• Asian-Australasian Journal of Animal Sciences
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• 제29권3호
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• pp.436-443
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• 2016

Exposure to cold may affect growth performance in accordance with the metabolic and immunological activities of animals. We evaluated whether ambient temperature affects growth performance, blood metabolites, and immune cell populations in Korean cattle. Eighteen Korean cattle steers with a mean age of 10 months and a mean weight of 277 kg were used. All steers were fed a growing stage-concentrate diet at a rate of 1.5% of body weight and Timothy hay ad libitum for 8 weeks. Experimental period 1 (P1) was for four weeks from March 7 to April 3 and period 2 (P2) was four weeks from April 4 to May 1. Mean ($8.7^{\circ}C$) and minimum ($1.0^{\circ}C$) indoor ambient temperatures during P1 were lower (p<0.001) than those ($13.0^{\circ}C$ and $6.2^{\circ}C$, respectively) during P2. Daily dry matter feed intake in both the concentrate diet and forage groups was higher (p<0.001) during P2 than P1. Average daily weight gain was higher (p<0.001) during P2 (1.38 kg/d) than P1 (1.13 kg/d). Feed efficiency during P2 was higher (p = 0.015) than P1. Blood was collected three times; on March 7, April 4, and May 2. Nonesterified fatty acids (NEFA) were higher on March 7 than April 4 and May 2. Blood cortisol, glucose, and triglyceride concentrations did not differ among months. Blood CD4+, CD8+, and CD4+CD25+ T cell percentages were higher, while CD8+CD25+ T cell percentage was lower, during the colder month of March than during May, suggesting that ambient temperature affects blood T cell populations. In conclusion, colder ambient temperature decreased growth and feed efficiency in Korean cattle steers. The higher circulating NEFA concentrations observed in March compared to April suggest that lipolysis may occur at colder ambient temperatures to generate heat and maintain body temperature, resulting in lower feed efficiency in March.

• 생명과학회지
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• 제20권5호
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• pp.644-648
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• 2010

본 논문은 선충 포식성 곰팡이에 대한 선충의 영향을 조사한 연구로, 소나무 기생곰팡이인 E. vermicola에 미치는 소나무 선충의 영향을 체계적으로 분석하였다. 선충 대사물과 선충 균질액 모두 E. vermicola의 성장을 빠르게 촉진하였으나, 선충 대사물이 선충 균질액보다 약간 높은 효과를 보였다. 또한 소나무 선충이 생성하는 휘발성 물질이 E. vermicola 성장에 미치는 영향을 분석하는 새로운 실험방법을 개발하였다. 본 연구결과에 따르면, 선충의 휘발성 물질은 E. vermicola에 아무런 영향을 끼치지 않는다는 재현성 있는 결과를 도출하였다. 본 연구는 소나무 선충의 생물학적인 조절인자로서 E. vermicola을 적용할 수 있는 정보를 제공할 수 있을 것이다.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 춘계학술대회 및 국제심포지움 초록집
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• pp.96-96
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• 2005

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2004년도 생명공학 실용화를 위한 비젼
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• pp.213-213
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• 2004

• 한국작물학회:학술대회논문집
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• 한국작물학회 2004년도 추계학술발표회
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• pp.94-95
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• 2004

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.454-455
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• 2005

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.452-453
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• 2005

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.444-445
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• 2005

• Asian-Australasian Journal of Animal Sciences
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• 제25권11호
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• pp.1568-1574
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• 2012

Three Holstein steers in the growing phase, each with a ruminal cannula, were used to test the hypothesis that the synchronization of the hourly rate of carbohydrate and nitrogen (N) released in the rumen would increase the amount of retained nitrogen for growth and thus improve the efficiency of microbial protein synthesis (EMPS). In Experiment 1, in situ degradability coefficients of carbohydrate and N in feeds including Korean rice wine residue (RWR) were determined. In Experiment 2, three total mixed ration (TMR) diets having different rates of carbohydrate and N release in the rumen were formulated using the in situ degradability of the feeds. All diets were made to contain similar contents of crude protein (CP) and neutral detergent fiber (NDF) but varied in their hourly pattern of nutrient release. The synchrony index of the three TMRs was 0.51 (LS), 0.77 (MS) and 0.95 (HS), respectively. The diets were fed at a restricted level (2% of the animal's body weight) in a $3{\times}3$ Latin-square design. Synchronizing the hourly supply of energy and N in the rumen did not significantly alter the digestibility of dry matter, organic matter, crude protein, NDF or acid detergent fiber (ADF) (p>0.05). The ruminal $NH_3$-N content of the LS group at three hours after feeding was significantly higher (p<0.05) than that of the other groups; however, the mean values of ruminal $NH_3$-N, pH and VFA concentration among the three groups were not significantly different (p>0.05). In addition, the purine derivative (PD) excretion in urine and microbial-N production (MN) among the three groups were not significantly different (p>0.05). In conclusion, synchronizing dietary energy and N supply to the rumen did not have a major effect on nutrient digestion or microbial protein synthesis (MPS) in Holstein steers.

• Asian-Australasian Journal of Animal Sciences
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• 제32권1호
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• pp.126-136
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• 2019

Objective: This study was performed to compare fat content, reducing sugar contents, sensory traits, and fatty acid (FA) and volatile compound profiles in longissimus thoracis (LT) among Korean cattle (KC), Holstein (HO), and Angus (AN) steers. Methods: Twelve LT samples (about 500 g each) of KC with an average age of $31{\pm}0.42months$, an average carcass weight of $431{\pm}12.5kg$, and a quality grade (QG) of 1+ were obtained from the joint livestock products market. Twelve LT samples of HO cattle with an average age of $24{\pm}0.54months$, an average carcass weight of $402{\pm}7.81kg$, and a QG of 2 were also obtained from the same market. Twelve LT samples of AN steers with an average age of about 20 months and a QG of choice were purchased from a beef delivery company. After slaughter, samples were kept at $4^{\circ}C$ for 42 days and prepared for immediate analysis or stored at appropriate conditions. The chemical composition, color, pH, shear force, collagen content, reducing sugars, sensory evaluation, FA composition, and volatile compound content for each LT sample were analyzed. Results: The LT of KC had the highest (p<0.05) fat content, the highest reducing sugar content, and the highest scores in the sensory evaluation (flavor, tenderness, juiciness, and overall acceptance). All the sensory traits were positively correlated (p<0.001) with intramuscular fat and reducing sugar content. Several FAs and volatile compound profiles varied among the breeds. KC LT had the highest (p<0.05) concentrations of acetaldehyde, 3-methyl butanal, and 3-hydroxy-2-butanone, and these volatile compounds were positively correlated (p<0.05) with all the sensory traits. Conclusion: Variations in fat content and reducing sugar contents and FA and volatile compound profiles may contribute to differences in the sensory quality of LT among breeds.