• 한국환경과학회지
• /
• 제28권5호
• /
• pp.495-502
• /
• 2019

This study was conducted to investigated the possibility of inactivating wilt germs (Fusarium oxysporum f. sp. radicis lycopersici) using Dielectric Barrier Discharge (DBD) plasma in a hydroponic system. Recirculating hydroponic cultivation system for inactivation was consisted of planting port, LED lamp, water tank, and circulating pump for hydroponic and DBD plasma reactor. Two experiments were conducted: batch and intermittent continuous process. The effect of plasma treatment on Total Residual Oxidants (TRO) concentration change, Fusarium inactivation and growth of lettuce were investigated. In the batch experiment, most of the Fusarium was inactivated at a TRO concentration of 0.15 mg/L or more at four-day intervals. There was no change in lettuce growth after two times of plasma treatment for one week. The intermittent continuous experiment consisted of 30-minute, 60-minute, and 90-minute plasma treatment in 2 day intervals and 30-minute treatment a one-day; most of the Fusarium was inactivated only by treatment for 30-minute every two days. However, if inactivation under $10^1CFU/mL$ is required, it will be necessary to treat for 60 minutes in 2 day intervals. The plasma treatment caused no damage to the lettuce, except the 30 min plasma treatment ay the one-day interval. It was considered that the residual TRO concentration was higher than that of the other treatments.

• 한국양식학회지
• /
• 제18권4호
• /
• pp.231-235
• /
• 2005

본 연구는 치어기 넙치의 여름철 적정 사료공급 횟수를 조사하기 위해 평균무게 3.7g의 실험어를 300${\iota}$ 원형수조에 각 수조당 80마리씩 3반복으로 무작위 배치하여 사료공급 횟수를 달리하여 6주간 사육하였다. 사료공급 횟수는 2일 1회(09:00), 1일 1회(09:00), 1일 2회(09:00, 18:00), 1일 3회(09:00, 13:00, 18:00) 및 1일 4회(09:00, 12:00, 15:00, 18:00)로 설정하였으며, 매회 실험어가 먹을 때까지 만복공급 하였다. 생존율은 2일 1회 사료공급구가 가장 낮게 나타났으며, 1일 1회 이상의 사료공급구간에서는 유의적인 차이가 나타나지 않았다. 증체율 및 일일사료 섭취율은 사료공급횟수가 증가함에 따라서 증가하였지만, 1일 2회 이상 사료를 공급한 실험구들 간에는 유의한 차이가 없었다. 사료효율 및 단백질 전환효율은 사료공급횟수에 유의한 영향을 받지 않아 모든 실험구간에 차이가 없었다. 사육실험 종료 후, 전어체의 수분, 단백질, 지방 및 회분함량은 모든 실험구에서 유의적인 차이가 나타나지 않았다. 이상의 결과로 볼 때, 3.7${\~}$19.0g 넙치 치어 시기의 여름철(수온 $24^{\circ}C$) 배합사료의 적정공급 횟수는 사육관리 시간 및 비용 등 경제적인 측면을 고려하였을 때 1일 2회일 것으로 사료되며, 이때 사료섭취율은 $2.63{\~}2.78\%$가 적당할 것으로 판단된다.

• 생물환경조절학회지
• /
• 제12권2호
• /
• pp.77-82
• /
• 2003

본 실험은 토마토 양액재배에서 펄라이트 배지를 순환식 재배방법에 적용하고자 수행되었다. 펄라이트 배지의 입자를 소립(ø1∼2mm 미만), 중립(ø2∼3mm), 대립(ø4∼5 mm)으로 분리하여 양액공급량에 따른 토마토의 생육을 검토한 결과는 아래와 같다. 제 3화방 개화(초기생육)시 초장은 중립과 대립에서는 양액공급량이 많을수록 길었으나 소립에서는 양액공급량에 관계없이 길어 초기에 생육관리는 대립일수록 1일 양액공급량이 많아야 할 것으로 생각되었다. 그러나 제 3화방 개화기 이후는 소립에서는 주당 1일 공급량을 1.5L로, 그리고 중립과 대립에서는 주당 1일 3.0L로 관리하는 것이 착과수가 많고 수량이 높았다 기형과율은 펄라이트 입자의 크기에 관계없이 양액공급량이 많을수록 적었다. 근활력은 정식 후 50일까지는 입자크기 및 양액공급량에 관계없이 증가하였으나, 50일 이후부터는 감소하기 시작하여 정식 후 100일에는 소립에서는 양액공급량이 많을수록, 그리고 중립과 대립에서는 양액공급량이 적을수록 감소하는 경향이 컸다. 소립에서는 앙액공급량이 증가할수록 모든 무기성분함량이 감소하는 경향이었으나 중립과 대립에서는 증가하는 경향이었다 N. K. Ca및 Mg의 함량은 소립에서는 양액공급량이 1일 3.0L/주 처리구에서 가장 적었으나 대립과 중립에서는 1일 3.0L/주 처리구에서 가장 많았다. 이상의 결과에서 토마토 순환식 양액재배시 펄라이트 입자는 중립과 대립의 사용이 유리하고 양액공급량은 주당 1일 3.0L 관리하는 것이 유리하였다.

• 한국양식학회지
• /
• 제15권3호
• /
• pp.123-129
• /
• 2002

사육기간 중 수온은 12.6~24.5$^{\circ}C$ 였고, 염분은 27.32~33.10 $\textperthousand$, 용존산소는 7.05mg/L이상으로 양호한 수질상태를 보였다. 6~9월 해만가리비 성장기에 식물플랑크톤의 우점종은 편모조류인 Ceratium sp.가 35.2% 출현하였다. 플랑크톤의 밀도는 대체적으로 8~9월에 낮았고, 6월과 10월에 높았으며, chlorophyll-a는 1.69~7.40 $\mu\textrm{g}$/L 였다. 해만가라비 치패의 선발에 따른 성장차이를 알아보기 위하여 선발시험구(평균각고 21.47${\pm}$0.80 mm)와 비교시험구(평균각고 16.59${\pm}$0.99 mm)를 조성하여 185일간 사육한 결과, 각고는 선발시험구 0.17 mm/day, 비교시험구 0.19 mm/day 였고, 전중량은 선발시험구 0.17 g/day, 비교시험구 0.16 g/day 였다. 각고의 일간성장률은 선발시험구 0.487%, 비교시험구 0.606%였고, 전중량의 일간성장률은 선발시험구 1.600% 및 비교시험구 1.972%였다. von Bertalanffy성장모델에 의해 얻어진 각고의 최대 예상값은 54.08 mm(선발시험구) 및 52.62 mm(비교시험구)였다. 생존율은 선발구는 80.0%, 비교시험구는 87.0%의 생존율을 보였다. 선발시험구의 치패는 상품크기인 평균각고 5 cm이상으로 성장하는데 3개월이 소요되어 비교시험구보다 1개월 단축되었으나, 12월까지 계속 사육시에는 가리비류에서 나타나는 보상성장(compensatory growth) 효과가 나타나 양 시험구간의 성장차이에 유의차가 없었다.

• 대한치과교정학회지
• /
• 제35권5호
• /
• pp.351-360
• /
• 2005

이 연구는 $PGE_2$ 생합성 억제제인 인도메타신의 투여 시 성장기 개의 하악두 연골에 나타나는 cyclooxygenase-2 (GOX-2)와 insulin-like growth factor 1(IGF-1)의 발현과 분포를 관찰하여 인도메타신이 하악두 연골 성장에 미치는 영향을 규명하기 위하여 시행하였다 생후 12- 3주된 잡견 8마리를 4군으로 구분하였다 통상적 복용량인 인도메타신 2mg/Kg/day을 각각 7일과 14일간 투여한 군 과량인 8mg/Kg/day을 14일간 투여한 군과 무처치군인 대조군으로 구분하였으며. 하악두를 연구대상으로 하였다. 연구대상 하악두는 $5{\mu}m$ 두께의 절편을 만들어, H-E 중염색, COX-2 면역염색 IGF-1 면역염색을 시행하여 광학 현미경으로 검경하였으며, tartrate resistant acid phosphatase(TRAP) 염색 후 파연골세포의 수를 측정하여 다음과 같은 결과를 얻었다. 인도메타신은 하악두 연골의 증식대에서 COX-2와 IGF-1의 발현과 분포를 억제시켰으며, 인도메타신의 투여기간에 비례해서 파연골세포 수는 유의성 있게 감소하였다 (p<0.01) IGF-1의 발현과 분포는 인도메타신의 투여 양과 기간에 비례하여 억제되었다 이상의 결과에 의하면 인도메타신의 투여는 하악두 연골에서 COX-2와 IGF-1의 발현과 분포를 억제하고 파연골세포의 수를 감소시켜 하악두 성장을 억제할 가능성이 있음을 시사한다.

• Journal of Animal Science and Technology
• /
• 제65권2호
• /
• pp.377-386
• /
• 2023

The effect of different commercially available bedding materials on the growth performance and carcass characteristics of ducks for 42 days was investigated. 336 one-day-old White-Pekin ducklings (60.48 ± 0.16 g) were randomly allocated into 24-floor pens with one of the three beddings namely i) coco peat, ii) rice husks, or iii) sawdust. 14 ducklings per pen and 8 replicate pens per bedding material were used. Birds were fed a starter diet from days 1-21 and a grower diet from days 22-42. Weekly growth performance evaluation was conducted for the average body weight, weight gains, daily feed intake, and feed conversion efficiency. One bird per pen was sacrificed on day 42 for the evaluation of carcass characteristics including the carcass, breast, and leg muscle percentages. Breast and leg muscle samples were then collected and analyzed for their proximate and pH values. Higher body weights (p < 0.05) were noticed with rice husks on day 42 only. Improved daily gains (p < 0.05) were also noticed for birds raised with rice husks over the entire period (days 1-42). Concerning feed intake, higher values (p < 0.05) were similarly noted with rice husks for the grower phase (days 22-42), and the entire experimental period (days 1-42). Marginally improved feed intake values were also noted with the use of rice husks as the bedding materials on day 42 (p = 0.092). Improved feed efficiency (p < 0.05) was noticed with rice husks on day 35, the grower period, and the entire 42-day period. However, no significant differences were noticed for most of the carcass characteristics that were evaluated. Nevertheless, higher (p < 0.05) pH values for the breast muscle were noticed with the use of coco peat and sawdust as the bedding. Conclusively, the bedding type could have a significant impact on the growth performance of ducks without adverse effects on carcass characteristics. The use of rice husks as bedding might be advantageous and is therefore recommended.

• Asian-Australasian Journal of Animal Sciences
• /
• 제5권4호
• /
• pp.659-664
• /
• 1992

Twelve day old Pabna zebu calves of similar weights were assigned at random to 3 different calf starter-rations namely $T_0$, $T_1$ and $T_2$ to determine the effect of feeding regimes and growth pattern of calves upto 3 months of age. Calves allowed to intake starter 0.5 percent of body weight from 2nd week on to 7th weeks of age, while starter at 1 percent of body weight was allowed later on upto 13th weeks of age. Calves started to intake green grass after 2nd to 3rd weeks and average intake per day was limited to 1 kg upto the end of experiment, while calves started to take rice straw ad libitum after 6th weeks of age. Colostrum feeding was offered ad libitum and in addition calves suckled their dam's milk shortly before and after milking usually in the morning and evening. Growth of calves in different treatment groups was found statistically insignificant. The mean growth rate per head per day ranged from 196.43-375.0 g for $T_0$ group, 185.72-360.72 g for $T_1$ group and 180.1-385.72 g for $T_2$ group respectively between 1st to 7th weeks of age while the growth rate ranged from 309.53-328.57 g for $T_0$, 304.29-342.86 g for $T_1$ and 304.77-333.30 g for $T_2$ groups respectively from 9th weeks on to the end of the experiment.

• Asian-Australasian Journal of Animal Sciences
• /
• 제10권2호
• /
• pp.178-184
• /
• 1997

Purified diets containing five graded levels of lysine were fed to a total of 125 growing chicks (25 chicks per treatment) to evaluate lysine requirements for growth and maintenance. A model was developed to separate lysine requirement for maintenance from requirement for growth. Based on weight gain response, the daily lysine requirement for growth was 12.06 mg/g gain and the daily lysine requirement for maintenance was 0.332 times metabolic body size ($W^{0.75}$). Similarly, the lysine requirement for growth was 0.457 mg/mg nitrogen gain and the daily lysine requirement for maintenance was 0.344 times metabolic body size. The plateau of plasma lysine concentration was reached at 354.75 mg intake/day. The total lysine requirement was 414.27 mg/day or 1.0% of the diet, 420.11 mg/day or 1.01% of the diet based on weight gain response and N gain response, respectively. Previous lysine requirements for growing chicks of 1-28 days old were in close agreement with these estimates. As a percentage of protein, lysine requirement was calculated to be 7.3% and the reported lysine content of chick muscle crude protein of 7.46% was closely related.

• Journal of Animal Science and Technology
• /
• 제56권3호
• /
• pp.7.1-7.7
• /
• 2014

The recognition that omega-3 polyunsaturated fatty acids (n-3 PUFA) possess potent anti-inflammatory properties in human models has prompted studies investigating their efficacy for animal growth and immunity. This study examined the effect of feeding an n-3 PUFA-enriched diet on growth and immune response of weanling piglets. Newly weaned pigs (averaging $27{\pm}2$ days of age and $8.1{\pm}0.7kg$ of body weight) were assigned randomly to receive a control (3% vegetable oil, n = 20) or n-3 PUFA-supplemented (3% marine n-3 PUFA, n = 20) diet for 28 day after weaning. Female pigs consuming the n-3 PUFA-enriched diet were lighter at week 4 post-weaning than those fed the vegetable oil supplement. Weanling pigs gained more weight, consumed more feed and had better growth to feed ratios between days 14 and 28 than between days 0 and 14 post-weaning. Plasma insulin-like growth factor I (IGF-I) decreased between days 0 ($87.2{\pm}17.0ng/mL$) and 14 ($68.3{\pm}21.1ng/mL$) after weaning and then increased again by day 28 ($155.2{\pm}20.9ng/mL$). In piglets consuming the vegetable oil-enriched diet, plasma tumor necrosis factor alpha (TNF-${\alpha}$) increased from $37.6{\pm}14.5$ to $102.9{\pm}16.6pg/mL$ between days 0 and 14 post-weaning and remained high through day 28 ($99.0{\pm}17.2pg/mL$). The TNF-${\alpha}$ increase detected in the piglets fed vegetable oil was not observed in the piglets fed n-3 PUFA. Results indicate that weaning induces considerable immune stress in piglets and that this stress can be mitigated by dietary supplementation of n-3 PUFA.

• Asian-Australasian Journal of Animal Sciences
• /
• 제12권3호
• /
• pp.381-387
• /
• 1999

Two experiments were conducted to subdivide threonine (exp. 1) and glycine (exp. 2) requirements of broilers into maintenance and growth requirements. Purified diets containing five graded levels of threonine (exp. 1) and glycine (exp. 2) were fed to growing chicks to estimate threonine (exp. 1) and glycine (exp. 2) requirements for growth and maintenance. A model developed to divide threonine requirement for maintenance from that for growth yielded a requirement for growth of 8.946 mg/g weight gain and 0.341 mg/mg N gain; the maintenance requirement was 0.033 or 0.030 mg per unit of metabolic body size $(Wg^{0.75})$. The plateau of plasma threonine concentration occurred at 279.4 mg threonine intake/day. The total threonine requirement was 289.1 mg/day or 0.69% of the diet, 294.1 mg/day or 0.71% of the diet based on weight gain and nitrogen gain responses, respectively. These estimates were in close agreement with previous estimates of threonine requirements. From the relationship of weight gain to N gain, 5.46% of the retained protein consisted of threonine; the reported threonine content of chick muscle was 4.02%. The glycine requirement for maintenance could not be determined due to failure to obtain data allowing extrapolation to zero response. However, ADG increased slightly up to 0.56% glycine.