• Development and Reproduction
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• v.20 no.2
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• pp.109-118
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• 2016

This study monitored the morphological development of embryo, larvae and juvenile yellowtail kingfish, Seriola lalandi, for their aquaculture. The fertilized eggs obtained by natural spawning were spherical shape and buoyant. Fertilized eggs were transparent and had one oil globule in the yolk, with an egg diameter of $1.35{\pm}0.04mm$ and an oil globule diameter of $0.32{\pm}0.02mm$. The fertilized eggs hatched 67-75 h after fertilization in water at $20{\pm}0.5^{\circ}C$. The total length (TL) of the hatched larvae was $3.62{\pm}0.16mm$. During hatching, the larvae, with their mouth and anus not yet opened. The yolk was completely absorbed 3 days after hatching (DAH), while the TL of post-larvae was $4.72{\pm}0.07mm$. At 40 DAH, the juveniles had grown to $30.44{\pm}4.07mm$ in TL, body depth increased, the body color changed to a black, yellow, and light gray-blue color, and 3-4 vertical stripes appeared. At 45 DAH, the juveniles were $38.67{\pm}5.65mm$ in TL and $10.10{\pm}0.94mm$ in body depth. The fish were green with a light orange color, with 7 faint green-brown stripes on the sides of their body. At 87 DAH, the juveniles had grown to 236.11 mm in TL, 217.68 mm in fork length, and 136.5 g in weight. The fish resembled their adult form, with a light yellow-green body color, loss of the pattern on the sides of their body, and a yellow coloration at the tip of the caudal fin.

• Korean Journal of Ecology and Environment
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• v.53 no.3
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• pp.221-228
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• 2020

We studied the development of the endangered gold-spotted pond frog, Pelophylax chosenicus eggs and analyzed growth and survival rate of the tadpoles while feeding different feed to obtain the basic data on the its biological traits and reproduction. We observed the fertilized eggs of gold-spotted pond frog that naturally spawned in a breeding tank using a microscope. Fertilized eggs were sphere shape surrounded by colloid layers, clearly distinct with animal and plant poles. The fertilized eggs hatched 31 hours after fertilization and operculum complete at 175 hours after fertilization at water temperature of 27.0±1.0℃. As a result of growth and survival rate by different feed from 35 days after mouth open stage, vegetable feed (VF) group and tetra-min (T) group were significantly higher average weight gain rate (WG)(5843.9% and 5736.3%, respectively) and average specific growth rate (SGR) (11.67% and 11.62, respectively) compared with other groups (WG: 641.8~4625.2%, SGR: 5.72~11.01%). The vegetable (V) group showed the lowest growth rate (P<0.05). The average feed efficiency was 177.83% in the VF group, about 17 times higher than the V group. In addition, the average survival rate of the VF and T groups were the high at 97.5% and 100%, respectively, and the V group was the lowest at 32.5%. Therefore, the more efficient feeds for successful breeding is singly with VF or T.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.217-224
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• 1992

The study was undertaken to determine the effect of dietary magnesium on the eggshell quality and other performance in laying Tsaiya ducks and Leghorn hens. Twenty-five Tsaiya ducks and 25 Leghorn hens were raised in individual cages. The basal diet was mainly consisted of corn starch and isolated soybean protein. At the beginning of the experiments, birds were fed for 10 days with the basal diet supplemented with 500 mg/kg Mg (1070 mg/kg in total by analysis) in order to allow the birds adapting to the new diet. Both Tsaiya ducks and Leghorn hens were then each randomly divided into five groups and each group of five birds were fed with the experimental diets containing 690, 1070, 1690, 2150 or 2380 mg/kg Mg, respectively for 21 days. Eggs were collected in order to measure eggshell quality, Mg and Ca content of the eggshell. At the end of the experiments, blood samples of all birds were taken from their brachial veins for measuring the concentration of Mg and Ca in the plasma. Experimental results appeared that the dietary Mg content did not significantly affect egg production, egg weight, eggshell breaking strength and thickness in both Tsaiya ducks and Leghorn hens. In Tsaiya ducks, however, the plasma Mg concentration was affected by the dietary Mg content, but the plasma Mg almost reached a plateau (4.66 mg/dl) as long as the dietary Mg level was over 1070 mg/kg. In Leghorn hens, the plasma Mg level was significantly increased from 1.66 mg/dl to 4.03 mg/dl when the dietary Mg content in the diet had been increased from 690 mg/kg to 2380 mg/kg, suggesting that the plasma Mg concentration seems to be directly influenced by the Mg absorbed in the intestine. In the Tsaiya ducks, however, the dietary Mg level did not significantly affect the eggshell Mg content (from 0.113% to 0.123%). Whereas, there was a negative correlation between the eggshell thickness and eggshell Mg content (r = -0.50, p<0.01), revealing that the increase in eggshell Mg content probably associated with the impairment of eggshell quality in Tsaiya ducks. In Leghorn hens, however, there was no significant correlation between eggshell quality and eggshell Mg content, although the Mg content in the eggshell was also increased from 0.279% to 0.427% when the dietary Mg had been elevated from 690 mg/kg to 2380 mg/kg.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.5
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• pp.477-483
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• 1985

This paper describes seasonal changes of total length, hepatosomatic index (HSI), fatness, egg-diameter composition, and fecundity of the longchin goby Chasmichthys dolichognathus(HILGENDORF). The specimens used were captured in the tide pool of Tongbaekseom, Pusan, Korea from February 1983 to January 1984. The age of longchin goby, tested by size frequency, was believed to be usually one year which grows to 8.0 cm in total length. The annual variations of HSI reached the maximum in the early spring when the gonad was actively growing and decreased during the spawning season from April to July. The coefficients of fatness were represented low values for the spawning periods. Frequency distribution of the egg diameter of mature ovary has three modes: one is the evident mode of the ripe eggs group, and the other two are modes of maturing and immature eggs groups. And an individual is considered as spawns one in the spawning season. Relationships between the fish size in total length (TL cm) and the number of ovarian eggs(F), the fish weight (BW g) and the number of ovarian eggs are indicated by the exponential equation respectively : F=42.585 $TL^{1.608}$, F= 524.589 $BW^{0.475}$.

• The Korean Journal of Malacology
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• v.28 no.2
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• pp.145-156
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• 2012

Larval development of the Manila clam Ruditapes philippinarum reared in an indoor tank system was examined in this study using light microscope and scanning electron microscope. To induce spawning and subsequent larval development, clams were collected from the intertidal zone at Gim-nyeong harbor in Jeju Island in August 2011. After 2 days of rearing in the tank, all Manila clams spawned in the midnight. Non-feeding trochophore larvae appeared 7hrsafter fertilization and the first D-shape larvae could be observed at 19 hrs. Twenty one days after fertilization the pediveliger larvae crawling on the bottom of the tank with well-developed foot were observed. Histology indicated that all the clams used in this study were in the ripe stage prior to spawning and the gonad-somatic index (GSI), a ratio of the egg mass to the tissue weight, of the ripe female measured by ELISA was 28.6%. The GSI of female clam declined to 17.3% after the massive spawning in the tank, suggesting that Manila clam discharged 40% of the total eggs during the first spawning event. In conclusion, spawning and subsequent larval development of Manila clam was successfully carried out in this study using an indoor tank system, and the information obtained in the present study could be useful in future Manila clam hatchery development.

• Korean Journal of Environment and Ecology
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• v.31 no.1
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• pp.24-29
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• 2017

This study was conducted to identify nesting habits and breeding biology of barn swallow in Gwangju, Korea, for the breeding season 2012 to 2014. All nests were attached to vertical walls and roofs of buildings and situated at mean height $2.9{\pm}0.3m$ above ground with nest diameter $18.2{\pm}3.2cm$, nest depth $9.8{\pm}3.1cm$, nest cup diameter $11.2{\pm}1.5cm$ and nest cup depth $3.27{\pm}0.80cm$. Nests were attached to cemented walls (44.9%), wooden materials (23.1%), bricks (21.8%) and lighting (6.4%). The average clutch size was 4.5 and ranged 2~5. Mean egg length was $18.23{\pm}0.73mm$, breadth $13.11{\pm}0.25mm$, volume $1.60{\pm}0.11cm^3$, shape index $1.39{\pm}0.05$ and weight $1.69{\pm}0.15g$. Hatching and fledgling success rate were 89.1% and 84.5%. Main causes for reproductive failures were unhatched eggs, predation, nest destruction and desertion. These results are expected to be widely used as data for habitat preservation and species management of barn swallows.

• Journal of Animal Science and Technology
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• v.63 no.3
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• pp.545-562
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• 2021

A 3 yr experiment was conducted to evaluate the influence of diet and feeding location on animal performance, carcass characteristics, whole blood counts, and internal parasite burden of lambs assigned to 1 of 4 treatments: 1) confinement fed 71% alfalfa, 18% barley pellet, 5% molasses, 0.013% Bovatec, 6.1% vitamin/mineral package diet (CALF), 2) confinement fed 60% barley, 26% alfalfa pellet, 4% molasses, 2.5% soybean-hi pro, 0.016% Bovatec, 7.4% vitamin/mineral package diet (CBAR), 3) field fed 71% alfalfa, 18% barley pellet, 5% molasses, 0.013% Bovatec, 6.1% vitamin/mineral package diet (FALF), and 4) field fed 60% barley, 26% alfalfa pellet, 4% molasses, 2.5% soybean-hi pro, 0.016% Bovatec, 7.4% vitamin/mineral package diet (FBAR). A year × location interaction was detected for ending body weight (BW), average daily gain (ADG), and dry matter intake (DMI); therefore results are presented by year. In all years, cost of gain and DMI were greater for CALF and FALF than for CBAR and FBAR feed treatments (p ≤ 0.03). In yr 2 and 3 field treatments had greater ending BW and ADG than confinement treatments. For all years, diet did not affect ending BW or ADG. In yr 1 dressing percent and rib eye area were greater for field finished lambs than confinement finished (p ≤ 0.02) and Warner-Bratzler shear force was greater for CALF and FALF (p = 0.03). In yr 2 lambs in FALF and FBAR treatments had greater leg scores and conformation than CALF and CBAR (p = 0.09). In yr 1, FALF had a greater small intestine total worm count than all other treatments. In yr 1, ending Trichostrongyle type egg counts were greater for FALF (p = 0.05). In yr 2, ending Nematodirus spp. egg counts were greater for FALF and lowest for CBAR (p < 0.01). Abomasum Teladorsagia circumcinta worm burden was greater in CALF than all other treatments (p = 0.07) in yr 2. While field finishing lambs with a grain- or forage-based diet we conclude that it is possible to produce a quality lamb product without adverse effects to animal performance, carcass quality or increasing parasite burdens.

• Korean Journal of Poultry Science
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• v.38 no.1
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• pp.59-69
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• 2011

This study was conducted to investigate the effects of dietary supplementation of CS682, a fermentation product of Actinomycetae(Nocardia sp. CS682), and its commercial product DSC682$^{(R)}$ on the performance, blood parameters, intestinal microflora, and immune response in laying hens. Hy-Line Brown$^{(R)}$ laying hens were housed in two bird cages. Feeding trial lasted 5 wk under 16.5 h:7.5 h(L:D) lighting regimen. In Exp.1, a total of 480 birds of 86 wk old were assigned to four dietary treatments: Control, Antibiotics (6 ppm avilamycin), CS682-0.1 (CS682 0.1%) and CS682-1.0 (CS682 1.0% supplementation). Each treatment was replicated five times with 24 birds (or 12 cages) per replication. In Exp. 2, a total of 1,000 birds of 26 wk old were assigned to five dietary treatments: Control, Antibiotics (6 ppm avilamycin), DCS682-0.05 (DCS682 0.05%), DCS682-0.1 (DCS682 0.1%), DCS682-0.2 (DCS682 0.2% supplementation). Each treatment was replicated five times with 40 birds (or 20 cages) per replication. In Exp. 1, there were no significant differences among treatments in egg production, egg weight, broken & soft egg production, feed intake, and feed conversion ratio. Also, there were no significant differences among treatments in eggshell thickness, eggshell color and Haugh unit. However, eggshell strength was significantly (p<0.05) greater in CS682 and Antibiotics treatments than Control, and egg yolk color was significantly (p<0.05) higher in CS682-1.0 than Control. In Exp. 2, feed intake was significantly (p<0.05) lower in DSC682-0.05 than Control. Lightness(L) of Hunter Lab color of eggshell of DCS and Antibiotics treatments was significantly (p<0.05) lower than Control. Egg yolk color of DCS 0.1 and 0.2 treatments was significantly (p<0.05) higher than Control. Haugh unit increased significantly (p<0.05) in Antibiotics and DCS682-0.1 treatments. The immunoglobulin levels of plasma (IgG and IgA) and eggyolk (IgY) were not significantly affected by treatments. Antibiotics and CS682 or DCS682 treatments significantly (p<0.05 or 0.01) influenced some of the erythrocytes and leukocytes parameters in blood. In Exp.1, mean corpuscular volume (MCV) decreased by CS682 treatments and mean corpuscular hemoglobin (MCH) was highest in Antibiotics treatments. In Exp.2, the level of monocyte (MO) decreased in DCS682-0.10 and 0.20 treatments. The cfu of C. perfringens and S. typhimurium in small intestinal content were highest in Control and lowest in Antibiotics in both experiments. In Exp. 2, DSC682-0.05 and -0.1 treatments were highest and Antibiotic treatment was lowest in Lactobacilli spp. The results of the present layer experiments indicated that supplementation of 0.1~0.2% CS682 or DCS682 may increase eggshell strength, color of eggshell and eggyolk, Haugh unit, and control harmful intestinal microbes.

• Korean Journal of Poultry Science
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• v.37 no.4
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• pp.347-354
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• 2010

The current work was carried out to investigate the effect of crossbred Korean native chickens (KNC) on performance and carcass ratio. Seven hundred twenty 1-d-old chicks were divided into groups by strain (A, B, C and D) and sex (male and female). Strains were A) (KNC egg-meat type C strains $\times$ KNC meat type S strains) $\times$ KNC meat type H strains, B) (KNC egg-meat type C strains $\times$ KNC meat type H strains) $\times$ KNC meat type S strains, C) (KNC native R strains $\times$ KNC meat type S strains) $\times$ KNC meat type H strains and D) (KNC native L strains $\times$ KNC meat type H strains $\times$ Ross broiler. Experimental diets consisted of 3 phases such as starter(0~5 weeks; CP 20.0%, ME 3,050 kcal/kg), earlier (5~8 weeks; CP 18.0%, ME 3,100 kcal/kg) and finisher (8~12 weeks; CP 16.0%, ME 3,150 kcal/kg). Body weight (BW) and feed intake (FI) was measured every week and carcass ratio(CR) was calculated at 5 and 10 week after starting experiment. There was no difference in BW among strains until 5 weeks (P>0.05), however D strain resulted in a higher BW after 5 weeks (P<0.05). Body weight gain (BWG) and FI in D strain were also significant higher compared to the other strains for all periods. However, D strains showed the lowest (P<0.05) fee conversion ratio (FCR). The other strains except D showed a similar BW, BWG, FI and FCR among strains. In addition, there were no differences in carcass weight (CW) and carcass ratio (CR) among strains at 5 weeks, however D strain showed higher CW and CR at 10 weeks. These results suggested the basic data that needed to develope the new strains.

• Journal of Nutrition and Health
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• v.42 no.8
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• pp.691-701
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• 2009

This study was conducted to evaluate the dietary quality of school-aged children from low-income families in comparison with those from higher income families. The socio-demographic and anthropometric data and one day 24-hour recall dietary intake data of 1,782 school-aged children were used for analysis from the data of 2001 National Health and Nutrition Survey. The children whose family had monthly household income 120% or lower than the 2001 Minimum Cost of Living were classified into Low Income Group (LIG), and the others were classified into Higher Income Group (HIG). The consumption levels of the food groups of the Korean Food Guide as well as the general nutritional status based on their weight and height, energy and nutrient intake were compared between LIG and HIG in elementary (n = 989), middle (n = 432), and high (n = 361) school-aged children, respectively. LIG tended to have lower weight, height, and BMI than HIG, but the difference was significant only in the weight and the BMI of the middle school-aged children. The energy intake of LIG didn't differ from that of HIG, but LIG consumed a higher percentage of energy from carbohydrate and a lower percentage of energy from fat than HIG. Some micronutrient intake was lower in LIG than HIG in case of the elementary and the middle school-aged children. The average numbers of servings of milk dairy products and fruits consumed by LIG were significantly lower than those consumed by HIG in the elementary and the middle school-aged children, and they were less than the respective recommended serving. The average number of servings of meat fish egg beans consumed by LIG was lower than that consumed by HIG in the middle and the high school-aged children, and it was also less than the recommended serving. The results suggested that the diet of children from low-income families should be intervened by strategies different from the other children in order to improve the consumption level of milk dairy products, fruits, and meat fish egg beans.