This study was designed to determine whether low-density lipoporoteins (LDL) extracted from egg yolk in extender improve the function of Korean Jeju Black Bull semen. The semen was cryopreserved with 5% ethylene glycol (EG) or 7% glycerol (G) extenders containing 10% egg yolk (EY), 4% LDL and 5% EY or 8% LDL. Frozen-thawed sperm were evaluated sperm motility, viability, membrane integrity and acrosome integrity. Post-thawed sperm motility has been significantly higher (p<0.05) in 4% LDL + 5% EY (; EG and ; 7% G) than 8% LDL (; EG and ;G). Treatment of 4% LDL + 5% EY-EG () has been significantly improved sperm viability compared to other treatments except 10% EY - EG. Moreover, in membrane integrity, swollen sperm ratio has been only significantly increased (p<0.05) in 4% LDL + 5% EY - EG () among all treatments. In assess to detect acrosome integrity, especially, AR pattern ratio has been significantly decreased (p<0.05) in 4% LDL + 5% EY - EG among all treatments. In sperm viability as time passes, between 4% LDL + 5% EY and 10% EY, there was no significant difference, but 8% LDL was significantly decreased sperm viability in EG (1 and 2 hrs) and G (30 min, 1, 2, 5 and 12 hrs) extender. However, there were no significant differences among all treatments except 8% LDL-G in sperm membrane integrity. 8% LDL-G has been significantly decreased swollen sperm ratio at 5 hrs after thawed. It is concluded from these results that 4% LDL + 5% EY to the freezing extender showed more positive effect on the frozen-thawed spermatozoa in Korean Jeju Black bull.

This study was designed to determine whether low-density lipoproteins (LDL) from egg yolk and taurine, hypotaurine and trehalose as antioxidant in extender improve the freezability and fertility of Korean Jeju Black Bull semen. The semen was cryopreserved with tris egg yolk extenders containing 7% glycerol and treated 4% LDL, 20 mM taurine, hypotaurine and trehalose. Frozen-thawed sperm were evaluated motility, viability, membrane, and acrosome integrity and sperm penetration ability. The results were compared to semen cryopreserved in tris egg yolk extender only as control. Frozen-thawed semen evaluation cleary indicated that the addition of LDL and LDL-antioxidants (taurine, hypotaurine and trehalose) combination were significantly improved (p<0.05) the viability (%; with staining test using eosin-Y) compared to control spermatozoa. Also, in membrane integrity (%; with supravital hypo-osmotic swelling test), not only LDL-antioxiants combination but also LDL were significantly increased (p<0.05) the swelled sperm using HOST compared to control. Sperm acrosome integrity state was classified by CTC (chlortetracycline) staining test. F pattern was significantly increased in LDL-antioxidant combination than control (p<0.05) and B pattern was not significantly differences among all treatments and control. However, AR pattern was significantly decreased in LDL-antioxidants combination than control (p<0.05). Pronucleus formation and sperm penetration index (SFI) were significantly increased in LDL and LDL-antioxidants combination than control (p<0.05). Especially, LDL-taurine significantly improved pronucleus fomation and SFI than LDL (p<0.05). It was concluded that LDL and LDL-antioxidants in extender improved the freezability and fertility of Korean Jeju Black bull spermatozoa.

벼 재배 시 녹비작물 투입은 화학비료의 대체뿐만 아니라 토양 물리･화학성을 변화시킨다. 특히 두과 녹비는 토양의 내수성입단 형성 등으로 토양 물 이동 특성에 많은 영향을 미친다. 본 시험은 두과 녹비작물인 헤어리베치를 2007년부터 2008년 5월까지 재배하였다. 투입 시기는 5월 14일이었고 투입량은 2,100 kg/10a를 투입하여6월2일에 중생종인 풍미벼를 기계이앙하였다.물 소요량은7월8일부터 벼 수확기까지 시험구에 계량기를 설치하여 물소요량을 산정하였다. 조사기간의 강수량은 7월 541 mm, 8월 217 mm, 9월은 10일간 강수량이 51 mm 였다. 물관리 처리는 관행 물관리와 7일에 1회 간단관개를 처리하였다. 관행 물관리는 녹비작물 헤어리베치를 투입한 구에서 많이 소모 되었고 주1회 물관리는 관행물관리가 헤어리베치 투입구보다 많았다. 따라서 녹비작물 헤어리베치 투입 시 주1회 물관리를 할 경우 물절약이 가능할 것으로 생각되었다.

녹비작물은 농업생산의 건전성과 지속성 유지를 위하여 작부체계내의 재배기술이 중요하다. 특히 두과 녹비작물인 헤어리베치는 공중질소를 고정할 뿐만 아니라 생초 생산력과 질소함량이 높아서 생물비료로써는 높은 효과를 가지고 있다. 본시험은 이러한 효과를 가진 헤어리베치의 답리작에서 안전성을 구명하고자 파종방법별 녹비생산력 및 토양 이화학성의 변화를 구명하고 수행하였다. 시험장소는 경기도 수원시 서둔동 국립식량과학원 벼 시험포장에서 벼 수확 후 답리작으로 시험을 수행하였다. 시험토양은 신흥통으로 식양질이었고, 헤어리베치는 중국에서 도입한 H-1을 파종하였다. 파종방법은 벼 입모중 파종과 벼수확 후 부분경운파종 및 세조파를 하였다. 입모중파종과 부분경운파종이 세조파에 비하여 녹비 생산성이 우수하였고 토양물리성도 개선되는 경향이었다.