• Korean Journal of Poultry Science
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• v.27 no.3
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• pp.181-187
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• 2000

This work was designed to investigate the performances of broiler breeder hens upon the addition were vitamin and mineral supplements in feeds. Animals were divided into for feed groups such as control, T$_1$,T$_2$and T$_3$, and each treatment has four replications. All broiler breeder hens were housed individually, and were fed with identical iso-metaboilic energy and iso-protein, except for vitamins and minerals. Different sources and levels of vitamins and minerals were added to the basic feeds according to the treatments. At the end of the experiments, general laying rate(hen days), average egg weight, hatching egg laying rate(Hen day) every day. Hatching egg weight, sterility, embryo mortality, hatching rate and chick weight were examined. Although, early laying rate in all treatment groups were reduced during cold term management, general egg laying rate was increased only T$_3$group which was contanining vitamin C. However, similar results were obtained in the rates of general and hatching egg laying. General egg laying rate were somewhat higher of Control, T$_2$and T$_3$ groups than that of T$_1$group. In addition, the laying rates of general and hatching eggs slightly improved in the T$_3$group rather than those of Control group. Egg weight was reduced with the increasing of laying rate, showing the highest in the T$_3$group. The laying rate showed significantly lower value than those of any other groups. Egg weight was about 65g in T$_3$group. The results of hatching performance for production ability of Broiler breeder hens were fed experimental diet, although the rates of non-hatched and hatched eggs increased in order of Control, T$_1$T$_2$and T$_3$groups. However, the rate of embryo mortality was declined in order Control, T$_1$T$_2$and T$_3$groups.

• Animal Bioscience
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• v.37 no.3
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• pp.500-508
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• 2024

Objective: Due to current selection practices for increased egg production and peak persistency, the production profile, age at maturity, and body weight criteria for commercial layers are constantly changing. Body weight and age at the time of photostimulation will thus always be the factors that need to be adequately addressed among various production systems. The current study was carried out to determine the effects of pullets' body weight (low, medium, and heavy) on their performance, welfare, physiological response, and hormonal profile. Methods: With regard to live weight, 150 16-week-old pullets were divided into three groups using a completely randomized design (CRD) and held until the 50th week. One-way analysis of variance was used to evaluate the data under the CRD, and the least significant difference test was used to distinguish between treatment means. Results: In comparison to the medium and light birds, the heavy birds had higher body weight at maturity, an earlier age at maturity, and higher egg weight, eggshell weight, eggshell thickness, egg yolk index, breaking strength, egg surface area, egg shape index, egg volume, and hormonal profile except corticosterone. However, the medium and light birds had lower feed consumption rates per dozen eggs and per kilogram of egg mass than the heavy birds. Light birds showed greater body weight gain, egg production, and egg specific gravity than the other categories. At 20 weeks of age, physiological response, welfare aspects, and catalase were non-significant; however, at 50 weeks of age, all these factors-aside from catalase-were extremely significant. Conclusion: The findings of this study indicate that layers can function at lower body weights during photostimulation; hence, dietary regimens that result in lighter pullets may be preferable. Additionally, the welfare of the birds was not compromised by the lighter weight group.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.1
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• pp.19-24
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• 2008

The purpose of this study was to detect expression of genes related to egg production in Taiwan Country chickens by suppression subtractive hybridization. Liver samples of mRNA extraction from two Taiwan Country chicken strains (L2 and B), originated from the same population but with very distinct egg production rates after long-term selection for egg and meat production respectively. Two-way subtraction was performed. The hepatic cDNA from the low egg production chickens (B) was subtracted from the hepatic cDNA from the high egg production strain (L2). The reversed subtraction (L2 from B) was also performed. The resulting differentially expressed gene fragments were cloned and sequenced. We sequenced 288 clones from the forward subtraction and 96 clones from the reverse subtraction. These genes were subjected to further screening to confirm the differential expression between the two genetic breeds of chickens. The apolipoprotein B (apoB) was expressed to a greater extent in the liver of the L2 than in the B line chickens. The 5-aminoimidazole- 4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (PURH) was expressed to a greater extent in the liver of the B than in the L2 strain chickens. We demonstrated that both apoB and PURH were more highly expressed in the liver than that in other tissues (muscle, ovary, and oviduct) in laying Taiwan Country chickens. Taken together, these data suggest that after the selection for egg production, expression of apoB and PURH genes were also changed. Whether the changed expression of these genes is directly related to egg production is not known, but these two genes may be useful markers for egg laying performance in Taiwan Country chickens.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.6
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• pp.607-610
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• 1995

An experiment was conducted to study the effects of Ascorbic Acid (AA) supplementations in the layer and broiler diets kept in the natural hot humid tropical climate ($20-35^{\circ}C$). The layers and the broilers were fed on normal commercial diet as control while supplementation of 400 and 600 mg/kg Ascorbic Acid made up the experimental diets. The results showed that AA supplementation in the layers significantly reduced egg weight and increased Haugh unit values of the eggs, but produced no significant effects on feed intake, body weight, egg production, respiratory rate and body temperature. The shell thickness was slightly improved, though not significantly, with AA supplementation. AA supplementation in broilers improved body weight gain and FCR and reduced the effect of heat stress as shown by lower body temperature and respiratory rates.

• Korean Journal of Veterinary Research
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• v.40 no.3
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• pp.551-561
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• 2000

Swine respiratory diseases have induced severe economic losses in swine industry worldwide. Several methods have been developed and applied to prevent and control the disease. However, those are still problematic in swine industry. Recently, the use of egg yolk antibodies with several advantages was introduced and applied to control diseases in animal as well as human. As the first step of the use of egg yolk antibodies in the control of the swine respiratory diseases, we investigated the immunogens of the causative agensts of the diseases and immune response in egg yolk of hens immunized with them. Bacterial antigens prepared from Bordetella bronchiseptica, Pasteurella multocida 3A and 4D, and Actinobacillus pleuropneumaniae serotype 2 and 5 were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blot and toxicity test in mice. The antigens were injected into laying hens in order to produce antibodies against them in egg yolk. After chickens were immunized three times in 2 weeks interval, the profile of antibody production was examined by ELISA. The production of antibody in egg yolk was started in 2 weeks after the first injection, reached peak in 6-8 weeks and maintained until 12 weeks. Of two adjuvants used in this study, ISA70 was more effective than aluminum hydroxide gel in enhancing immunogenecity, laying rates and safety in hens. These results suggested that egg yolk antibodies could be a good source for production of antibodies specific to pathogenic bacteria inducing respiratory diseases of swine.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.288-295
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• 1998

Egg production of Acartia steueri was estimated in llkwang Bay, located in the southeastern coast of Korea. The equation, combining fecundity, temperature and chlorophyll a, obtained under the laboratory experiments, was applied to the in situ temperature and chlorophyll a for the estimation of field egg production. Mean egg size was $80.52{\mu}m$. Prosome length of adult females was not correlated with egg size. Egg production of field population ranged from 0.32 to $63.32{\mu}gC\;m^{-3}d^{-1}$ with a mean of $13.33{\mu}gC\;m^{-3}d^{-1}$, which were equivalent to $7.1\~1407.1\;eggs\;m^{-3}d^{-1}$ and $296.1\;eggs\;m^{-3}d^{-1}$, respectively. Fecundity of adult females ranged from 5.4 to $12.5\;eggs\;female^{-1}d{-1}$ with a mean of $8\;eggs\;female^{-1}d^{-1}$. Specific egg production rates ranged from 0.028 to 0.117 $d^{-1}$ with a mean of 0.064 $d^{-1}$. Considering the egg Production ($\%$ female body carbon) as a function of temperature and chlorophlrll a concentration, our results showed rather low fecundity, which might be underestimated. Probable cannibalism of egg by the adults were thought to be pan of the reason for this low estimated fecundity.

• Korean Journal of Poultry Science
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• v.27 no.2
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• pp.133-153
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• 2000

The egg's interior quality is one of the most important criteria for commercial producers and consumers. Internal quality is complex, including aesthetic factors such as taste, freshness, nutritional and processing values, and the genetic influences upon these upon these factors ranges from none to considerable. The rate of cholesterol synthesis in the hen is very high compared to other animals and humans. Genetic selection, diet drugs and other chemicals can alter cholesterol concentration in the plasma of laying hen, but attempts to manipulate the cholesterol concentration in the egg yolk are generally unsuccessful since the cholesterol can only be changed to a small extent. Factors which may affect the degree of pigmentation of the yolk include the type of xanthophyll and its concentration in the feed, the feed composition, and the health of the hen. Several feed ingredients interact with carotenoid pigment to improve or reduce their deposition rates in yolks. Egg weight is determined by genetics, body size prior to first egg housing density, environmental temperature, lighting program, total feed consumption, calcium, phosphorus, niacin, water, methionine, total sulfur amino acids, energy, linoleic acid, fat and protein levels. Eggs need to be promote levels. Eggs need to be promoted a versatile commodity and new processed egg items need to be developed. Organic eggs are laid by hens which were raised in chemical and drug frdd environments. There are still difficulties in producing these eggs due to the availability of organic poultry feeds and cost of organic grains.

• Korean Journal of Poultry Science
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• v.38 no.3
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• pp.239-245
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• 2011

Pigments in the diet affect yolk colors. Due to variations in both the bioavailability of pigments in chickens and their amounts occurring in the feed ingredients, concern about egg quality arises in terms of yolk color. In this study, the effects of pigments, produced through cell culture in the laboratory, on yolk colors were determined for 4 weeks in laying hens receiving one of the 6 dietary treatments: control diets containing 1) no synthetic pigments (CON); 2) canthaxanthin (4 ppm) purchased from BASF (BASF); 3) cultured cells so that the diet had canthaxanthin at 4 ppm (CX); 4) cultured cells so that the diet had lycopene at 30 ppm (LP); 5) canthaxanthin (4 ppm) that was purified from cultured cells (SPCX); or 6) lycopene (30 ppm) that was purified from cultured cells. Relation between deposition of pigments into yolks and egg production was also tested. Yolk color of eggs from chickens fed dietary CX was significantly enhanced, which was slightly but significantly below that of BASF. Results from other treatments were lower than those of CX. Deposit rates of pigments into yolks were: BASF > CX > SPCX > LP > SPLP. The amounts of pigments, with the exception of SPLP, in feed were not changed during the storage for 4 weeks at $25^{\circ}C$. Egg production rates varied among treatments during the initial phase of the study but became relatively uniform at the later stage, except for CON and LP groups. The results of the present study indicate that the deposition of pigments into yolks is independent of egg production.

• Korean Journal of Poultry Science
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• v.29 no.2
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• pp.117-124
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• 2002

Betaine functions as an osmoregulators in the cells and its inclusion in diet can spare the choline and carcass fat reduction in chicken. Thus, two hundred eighty eight laying hens were fed with 0, 500, 1,000, 2,000 ppm of betaine from seventy eight to eighty six weeks of age during the environmentally high temperature stress. Com and soybean basal diets contained 2,800 kcal/kg ME and 16% CP. Egg production, feed intake, and feed conversion were examined for eight weeks. Egg quality characters, serum cholesterol, liver betaine, and lower ileal osmolality were measured at the end of experiment. Egg Production rates of hens fed with 500 or 2,000 ppm of betaine were 75.06 and 75.02%, respectively and tended to increase compared to the control. The feed conversion(FCR) of these treatments was significantly(P<0.05) improved compared to that of control although it did not significantly differ in the e99 Production rates between 500 and 2,000 ppm of betain groups. Eggshell breaking strength of hens fed betaine was significantly(P<0.05) higher than those of control. However, betaine supplements did not influence to improving the albumen height and Haugh unit. Liver betaine in hens fed with betaine was linearly increased unto 2,000 ppm. The birds fed with 2,000 ppm betaine showed significantly(P<0.05) higher in the liver betaine than the control birds. Total cholesterol and triglyceride tended to be increased by dietary betaine supplement. The lower ileal osmolality in betaine supplement group tended to be slightly decreased. As a result, dietary betaine supplement tended to improve the egg Production and eggshell Quality in laying hens during heat stress.