• Fisheries and Aquatic Sciences
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• 제27권8호
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• pp.475-487
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• 2024

Larviculture of commercially important aquaculture species faced limitations associated to the incomplete understanding of larval nutrition and the inability to total replacement of live feeds by formulated diets at the early larval stage. The main challenges to alternatives of live feed in larval fish culture are related to the inherent behaviors of the larvae and the incomplete knowledge and practice leading to the inefficiency of using micro diets. Although significant achievement has been reached in the complete replacement of live feeds by formulated micro diets in freshwater species and marine shrimps, its success is far from complete in marine finfishes. However, recent progress in biotechnological advances in manufacturing process and advanced knowledge of the nutritional necessities of larvae indicated improvements in the field. A range of technologies in the manufacturing of micro diets for larval fish are in place currently. To this end, several achievements of substituting live feeds with formulated micro diets at later stages of larval development have been reported by various researchers providing a clue on the prospects for the future. Therefore, the objective of this review is to compile existing information on the challenges of substituting live feeds by formulated diets in the past and prospects for future development.

• 한국정보시스템학회지:정보시스템연구
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• 제32권4호
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• pp.137-147
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• 2023

Purpose The domestic aquaculture industry in South Korea utilizes both formulated feeds and live feeds for the cultivation of fish. While nutrient-rich live feeds, particularly using fry, have been preferred since the past, formulated feeds are gaining attention due to issues related to overfishing and environmental concerns. Formulated feeds are advantageous for storage and supply but require a sustained feeding regimen due to the comparatively slower growth rate compared to live feeds. As the aging population in rural areas leads to a shortage of labor, automated feeding systems are increasingly being adopted in aquaculture facilities. To enhance the efficiency of such systems, it is crucial to quantitatively analyze the behavioral changes in fish based on the presence or absence of feed. Design/methodology/approach In the study, RGB cameras and infrared cameras were used to analyze fish activity according to feeding, and an outline extraction algorithm was applied to analyze the differences resulting from this. Findings Unlike RGB cameras, infrared cameras are more suitable for analyzing underwater fish activity as they convert objects' thermal energy into images. It was observed that Canny, Sobel, and Prewitt filters showed the most distinct identification of fish activity.

• 대한수의학회지
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• 제23권2호
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• pp.187-191
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• 1983

In the course of surveying the internal parasites of domestic animals, a large number of eggs and mites were detected in the feces and feeds of cattle, pigs, chickens and ducks. Three kinds of mites were identified in the present studies: Acarus siro (Linnaeus), Tyrophagus putrescentiae (Schrank) and Cheyletus malaccensis (Oudemans). The eggs of the mites were similar to those of flukes. In the fecal examination, therefore, it is necessary to differentiate the mite eggs from fluke eggs. The mites found in the present studies live by organic materials. Thus, they were found in the mixed commercial animal feeds. The spoiling of animal feeds by these mites remains to be verified. The damage of the gut epithelium of animals by these adult mites has to be examined more thoroughly, although macroscopic changes were not detected in the present studies. In the commercial animal feeds, the mites were largely found during the warm, humid seasons. As these mites can cause dermatitis in man, care should be taken not to contact continuously with the contaminated feeds.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2003년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.199-200
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• 2003

After more than 5 years of turbot culture in China, low percent survival and high occurrences of abnormally pigmented juveniles are still major problems for fish farmer. Much research has been directed toward determining the optimal feeding strategies and nutritional requirements for marine flatfish larvae, and considerable advances have been made. The most common live feeds include :Artemia, rotifer and copepods. (omitted)

• 한국양식학회지
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• 제11권4호
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• pp.437-447
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• 1998

조피볼락 종묘생산시 발생하는 대량폐사를 막기 위하여 자어의 다양한 먹이생물을 공급하여 성장을 비교하였고 여러 가지 방법으로 먹이생물을 영양강화시켜 공급하여 그에 따른 조피볼락 자어의 생존율과 성장률을 비교하였다. 성게 유생은 쉽게 구할 수 있으나 조피볼락 자어의 생존율을 저하시켰고 유생의 지방산 분석 결과를 볼 때 그다지 적합한 먹이로 생각되지 않는다. Rotifer나 Artemia nauplii를 단독으로 조피볼락의 자어를 먹이로 공급하는 것보다 혼합공급하는 것이 더 효과저거인 것으로 나타났다. 그리고 rotifer나 Artemia nauplii를 ${\omega}$-yeast, Spirulina platensis나 Super Selco로 영양강화시킨후에 먹이로 공급할 경우 자어의 생존율이나 성장률에서 많은 개선을 보였다. Rotifer를 Super Selco로 영양강화를 시켰을 경우 $\omega$-yeast로 영양강화를 시킨 경우보다 높은 생존율과 성장률의 결과를 보였다. 산출 후 10일 경에 대량폐사가 발생하였으며 초기에는 rotifer가 자어의 먹이로 우수한 것으로 나타났으나 10일 경 이후부터는 Artemia nauplii가 우수한 먹이로 판단된다. 그러나 rotifer와 Artemia nauplii 혼합 공급하였을 경우 rotifer나 Artemia nauplii를 단독 공급하는 경우보다 우수한 결과를 보였다.

• Asian-Australasian Journal of Animal Sciences
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• 제14권12호
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• pp.1728-1733
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• 2001

An experiment was conducted at the experimental duck farm of Cantho University in the Mekong Delta of Vietnam to evaluate the effects of offering pairwise feeds with different crude protein (CP) levels to Cherry Valley broiler ducks from 28-63 days of age on feed intake and performance. Five diets consisting of mixtures of soya bean meal, fish meal, maize meal and fine rice bran, were formulated to give isocaloric diets with 30, 24, 18, 16 and 12% CP. These were offered separately as pellets to growing ducklings in the following combinations: 30+18, 30+12, 24+16 and 18+12. A diet with 20% CP (CP20) was used as control. All the diets were offered ad libitum. Daily feed intakes (g dry matter, DM) were 161, 168, 150, 101 and 143 g for the 30+18, 30+12, 24+16, 18+12 and CP20 treatments, respectively. CP intakes were 29.6, 27.0, 24.8, 17.1 and 22.9% of total DM intake, and the ratio of methionine+cystine to lysine was 0.76, 0.75, 0.75, 0.76 and 0.75 for the 30+18, 30+12, 24+16, 18+12 and CP20 treatments, respectively. Live weights at 63 days of age were 2,937, 3,054, 2,898, 2,200, and 2,811 g (p<0.001), and daily live weight gains 57.8, 61.7, 57.0, 38.5 and 55.7 g (p<0.001) for the 30+18, 30+12, 24+16, 18+12 and CP20 treatments, respectively. The weights and yields of the carcass, breast and thigh muscles, and heart decreased in the order 30+18, 30+12, 24+16, CP20 and 18+12 (p<0.001). The present study suggests that growing broiler offered a combination of high and low protein feeds pairwise will eat excessive amounts of the high protein feed, thus resulting in protein intakes above requirements.

• 한국수산과학회지
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• 제36권6호
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• pp.735-742
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• 2003

In order to develop a logical method for using selective fishing gear, the behaviour and habits of the aquatic animals must be investigated. However, until now, little national research has been carried out to investigate the behaviour and habits of the common octopus (Octopus minor). The purpose of this study henceforth, is to compile necessary behavioral data to develop fishing gear to catch the common octopus. Behaviour and habits of the common octopus were observed while breeding in a water tank from February to May, 2003. The feeding habits of common octopus are more vigorous at night than in the daytime. The common octopus feeds on 1-4 bait crabs per day and consume each crab in 40-50 min. The sensory organs of the common octopus are more influenced by the sense of touch and smell, than by vision. Using live bait is more effective and advantageous than using dead bait, as the common octopus responded more to live bait. The hiding habits of the common octopus were very intensive, as they hid around all the shelters that were provided in this study. They demonstrated territorial behavior and struggled to maintain their sphere of influence. In addition, out of the various colors for shelters and bait supplied, the common octopus preferred light colors.

• Journal of Animal Science and Technology
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• 제65권2호
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• pp.427-440
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• 2023

The current study evaluated carbon dioxide (CO₂) emissions from beef and pork production and distribution chains in the South Korean meat industry. Data from industrial example farms and slaughterhouses were assessed on the basis of both the guidelines from the United Kingdom's Publicly Available Specification (PAS) 2050:2011 and the Korea Environmental Industry & Technology Institute carbon footprint calculation. The main factors for our estimations were animal feeds, manure waste, transportation, energy and water, refrigerants, and package data. Our analyses show that 16.55 kg CO₂ equivalent (eq) was emitted during the production of 1 kg of live cattle. When retail yields and packing processes were considered, the CO₂-eq of 1 kg of packaged Hanwoo beef was 27.86 kg. As for pigs, emissions from 1 kg of live pigs and packaged pork meat were 2.62 and 12.75 kg CO₂-eq, respectively. While we gathered data from only two farms and slaughterhouses and our findings can therefore not be extrapolated to all meats produced in the South Korean meat industry, they indicate that manure waste is the greatest factor affecting ultimate CO₂ emissions of packaged meats.

• Asian-Australasian Journal of Animal Sciences
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• 제26권8호
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• pp.1111-1118
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• 2013

The objective of this study was to determine the effects of whole linseed supplementation on performances and milk fatty acid composition of dairy cows. Thirty six Holstein Friesian crossbred lactating dairy cows were blocked by milking days first and then stratified random balanced for milk yields and body weight into three groups of 12 cows each. The control group received 300 g of palm oil. The second group was supplemented with 344 g/d of top-dressed whole linseed plus 150 g of palm oil and the third group was supplemented with 688 g/d of top-dressed whole linseed. All cows also received ad libitum grass silage (Brachiaria ruziziensis), had free access to clean water and were individually housed in a free-stall unit and individually fed according to treatments. Residual feeds were collected on 2 consecutive days weekly and at the end of the experiment. Feed samples were pooled to make representative samples for proximate and detergent analyses. Daily milk yields were recorded. Milk samples were collected on 2 consecutive days weekly. Live weights were recorded at the start and at the end of the experiment. Milk samples were taken on d 56 of the experiment and subjected to milk fatty acid composition. The results showed no statistical significant differences in intakes, live weight change, milk yields and milk compositions, however, C18:1, C18:3 and unsaturated FAs were increased while saturated FAs were reduced by whole linseed supplementation. It is recommended that the addition of 300 g/d oil from whole linseed could be beneficial to lactating dairy cows in early lactation.

• 환경생물
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• 제39권4호
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• pp.471-478
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• 2021

흰점박이꽃무지(Protaetia brevitarsis seulensis) 유충의 대체사료인 한약재 부산물 발효원인 유용미생물(Effective microorganism, EM)과 느타리버섯 종균(Oyster mushroom fungi, OM)을 비교하였다. 각 발효된 사료의 영양성분을 비교한 결과, 조회분을 제외한 조단백, 조지방, 조섬유 함량이 OM 발효사료에서 높게 나타났다. 각 발효된 사료로 사육된 흰점박이꽃무지 유충의 영양성분을 비교한 결과 차이가 관찰되지 않았다. 각 발효사료별 흰점박이꽃무지 유충의 생체중을 주별 비교 분석한 결과, 3주차 관찰시기부터 EM과 OM을 이용한 사료에서 흰점박이꽃무지 유충 평균중량이 유의하게 높았다. 유충 사육 시 생존율은 발효사료의 경우 동일하게 96.7%이나, 비발효사료의 경우 9.8%로 매우 낮았다. 본 실험결과, 흰점박이꽃무지의 생육에 먹이 원의 발효는 꼭 필요했으며, OM은 EM을 대체할 수 있는 흰점박이꽃무지 대체사료의 발효원으로 더 안정적이었다.