• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1150-1157
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• 2011

Streptomyces sampsonii KK1024 having strong chitinolytic activity was isolated from crab-shell rich soil at Muan, Jeolanamdo. The KK1024 produced chitinase, protease, gelatinase and lipase. When 50% of KK1024 culture broth was treated to juveniles and eggs of root-knot nematode, juvenile mortality at 3 days was 81.67% and egg hatch rate at 5 days was 2.00%. When $183.7{\mu}g\;mL^{-1}$ of crude enzyme produced by KK1024 was treated, juvenile mortality at 3 days was 96.00% and egg hatch rate at 5 days was 5.33%. At 1% of butanol extract from KK1024, juvenile mortality was highest with 90.00% and egg hatch rate was lowest with 0%. The comparison of the effect of KK1024 culture broth with only medium, synthetic fertilizer, and commercial nematicide on tomato growth and nematode infection was examined in pot trials. KK1024 culture broth showed lower number of egg mass and gall in plant, and population of juveniles in soil compared with only medium and synthetic fertilizer treatment, but not in commercial nematicide. However, the highest shoot weight and length was discovered in KK1024 culture broth. These results suggest that Streptomyces sampsonii KK1024 producing lytic enzymes and nematicidal compounds can be one of candidates for biocontrol agents against root-knot nematodes.

• Korean Journal of Poultry Science
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• v.50 no.4
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• pp.303-310
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• 2023

The current study was conducted to compare the effect of crossbred on the body weight and laying performance of Korean native chicken from hatch to week 40. A total of 873 one-day-old chicks were divided into twelve crossbreds (i.e., CFCK, CFYC, CFYD, CKCF, CKYC, CKYD, YCYD, YCCF, YCCK, YDCF, YDCK, and YDYC) and commercial layer (Hy-Line Brown) were obtained as a counterpart in the study. All the birds are raised in battery cages (76 × 61 × 46 cm³) and then raised until 14 weeks and subsequently moved to layer battery cages (60 × 25 × 45 cm³) and raised until 16 weeks. The body weight and viability were measured biweekly from hatching to week 16. The week of 16, body weight range was about 1,010.24 to 1,411.77 g. The body weight of specific crossbreeds (i.e., CKCF, YCYD, and YDYC) was found to be comparable to that of Hy-Line Brown). The viability hatch to week 14 range was about 55 to 100% and however week 14 to 16 range was 80 to 100%. The crossbred (i.e., CKCF) recorded superior (P<0.05) viability throughout the whole experiment period, even compared with Hy-Line Brown (100% vs 96%). Our results are indicating that crossbreds Korean native chicken including CKCF, and YDYC has the potential to enhance key features of laying hens during the growing phase like optimal body weight and higher viability.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.10
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• pp.1501-1509
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• 2003

The simultaneous addition of xylanase (5,600 EXU/kg) and phytase (500 FTU/kg) feed enzymes to wheat-based broiler diets was investigated. Starter, grower and finisher diets, with three tiers of nutrient specifications, were fed to 1,440 broiler chicks kept on deep litter from 1-42 days post-hatch, without and with xylanase plus phytase, to determine the effects of diet type and enzyme supplementation on growth performance. The nutrient specifications of type A diets were standard; energy density and protein/amino acid levels were reduced on a least-cost basis to formulate type B diets and further reduced to type C diets. Phosphorus (P) and calcium (Ca) levels were adjusted in supplemented diets. From 1-42 days post-hatch, diet type significantly influenced growth performance. Birds on type C diets had lower growth rates (2,429 vs. 2,631 g/bird; p<0.001), higher feed intakes (4,753 vs. 4,534 g/bird; p<0.005) and less efficient feed conversion (1.96 vs. 1.72; p<0.001) than birds offered type A diets. Enzyme supplementation increased growth rates by 3.2% (2,580 vs. 2,501 g/bird; p<0.005) and improved feed efficiency by 2.7% (1.80 vs. 1.85; p<0.05) over the entire feeding period. There were no interactions between diet type and enzyme supplementation. At 21 days, 5 out of 30 birds per pen were transferred to cages to ascertain treatment effect on apparent metabolisable energy (AME) and nitrogen (N) retention. Xylanase plus phytase enhanced AME (13.48 to 13.91 MJ/kg DM; p<0.001) and N retention (56.3 to 59.7%; p<0.005). Carcass and breast weights of the caged birds were determined following commercial processing. Diet type significantly influenced breast weight, carcass weight and yield. Birds offered Type A diets, in comparison to Type C diets, supported heavier breast (467 vs. 424 g; p<0.001) and carcass weights (1,868 vs. 1,699 g; p<0.001) with superior carcass yields (71.8 vs. 70.6%; p<0.005). Enzyme addition increased carcass weight by 3.9% (1,752 vs. 1,821 g; p<0.005) and breast weight by 5.8% (431 vs. 456 g; p<0.01) without influencing yields. Feed ingredient costs per kg live weight gain and per kg carcass weight indicated that enzyme addition was economically feasible, where supplementation of Type A diets generated the most effective results. Importantly, soluble and total non-starch polysaccharide and phytate contents of the wheat used were typical by local standards. This study confirms the potential of supplementing wheat-based broiler diets with xylanase plus phytase but further investigations are required to define the most appropriate inclusion rates and dietary nutrient specifications in this context.

• The Korean Journal of Pesticide Science
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• v.8 no.1
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• pp.54-62
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• 2004

The selective toxicity of spirodiclofen and fluacrypyrim+tetradifon to the predatory mite, Phytoseiulus persimilis and the tea red spider mite, Tetranychus kanzawai was evaluated. The bean leaf discs with adult females or eggs of both species were sprayed with several concentrations of spirodiclofen or fluacrypyrim+tetradifon. Spirodiclofen and fluacrypyrim+tetradifon were much less toxic to P. persimilis than to T. kanzawai. Although the survival rate of adult females of P. persimilis tended to decrease with increasing concentrations of spirodiclofen, 92-68% of predators survived at concentrations of 22.5-180 ppm. Likewise, reproduction was reduced with increasing spirodiclofen concentration. Spirodiclofen did not affect the hatch of P. persimilis eggs. Survival of immature predators decreased with increasing spirodiclofen concentration, however, 88-20% of immature predators reached adulthood at 22.5-90 ppm. In the case of fluacrypyrim+tetradifon, the survival rate of adult females of P. persimilis tended to decrease with increasing concentrations of fluacrypyrim+tetradifon. However, 94-72% of predators remained alive at concentrations of 22.5-180 ppm. Likewise, reproduction was reduced with increasing fluacrypyrim+tetradifon concentration. Fluracypyrim+tetradifon did not affect the hatch of P. persimilis eggs. Survival of immature predators decreased with increasing fluacrypyrim+tetradifon concentration, however, 100-86% of immature predators reached adulthood at 22.5-180 ppm. Based on the results, spirodiclofen and fluacrypyrim+tetradifon appeared to be promising candidates for use in integrated mite management programs where P. persimilis is the major natural enemy.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.3
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• pp.237-242
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• 2003

Microstructure of otoliths and early growth in total length of laboratory-reared river puffer, Takrifugu obscurus were observed from 1 to 63 days after hatching. The total length of Takifugu obscurus was 3.09${\pm}$0.02 mm, 4.96${\pm}$0.24 mm, 5.39${\pm}$0.42 mm,9.13${\pm}$0.59 mm, 10.78${\pm}$0.96, 16.40${\pm}$2.31 mm, 30.49${\pm}$l.53 mm in 1, 10, 20, 30, 34, 43, 63 days respectively. The mean radius of otoliths was 14.20${\pm}$1.21 $\mu\textrm{m}$ in 1 day, 31.06${\pm}$2.31 $\mu\textrm{m}$ in 10 days,57.19${\pm}$6.19 $\mu\textrm{m}$ in 20 days,127.13${\pm}$13.13 $\mu\textrm{m}$ in 34 days,190.79${\pm}$17.08 $\mu\textrm{m}$ in 43 days and 281.85${\pm}$23.81 $\mu\textrm{m}$ in 63 days after hatching. Growth of otoliths were similar to the growth pattern in total length during 20-63 days after hatching. Hatch mark was distinguished with other growth increments and within a hatch mark two or three increments were observed. The number of growth increments was correlated with the days after hatching between 20 and 63 days after hatching.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.1
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• pp.7-14
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• 1974

1. Stylochus ijimai spawns from May to October with peak spawning from July to September, P. obscurus spawns from June to October with peak spawning from July to September. 2. S. ijimai spawns approximately 96,000-132,000 eggs by one spawning. 1. Just after spawnings, the eggs of S. ijimai were $102\mu$ in diameter, and those of P. obscurus were $108\mu$. 4. S. ijimai and P. obscurus have simple eggs. S. ijimai develop indirectly having Gotte larvae, while P. obscurus develop directly. 5. These two species show very similar patterns of early developments from maturation division of eggs to the gastrula stage. 6. The zygots of S. ijimai reaches mesentoblast stage 48 hours after fertilization, and Gotte larvae hatch out 7 days after fertilization. The zygots of P. obscurus reaches mesentoblast stage 72 hours after fertilization, and juveniles hatch out 14 days after fertilization. 7. S. ijimai, have 14 days of planktonic larvae stages bearing strong phototacic behavior : P. obscurus have 7 days of planktonic life without phototacic behavior. 8. Newly hatched larvae of S. ijimai and P. obscurus are $138\mu\;and\;170\mu$ in length respectively. The early creeping forms of S. ijimai and P. obscurus are $152\mu\;and\;185\mu$ in length respectively. 9. In the early creeping stage S. ijimai are characterized by testing processes and flattening of the body. In the same stage P. obscurus lost 2 eye-spots in the cerebral area. 10. The early creeping larvae of these two species were found only in mud-flat substrates.

• The Korean Journal of Pesticide Science
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• v.6 no.4
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• pp.257-263
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• 2002

This study was carried out not only to investigate the toxicities of 12 registered insecticides on different developmental stages, but also to determine the sublethal effects on longevity and reproduction of newly emerged adult female and development of the next generation in the rice skipper, Parnara guttata. Fenitrothion, fenthion, cartap hydrochloride, ethofenprox highly suppressed egg-hatch. All insecticides treated showed high larvicidal activity on the 1st to 2nd instar larva. The insecticides showed higher larvicidal activities on the 5th instar larva were fenitrothion, fenthion, ethofenprox, fipronil, methoxyfenozide, tebufenozide and Bt. var. kurstaki. The sublethal doses of fenthion, tebufenozide, cartap hydrochloride, methoxyfenozide, ethofenprox, imidacloprid and fipronil shortened the longevities of newly emerged adult female from the treated larva ($3{\sim}4$ instar). BPMC, imidacloprid, ethofenprox, fipronil and methoxyfenozide delayed the preoviposition periods of adult females and decreased the number of eggs laid when they were treated at the larval stages of the previous generation. Ethofenprox caused severe sublethal effects on P. guttata offspring, completely blocking the production. All insecticides except fenitrothion affected the egg viability, and all eggs from the adult females emerged from the survivors treated larvae with imidacloprid or fipronil fail to hatch. IGRs, methoxyfenozide and tebufenozide showed an adverse effect on the development of next generation larva.

• Clinical and Experimental Reproductive Medicine
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• v.21 no.1
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• pp.49-62
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• 1994

In mammalian development, the embryo which is in the process of compaction, involves a progressive flattening of blastomeres against each other with the consequence that the embryo assumes a spherical shape. This stage happens in the first differentiation. The present study was aimed to examine the involvement of other metal ions in compaction by treating with various divalent cations in the absence of $Ca^{++}$. When 8-cell embryos were cultured in $Ca^{++}$-free medium for 24hrs, they developed to 16-cell stage but did not compaction, and degenerated after 48hrs of culture. Embryos were cultured in $Ca^{++}$-free medium for 24hrs and then transferred to the control medium showed the normal compaction afterwards. When 8-cell embryos were cultured in the presence of $Ni^{++}$, known as a $Ca^{++}$ inhibitor, they cleaved to 16-cell stage but did not compact in the absence of $Ca^{++}$. On the other hand, embryos cultured in the media containing both $Ca^{++}$ and $Ni^{++}$ developed normally so that they underwent compaction during culture for 48hrs. However, they failed to hatch during further 24hrs in the same medium, indicationg that $Ni^{++}$ may exert some harmful effects. Embryos grow in the control medium that contained $Ca^{++}$ but not $Ni^{++}$, developed to the hatched blastocysts. The treatment with $Cd^{++}$ $10^{-1}$,$10^{-2}{\mu}M$, $Mn^{++}$ or $Ba^{++}$ 10,100, $1000{\mu}M$ in $Ca^{++}$-free medium, respectively, inhibited compaction and embryonic degeneration began as in $Ca^{++}$-free medium. When 3, 5, 10mM of $Sr^{++}$, known as a substitute for $Ca^{++}$ in cell, was added to $Ca^{++}$-free medium, respectively, compaction was induced unlike the above metal ions. Embryos were cultured in $Sr^{++}$ developed to blastocysts, but failed to hatch after 72hrs and degenrated. On the other hand, when embryos were cultured in 3, 5, 10mM of $Sr^{++}$ but in $Ca^{++}$-free medium for 24hrs respectively and then transferred to the control, they showed the similiar development as that in the control.

• Korean journal of applied entomology
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• v.49 no.2
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• pp.129-137
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• 2010

Four major agricultural insect pests, Bemisia tabaci, Myzus persicae, Plutella xylostella and Tetranychus urticae, were irradiated with 30, 50, 70, or 100 Gy electron-beam. Longevity, egg hatching, emergence, and fecundity of the test insects were measured. Hatchability of B. tabaci, P. xylostella and T. urticae declined with increasing irradiation doses, and all B. tabaci and T. urticae eggs were dead at 100 Gy. When eggs of B. tabaci, P. xylostella and T. urticae were irradiated, hatch was inhibited. B. tabaci adults grown from 70 Gy irradiated eggs did not lay eggs. Fecundity of P. xylostella from the 100 Gy irradiated eggs decreased. When B. tabaci, P. xylostella, M. persicae and T. urticae nymphs/larvae were irradiated, the results were similar as those of the hatched eggs. When P. xylostella pupae were irradiated with 100 Gy, fecundity of emerged adults decreased and no eggs hatched. When B. tabaci, P. xylostella, M. persicae and T. urticae adults were irradiated with 70 and 100 Gy, fecundity decreased and egg hatch of B. tabaci was inhibited. However, the longevity of adults did not change and electron-beam irradiation of all developmental stages had no effect on the longevity of adults.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.3
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• pp.382-392
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• 2012

This study evaluated the effects of dietary anticoccidial drugs plus antibiotic growth promoters (AGPs) on parameters of immunity in commercial broiler chickens. Day-old chicks were raised on used litter from a farm with endemic gangrenous dermatitis to simulate natural pathogen exposure and provided with diets containing decoquinate (DECX) or monensin (COBN) as anticoccidials plus bacitracin methylene disalicylate and roxarsone as AGPs. As a negative control, the chickens were fed with a non-supplemented diet. Immune parameters examined were concanavalin A (ConA)-stimulated spleen cell proliferation, intestine intraepithelial lymphocyte (IEL) and spleen cell subpopulations, and cytokine/chemokine mRNA levels in IELs and spleen cells. ConA-induced proliferation was decreased at 14 d post-hatch in DECX-treated chickens, and increased at 25 and 43 d in COBN-treated animals, compared with untreated controls. In DECX-treated birds, increased percentages of $MHC2^+$ and $CD4^+$ IELS were detected at 14 d, but decreased percentages of these cells were seen at 43 d, compared with untreated controls, while increased $TCR2^+$ IELs were evident at the latter time. Dietary COBN was associated with decreased fractions of $MHC2^+$ and $CD4^+$ IELs and reduced percentages of $MHC2^+$, $BU1^+$, and $TCR1^+$ spleen cells compared with controls. The levels of transcripts for interleukin-4 (IL-4), IL-6, IL-17F, IL-13, CXCLi2, interferon-${\gamma}$ (IFN-${\gamma}$), and transforming growth factor${\beta}$4 were elevated in IELs, and those for IL-13, IL-17D, CXCLi2, and IFN-${\gamma}$ were increased in spleen cells, of DECX- and/or COBN-treated chickens compared with untreated controls. By contrast, IL-2 and IL-12 mRNAs in IELs, and IL-4, IL-12, and IL-17F transcripts in spleen cells, were decreased in DECX- and/or COBN-treated chickens compared with controls. These results suggest that DECX or COBN, in combination with bacitracin and roxarsone, modulate the development of the chicken post-hatch immune system.