Effects of Palm Kernel Expellers on Growth Performance, Nutrient Digestibility, and Blood Profiles of Weaned Pigs

서자겸,W. Kim,J. Kim,J.K. Kim,S.C. Kim,Y. Jang,K. Jang,K. Kim,B. Kim,S. Park,I. Park,M. K. Kim,서강석,H.B. Kim,김인호,서성원,송민호 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.7

This experiment was conducted to investigate the effects of palm kernel expellers on growth performance, nutrient digestibility, and blood profiles of weaned pigs. A total of 88 weaned pigs (6.94±0.76 kg body weight [BW]; 28 d old) were randomly allotted to 2 dietary treatments (4 pigs/pen; 11 replicates/treatment) in a randomized complete block design (sex as a block). The dietary treatments were a typical nursery diet based on corn and soybean meal (CON) and CON added with 20% of palm kernel expellers (PKE). Pigs were fed for 6 wk using a 3-phase feeding program with declining diet complexity and with phases of 1, 2, and 3 wk, respectively. Blood was collected from randomly selected 2 pigs in each pen before weaning and on d 7 after weaning. Pigs were fed respective dietary treatments containing 0.2% chromic oxide from d 29 to 35 after weaning. Fecal samples were collected from randomly selected 2 pigs in each pen daily for the last 3 days after the 4-d adjustment period. Measurements were growth performances, digestibility of dry matter, nitrogen and energy, white and red blood cell counts, packed cell volume, and incidence of diarrhea. The PKE increased average daily gain (ADG) (246 vs 215 g/d; p = 0.06) and average daily feed intake (ADFI) (470 vs 343 g/d; p<0.05) and decreased gain-to-feed ratio (G:F) (0.522 vs 0.628 g/g; p<0.05) during phase 2 compared with CON, but did not affect growth performance during phase 1 and 3. During overall experimental period, PKE increased ADG (383 vs 362 g/d; p = 0.05) and ADFI (549 vs 496 g/d; p<0.05) compared with CON, but did not affect G:F. However, no differences were found on digestibility of dry matter, nitrogen, and energy between CON and PKE. The PKE reduced frequency of diarrhea (15% vs 25%; p = 0.08) for the first 2 wk after weaning compared with CON. Similarly, PKE decreased white blood cells (8.19 vs 9.56×103/μL; p = 0.07), red blood cells (2.92 vs 3.25×106/μL; p = 0.09), and packed cell volume (11.1% vs 12.6%; p = 0.06) on d 7 after weaning compared with CON. In conclusion, addition of 20% palm kernel expellers to nursery diet based on corn and soybean meal had no negative effects on growth performance, nutrient digestibility, and blood profiles of weaned pigs.

The co-injection of antioxidants with foot-and-mouth disease vaccination altered growth performance and blood parameters of finishing Holstein steers

서자겸,송민호,조남철,김운수,정신용,김종남,이세영,서성원 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.6

Objective: This study was conducted to evaluate whether the co-injection of antioxidants together with foot-and-mouth disease (FMD) vaccination has the potential to attenuate the negative effects caused by vaccination in Holstein finishing steers. Methods: A total of 36 finishing Holstein steers (body weight [BW]: 608±45.6 kg, 17 months old) were randomly allocated to one of three treatments: i) control (CON, only FMD vaccination without any co-injection), ii) co-injection of commercial non-steroidal anti-inflammatory drugs (NSAID) with FMD vaccination at a ratio of 10:1 (NSAID vol/FMD vaccine vol) as a positive control (PCON), iii) co-injection of commercial mixture of vitamin E and selenium with FMD vaccination (VITESEL) (1 mL of FMD vaccine+1 mL of antioxidants per 90 kg of BW). Changes in growth performance and blood parameters because of treatments were determined. Results: No significant difference in BW, average daily gain, and dry matter intake of the steers was observed among the treatments. The FMD vaccination significantly increased white blood cells (WBC), neutrophils, platelets, and mean platelet volume (p<0.01) in blood analysis. The count of lymphocyte tended to increase after vaccination (p = 0.08). In blood analysis, steers in VITESEL tended to have higher numbers of WBC, neutrophils, and platelets compared to that of other treatments (p = 0.09, 0.06, and 0.09, respectively). Eosinophils in VITESEL were higher than those in PCON (p<0.01). Among blood metabolites, blood urea nitrogen and aspartate transaminase were significantly increased, but cholesterol, alanine transferase, inorganic phosphorus, Mg, and albumin were decreased after FMD vaccination (p<0.01). Conclusion: The use of antioxidants in FMD vaccination did not attenuate growth disturbance because of FMD vaccination. The metabolic changes induced by vaccination were not controlled by the administration of antioxidants. The protective function of antioxidants was effective mainly on the cell counts of leukocytes.

마늘 껍질 조사료 활용을 위한 in vitro 반추위 발효 성상 및 메탄 발생량 평가

유대겸,김한빈,문준범,이동빈,이은지,하재룡,이유경,서자겸 경상국립대학교 농업생명과학연구원 2022 농업생명과학연구 Vol.56 No.1

본 연구는 조사료 원료인 마늘 껍질의 사료적 가치와 메탄 발생량을 조사하기 위해 in vitro 발효 실험을 수행하였다. Garlic husk를 제외하고국내에서 널리 사용되는 4가지 조사료 원료(Oat hay, Annual ryegrass, Timothy, Tall fescue)를 실험의 처리구로 구성하였다. In vitro 48 시간발효 후 건물 소화율, 섬유소 소화율, 암모니아태 질소, 휘발성 지방산, pH, 메탄 발생량을 평가하였다. 가스 발생량은 3, 6, 9, 12, 24, 36 및48 시간에 각각 측정되었다. 최종 가스 발생량에서 Oat hay가 유의적으로 가장 높았다(p<0.01). Garlic husk는 처리구 중 가장 높은 메탄 발생량을나타내었다(p<0.01). Garlic husk의 건물 소화율은 Oat hay보다 유의적으로 낮았지만 Annual ryegrass, Timothy, Tall fescue보다 높았다(p<0.01). 섬유소 소화율은 Annual ryegrass에서 가장 낮았다(p<0.01). 총 휘발성 지방산 생성량은 Oat hay에서 가장 높았고(p<0.01), Garlic husk, Timothy, Tall fescue는 유사하였다. 본 연구의 in vitro 발효 성상과 메탄 발생량을 고려할 때, Garlic husk는 국내 주요 조사료를 대체할 영양적 가치를포함하고 있으나 메탄 저감 효과는 미미할 것으로 추정된다.

사료 접종 방법에 의한 in vitro 반추위 발효 상성 변화

유대겸,문준범,김한빈,양성재,박중국,이세영,서자겸 강원대학교 동물자원공동연구소 2019 동물자원연구 Vol.30 No.3

The objective of this study was to investigate the effect of different feed inoculation method on rumen fermentation in an in vitro. Three experimental treatments were used: control (CON, direct dispersion of feed (2 g) in rumen fluid), combinations of direct dispersion (1 g) and nylon bag (DNB, pore size: 50 μm, 1 g), and nylon bag (NB, 2 g). An in vitro fermentation experiment was carried out using strained rumen fluid for 48 h incubation time and timothy was used as a substrate. At the end of the incubation, in vitro dry matter digestibility (IVDMD), in vitro neutral detergent fiber digestibility (IVNDFD), pH, volatile fatty acids (VFA), ammonia nitrogen (NH3-N), and microbial community were evaluated and gas production was estimated at 3, 6, 12, 24, 48 h incubation periods. Gas production was higher in CON than DNB and NB at 6 and 12 h incubation time (p<0.01). There were no differences in final gas production, pH, NH3-N concentration, total VFA production, and VFA profiles among treatments. The IVDMD was lowest in CON (p<0.01) but the IVNDFD was not differed by feed distribution methods. There were no significant differences in general bacteria and fungi. Protozoa count was highest in NB treatment among treatments (p<0.01). The abundance of cellulolytic bacteria, Ruminococcus flavefaciens and Fibrobacter succinogenes, was highest in the CON among treatments (p<0.01). 생물학적 평가 방법 중 in situ와 in vitro 평가 방법은 비용 및 시간을 절약할 수 있으며 동물 복지 측면에서 제약이 적어 주목되고 있는 방법이다. In vitro 실험에서 사용되는 사료 접종법으로 배양병에 직접 사료를 담는dispersion 방법은 실제 반추위 발효 상황에 근접한 조건에서 실험할 수 있는 장점이 있지만, 시간과 노동력이 많이 소모된다. 반대로 사료 주머니를 이용한 방법은 실험 수행의 편이성이 있지만 첨가제 실험 수행의 제약이 있으며, 미생물 활성과 섬유소 소화율이 저하되는 단점이 있다. 본 실험은 dispersion 방법과 사료 주머니 방법을 조합하여 보다 편리한 방법으로 dispersion에 가까운 높은 재현성의 발효 성상과 소화율 평가 가능할 것이라고 생각하여 in vitro 발효 성상과 미생물 조성을 비교하였다. Dispersion 방법과 nylon bag을 조합한 실험에서 건물 소화율은 세척 과정에서 미생물 및 사료 입자의 유실로 과대평가될 수 있지만 이론적 최대 가스 발생량 Vmax,가스 발생량에 대한 분해 속도 상수 Kg에서 유의적 차이가 나타나지 않으며, IVNDFD, pH, NH3-N, total VFA발생량 그리고 VFA 조성에서도 유의적 차이가 나지 않았다. Real-time PCR을 이용한 미생물 조성 분석에서는 general bacteria의 절대량에서 유의적 차이가 나지 않았다. 상기의 결과를 종합해 볼 때, in vitro 실험에서 사료 주머니의 사용은 충분히 적용가능하며 일반적인 방법인 dispersion과 비교해 볼 때, 영양소 이용에 있어 반추미생물의 사료 접촉을 방해하지 않을 것으로 생각된다. 하지만 in vitro bach culture 방법은 배양조건에서 제약이 있어, 향후 연속배양 방법과 in situ의 실험을 통해 본 실험의 실험결과에 대한 추가적인 규명이 필요할 것으로 사료된다.

지구온난화에 따른 국내 기후변화와 젖소 착유우의 생산효율에 미치는 영향 평가 : 모델 시뮬레이션을 이용한 접근

이정진,이준성,김종남,서자겸,조남철,박성민,기광석,서성원 한국유기농업학회 2013 韓國有機農業學會誌 Vol.21 No.4

지난 25년간 지구온난화로 인한 국내 기후변화 양상은 지역 간에 차이가 있어, 고온지역은 평균온도의 증가를 보이지는 않았으나, 최저기온의 지속적인 상승과 그에 따른 열대야 발생을 확인할 수 있었다. 또한 그로 인한 젖소의 고온스트레스 발생, 섭취량의 감소 및 생산성 저하가 예상된다. 저온지역의 경우에는 여름철 평균온도 및 최저온도의 상승으로 인해 연평균기온이 유의적으로 상승한 반면, 겨울철에는 오히려 최저기온의 지속적인 하강이 관찰됨에 따라 동물의 저온스트레스가 가중될 것으로 예상된다. 착유우가 저온스트레스 상태에 있을 때는 에너지요구량과 건물섭취량이 증가하여 생산 효율이 떨어지며, 사료효율의 감소로 경제성은 감소되고 우유 생산비는 증가한다. 특히, 극심한 저온스트레스 또는 사료, 음수 및 우사바닥의 결빙은 섭취량 감소를 야기하며 이에 따른 생산성의 저하는 더욱 가중될 것으로 예상된다. 결론적으로 지구온난화로 인한 기후변화에 따른 지역별 영향은 다르며, 온도 스트레스에 의한 낙농우의 생산성 저하를 최소화하고, 동물의 복지와 건강을 증진시키기 위해서는 지역별 기후변화 특성에 맞춘 사양기술의 개발이 필요하다. The objectives of this study were to access climate change by global warming in Korea, and to investigate its effects on production efficiency of lactating dairy cows. Two regions, Daegu and Daekwanryung, were selected to represent a warm and a cold area, respectively. Time-series analyses on meteorological records for 25 years (from January 1, 1988 to December 31, 2012) revealed significant and different climate changes in two regions. In the warm area there has been a significant (P<0.05) increase in low temperature during the summer, which can cause heat stress to the animal. On the other hand, a decrease in low temperature during the winter was observed in the cold region (P<0.01), and cold stress in winter can thus be an issue in this region. Simulations using a model integrated the Korean feeding standard for dairy cattle and the environmental effect module of Cornell Net Carbohydrate and Protein System, indicated that a reduction in feed efficiency can be a problem during the winter in the cold region while during the summer in the warm area. We conclude that the effect of climate change by global warming varies in different areas in Korea and a region-specific management strategy should be developed in order to maintain productivity, health and welfare of lactating dairy cows.

경남지방 한우의 경락가격에 관여하는 요인별 기여도 분석

박후락,엄승훈,박재해,서자겸,조성근,신택순,조병욱,박현철,이은주,선두원,임현태,이정규,김병우 경상대학교 농업생명과학연구원 2015 농업생명과학연구 Vol.49 No.6

본 연구에서는 2009년부터 2011년 까지 6년간 경남지방 도축장에서 도축한 한우 63,388두에 대한 도 축성적 자료를 근거로 하여 한우의 경락단가 결정에서 있어 가장 큰 영향을 미친다고 생각되는 등지방 두께, 등심단면적, 도체중 및 근내지방도가 경락가격에 영향을 미치는 기여도를 분석하기 위하여 최소 제곱 평균법으로 SAS @9.3 Package/PC를 이용하여 분석하였으며, 본 연구의 결과를 요약하면 다음과 같다. 각 요인에 대한 분산분석 즉, 유의성 검정 결과 조사한 형질에 대해 성, 도축계절, 도축년도의 효 과에 대해 고도의 유의성(p<0.01)을 나타내었다. 표현형 상관에서 모든 형질간의 정의상관을 확인 할 수 있었으며 경락단가에 대해서는 근내지방도가 가장 높은 0.70의 정의 상관을 나타내었으며, 총 가격 에서는 경락단가를 제외한 도체형질 중에서 도체중이 0.74로 가장 높은 정의 상관을 나타내었다. 요인 별 기여도 분석에서 경락단가에 대한 근내지방도의 기여도는 95.41%로 가장 높게 나타났고, 총가격에 서도 근내지방도가 52.57%로 가장 높았고 다음으로 도체중이 44.31%로 기여도가 높은 것으로 나타났 다. 이상의 연구결과를 통해 한우의 경락단가, 총가격에 대한 요인별 기여도를 산출해낼 수 있었다. 한 우의 경락단가를 높이기 위해서는 근내지방도 위주의 개량이 적합하고 총가격을 위해서는 도체중까지 고려한 개량 및 사양 방법이 필요할 것으로 사료된다. 본 연구는 분석 결과를 통해 경락단가와 총가격 의 기여도를 고려하여 가장 높은 수익을 얻도록 전략적으로 출하시기를 선택하는데 기초자료로 활용하 고자 하며 각 형질들의 환경요인에 따른 분산분석결과를 통해 한우농가 수입증대를 위한 한우 개량 방 향제시를 위한 기초자료로 활용하고자 한다. The aim of this study was to estimate the effect of sex, slaughtered season and year on carcass traits, and also estimated the corresponding effects of the contribution to auction and total prices of carcass traits. The data used in this study was the carcass grade of Hanwoo(63,388 heads) slaughtered from 2009 to 2011. Carcass traits were affected significantly(p<0.01) by sex, slaughtered season and year. The R-Square of auction prices, analyzed the contribution of causes using the squared semi-partial correlation, was 0.51. The contributions of auction prices of backfat thickness, eye muscle area, carcass weight and marbling score were 3.08, 0.83, 0.66 and 95.41%, respectively. The R-Square of total price was 0.75, and the contributions of marbling score and carcass weight were 44.31% and 52.57%. respectively. According to the results of this study, it could be calculated the contributions to auction prices and total prices of each carcass traits. In order to increase the auction price of Hanwoo, improving the marbling score is required and to increase the total price of Hanwoo, improvement of the carcass weight is required. Based on this study, the results could be used for determining strategic shipping date, and it can be used as baseline data to improve Hanwoo for increasing farmers incomes.

돈피의 첨가 수준에 따른 유화소시지의 품질특성 변화

배석현,조병욱,조성근,김병우,서자겸,유장곤,신택순 경상대학교 농업생명과학연구원 2015 농업생명과학연구 Vol.49 No.5

본 실험은 돈피를 첨가하지 않은 대조구와 돈피를 4% 첨가한 처리구 1, 8% 첨가한 처리구 2, 12% 첨가한 처리구 3으로 돈피 첨가수준을 달리하여 제조된 유화소시지를 4±1℃의 냉장온도에 저장하면서 15일간 5일 간격으로 이화학적 성질, 저장성 실험, 관능검사를 실시하였다. 제품 제조시 돈피를 지방 대체제로 사용하여 돈피의 첨가 비율만큼의 지방은 제외하였다. 지방의 비율이 낮아지고 돈피 첨가수준 이 높아짐에 따라 pH, 전단가, 경도, 검성와 씹힘성은 전 처리구에서 유의적으로 증가했고, 지방산패도 (TBARS: thiobarbituric acid reactive substances)와 휘발성 염기태질소(VBN: volatile basic nitrogen)도 유의적 차이는 나타나지 않았고 증가하는 경향을 보였지만 전 저장기간 동안 가식권에 있 었다. 관능평가에 있어서는 돈피를 8%를 첨가한 처리구 2가 가장 좋은 평가를 받았다. 저장기간이 경 과함에 따라 포장 감량(purge loss), 연도, 경도, 검성, 씹힘성은 전 처리구에서 유의적으로 증가하였으 나(p<0.05), TBARS와 VBN은 증가하였으나 유의성을 나타내지 않았다. pH는 대조구에서는 증가했으나 나머지 처리구에서는 변화가 없었다. 이상의 결과를 종합하면, 대조구와 전 처리구에서 이화학적 성질 이 가식권 내 값을 유지하므로 관능평가에서 잠재적인 소비자들에게 우수한 기호성을 획득한 돈피 함량 이 8%가 최적의 첨가량임을 알 수 있다. This research was designed to investigate changes in quality based on physico-chemical properties and sensory quality of emulsified sausages with different levels of pork rind added during different storage periods of 0, 5, 10 and 15 days. As pork rind is added as a replacer for fat in emulsified sausage, the same ratio of fat is removed from the samples. The research was conducted with four groups of emulsified sausages including different pork rind levels(Control: 0%, T1: 4%, T2: 8%, T3: 12% pork rind added) and stored at conventional refrigerator at 4±1℃. As more amount of pork rind was added, all of the physico-chemical values of emulsified sausages not only pH, shear force, hardness, gumminess and chewiness were increased, but TBARS and VBN were also increased. Although there was no great differences among all of the values of physico-chemical properties from four treatments, T2(8%) got the best score in sensory quality. All of the values of physico-chemical properties are increased according to the storage periods within safety level, including the values of pH of C. Based on the results in this study, adding 8% of pork rind as replacer of fat is the best for emulsified sausages, reducing the certain amount of fat.

Changes in the ruminal fermentation and bacterial community structure by a sudden change to a high-concentrate diet in Korean domestic ruminants

이민경,정신용,서자겸,서성원 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.1

Objective: To investigate changes in rumen fermentation characteristics and bacterial community by a sudden change to a high concentrate diet (HC) in Korean domestic ruminants. Methods: Major Korean domestic ruminants (each of four Hanwoo cows; 545.5±33.6 kg, Holstein cows; 516.3±42.7 kg, and Korean native goats; 19.1±1.4 kg) were used in this experiment. They were housed individually and were fed ad libitum with a same TMR (800 g/kg timothy hay and 200 g/kg concentrate mix) twice daily. After two-week feeding, only the concentrate mix was offered for one week in order to induce rapid rumen acidosis. The rumen fluid was collected from each animals twice (on week 2 and week 3) at 2 h after morning feeding using an oral stomach tube. Each collected rumen fluid was analyzed for pH, volatile fatty acid (VFA), and NH3-N. In addition, differences in microbial community among ruminant species and between normal and an acidosis condition were assessed using two culture-independent 16S polymerase chain reaction (PCR)-based techniques (terminal restriction fragment length polymorphism and quantitative real-time PCR). Results: The HC decreased ruminal pH and altered relative concentrations of ruminal VFA (p<0.01). Total VFA concentration increased in Holstein cows only (p<0.01). Terminal restriction fragment length polymorphism and real-time quantitative PCR analysis using culture-independent 16S PCR-based techniques, revealed rumen bacterial diversity differed by species but not by HC (p<0.01); bacterial diversity was higher in Korean native goats than that in Holstein cows. HC changed the relative populations of rumen bacterial species. Specifically, the abundance of Fibrobacter succinogenes was decreased while Lactobacillus spp. and Megasphaera elsdenii were increased (p<0.01). Conclusion: The HC altered the relative populations, but not diversity, of the ruminal bacterial community, which differed by ruminant species.

Saccharomyces boulardii 세포벽 추출물이 in vitro 반추위 발효성상에 미치는 영향

문준범,김한빈,서자겸 강원대학교 동물생명과학연구소 2022 동물자원연구 Vol.33 No.3

본 연구의 목표는 S. boulardii 유래 세포벽 추출물(CWSB)의 첨가가 반추위 발효에 미치는 영향을 평가하는 것이다. 본 연구의 in vitro 발효 실험은 CWSB의 첨가용량이 다른 2개의 실험으로 구성되었다. 실험 1에서는 대조구(CON, 시험사료)와 CWSB0.05(시험사료+CWSB 0.5g/kg 첨가), CWSB0.075(시험사료+CWSB 0.75g/kg 첨가)의 처리구로 구성되었고, 실험 2의 처리구는 대조구(CON, 시험사료)와 CWSB0.5(시험사료+ CWSB 5g/kg 첨가), CWSB1.0(시험사료+CWSB 10g/kg 첨가)의 처리구로 구성되었다. In vitro 배양 이후 3, 6, 12, 24, 48h 동안 발생한 가스 발생량 및 48h 배양 이후 발효 성상을 분석하였다. 실험 1에서는 CWSB0.05 처리구에서 유의적으로 높았던 Vmax(p<0.01)를 제외한 모든 반추위 발효성상에서 처리구간 유의적 차이가 관찰되지 않았고, 이에 따라 사료 내 0.5%, 1%의 고용량 첨가 수준을 설정한 실험 2를 수행하였다. 실험 2에서의 CWSB1.0 처리구는 대조구에 비해 총 VFA 발생량이 유의적으로 높았으나 전체 배양시간 내 가스 발생량 및 건물 소화율, 섬유소 소화율은 대조구와 유의적인 차이를 나타내지 않았다. 본 연구 결과를 종합해 볼 때, CWSB의 첨가수준은 0.5% 이상에서 반추위 발효 개선효과를 나타낼 것으로 추정된다. The aim of this study was to investigate the effects of dietary supplementation with yeast cell wall extracts from Saccharomyces boulardii (CWSB) on rumen fermentation in an in vitro model. Experiment 1 comprised control (CON, no additive), CWSB0.05 (0.5 g CWSB/kg of substrate), and CWSB0.075 (0.75 g CWSB/kg of substrate) treatment groups, and experiment 2 comprised control (CON, no additive), CWSB0.5 (5 g CWSB/kg of substrate), and CWSB1.0 (10 g CWSB/kg of substrate) treatment groups. In vitro fermentation experiments were performed for 48 h. Gas production was measured after 3, 6, 12, 24, and 48 h of incubation. At the end of the incubation period, in vitro dry matter degradability (IVDMD), neutral detergent fiber degradability (IVNDFD), pH, volatile fatty acid (VFA) levels, and ammonia nitrogen (NH3-N) levels were evaluated. In experiment 1, no significant differences in gas production were observed at any incubation time points, but the theoretical maximum gas production (Vmax) was significantly higher in the CWSB0.05 treatment group (p<0.01) than the other treatment groups. Fermentation parameters, including nutrient degradability, pH, and VFA and NH3-N levels, did not differ between the treatment groups (p>0.05). In experiment 2, gas production after 12 h of incubation tended to increase after supplementation with 1% CWSB (p=0.09). The CWSB1.0 group showed an increased total VFA production, but there were no differences in IVDMD or IVNDFD among the treatment groups. The results of the present study confirmed that a supplementation rate greater than 0.5% CWSB might be recommended to improve rumen fermentation.

Contribution analysis of carcass traits and seasonal effect on auction price for Hanwoo steers

강태훈,조성근,서자겸,김명후,김병우 충남대학교 농업과학연구소 2019 Korean Journal of Agricultural Science Vol.46 No.3

The aim of this study was to analyze the contribution of carcass traits (backfat thickness, eye muscle area, carcass weight and marbling score) and the season at slaughter to the price (auction and market) using squared semi-partial correlation. The season at slaughter (summer expressed as season_2, autumn as season_3, and winter as season_4) were added into the estimation as dummy variables, and spring was set as a default variable. In this study, the carcass grades of 22,298 Hanwoo steers slaughtered from 2012 to 2017 were used to performmultiple regression analysis. The rankings of the contribution of the carcass traits and the seasons at slaughter to the auction prices were in the order of marbling score (68.63%), season_4 (11.88%), backfat thickness (10.45%), eye muscle area (6.11%), season_3 (2.19%), season_2 (0.45%) and carcass weight (0.28%). (R-square of the regression = 0.4101). The rankings of the contribution to the total prices were in the order of carcass weight (51.74%), marbling score (32.12%), season_4 (6.04%), backfat thickness (5.54%), eye muscle area (3.22%), season_3 (1.14%), and season_2 (0.19%). (R-Square of the regression = 0.6486). As a result, season_3 and season_4 had a negative effect on the auction price and total price. Because of seasonal event such as Korean Thanksgiving Day and Korean New Year’s Day on season_3 and season_4, much supply was needed to meet the high demand. Thus, the seasonal effect at slaughter could be another factor to be cosideredin when considering of slaughter or breeding.