• 한국초지조사료학회지
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• 제40권3호
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• pp.149-155
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• 2020

Cattle feeding in South Korea has been heavily dependent on domestically produced rice straw and imported grain. Around 42% of domestically produced rice straw is utilized for forage, and the remainder is recycled to restore soil fertility. Approximately 35% of round baleages were made with rice straw. However, higher quality hay is desired over rice straw. Due to increasing stockpiles of rice, there has been an economic burden on the government to store the surplus; therefore production of annual forage crops in rice fields has been further promoted in recent years. Hay import from the USA currently constitutes more than 80% of total imported hays. The main imported hays are alfalfa (Medicago sativa), timothy (Phleum pretense), and tall fescue (Festica arundinacea). The estimated forage required for cattle feeding was approximately 5.4 million MT in 2016. Domestically produced forage sates only 43% of that value, while low quality rice straw and imported hay covered the rest of demand by 33% and 20%, respectively. As utilization of domestically produced forage is more desirable for forage-based cattle production, long-term strategies have been necessary to promote domestic production of high quality baleage. One such strategy has been utilizing the fertile soil and abundance of fallow rice fields of western region of S. Korea to produce forage crops. Italian ryegrass (Lolium multiflorum) is the most successfully produced winter annual in the region and is approximately 56% of the total winter annual forage production. Forage sorghums (Sorghum bicolor), sorghum × sudangrass hybrids, and hybrid corn (Zea mays) produce a substantial amount of warm-season forage during summer. Produced forage has been largely stored through baleage due to heavy dew and frequent rains and has been evaluated according to S. Korea's newly implemented baleage commodity evaluation system. The system weighs 50% of its total grading points on moisture content because of its importance in deliverable DM content and desirable baleage fermentation; this has proved to be an effective method. Although further improvement is required for the future of forage production in South Korea, the current government-led forage production in rice fields has been able to alleviate some of the country's shortage for quality hay.

• 한국초지조사료학회지
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• 제37권1호
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• pp.1-9
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• 2017

This research was conducted to investigate the effects of feeding high and low forage diets with different forage sources on rumen fermentation characteristics and blood parameters of Holstein cows during the dry period. Eight Holstein cows were completely randomized assigned to two groups and repeated measurement was utilized in the analysis. Cows in two treatments were fed with diets with high (F:C = 70:30, 70F; forage source: mixed-sowing whole crop barley and Italian ryegrass silage, BIRG) and low (F:C = 55:45, 55F; forage source: tall fescue hay, TF) forage level. Rumen fluid pH was higher in 70F group. Levels of acetic acid, propionic acid, and butyric acid showed a similar pattern: from the lowest value at 07:30 h to the highest at 10:30 h and then decreased in both groups. The ratio of acetic acid to propionic acid was significantly higher (p < 0.05) in 55F group at 09:30 and 10:30 h. Rumen fluid $NH_3-N$ concentrations were significantly higher (p < 0.05) in 70F group at 09:30 and 10:30 h. Blood urea nitrogen was significantly higher (p < 0.05) in 70F group. It was concluded that BIRG based diet with a high forage level had no adverse effects on rumen fermentation, some blood chemical parameters, and immune system in dry Holstein cows and could be used as a forage source instead of imported TF.

• 농업과학연구
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• 제48권4호
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• pp.975-985
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• 2021

The sufficient amount of protein supply is crucial for improving the growth performance of growing beef cattle. In addition, due to the improvement in the genetic potential of the carcass weight of Hanwoo steers, dietary protein requirements may be increased during the rapid growth period. Accordingly, the dietary crude protein (CP) level in growing Hanwoo steers has been increasing in the field. However, little scientific evidence is available in relation to this. Therefore, this study was conducted to test whether a higher dietary CP level than convention would improve the growth performance and body metabolism in growing Hanwoo steers. Fifty growing Hanwoo steers were randomly divided into two groups and fed either a commercial diet (CON) or a higher CP (HCP) concentrate mix, provided with a similar level of dietary energy. Tall fescue hay was provided ad libitum. The dietary CP level did not affect growth performance and blood metabolite. Nitrogen intake, predicted nitrogen excretion, and retained nitrogen were higher in the HCP group than in the CON group (p < 0.01). Although there was no difference in the nitrogen utilization efficiency, the growth efficiency per retained nitrogen decreased in the HCP group (p = 0.02). A higher dietary CP level may increase nitrogen retention in growing Hanwoo steers without improving growth performance, which leads to reduced growth efficiency per retained nitrogen. Furthermore, considering the high price of feed protein and increased nitrogen excretion to the environment, a further increase in the protein level may not be sustainable.

• 한국수정란이식학회지
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• 제19권1호
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• pp.53-59
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• 2004

본 실험은 한우 400두를 공시하여 사양조건에 따른 blood urea nitrogen(BUN)의 농도가 암소의 번식에 미치는 영향을 조사하였으며 또한 body condition score(BCS)가 번식효율에 미치는 영향을 조사하였다. 1 화본과 식물이 주종인 초지에서 방목을 하였을 때 BUN의 평균농도는 7.39$\pm$2.65 mg/㎗ 이었으며 발정이 육안적으로 확인된 암소의 58.2%가 4∼8 mg/㎗ 사이에 분포하였으며 수태율도 높은 경향을 보였다. 2.사사기 농후사료를 급여하였을 때 BUN의 평균 농도는 12.36$\pm$2.92 mg/㎗이었으며 8∼14 mg/㎗사이에서 높은 수태율을 보였다. 3. BCS가 2.5∼3.5사이에 있을 때 분만 후 발정재귀가 가장 빠르게 나타났으며 수태율도 높은 경향을 나타내었다. 4. 방목기, 사사기에서 BUN과 BCS상호간의 다소의 차이는 있었으나 유의성은 인정되지 않았다. 이상의 결과를 종합해 보면 사양조건에 따라 적정 BUN및 BCS의 수준을 유지할 때 번식의 효율을 증대시킬 수 있을 것이라 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권6호
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• pp.826-833
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• 2019

Objective: This study was performed to evaluate whether hot temperature and rumen-protected fat (RPF) supplementation affect growth performance, rumen characteristics, and serum metabolites in growing stage of Korean cattle steers. Methods: Twenty Korean cattle steers ($230.4{\pm}4.09kg$ of body weight [BW], $10.7{\pm}0.09months$ of age) were divided into a conventional control diet group (n = 10) and a 0.8% RPF supplementation group (n = 10). Steers were fed 1.5% BW of a concentrate diet and 4 kg of tall fescue hay for 16 weeks (July 10 to August 6 [P1], August 7 to September 3 [P2], September 4 to October 1 [P3], October 2 to 30 [P4], of 2015). Results: The mean temperature-humidity index (THI) was higher (p<0.001) in P1 (76.8), P2 (76.3), and P3 (75.9) than in P4 (50.9). The mean THI of P1-3 were within the alert heat stress (HS) category range according to previously reported categories for feedlot cattle, and the mean THI of P4 was under the thermo-neutral range. Neither month nor RPF supplementation affected (p>0.05) average daily gain and gain to feed ratio. Month and RPF supplementation affected concentrations of glucose, albumin, and high-density lipoprotein (HDL); those of albumin and glucose tended to decrease (p<0.10), but HDL concentration increased (p<0.01) by RPF supplementation. Neither month nor RPF affected (p>0.05) ruminal pH, $NH_3-N$, and volatile fatty acid concentrations, whereas the C2:C3 ratio was affected (p<0.05) by month. Conclusion: Korean cattle may not have been significantly affected by alert HS during the growing stage. Growth performance was higher during hotter months, although some changes in blood metabolites were observed. The RPF supplementation affected some blood lipids and carbohydrate metabolites but did not affect growth performance.

• Journal of Animal Science and Technology
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• 제51권1호
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• pp.45-52
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• 2009

본 연구는 홀스타인 젖소의 반추위에서 순수분리 및 동정된 섬유소 분해균인 Ruminococcus flavefaciens (H-20) 및 Fibrobactor succinogenes (H-23)의 혼합 배양액(DFM)을 수준별로 반추동물에 적용하였을 때 반추위발효와 섬유소분해효소 활성에 미치는 영향을 평가하였다. 대사시험은 반추위 fistula가 장착된 12개월령 한우 암소 4두를 이용하여 $4\times4$ Latin square 방법으로 실시되었다. 모든 처리구는 기초사료로, 농후사료 2 kg에 톨페스큐와 오차드그라스의 혼합건초 3 kg을 1일 2 회로 나누어 균등 급여하였으며, DFM을 사용하지 않은 처리구(control), 기초사료를 포함하여 1% (50 ml/day, H20 + H23), 3% (150 ml/day, H20 + H23) 및 5% (250 ml/day, H20 + H23) 수준의 네 처리군으로 나누어, 사료 급여시 DFM을 반추위 cannula 안으로 직접 주입하여 실시하였다. 본 실험 결과 급여 후 모든 시간에서, 처리구는 반추위액내 pH의 유의적 차이가 나타나지 않았으나, 반추위 암모니아 질소의 농도에서 DFM투여 후 1시간에 3% 처리구(19.47 mg/dl)는 5% 처리구(17.27 mg/dl)와 차이는 없었지만, 대조구 및 1% 처리구(14.5 및 14.9 mg/dl)와 비교하여 유의적으로 높은 농도를 보였다(p<0.05). 섬유소분해효소활력은 전체적으로 유의한 효과가 나타나지 않았으나, xylanase는 0시간에 5% 처리구($119.49\;{\mu}mol$/ml/min)가 3% 처리구($72.02\;{\mu}mol$/ml/min)와 비교하여 유의적으로 높은 농도를 보였다(p<0.05). VFA 농도는 butyric acid에서 급여후 1시간에 대조구(15.71 mM)와 비교하여 3% 처리구(24.48 mM)에서 유의적으로 높은 농도를 보였다(p<0.05). 이러한 결과로 미루어 보아 혐기성 섬유소분해 박테리아 배양액의 공급은 최소 3% 이상에서 반추위발효에 개선효과가 있는 것으로 나타났다.

• 농업생명과학연구
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• 제45권5호
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• pp.63-71
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• 2011

본 연구는 바이오디젤유 부산물로 제조한 공액리놀레산(Conjugated Linoleic Acid, CLA)을 비유중기 착유우에 첨가 수준을 달리하여 급여하였을 때 산유량, 유성분 및 혈액성상에 미치는 영향을 조사하고자 실시하였다. 공시동물은 비유중기 홀스타인 20두($631{\pm}25.0kg$)로 시험구당 5두를 배치하였으며, 기초사료($NE_L$ 32 Mcal/d, CP 17%)로 농후사료(12kg), 옥수수 사일리지(15kg) 및 톨페스큐+오차드그라스 건초(4kg)를 1일 2회 균등 급여하였다. CLA의 1일 급여수준은 0(대조구), 50(T1), 100(T2) 및 150g(T3)으로 달리하여 네처리군을 설정하고 예비 시험 2주와 본 시험 4주를 수행하였다. 착유우에 CLA의 급여량이 증가함에 따라 산유량과 4% FCM은 점진적으로 증가하였으나, 유지방 함량은 유의적으로 감소하였다(p<0.05). 사료중 CLA 첨가 수준이 증가함에 따라, 우유의 Stearic acid와 Oleic acid 함량은 감소한 반면, total CLA 함량은 증가하였다(p<0.05). 따라서 본 연구에서는 비유중기 착유우 사료에 바이오디젤유 부산물로 제조한 CLA를 첨가하는 것은 유생산량 증가와 유지방 내 CLA 함량 증가에 유리할 것으로 판단된다.