• Asian-Australasian Journal of Animal Sciences
• /
• 제27권7호
• /
• pp.1057-1068
• /
• 2014

The major goals of the poultry industry are to increase the carcass yield and to reduce carcass fatness, mainly the abdominal fat pad. The increase in poultry meat consumption has guided the selection process toward fast-growing broilers with a reduced feed conversion ratio. Intensive selection has led to great improvements in economic traits such as body weight gain, feed efficiency, and breast yield to meet the demands of consumers, but modern commercial chickens exhibit excessive fat accumulation in the abdomen area. However, dietary composition and feeding strategies may offer practical and efficient solutions for reducing body fat deposition in modern poultry strains. Thus, the regulation of lipid metabolism to reduce the abdominal fat content based on dietary composition and feeding strategy, as well as elucidating their effects on the key enzymes associated with lipid metabolism, could facilitate the production of lean meat and help to understand the fat-lowering effects of diet and different feeding strategies.

• Asian-Australasian Journal of Animal Sciences
• /
• 제12권5호
• /
• pp.723-727
• /
• 1999

Two experiments were conducted to determine the effect of feeding levels on intake and nutrient utilization of oat (Avena sativa) hay (OH) by goats and potential feeding value of leftovers from high levels of offer in sheep. In experiment 1, the goats (15) were offered OH at three levels of feeding to give leftovers of about 20% (T-1), 35% (T-2) and 50% (T-3) of DM offered. A marked effect of refusal rate of OH on intake and digestibility of nutrients was evident. Allowing selective consumption at higher levels (T-2 and T-3), the intake of DCP and TDN from OH was found not only to meet the maintenance requirement but provided surplus nutrients for moderate production. In experiment 2, Sheep (3) were offered one of the three dietary treatments viz OH, refusals left uneaten by goats in T-2 and T-3 (OHR) and 3% urea treated oat hay refusals (UTR) in a $3{\times}3$ latin square design. Though the potential feeding value of leftovers (OHR and UTR) was lower than OH, the results confirm the possibility of their effective use. It was concluded that feeding above the conventional ad libitum level could be an alternative to improve the performance of ruminants fed feeds like oat hay. The potential impact of the strategy would, however, depend on the effective reutilization of leftovers for feeding other animals.

• Journal of Animal Science and Technology
• /
• 제63권5호
• /
• pp.1086-1097
• /
• 2021

This study examined the impact of using total mixed ration (TMR) and concentrate on feed intake, daily gain, carcass yield grade, and carcass quality grade of Hanwoo steers and its subsequent economic efficiency. Thirty six 7-month-old Hanwoo steers were assigned to one of the four treatment groups, and each group was divided into three repeated pens, with each repeated pen comprising three steers. The treatment groups were: 1) separate feeding with commercial concentrate and forage (namely, SCF) for the entire experimental period; 2) TMR feeding for a growing period followed by SCF for the early and late fattening period (namely, TMRGSCF); 3) TMR feeding for growing and an early fattening period followed by SCF for the late fattening period (namely, TMREFSCF); and 4) TMR feeding for the entire experimental period (namely, TMRW). The results showed that the SCF treatment had significantly (p < 0.05) higher feed intake during the growing period than other treatments. In contrast, the total feed intake had little difference during early and late fattening as well as the whole period regardless of feeding strategies. Daily gain showed no difference during the growing period. However, it was significantly higher in SCF and TMREFSCF treatments for the early and late fattening period, respectively (p < 0.05). The daily gain during the total raising period is in the order of TMREFSCF > TMRGSCF > SCF > TMRW. Carcass characteristics, including carcass weight, loin eye muscle area, and carcass yield grade, did not significantly differ among different treatments. However, TMRW treatment, wherein TMR was fed for a long time, showed that the cold carcass weight was less compared with other treatments, but carcass yield grade was higher with thinner backfat. Backfat thickness was in the order of SCF > TMRGSCF > TMREFSCF > TMRW, showing that the thickness reduced with longer TMR feeding (p < 0.05). TMRGSCF, which numerically had a higher carcass quality grade, showed higher economic efficiency, whereas SCF showed low economic efficiency. In conclusion, it was more feasible to apply TMR strategy in the growing and early fattening period and then SCF for the early or late fattening period to improve carcass yield, quality grade, and economic efficiency.

• 한국수산과학회지
• /
• 제41권4호
• /
• pp.282-288
• /
• 2008

Feeding ecology of the white-spotted conger eel Conger myriaster in the Southern Sea of Korea was examined. Specimens were caught monthly from January 2004 to December 2006. Primary prey items of C. myriaster included fish, shrimp, and crabs. C. myriaster exhibited a nocturnal feeding strategy and preyed upon a wide range of pelagic fish groups(e.g., Engraulis japonicus, Glossanodon semifasciatus, and Maurolicus muelleri). This species was also an opportunistic feeder that exploited the available prey in each area(i.e., fish in the A area and shrimp in the B area). The composition of the diet of C. myriaster exhibited seasonal fluctuations that were related to food availability during each season. The observed ontogenetic shifts in diet were relatively clear, despite substantial overlap between the 10 cm and 20 cm groups of C. myriaster.

• Journal of Ecology and Environment
• /
• 제44권1호
• /
• pp.54-61
• /
• 2020

Background: Most fish undergo prey switch from juvenile to adult. It is thought that slightly different feeding habits occur among adult fishes due to growth, spawning, habitat change, and so on. Therefore, the diet of the John Dory Zeus faber (≥ 24 cm TL) was studied in the coastal waters of Korea by analysis of stomach contents, with comparison by season and size class of diet composition and prey diversity. Monthly samples were taken from February 2017 to January 2018. Results: The results showed that the John Dory was a piscivorous predator, and pisces had occupied 82.3% of IRI%. Trichiurus lepturus and Trachurus japonicus were important preys in all size classes and seasons. Diet composition differed among the size classes and seasons (Chi-square test, P < 0.05). As body size of Z. faber increased, the occurrence of benthic fish (Glyptocephalus stelleri) tended to increase. The seasonal prey composition also changed depending on the abundant species of each season. Conclusions: Z. faber is a piscivorous predator. The consumption habits of Z. faber appear to different results by their size and seasons. This study suggests that Z. faber could be considered an opportunistic predator.

• 현장농수산연구지
• /
• 제7권1호
• /
• pp.97-108
• /
• 2005

본 연구는 사료내 적정 셀레늄수준(0.9ppm)에서 Se-SMC(유기셀레늄강화버섯폐배지)의 급여사양기간(2개월, 4개월, 6개월)을 달리 했을 때, 비육후기 한우의 조직 내 셀레늄함량에 미치는 영향을 조사하여 최대포화축적기간을 제시하고자 실시하였다. Se-SMC 급여기간에 따른 비육후기 한우의 건물섭취량은 급여기간과 셀레늄수준에 의하여 처리구 간에 유의한 차이가 나타나지 않았고, 셀레늄이 사료섭취의 제한요인으로 나타나지 않았다. 또한, 사양시험 개시체중과 종료체중은 급여기간이 증가함에 따라 유의하게 낮았다(p<0.01). 하지만, 총 증체량은 급여기간이 증가함에 따라 유의하게 증가하였으나(P<0.0001), Se-SMC에 의한 효과 또한 나타나지 않았다. 한편, 사료내 셀레늄수준은 한우의 혈중 셀레늄농도를 유의하게 증가시켰으나(p<0.0001), 급여기간에 따른 효과는 나타나지 않았다. 등심내 셀레늄함량은 급여기간과 사료내 셀레늄수준에 의하여 유의한 효과가 나타나지 않았다. 후지내 셀레늄함량은 급여기간이 증가함에 따라 유의하게 증가하였으나(p<0.05), Se-SMC의 4개월 급여군과 6개월 급여군간에는 유의한 차이가 나타나지 않았다. 간내 셀레늄함량은 급여기간의 효과는 나타나지 않았지만, 셀레늄효과는 대조구에 비하여 유의하게 증가하였다(p<0.0001). 따라서, 본 연구에서 근육내 셀레늄에 대한 Se-SMC급여기간은 4개월 정도가 적당할 것으로 생각된다.

• 한국동물학회:학술대회논문집
• /
• 한국동물학회 2003년도 한국생물과학협회 학술발표대회
• /
• pp.153.2-153
• /
• 2003

No Abstract, See Full Text

• Journal of Microbiology and Biotechnology
• /
• 제11권5호
• /
• pp.739-748
• /
• 2001

A self-organizing fuzzy logic controller using a genetic algorithm is described, which controlled the glucose concentration for the enhancement of flavonoid production in a fed-batch cultivation of Scutellaria baicalensis G. plant cells. The substrate feeding strategy in a fed-batch culture was to increase the flavonoid production by using the proposed kinetic model. For the two-stage culture, the substrate feeding strategy consisted of a first period with 28 g/I of glucose to promote cell growth, followed by a second period with 5 g/I of glucose to promote flavonoid production. A simple fuzzy logic controller and the self-organizing fuzzy logic controller using a genetic algorithm was constructed to control the glucose concentration in a fed-batch culture. The designed fuzzy logic controllers were applied to maintain the glucose concentration at given set-points of the two-stage culture in fed-batch cultivation. The experimental results showed that the self-organizing fuzzy logic controller improved the controller\`s performance, compared with that of the simple fuzzy logic controller. The specific production yield and productivity of flavonoids in the two-stage culture were higher than those in the batch culture.

• 한국어류학회지
• /
• 제24권2호
• /
• pp.77-83
• /
• 2012

통영주변해역에서 2010년 1월부터 12월까지 문치가자미 395개체를 채집하여 위내용물을 분석하였다. 채집된 개체는 표준체장 10.5~38.8 cm의 체장범위를 나타내었다. 문치가자미는 저서성 육식어류로써 주로 이매패류, 단각류, 갯지렁이류를 섭식하였고, 그 외 약간의 유형동물류, 산호충류, 등각류, 요각류, 주걱벌레붙이류, 새우류, 게류, 거미불가사리류를 섭식하였다. 문치가자미는 generalized feeder의 섭식전략을 나타냈고, 체장이 커짐에 따른 주 먹이생물의 변화는 나타내지 않았으며, 먹이생물의 크기변화는 나타나지 않았다.

• Fisheries and Aquatic Sciences
• /
• 제8권3호
• /
• pp.128-131
• /
• 2005

The effects of alternate-week feeding strategies on growth and feed efficiency ratio of juvenile Nile tilapia were investigated in a recirculating aquaculture system. Twenty fish initially weighing 25.5 g were randomly distributed into each of 18 tanks to conduct three replicates for each of six different feeding strategies. Weight gain of fish in the control that were fed daily for 6-week feeding trial was significantly higher than those of fish subjected to various alternate-week feeding regimes. Weight gain of fish that were starved for 3 weeks and then fed daily for 3 weeks (3WS+3WF) was not significantly different from that of fish, starved and fed daily for alternate 1-week period during the trial (1WS+1WF), but was significantly higher than those of fish starved for 2 weeks, and fed for 2 weeks (2WS+2WF); fish starved for 4 weeks and fed for 2 weeks (4WS+2WF); and fish fed for 5 weeks and fed for 1 week (5WS+1WF.) The amount of feed supplied to fish in the groups of 1WS+1WF and 3WS+3WF was significantly lower than that fed to fish in the control group, but significantly higher than the amount feed supplied to fish in the other three groups. Feed efficiency ratio for fish in the control group did not differ from that for fish in the groups of 1WS+1WF, 2WS+2WF and 3WS+3WF, but was significantly higher than that for fish in the groups of 4WS+2WF and 5WS+1WF. In conclusion, juvenile Nile tilapia that were subject to starvation for 1 to 5 weeks did not exhibit compensatory growth sufficient to attain the same weight as fish fed daily for 6 weeks. In addition, fish subjected to starvation exhibited low feed efficiency ratio compared to fish fed daily, which were probably attributable to poor weight gain.