• Journal of Aquaculture
• /
• v.18 no.1
• /
• pp.45-51
• /
• 2005

The optimum salinity and the effects of rapid salinity change on oxygen consumption and ammonia nitrogen excretion were examined in River Puffer Takifugu obscrus (total length 9.5$\pm$0.9 cm, total weight 18.7$\pm$5.4 g). Fish examined at the different transfer medium salinity (2, 12, 22 and 32 psu) after 2 months of acclimation period at each salinities. The routine metabolic rates of River puffer are shown as parabola equation, $Y=-0.0873X^2+0.6384X-0.690$ for oxygen consumption and $Y=-2.1667X^2+7.1672X+31.999$ for ammonia nitrogen excretion with the salinity medium at 2, 12. 22 and 32 psu. The oxygen consumption and ammonia nitrogen excretion of River puffer trans-ferred to the low salinity medium (2 and 12 psu) showed significantly difference in each salinities rearing groups than to salinity of 22 and 32 psu. Fish has a diurnal rhythm in relate to feeding, it was showed that the peak of oxygen consumption appeared at 3 hours after feeding and the ammonia nitrogen excretion rate reached maximum 4 hours after feeding. These results may indicate that the optimum salinity for rearing of River puffer is 22 psu based on growth and feed conversion ratio. The rapid change of medium salinity had no effects on the oxygen consumption and nitrogen excretion in River puffer based on this experiment.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.32 no.2
• /
• pp.144-148
• /
• 1999

This study was conducted to test actual oxygen consumption rates of Nile tilapia (Oreochromis niloticus) at a commercial scale high density culture tank in the recirculating culture system, with a special emphasis on the oxygen consumption rate of this species with different daily feeding frequencies. Nile tilapia, an average of 400 g and a total wright of 390 kg, were stocked in a circular concrete tank of 2.9 m in diameter and 0.8 m in depth, in a recirculating culture system. The fish were fed commercial diet 1, 2, 5, and 9 times per day between 09:00 h and 19:00 h. feed was evenly supplied where the fish were fed more than once a day. Dissolved oxygen of influent and effluent water was monitored every 50 seconds by a computer with electrodes for 24 hours. The standard metabolic rate of tilapia was $39.31{\pm}4.4mg\;O_2/kg$ fish/hr in the present study. The maximum oxygen consumption was reached between 30 to 50 minutes after feeding. The maximum oxygen consumption levels of 1, 2, 5, and 9 feeding times per day were 161.2, 123.4, 111.1 and 111.1 mg $O_2/kg$ fish/hr, respectively. While the mean oxygen consumption levels of 1, 2, 5, and 9 feeding times per day were $79.9{\pm}21.5,\;81.3{\pm}14.8,\;84.2{\pm}9,9$ and $98,9{\pm}11.0mg\;O_2/kg$ fish/hr, respectively. These results show that oxygen consumption rates are not much different between the feeding frequencies. These results could be used to design to provide desirable oxygen supply system in the recirculating high-density tilapia culture system.

• Korean Journal of Poultry Science
• /
• v.29 no.1
• /
• pp.25-35
• /
• 2002

Two experiments were conducted to studs the effects of early-life feed restriction, ages and duration on compensatory growth, feed efficiency, and abdominal fat pad deposition in broilers. The chicks were randomly assigned to four treatments (experiment 1) or seven treatments (experiment 2) . Each dietary treatment was replicated with three floor pens in both experiments, and twenty chicks were assigned to each pen. In experiment 1, birds in control group (C) were full-fed throughout the study. For treatments 1, 2, and 3, bards were fed diets containing 0.75 kcal ME/gB $W^{o.67}$/d for 3 d(T1), 1.5 ㎉ ME/gB $W^{o.67}$/d for 5 d (T2), and 2.25 local ME/gB $W^{0.67}$/d for 7 d (T3), all imposed beginning at 7 d of age. The selected value seems appropriate for maintenance feeding because the feed restriction at T1 resulted no growth in virtually. Although the birds previously subjected with restricted feeding significantly (P<0.05) enhanced growth partly (in 22~49 d), the weight gain over the entire growth period (7-49 d) was not influenced by the restricted feeding Programs. Whereas, the restricted feedings had effects with significant (P<0.75) increase in feed intake not only in 22~49 d, but in overall period (7-49 d). The feed conversion for the birds previously subjected with restricted feeding was significantly (P<0.05) improved after 21 d. The birds with restricted feedings (T1,T2,T3) showed better (P<0.05) feed conversion ratio than C both in 22-49 d and in 7-49 d. The restricted feeding programs did not show effects in reducing for abdominal fat pad deposition or mortality In experiment 2, the birds of C were full-fed in overall period. But for treatments 1, 2, 3, 4, 5, and 6 (T1-T6),the birds were fed diets containing 0.75 ㎉ ME/gB $W^{0.67}$/d for 3 or 5 d, starting at either 4, 7 or 10 d of age. The selected value seems appropriate for maintenance feeding because the feed restriction resulted no growth in virtually; which was same as experiment.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.3
• /
• pp.26-36
• /
• 2012

Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke diesel engine is of great economic importance. A motor-driven cylinder lubricator for Sulzer RT-flex large two-stroke diesel engines developed by authors is in need of mounting a quill system to lubricate cylinder parts for a smooth operation. In order to apply the common-rail lubricating system to the developed cylinder lubricator as the second research stage, the mechanical quill system with a progressively quantitative distributor (M.D.S.) is improved in the electronically controlled quill system with an accumulating distributor (E.D.S.). In this study, the effects of lubricator motor speed, plunger stroke and cylinder back pressure on oil feed rate and inequality rate are experimentally investigated by applying E.D.S. to the developed cylinder lubricator. It is found that the oil feed rate of E.D.S. is higher than that of M.D.S. because of the increase of delivery speed and volume by changing the role of accumulator in the same experimental condition. It can be also shown that, in E.D.S., the inequality rate is decreased a little or hardly unchanged as the cylinder back pressure and plunger stroke is elevated, while the inequality rate increased in M.D.S.. The inequality rates of E.D.S. and M.D.S. are lowered as the lubricator motor speed is increased.

• Asian-Australasian Journal of Animal Sciences
• /
• v.11 no.1
• /
• pp.21-29
• /
• 1998

Four feeding trials with 260 pigs were conducted to evaluate the effects of supplementing the diet with different amino acids on growth performance and blood metabolites for weanling, growing and finishing pigs. One hundred twenty weanling pigs (Exp. 1, BW 8 kg), eighty growing pigs (Exp. 2. BW 20 kg), thirty growing pigs (Exp. 3, BW 29 kg) and thirty finishing pigs (Exp. 4, BW 50 kg) were randomly allotted to different dietary treatments according to sex and body weight. Pigs weight and feed consumption were measured at initiation and termination of each trial with 4 weeks. At the end of trial, blood samples from three pigs selected in each pen (Exp. 1) and each pig (Exp. 2) were obtained to determine the level of blood urea nitrogen, glucose, insulin and cortisol in the serum. In Exp. 1, pigs fed diet supplemented both with lysine and methionine had the best feed conversion ratio (p < 0.05), but no significant differences (p > 0.05) were observed in ADG and ADFI. Pigs receiving control diet obtained the obtained the optimal ADG (p < 0.05), ADFI (p < 0.05) and F/G for the whole period. No differences were detected in serum glucose, insulin and cortisol concentrations. In Exp. 2, pigs receiving the control diet exhibited the lowest serum urea nitrogen (p < 0.05), ADG, F/G and serum insulin concentration increased linearly (p < 0.05) with the inclusion of lysine, methionine, threonine and tryptophan in diets. No significant differences (p > 0.05) were detected for glucose and cortisol content in pigs serum among dietary treatments. In Exp. 3 and 4, pigs growth rate increased linearly (p < 0.01), and feed conversion efficiency was also improves by addition of lysine, methionine, threonine and tryptophan. In conclusion, pigs fed diets supplemented with lysine, methionine, threonine and tryptophan together obtained optimal growth performance in growing and finishing periods.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.10
• /
• pp.1473-1478
• /
• 2008

An experiment was conducted to investigate the mechanism for the effect of tetrabasic zinc chloride (TBZC) in enhancing growth performance of weanling piglets. Gut-brain peptides play an important role in the regulation of growth and appetite in animals. This study evaluated the effects of TBZC on blood concentrations of growth hormone (GH), ghrelin, insulin-like growth factor-I (IGF-I), cholecystokinin (CCK) and neuropeptide Y (NPY). Seventy-two weanling piglets (Landrace$\times$Large White) with an initial body weight (BW) of $6.7{\pm}0.16kg$ and aged $24{\pm}1days$ were assigned to three dietary treatments: i) control diet without TBZC supplement, ii) the control diet supplemented with 2,000 mg Zn from TBZC/kg and iii) TBZC-supplemented diet pair-fed with respect to the control diet. Each treatment had six replications (pens) of four piglets. At the end of a 14-d experimental period, piglets were weighed and feed consumption was measured, and blood samples were collected for assays of GH, ghrelin, IGF-I, CCK and NPY concentrations. The inclusion of TBZC in the diet increased average daily gain (p<0.01), average daily feed intake (p<0.05), and feed conversion ratio (p<0.05). Pair-fed piglets had higher ADG, and lower FCR than (p<0.05) Control piglets. Supplementation of the diet with TBZC increased (p<0.05) serum GH and plasma ghrelin levels in weanling piglets, but did not affect (p>0.05) serum IGF-I and plasma NPY and CCK concentrations. Pair-fed piglets had lower (p<0.05) serum GH levels than TBZC-supplemented piglets, but did not (p>0.05) differ from Control piglets. These data indicated that TBZC elevated the concentration of ghrelin and GH. This observation may partly explain the beneficial effects of TBZC on growth performance of weanling piglets.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.10
• /
• pp.1506-1515
• /
• 2008

Two feeding trials were conducted to assess the relative bioavailability (RBV) of methionine hydroxy analogue calcium salt (MHA-Ca) in comparison to DL-methionine (DL-Met). Male Ross 308 (1-38 days) and Cobb 500 chickens (1-42 days) were used in studies 1 and 2, respectively. Experimental diets based on wheat and soybean meal or sorghum and soybean meal were fed during three phases. In both experiments graded levels of DL-Met and MHA-Ca were supplemented to Met+Cys deficient basal diets. Additionally, in experiment 1, increasing levels of a DL-Met preparation diluted with corn starch to 65% purity (DL-Met65) were supplemented. Birds were kept in floor pens and feed and water were available ad libitum. Body weights and feed consumption were recorded at the beginning and end of the experimental periods and weight gain and feed efficacy were computed subsequently. At the end of the experiments, a number of birds were slaughtered for carcass evaluation (dressing percentage, breast meat yield). Dose response data were analysed by both ANOVA and nonlinear common plateau asymptotic regression. In both experiments birds responded significantly to increasing levels of either methionine source. However, RBV of MHA-Ca compared to DL-Met was markedly (in many cases significantly) below 84%, the value which would have been expected from MHA-Ca's chemical characteristics. Excluding some extremely low RBV figures of trial 2, RBV of MHA-Ca averaged to about 63% in relation to DL-Met. In addition, supplementation of DL-Met65 allowed confirmation of nonlinear common plateau asymptotic regression to be suitable to determine RBV.

• Asian-Australasian Journal of Animal Sciences
• /
• v.25 no.7
• /
• pp.1009-1014
• /
• 2012

Environmental stress boosts the levels of stress hormones and accelerates energy expenditure which subsequently imbalance the body's homeostasis. L-ascorbic acid (L-AA) has been recognized to mitigate the negative impact of environmental stress on production performances in birds. The present investigation was carried out to elucidate the effect of different dietary levels of L-AA on production performance, egg quality traits and fertility in Japanese quail at low ambient temperature. Sixty matured females (15 wks) were equally divided into three groups (20/group) based on the different dietary levels of L-AA (0, 250 and 500 ppm) and coupled with an equal number of males (1:1) obtained from the same hatch. They were managed in uniform husbandry conditions without restriction of feed and water at 14 h photo-schedule. Except for feed efficiency, body weight change, feed consumption and hen-day egg production were recorded highest in 500 ppm L-AA supplemented groups. Among the all egg quality traits studied, only specific gravity, shell weight and thickness differed significantly (p<0.05) in the present study. Fertility was improved significantly ($p{\leq}0.01$) to a dose dependent manner of L-AA. The findings of the present study concluded that dietary L-AA can be a caring management practice at least in part to alleviate the adverse effect of cold induced stress on production performance in Japanese quail.

• Korean Journal of Veterinary Research
• /
• v.49 no.4
• /
• pp.335-343
• /
• 2009

The pathogenicity and acute toxicity of Lactobacillus (L.) pentosus PL11 from eel (Anguilla japonica) were investigated using male and female Sprague-Dawley rats. The pathogenicity of L. pentosus PL11 was examined after treating the rats with $10^{11}$ CFU/mL, $10^9$ CFU/mL or $10^7$ CFU/mL doses of L. pentosus PL11 culture or 0.85% NaCl (Control) intragastrically. For acute toxicity studies, rats were treated with dried culture broth of L. pentosus PL11 at doses of 5,000 mg/mL, 2,500 mg/mL, 1,250 mg/mL or 625 mg/mL or Lactobacilli MRS broth (Control), and clinical signs or mortalities were monitored for two weeks. The results of the present investigation revealed no mortalities or obvious clinical signs in rats administered with the live bacterial cultures or dried culture broth at any investigated dose level. Also, no significant differences were observed in net body weight gain, gross pathological findings, feed and water consumption and body temperature among the different treatment groups and between the treated and control rats. It can be concluded from the above findings that L. pentosus PL11 is a safe probiotic strain with potential as feed additive to increase the feed efficiency or health of fish.

• Journal of the Korean Home Economics Association
• /
• v.18 no.4
• /
• pp.95-101
• /
• 1980

This study was carried out to investigate the effect of the diet supplemented with various amounts of ginseng powder on the growth rate and blood glucose level in rat. Male Albino rats, weighing between 90 to 100g, were divided into 5 diet groups of 6 rats each. experimental diets contained 0, 2, 4, 6 and 8% ginseng powder which was substituted for rice powder and were designated C, G-2, G-4, G-6 and G-8, respectively. The diets were fed for 3 weeks. Throughout feeding period, feed consumption, body weight, feed and protein efficiency ratios were measured, organ weights and blood glucose level were determined at the end of the experimental period. the results are summarized as follows. 1. rats in G-2 group consumed the highest amount of diet among all groups. 2. Body weight gain was significantly higher in G-2 and G-4 than in other groups. 3. Feed and protein efficiency ratios were a little higher in G-4 than in control group. And those of group G-8 were the lowest among those of other groups. 4. The weight of liver was significantly lower I G-4 than in control group. The weight of kidney was significantly lower I G-4 and G-8 than in control group. The weight of heart was significantly lower I G-4 and G-8 than in control group. While, the weight of spleen was greater in ginseng powder diet than in control group. 5. Supplementing ginseng powder in diet resulted in deceased nitrogen in liver. 6. Blood glucose was decreased with increased level of ginseng powder diet.