• Journal of Biosystems Engineering
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• 제37권6호
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• pp.373-384
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• 2012

Purpose: In EU, the animal welfare regulations are strengthening. Also, in Korea, for strengthening of animal protection laws, animal welfare farm certification scheme is being prepared to enforce. To get the certification of animal welfare farm, especially for sows, individual specific feeding in sow group is necessary in accordance with the animal welfare regulation. Also, liquid feeding is reported to be more effective for farrowing as well as dry sow. Therefore, in this study, a electronic liquid sow feeder using RFID which could be fed to farrowing sow simultaneously is developed. Methods : We manufactured a prototype of appropriate elements which were evaluated in the preliminary test for selecting RFID tag, supply pump, mixing type, etc. With the prototype, the performance test for liquid feeding gilt was done in group raising training barn. Results : The performance test result shows the C.V.(coefficient of variation) of liquid mixing and feeding is 0.77~1.97% and 2.4~5.3%, respectively, which means the system could feed sows uniformly. The feeding time of pneumatically activated ball valve is 2 seconds per 0.9 kg of liquid feed. The eating time for gilt were 65 seconds in average. Conclusions : The prototype could feed sow uniformly, and deliver the liquid feed 9 times for a sow continuously. Also, total eating time for a sow was 18 minutes in one visit to the prototype of feeding station.

• Asian-Australasian Journal of Animal Sciences
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• 제17권2호
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• pp.283-300
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• 2004

Currently commercial dry sows are housed in individual stalls and subject to restricted feeding. These sows often show stereotypic behaviours which increase their maintenance energy requirement. Group housing is desirable to improve animal welfare and public perception. However, under restricted feeding systems, group-housed dry sows are also aggressive. The feed intake of these sows is variable, depending on their social rank, which results in different milk production and variable piglet performance. These problems can be solved by ad libitum feeding systems, but the large capacity of intake by dry sows will not allow this feeding system to be practical as high feeding level during pregnancy can reduce reproduction performance of sows. Current research indicates that feeding high fibre diets to dry sows enables sows to be fed ad libitum, but the effect of dietary fibre on feed intake and nutrient utilisation is dependent on the quality of fibre sources. Most research has focused on sugar beet pulp, straw, lucerne meal and by-products, but there is a need to identify and evaluate some widely available and cheap fibre materials and feed grains for developing the best strategy to control nutrient intake of dry sows while feeding ad libitum.

• Asian-Australasian Journal of Animal Sciences
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• 제6권1호
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• pp.91-97
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• 1993

This experiment was carried out to examine the effects of urea-treated rice straw feeding on the growth performance of crossbred Holstein heifers under different feeding conditions. In the first experiment, the animals were given diets having 2 levels of TDN and CP and 3 levels of crude fiber (22, 30 and 36%) which were formulated with urea-treated rice straw and concentrates. Daily weight gain of heifers was not different between 22% and 30% CF diets, but the reduction of TDN or CP level to 90% of the requirements decreased the weight gain. Fiber content of 36% also reduced the body weight gain. The reduction of TDN significantly reduced DM intake and increased feed conversion ratio. Feed cost per kg weight gain was significantly increased by an increase in CF to 36%. In the second experiment, separate feeding and total mixing feeding were compared. There were no significant differences between the two feeding systems in body weight gain although the possibility of superiority in SF to TMF remained. DM intake was not affected by the feeding system, but 30% CF diet gave higher DM intake. Feed cost per kg weight gain was lower in the 30% CF diet.

• Membrane and Water Treatment
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• 제11권1호
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• pp.79-85
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• 2020

A single-stage deammonification with a sequencing batch reactor (SBR) that simultaneous nitritation, anaerobic ammonia oxidation (anammox), and denitrification (SNAD) occur in one reactor has been widely applied for sidestream of wastewater treatment plant. For the stable and well-balanced SNAD, a feeding strategy of influent wastewater is one of the most important operating factors in the single-stage deammonification SBR. In this study, single-stage deammonification SBR (working volume 30L) was operated to treat a high-strength ammonium wastewater (1200 mg NH₄⁺-N/L) with different feeding strategies (single feeding and nine-step feeding) under the condition without COD. Each cycle of the step feeding involved 6 sub-cycles consisted of aerobic and anoxic periods for partial nitritation (PN) and anammox, respectively. Contrary to unstable performance in the single feeding, the step feeding showed better deammonification performance (0.565 kg-N/m³/day). Under the condition with COD, however, the nitrogen removal rate (NRR) decreased to 0.403 kg-N/m³/day when the Nine-step feeding strategies had an additional denitrification period before sub-cycles for PN and anammox. The NRR was recovered to 0.518 kg-N/m³/day by introducing an enhanced multiple-step feeding strategy. The strategy had 50 cycles consisted of feed, denitrification, PN, and anammox, instead of repeated sub-cycles for PN and anammox. The multiple-step feeding strategy without sub-cycle showed the most stable and excellent deammonification performance: high nitrogen removal efficiency (98.6%), COD removal rate (0.131 kg-COD/m³/day), and COD removal efficiency (78.8%). This seemed to be caused by that the elimination of the sub-cycles might reduce COD oxidation during aerobic condition but increase the COD utilization for denitrification period. In addition, among various sensor values, the ORP pattern appeared to be applicable to monitor and control each reaction step for deammonification in the multiple-step feeding strategy without sub-cycle. Further study to optimize the number of multiple-step feeding is still needed but these results show that the multiple-step feeding strategy can contribute to a well-balanced SNAD for deammonification when treating high-strength ammonium wastewater with COD in the single-stage deammonification SBR.

• 한국초지조사료학회지
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• 제35권1호
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• pp.1-5
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• 2015

본 연구는 흑염소 사양체계 확립에 대한 기초자료를 얻고자 방목과 사사형태의 사육이 흑염소의 번식능력과 자축의 발육성적에 미치는 영향을 조사하였다. 공시축은 흑염소 36두를 방목구와 사사구로 나누어 처리구당 18두씩 공시하여 2011년 4월부터 11월까지 8개월간 수행하였다. 단태의 비율은 방목구가 31.5%, 사사구가 37.0%로 통계적인 차이는 나타나지 않았다. 산자수는 방목구와 사사구가 각각 1.76과 1.69두로 사육형태에 따른 차이가 나타나지 않았으며, 이유 시의 두수는 방목구가 사사구 보다 높은 경향으로 나타났다(p=0.11). 사육형태에 따른 생시체중은 방목구가 2.3 kg, 사사구가 2.29 kg 로 나타나 차이가 나타나지 않았으나, 생후 90일 령 이유 시 방목구가 9.97 kg 로 사사구의 9.45 kg 보다 높은 경향으로 나타났으며(p=0.09), 포유기간 일당증체량에서도 방목구가 사사구 보다 높은 경향으로 나타났다(p=0.13). 이상의 결과를 종합해 보면, 흑염소를 방목과 사사형태로 사육하였을 때, 분만형태, 산자수 및 생시체중에는 차이가 없었으나, 이유두수 및 자축의 일당증체량에서는 방목사육 형태가 우수한 경향으로 나타나, 방목이 흑염소의 생리적 욕구를 충족시켜 건강한 흑염소 생산에 기여 할 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제33권12호
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• pp.2031-2038
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• 2020

Objective: This study aimed to determine the effect of intermittent feeding and cold water on performance and carcass traits in broiler chickens between 4 to 6 wk of age exposed to daily high temperature. Methods: Broilers were assigned to four treatment groups according to a 2×2 factorial design between 22 to 42 d of age (80 broilers per treatment, 4 replications). Broilers were divided into two main groups as feeding type (ad-libitum [AL] and intermittent [IF] for 6 h daily) and sub-groups as water temperature (normal [NW], 24.9℃ and cold [CW], 16.4℃). Heat treatment was applied between 11.00 to 17.00 h daily between 22 to 42 d of age. Results: Live weight at 6th wk was not affected by feeding type and water temperature, but the live weight was significantly higher in IF chickens at the 5th wk (p<0.05). Average weekly gain of IF broiler chickens were higher compared to AL group at 4, 5, and 6 wk of age (p< 0.05). Although feeding type did not affect feed intake in 4 and 5th wk, feed intake was higher in IF chickens at 6th wk (p<0.01). In addition, feeding type and water temperature did not affect feed conversion ratio and interactions were not significant (p>0.05). Water temperature had no significant effect on heart, liver, gizzard, and abdominal fat percentages (p>0.05). Conclusion: It is concluded that IF increased the average weekly gain in chickens reared under daily heat stress for 6 h between 22 to 42 d of age. IF in hot environmental conditions slightly increased performance without adversely affecting health, welfare, and physiological traits, whereas CW implementation had no significant effect on performance. It can also be said that IF suppresses a sudden increase in body temperature depending on age and live weight.

• 한국수산과학회지
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• 제52권5호
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• pp.468-473
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• 2019

A $2{\times}4$ factorial feeding trial was conducted to examine the effect of feed type and feeding frequency on the performance of sub-adult starry flounder Platichthys stellatus. Two feed types, sinking pellets (SP) and floating pellets (FP), were given to 480 fish housed in tanks. Triplicate groups of fish were fed each feed type at one of four feeding frequencies (one meal every two days, one meal per day, two meals per day, and three meals per day) for nine weeks. Weight gain (WG) and specific growth rate (SGR) of fish were affected by feeding frequency. However, WG and SGR were the same in fish fed SP at two and three meals per day; similarly, there was no difference in WG or SGR of fish fed FP at one meal, two meals, or three meals per day. Feed utilization of fish was affected by both feed type and feeding frequency. These findings suggest that two meals per day of the SP or one meal per day of FP are sufficient for optimum growth performance of sub-adult starry flounder.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제29회 추계학술대회논문집
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• pp.248-251
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• 2007

블로우다운 산화제 공급 방식은 부품 수가 적어 신뢰도가 높고, 별도의 가압 탱크가 존재하지 않아 발사체의 총 중량을 감소시킨다는 측면에서 효과적이지만, 일정한 추력 성능을 보장하지 않는 단점을 내재하고 있다. 따라서 본 연구에서는 각 부품의 수학적 모델링을 통해 블로우다운 산화제 공급방식 하이브리드 로켓의 성능 해석 모델을 제안하여, 고유의 성능 특성에 대하여 고찰하였다.

• Journal of Biosystems Engineering
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• 제28권6호
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• pp.531-536
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• 2003

This study was carried out to develop a vacuum nozzle seeder for large seeds and performance was tested on seed feeding, arranging. and sowing peformance. The results of this study were as follows： The operation of feeding device of the seeder was programmed to operate a period of setting time after sowing 6 rows. The setting time was decided based on a discharged seed by the angular speed of feeding roller. The arranging accuracy of 'tuktozwa', 'hukjong' and 'chambak' was 96.4％, 95.2％ and 89.4％ respectively. The working performance was 75.6sheet/hr which was 3.8 times higher than that of manual work. An average seeding rate of 1 grain was 97.8％.

• Asian-Australasian Journal of Animal Sciences
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• 제30권6호
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• pp.834-842
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• 2017

Objective: An experiment was to evaluate the interplay of dietary lipid sources and feeding regime in the transition from sow milk to solid food of abruptly weaned piglets. Methods: Soon after weaning, 144 piglets were selected and were trained over a 15 day period to experience gradually reducing dietary fat content from 12% to 6% for lard (L), soybean oil (S), and coconut oil (C) and their feeding behavior and diet preference then tested in a behavior observation experiment. Another 324 weaned piglets were used in three consecutive feeding experiments to measure the effect of different dietary fats on performance and feed choice in the four weeks after abrupt weaning. The lipid sources were used as supplements in a 3% crude fat corn/soya basal diet, with 6% of each being included to form diets 9C, 9S, and 9L respectively, and their effects on performance measured. Combinations of these diets were then further compared in fixed blends or free choice selection experiments. Results: Piglets pre-trained to experience reducing lipid inclusion showed different subsequent preferences according to lipid source, with a preference for lard at 9%, soybean oil at 3%, and coconut oil at 6% inclusion rate (p<0.001). Following abrupt weaning, whilst after 4 weeks those fed 9C had the heaviest body weights (18.13 kg, p = 0.006). Piglets fed a fixed 1:1 blend of 9C+9S had a poorer feed conversion ratio (FCR = 1.80) than those fed a blend of 9C+9L (FCR = 1.4). The 9C and 9L combination groups showed better performance in both fixed blend and free choice feeding regimes. Conclusion: After abrupt weaning, they still have dependence on high oleic acid lipids as found in sow milk. A feeding regime offering free choice combination of lipids might give the possibility for piglets to cope better with the transition at weaning, but further research is needed.