돈분액비를 시용한 중산간지 휴경답에서 다년생 목초의 초종별 영속성 및 건물생산성에 관한 연구

윤세형(Sei Hyung Yoon),김상우(Sang Woo Kim),임영철(Young Chul Lim),정민웅(Min Woong Jung) 한국초지조사료학회 2012 한국초지조사료학회지 Vol.32 No.4

This study was conducted to develop the technique for cultivation of forage crops using swine slurry in fallow paddy land located in the mid-mountain area (FPL). The field experiments were carried out from 2007 to 2009 on FPL at Kumsan, Chungbuk province in Korea. Swine slurry was prepared which decayed for 6 months. The experimental plots were consisted of seven treatments; tall fescue-based mixed pasture applied with chemical fertilizer (Control), mono-tall fescue pasture (MTF), tall fescue-based mixed pasture (TFBM), mono-Perennial ryegrass (MPR), mono-Italian ryegrass (MIR), mono-Red clover (MRC and mono), Reed canarygrass (MRCG) applied with swine slurry. The field of tall fescue-based pasture had been sown with a grasses mixture containing ‘Fawn’ tall fescue, ‘potomac’ orchardgrass, ‘Reveille’ Perennial ryegrass, and ‘kenblue’ Kentuky bluegrass, ‘Kenland’ Red clover. Seeding rates were 16, 6, 4, 2 and 2 (kg) per ha, respectively. DM yields of forages and rates of grass coverage were higher in MTF, TFBM and MRCG as compared with control treatment. This result means that FPL has contained with favorable conditions for growing grass, because forage productivity is more than 14.5 tons per ha per year in fallow paddy land. In addition, the farmer can save the trouble of repeated plowing and sowing every year, with the introduction of perennial grasses. The farmer must conduct the re-seeding and induce the improvement of management methods for the elevation of the persistence of red clover and perennial ryegrass, because both red clover and perennial ryegrass having high nutritive value and palatability was less persistent. Therefore, we suggest that FPL may be the good land for forage production utilizing swine slurry and swine slurry can be applied on FPL without any negative effects on DM production and the property of soil. FPL of Korea can be better utilized by applying swine slurry to the mono and/or mixed swards.

퇴구비를 시용한 중산간지 휴경답에서 초종별 영속성 및 건물생산성에 관한 연구

윤세형(Sei Hyung Yoon),지희정(Hee Chung Ji),이상훈(Sang-Hoon Lee),최은민(Eun-Min Choi),정민웅(Min Woong Jeong) 한국초지조사료학회 2010 한국초지조사료학회지 Vol.30 No.4

쌀 소비 감소로 인해 발생하는 중산간지 휴경답에서 노동력 절감을 위해 한번 파종으로 다년간 이용이 가능한 목초의 도입을 위해 본 시험을 수행하였다. 장소는 충남 금산이며 처리는 화학비료를 이용한 톨페스큐 위주 혼파조합(대조구)과 퇴비를 시용한 톨페스큐(Fawn) 단파구, 페레니얼 라이그라스(Reveille)단파구, 톨페스큐위주 혼파조합(톨페스큐 16, 오차드그라스 6, 페레니얼 라이그라스 4, 켄터키블루그라스 2, 화이트클로버 2(㎏/㏊)), 극만생 이탈리안 라이그라스(Ace), 레드클로버(Kenland)단파구 및 리드 카나리그라스(Venture)단파구를 두었다. 건물수량 및 영속성의 기준이 되는 목초율은 톨페스큐 단파구, 톨페스큐 위주 혼파구, 리드 카나리그라스가 우수하여 이 초종과 혼파조합이 중산간지 휴경답에서 퇴비를 이용하여 초지를 조성 이용할 경우 유리한 것으로 판명되었다. 또한 이 처리구의 ㏊당 연간 건물생산성은 15톤을 넘는 수준으로 중산간지 휴경답이 목초 재배에 매우 유리함을 입증하고 있다. 또한 다년생 목초의 도입으로 매년 반복되는 경운 파종하는 번거로움을 생략할 수 있는 유리함도 있다. 또한 사료가치와 기호성이 높은 레드클로버나 페레나얼 라이그라스는 영속성이 낮으나 보파 등 관리방법의 개선을 통해 이용이 가능할 수 있을 것이다. 극만생 품종으로 4-5년간 이용이 가능한 것으로 보고된 극만생 이탈리안 라이그라스는 국내에서 재배되는 이탈리안 라이그라스와 같은 경향을 보였다. 이는 다년생목초와 예취 및 비배관리를 동일하게 한 사실에 기인할 수도 있으므로 금후 이탈리안 라이그라스에 적합한 관리를 통해 재검토되어야할 필요가 있다. 이와 같이 중산간지 휴경답에 적합한 초종이나 혼파조합을 이용하면 생력적으로 사료가치와 기호성이 높은 양질 목초의 고위 생산성을 달성할 수 있음이 입증되었다. Recently, fallow paddy land located in the mid-mountain area (FPL) due to a decrease in rice consumption has increased in some regions of our country. So, grasses and forage crops available for years in once sowing should be introduced in FPL. This study was conducted to develop the technique for cultivation of grasses and forage crops using animal manure in FPL The field experiments were carried out from 2007 to 2009 on FPL at Kumsan, Chungbuk province in Korea. Cattle feedlot manure (CFM) was prepared by mixing feces and urine of cattle with rice straw in cattle feedlot for 6 months. The experimental plots were consisted of four treatments; tall fescue-based mixed pasture applied with chemical fertilizer (Control), mono-tall fescue pasture (MTFP), tall fescue-based mixed pasture (TFBMP), mono-Perennial ryegrass (MPR-FCM), mono-Italian ryegrass (MIR-FCM), mono-Red clover (MRC-FCM) and mono-Reed canarygrass (MRCG-FCM) applied with FCM. The field of tall fescue-based pasture had been sown with a grasses mixture containing 'Fawn' tall fescue, 'potomac' orchardgrass, 'Reveille' Perennial ryegrass, and 'kenblue' Kentuky bluegrass, 'Kenland' Red clover. Seeding rates were 16, 6, 4, 2 and 2㏊?¹, respectively. DM yields of forages and rates of grass coverage was higher in MTFP, TFBMP and MRCG-FCM as compated with control treatment. This result means that FPL has contained with favorable conditions for growing grass, because forage productivity is more than 15 tons per ha per year in fallow paddy land. In addition, the farmer can save the trouble of repeated plowing and sowing every year, due to the introduction of perennial grasses. The fanner must conduct the re-seeding and induce the improvement of management methods for the elevation of the persistence of red clover and perennial ryegrass, because both red clover and perennial ryegrass having high nutritive value and palatability was less persistent. Therefore, we suggest that FPL may be the good land for forage production utilizing FCM and FCM can be applied on FPL without any negative effects on DM production and the property of soil. FPL of Korea can be better utilized by applying FCM to the mono and/or mixed swards.

중부지역에서 유기조사료 생산에 적합한 작부체계에 관한 연구

윤세형(Sei Hyung Yoon),김종근(Jong Geun Kim),정의수(Eui Soo Jeong),성시흥(Si Heung Sung) 한국초지조사료학회 2007 한국초지조사료학회지 Vol.27 No.4

본 시험은 유기조사료 생산에 적합한 동·하계 사료작물을 선정하고, 이를 통한 지역별 유기조사료 생산을 위한 적정 작부체계를 선발하기 위하여 수행되었다. 관행재배 조건과 유기재배 조건에서의 사료작물별 생육특성의 차이는 하계사료작물에서 현저하게 나타났다. 즉 사료용 옥수수는 잡초 발생으로 생육이 억제되어 관행재배에 비해 현저한 수량감소를 나타낸 반면 수수×수단그라스 교잡종은 잡초 발생이 없어 관행 옥수수 대비 높은 수량을 나타내었다. 동계사료작물은 관행재배와 유기재배에 의한 차이는 크지 않았으나, 생산성 측면에서 이탈리안 라이그라스 보다 호밀이 우수하였다. 따라서 작부체계에 영향을 미치는 요인이 하계 사료작물에서는 잡초의 발생여부, 동계사료작물에서는 사료작물의 종류에 기인됨이 밝혀졌다. 이를 종합적으로 고려한 중부지역에서 유기조사료 생산을 위한 최적 작부체계는 중부지역에서는 수수×수단그라스와 호밀이라 할 수 있다. This experiment was conducted to investigate the selection of regional double cropping system for production of organic forage in middle part of Korea. The species of forage crop used in this experiment were corn, sorghum × sudangrass hybrid and japanese millet for summer crops and rye and Italian ryegrass for winter crops. Sorghum × sudangrass hybrid showed higher DM (dry matter) and TDN (total digestible nutrient) yield than that of corn. Dry matter yield of corn decreased to 56% that of control because of weed. In winter crops, DM and TDN yield of rye is higher than that of Italian ryegrass. Rye was more adequate to produce organic forage in middle part of Korea. We could not find out the difference of nutrient value between each treatments. It means that the amount of nutrient is affected by DM productivity of each crop. The result of this study indicated that sorghum×sudangrass hybrid (summer crop) and rye (winter crop) cropping system could be recommended as producing high yield of organic forage in middle part of Korea.

흑염소를 이용한 유기초지조성과 식생 개선 효과

윤세형(Sei Hyung Yoon),임영철(Young Cheol Lim),김종근(Jong Geun Kim),이종경(Joung Kyong Lee),최순호(Sun Ho Choi),조남철(Nam Chul Cho),최기춘(Ki Choon Choi) 韓國草地學會 2009 한국초지조사료학회지 Vol.29 No.3

본 연구는 제경법을 이용한 유기초지 조성기술을 확립하기 위하여 2005년부터 2007년까지 3년 동안 수행하였으며 방목축으로는 흑염소가 사용되었다. 시험설계는 관행조성구인 대조구, 퇴구비시용 후 방목구, 방목 후 퇴구비 시용구, 방목 후 퇴구비 시용 재방목구로 처리하였다. 목초정착률은 관행구인 대조구가 유기조성구에 비하여 현저하게 증가하였으며(p<0.05), 또한 건물생산성도 유기조성구에 비하여 대조구에서 현저한 증가를 나타냈다. 조성 후 연차가 경과함에 따라 식생 및 건물생산성이 개선되어 조성효과와 아울러 조성 후 관리의 중요성을 인식할 수 있다. 목초의 사료가치는 대조구와 유기조성구 모두 큰 차이는 나타나지 않았으며, 화본과 목초의 비율은 조성1년차가 2년차에 비하여 높은 경향을 보였다. 시험 종료 후 토양성분을 조사한 결과 pH와 양이온치환용량은 시험전과 거의 변화가 없었으나 유기물과 인산함량은 약간 증가하였다. This study was carried out to determine the effect of establishment of organic pasture by hoof cultivation with Korean black goat on productivity of grassland and properties of soil. This study was conducted from August, 2005 to September, 2008 at Cheonan, Korea. Experiment was designed composing with 4 treatment : Standard (Control, T1), Grazing after application of cattle manure (T2), Application of cattle manure after grazing (T3), Application of cattle manure at half of grazing (T4). The establishment ratio of pasture in control treatment increased significantly as compared with that of organic treatment (p<0.05). The yield of dry matter (DM) of pasture in control treatment increased significantly as compared with that of organic treatment. The contents of crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF) and dry matter digestibility (DMD) of pasture were not influenced by cattle manure and grazing method. Grasses coverage ratio in grassland in second year after grassland development were higher than that of first year. The contents of organic matter (OM) and P₂O? in soil samples collected in organic treatment at the end of the experiment were higher than those of control. However, The pH, and the concentrations of CEC (Ca, Na and Mg) in soil samples collected in organic treatment were hardly influenced, as compared with those at the beginning of the experiment. This study suggests that the grasses and legumes coverage ratio in grassland can be improved by suitable pasture management.

남부지역에서 유기조사료 생산에 적합한 작부체계에 관한 연구

윤세형(Sei Hyung Yoon),김종근(Jong Geun Kim),정의수(Eui Soo Jeong),임영철(Young Cheol Lim) 한국초지조사료학회 2008 한국초지조사료학회지 Vol.28 No.4

본 시험은 유기조사료 생산에 적합한 동ㆍ하계 사료작물을 선정하고, 이를 통한 지역별 유기조사료 생산을 위한 적정 작부체계를 선발하기 위하여 수행되었다. 관행재배 조건과 유기재배 조건에서의 사료작물별 생육특성의 차이는 하계사료작물에서 현저하게 나타났다. 즉 사료용 옥수수는 잡초 발생으로 생육이 억제되어 관행재배에 비해 현저한 수량감소를 나타낸 반면 수수×수단그라스 교잡종은 잡초 발생이 없어 관행 옥수수 대비 높은 수량을 나타내었다. 동계사료작물은 관행재배와 유기재배에 의한 차이는 크지 않았고, 호밀과 이탈리안 라이그라스 두 작물간 건물생산성 측면에서는 호밀이 약간 우세하였으나, 사료가치를 고려한 가소화영양소 총량에서는 이탈리안 라이그라스가 우수하였다. 그러나 그 차이는 크지 않아 남부지역에서는 호밀과 이탈리안 라이그라스 모두 유기조사료 생산에 적합한 동계사료작물로 판명되었다. 본 시험의 결과를 종합적으로 고려한 남부지역에서 유기조사료 생산을 위한 최적 작부체계는 수수×수단그라스 교잡종과 호밀 혹은 수수×수단그라스 교잡종과 이탈리안 라이그라스라 할 수 있다. This experiment was conducted to investigate the selection of regional double cropping system for production of organic forage in southern region of Korea. The species of forage crop used in this experiment were com, sorghum×sudangrass hybrid and japanese millet for summer crops and rye and Italian ryegrass for winter crops. In organic cultivation condition, sorghum×sudangrass hybrid showed higher DM(dry matter) and TDN(total digestible nutrient) yield than that of com. Dry matter yield of com which cultivated in organic condition decreased to about 35% that of control because of weed. In winter crops, DM and TDN yield of rye is similar to that of Italian ryegrass. We could not find out the difference of nutrient value between each treatments. It means that the amount of nutrient is affected by DM productivity of each crop. The result of this study indicated that sorghum×sudangrass hybrid (summer crop) and rye (winter crop), sorghum×sudangrass hybrid (summer crop) and Italian ryegrass (winter crop) cropping system could be recommended as producing high yield of organic forage in southern region of Korea.

초지에서의 돈분액비 시용수준에 관한 연구

윤세형(Sei Hyung Yoon),임영철(Young Chul Lim),김종근(Jong Geun Kim),정의수(Eui Soo Jeong) 한국초지조사료학회 2006 한국초지조사료학회지 Vol.26 No.2

This experiment was carried out to investigate the availability of swine slurry on mixed grassland pasture. Three types of fertilizer was used, chemical fertilization(N-P₂O?-K₂O=210-150-180 ㎏/㏊), no fertilization and swine slurry was further subdivide into three groups (100%, 150%, 200%) as compared to the level of N used in the chemical fertilizer. The results showed that dry mater yield of forage was increased with increasing application level of swine slurry. Production of dry matter of swine slurry 200% was similar to that of chemical fertilizer, but percentage of legume in mixed pasture was lower in chemical fertilization. Percentage of legume was increased with increasing application level of swine slurry. Level of NO₃-N in filtered water was very low in all groups applied with swine slurry. Based on this results the optimum level of swine slurry application is 200% of the normal standard of N fertilizer used in grassland pasture.

검은줄오갈병 발생이 심한 지역에서 옥수수 품종의 발병률과 사초 생산성 비교

최기준,임영철,윤세형,지희정,이상훈,정민웅,서성,박형수,김기용,Choi, Gi Jun,Lim, Young Chul,Yoon, Sei Hyung,Ji, Hee Chung,Lee, Sang-Hoon,Jung, Min Woong,Seo, Sung,Park, Hyung Soo,Kim, Ki-Yong 한국초지조사료학회 2013 한국초지조사료학회지 Vol.33 No.2

This experiment was carried out to select a resistant corn variety for rice black-streaked dwarf virus (RBSDV) disease in a RBSDV prevalent area (Gochang of Jeollabukdo) from 2006 to 2008. Ten corn varieties for silage preparation were cultivated with first cropping and second cropping system in an RBSDV field, and were tested outbreak rates of RBSDV and dry matter (DM) yield of forage. The outbreak rates of RBSDV were significantly different between corn varieties. Therefore, the resistance degree of corn varieties for RBSDV were divided into 4 groups; very resistant ('Kwangpeyongok' and 'Kwanganok'), resistant ('P3156' and 'P3394'), mildly resistant ('Cheonganok' and 'P32P75') and susceptible ('Suwon19', 'DK697' and 'GW6959') groups respectively. DM yield of forage in RBSDV fields exhibited comparatively significant differences between varieties (p<0.05). DM yield of resistant varieties ('Kwangpeyongok', 'Kwanganok', 'P3156' and 'P3394'), were higher (14~26%) than those of susceptible varieties ('Suwon 19', 'DK697' and 'GW6959'). Therefore, resistant varieties were recommended for increasing forage productivity in field of RBSDV prevalent areas. 본 시험은 사료용 옥수수의 검은줄오갈병에 대한 저항성 품종을 선발하기 위하여 2006년부터 2008년까지 전라북도 고창에서 수행하였다. 국내외 사료용 옥수수 10품종을 1모작과 2모작으로 재배하여 품종에 따른 검은줄오갈병의 이병률과 수량성을 조사하였다. 그 결과 사료용 옥수수 품종에 따른 검은줄오갈병의 발병률이 차이가 있는 것으로 나타났다 (p<0.05). 검은줄오갈병에 대한 저항성의 정도를 4개의 그룹으로 분류하면, 매우 강한 그룹은 '광안옥'과 '광평옥', 강한 그룹은 'P3156'과 'P3394', 중간 그룹은 '청안옥'과 'P32P75', 약한 그룹은 'NC7117', '수원 19호' 'DK697' 및 'GW6959' 품종이었다. 검은줄오갈병 발생에 따른 사료용 옥수수의 건물수량은 품종 간에 차이가 있었으며 (p<0.05), 검은줄오갈병 저항성 품종인 '광안옥', '광평옥', 'P3156' 및 'P3394' 품종은 이병성 품종보다 건물수량이 14~26% 많았다. 따라서 검은줄오갈병 발생이 심한 지역에서 옥수수 재배를 할 때는 반드시 저항성 품종을 선택하는 것이 중요하다.

중부지역에서 검은줄오갈병 발생이 사료용 옥수수 품종의 조사료 생산성에 미치는 영향

최기준,임영철,윤세형,지희정,이상훈,정민웅,김원호,박형수,김기용,Choi, Gi Jun,Lim, Young Chul,Yoon, Sei Hyung,Ji, Hee Chung,Lee, Sang-Hoon,Jung, Min Woong,Kim, Won,Park, Hyung Soo,Kim, Ki-Yong 한국초지조사료학회 2017 한국초지조사료학회지 Vol.37 No.1

본 시험은 중부지역에서 사료용 옥수수의 검은줄오갈병 발생이 조사료 생산성 에 미치는 영향을 조사하기 위하여 2006년부터 2008년까지 충청남도 천안에서 수행되었다. 사료용 옥수수의 공시품종은 국내에서 재배되고 있는 10품종으로 하였고, 재배방법은 4월 하순에 파종하는 1모작 재배와 5월 중하순에 파종하는 2모작 재배로 나누어 재배하였으며, 품종별 검은줄오갈병의 발생률과 수량성을 조사하였다. 우리나라 중부지역에서 사료용 옥수수의 품종별 검은줄오갈병의 발생률은 차이가 있었다(p<0.05). 검은줄오갈병에 강한 품종은 광안옥, P3156, 광평옥 및 P3394 품종이었고 약한 품종은 'NC+7117', '수원19호' 'DK697' 및 'GW6959' 품종이었다. 검은줄오갈병 발생에 따른 사료용 옥수수의 조사료 건물수량은 품종 간에 차이가 있었으며(p<0.05), 검은줄오갈병 발생이 많았던 수원 19호와 GW6959 품종의 건물수량이 검은줄오갈병 발생이 적었던 광평옥과 P3156 품종보다 20% 정도 적었다. 옥수수의 품종별 암이삭 비율은 검은줄오갈병 발생이 많았던 NC+7117 및 GW6959 품종이 약 29%로 가장 낮았고 검은줄오갈병의 발생이 적었던 광평옥, P3394 및 P3156 품종에서는 각각 34.0, 38.7 및 36.4%으로 높은 경향이었다. 따라서 우리나라 중부지역에서 사료용 옥수수를 재배할 때는 검은줄오갈병에 강한 품종을 선택하고 파종시기의 조절이 매우 중요하다 할 것이다. This experiment was carried out to study the effect of rice black-streaked dwarf virus(RBSDV) infection rate on forage productivity of corn varieties in Cheonan of chungcheongnamdo from 2006 to 2008. Forage corn varieties of 10 were cultivated with first cropping(seeding in the last ten days of April) and second cropping(seeding in the last ten days of May) system in field and tested the infection rates of RBSDV and productivity of forage. The Infection rate of RBSDV was significant difference between corn varieties in middle district of Korea. Resistant corn varieties for RBSDV were 'Kwanganok', 'P3156', 'Kwangpeyongok' and 'P3394' but susceptible varieties were 'Suwon19', 'DK697', 'GW6959' and NC+7117. Dry matter(DM) yield of forage corn according with infection rates of RBSDV in field was significant difference between varieties(p<0.05). DM yield of susceptible varieties, 'Suwon 19', 'DK697' and 'GW6959' was lower about 20% than that of resistant varieties, 'Kwangpeyongok' and 'P3156'. For increasing the productivity of forage corn, recommend of resistant varieties for RBSDV and control of seeding time are very important in middle district of Korea.

석문 간척지에서 돈분액비 및 석고처리가 여름철 사료작물 수량 및 토양이화학성에 미치는 영향

최기춘 ( Ki Choon Choi ),윤세형 ( Sei Hyung Yoon ),신재순 ( Jae Soon Shin ),김동관 ( Dong Kwan Kim ),한효심 ( Hyo Shim Han ),수판자니 ( Supanjani ),이경동 ( Kyung Dong Lee ) 한국환경농학회 2010 한국환경농학회지 Vol.29 No.4

Abstract: Soil physico-chemical properties and microbial densities are affected by organic sources and soil amendment applied to improve soil environments or quality. Generally organic fertilizer effects on forage crops yield and soil properties are partly due to changes of soil composition. We investigated the effects of swine slurry (SS), swine slurry composting-biofilteration(SCB) and chemical fertilizer(F) with gypsum(G) combinations on soil physico-chemical properties and yields of summer forage crop in the Sukmoon reclaimed tidal land in Korea. The forage crops used in this experiment were corn and sorghum×sudangrass hybrid(hereafter sorghum). Our results showed that the soil physico-chemical properties in the combined (F+G, SS+G, SCB+G) treatments increased contents of organic matter and exchangeable Ca2+, but exchangeable Na+, K+ and Mg2+ reduced to 1-10% for two forage crops, compared to non-combined (F, SS, SCB) treatment. The density of soil microorganism such as bacteria, actinomycetes and fungi, increased significantly by SS+G and SCB+G treatments. This means that treatment of combined organic fertilizer with G lowered salinity levels and improved with microbial growth. The combined treatments also increased the total yields 2.3-6.2% for corn and 2.0-8.7% for sorghum, compared with non-combined treatment. This experiment suggests the combined treatments could increase the total yields of summer forage crops and change of soil physico-chemical properties in the Sukmoon reclaimed tidal land in Korea.

볏짚 위주 사양 시 비육 흑염소의 농후사료 급여 수준이 발육, 도체특성 및 경제성에 미치는 영향

김상우(Sang Woo Kim),윤세형(Sei Hyung Yoon),김재환(Jae-Hwan Kim),고응규(Yeoung-Gyu Ko),김동훈(Dong hoon Kim),강근호(Geun Ho Kang),김영신(Young-Sin Kim),이상무(Sang Moo Lee),서상원(Sang Won Suh) 한국초지조사료학회 2012 한국초지조사료학회지 Vol.32 No.4

This study was conducted to examine the effect of feeding levels of concentrate feed on growth performance, meat quality and economic evaluation of Korean black goats. The 40 male Korean native goat were divided into four treatment groups T1 (1.5%), T2 (2.0%), T3 (2.5% feeding of concentrate feed body weight per day) and T4 (ab libitum) with ab libitum rice straw. Rice straw intake decrease as against feeding levels, however average daily gains were 22, 50, 69 and 94 g/day in T1, T2, T3 and T4 groups respectively levels (p<0.05). Dressing percentage were 41.77, 42.78, 46.12 and 49.78% in each group (p<0.05), also fat percentage were a significant increase according to feeding levels. In economic efficacy, T4 was higher than other treatment groups. In conclusion, both rice straw and concentrate feed ab libitum are good for feeding and management system on Korean black goats.