• Journal of Aquaculture
• /
• v.6 no.1
• /
• pp.29-46
• /
• 1993

In order to determine the optimum digestible energy to protein (DE/P) ratio in diets for Korean rockfish, Sebastes schlegeli, $45\%$ and $40\%$ protein diets with graded levels of DE/P ratio were fed to average 36g and 80g fish, respectively. The DE/P ratios in the $45\%$ protein diets ranged from 7.4 to 10.0 kcal/g protein, while those in the $40\%$ protein diets varied between 7.5 and 8.9 kcal/g protein. Both in the $45\%$ and $40\%$ protein diets, the changes in the DE/P ratios did not affect either the daily weight gain or the feed efficiency. However daily protein retention, daily energy retention, nutrient utilization and chemical composition in carcass varied depending on the DE/P ratios. Thus based on these parameters as criteria, the optimum DE/P ratio for both the $40\%$ and $45\%$ protein diets, estimated to be about 8 kcal/g protein. DE/P ratios more than 8 kcal/g protein, led to the deposition of a large amount of body fat, especially in the viscera. Any protein-sparing effect was not observed with the increase of the energy content in the diets. Apparent digestibility coefficients determined by the indirect method, using $Cr_2O_3$ as an indicator, were around $90,\;98\%\;and\;70\%$, for protein, lipid and digestible carbohydrate respectively, without any distinct differences between the diets.

• Journal of Animal Science and Technology
• /
• v.47 no.4
• /
• pp.513-524
• /
• 2005

This study was conducted to introduce recycling procedures of food waste(FW) as feed according to the dehydration, semi-dehydration fermentation and liquid fermentation methods through the on-site survey of companies related, to trace physico-chemical components and nutritional losses depending upon the processing stage for each method and finally to suggest more desirable methodology for the efficient utilization of FW as animal feed. For the dehydration method, dewatering of FW alone reduced(P<0.05) moisture(approximately 10%) and ether extract contents and increased(P<0.05) fiber contents. Dewatering and subsequent dehydration of FW decreased(P<0.05) contents of ether extract, limiting amino acids such as lysine, methionine and histidine, pepsin digestibility of protein by half, and NaCl content by 40%, increased(P<0.05) contents of fiber, crude ash, Ca and P, and did not alter(P>0.05) pH. The semi-dehydration fermentation method of FW did not affect(P>0.05) the chemical components, pepsin digestibility of protein, pH and NaCl content. For the liquid fermentation method, pasteurization and fermentation of FW decreased(P<0.05) contents of dry matter, ether extract, crude fiber, lysine and NaCl; however, it did not affect(P>0.05) other chemical components, pepsin digestibility of protein and pH. Among the processing methods, nutrient losses were highest for the dehydration method(25% of metabolizable energy loss, 12% of organic matter loss) and little for the semi-dehydration and liquid fermentation methods. The on-site survey of companies related revealed that the existence of foreign materials in FW products were problematic for all the three companies surveyed, thus it was necessary to develop a more efficient screener. Before feeding FW-containing diets to pigs, high quality of protein and energy feedstuffs needed to be fortified for the dehydration method. For the semi-dehydration fermentation method, the scientific diet formulation technology was required at the initial mixing stage. For the liquid fermentation method, possibly most energetic and proteinaceous feeds needed to be supplemented for the normal animal growth.

• Journal of Animal Science and Technology
• /
• v.47 no.4
• /
• pp.625-636
• /
• 2005

This study was conducted to determine effects of different ratios (3.5, 3.0 and 2.5) of nonfibrous carbohydrate (NFC) to ruminally degradable protein (RDP) on in vitro fermentation and lactation performance of dairy cows and optimum ratio of NFC to RDP in dairy rations. In vitro trial was conducted up to 12 hr with ruminal fluidtaken from ruminally cannulated Holstein cows. The level of dietary NFC did not affect ruminal pH. The ammonia-N concentration was not significantly different among treatments until 6 hr incubation, however, it was significantly (P < 0.05) decreased as the ratio of dietary NFC to RDP increased on 9 and 12 hr incubation. For volatile fatty acids, concentrations of both acetate and propionate were significantly (P < 0.05) increased on 3 hr incubation as dietary NFC contents of treatments increased, in other incubation times, they had no significant differences among treatments. Valerate and A:P ratio were not affected by the ratio of NFC to RDP. Isoacids and total VFAs were significantly (P < 0.05) increased with increasing dietary NFC contents and their values were highest in the treatment of 3.0 ratio. Meanwhile, for in vivo trial, 18 Holstein lactating cows were allotted to treatments in three groups of 6 cows. They were employed for 24 weeks to investigate nutrient intakes, and milk yield and composition according to different ratios of dietary NFC to RDP. Intakes of dry matter and energy were significantly (P < 0.01) increased, but NDF intake was significantly (P < 0.01) decreased as the ratio of dietary NFC to RDP increased. Milk yield for the ratio of 3.5 (32.7 kg) was significantly (P < 0.05) higher than those of other treatments. Milk fat (%) was significantly (P < 0.05) higher for the treatments of 3.0 (3.79 %) and 2.5 (3.79 %) than that (3.48 %) for the ratio of 3.5, but milk fat yield was not different among treatments. Contents and yields for milk protein and solids-not fat were linearly (P < 0.01) increased as the ratio of dietary NFC to RDP increased. However, milk urea nitrogen concentration was significantly (P < 0.05) decreased with increasing dietary NFC levels. Our results showed that the increasing level of NFC in the diet of dairy cows enhanced ruminal fermentation, N utilization and milk production and suggested that maximal fermentation and lactation performance were achieved when the dietary ratio of NFC to RDP was more than 3.0 in dairy rations.

• Journal of Plant Biotechnology
• /
• v.42 no.3
• /
• pp.161-167
• /
• 2015

Sweetpotato [Ipomoea batatas (L.) Lam] grows well in harsh environmental conditions, and is cultivated as one of the top seven food crops in the world. Recently, sweetpotato is drawing interest from people as a healthy food because it is high in dietary fiber, vitamins, carotenoids and overall nutrition value. However, few studies have been conducted on sweetpotato genome sequencing in spite of its importance. This review is aimed at increasing the efficiency of sweetpotato genome sequencing research as well as establishing a base for gene utilization in order to control useful traits. Recently, animal and plant genome sequencing projects increased significantly. However, sweetpotato genome sequencing has not been performed due to polyploidy and heterogeneity problems in its genome. Meanwhile research on its transcriptome has been conducted actively. Recently, a draft of the diploid sweetpotato genome was reported in 2015 by Japanese researchers. In addition, the Korea-China-Japan Trilateral Research Association of Sweetpotato (TRAS) has conducted research on gene map construction and genome sequencing of the hexaploid sweetpotato Xushu 18 since 2014. The Bill & Melinda Gates Foundation launched the 'sweetpotato genomic sequencing to develop genomic tools for Sub-Sahara Africa breeding program'. The chloroplast genome sequence acquired during sweetpotato genome sequencing is used in evolutionary analyses. In this review, the trend of research in the sweetpotato genome sequencing was analyzed. Research trend analysis like this will provide researchers working toward sweetpotato productivity and nutrient improvement with information on the status of sweetpotato genome research. This will contribute to solving world food, energy and environmental problems.