한우의 에 너지원 사료에 따라 차이가 있는지를 조사하고자 본 연구 가 수행되었다. 본 실험은 국내 한우 비육우 사육에 주로 이용되는 에너지원 사료인 옥수수(T1), 생미강(T2), 소맥 (T3), 소맥피(T4)를 이용하여 in vitro 반추위 발효실험을 진행하여 발효 24시간 후 배양액의 발효 성상, 미생물체 단백질 합성량(MPS), 미생물의 아미노산 조성 및 미생물 균총 변화를 분석하였다. 배양액의 pH는 T4가 6.02로 다 른 처리구들에 비해서 가장 높았으며, T1은 4.84로 가장 낮았다(p<0.05). Total VFA 농도는 T2가 96.80mM로 다른 처리구들에 비해서 가장 높았고, T1이 53.35mM로 가장 낮았다(p<0.05). 미생물체 단백질 합성량은 T3가 222.50g/L로 다른 처리구들에 비해서 높았으며(p<0.05), T1과 T4는 유의적인 차이는 없었지만 T1이 가장 낮았다. DGGE band 분석결과 모든 처리구는 57.5% 이하의 유사도를 나타내었으며, 급여되는 사료에 따라서 미생물 군집 이 다르게 나타났다. 미생물 내 총 아미노산 함량은 T3와 T4가 다른 처리구보다 높았다(p<0.05). 미생물의 아미노산 조성 중 대부분의 필수 아미노산은 T4가 다른 처리구들에 비해서 낮았다. 하지만 methionine은 다른 필수 아미노산 과 다르게 T4에서 가장 높았다(p<0.05). 곡류 사료 위주의 급여 시 결핍되기 쉬운 lysine은 모든 처리구에서 미생물 의 아미노산 조성이 8.05~8.98%의 범위에 있었다. 따라서, 본 연구에서 반추 가축 급여 에너지 사료원에 따른 반추 위 내 미생물 발효특성과 미생물 군집의 차이가 미생물의 아미노산 조성을 변화시킨다는 것을 확인하였다.