• Asian-Australasian Journal of Animal Sciences
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• v.1 no.3
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• pp.173-178
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• 1988

To study the effects of utilizing extruded full fat soybean (FFS) in layer diets, 300 White Leghorn pullets were put in trial divided into 5 treatments; control (commercial soybean meal as protein source), FFS 50% (replacing 50% of soybean meal with FFS), FFS 100% (replacing all amount of soybean meal with FFS), soybean oil and tallow added treatment. Each treatment consisted of 5 replicates of 12 birds. Egg production and feed efficiency from hens fed control diet were significantly lower than from hens fed the other diets. Significant differences in egg production and feed efficiency were found between the control and the other treatments. Cholesterol concentration of serum and egg yolk were not affected by any dietary treatment. Feeding extruded full fat soybean did not cause pancreatic hypertrophy nor change in mortality. There was an indication that linoleic acid (C18:2), linolenic acid (C18:3) and iodine contents increased in the thigh and egg yolk lipid of the groups fed FFS or soybean soybean can serve as effective protein source for layer diets if economically justified.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.4
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• pp.741-746
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• 1992

The effects of 5%, 10%, 15% and 20% dietary cellulose levels on the nutrient utilization in chickens were investigated. Four experimental diets were alternatively given to 8 colostomized White Leghorn cockerels to make a $4{\times}4$ Latin-square design. The diets of 70 g.day were force-fed once a day, and water was given freely. The digestibilities of DM and energy increased linearly with the increase in dietary cellulose level. The digestibilities of ether extract and nitrogen-free extract were not so much influenced by the dietary cellulose level. The digestibility of acid detergent fiber was very low and not influenced by the dietary cellulose level. The digestibility of neutral detergent fiber was not different among the diets containing 5%-15% cellulose, but that of the 20% cellulose diet was diminished. This might be due to the reduction of hemicellulose digestibility. True digestibility and biological value of protein were also not influenced by the dietary cellulose level from 5% to 20%. In conclusion, no ill-effect was found even when the chicken was fed a diet containing 20% of cellulose.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.5
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• pp.603-609
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• 2011

Telomeres are special structures at the ends of eukaryotic chromosomes. Vertebrate telomeres consist of tandem repeats of conserved TTAGGG sequence and associated proteins. Birds are interesting models for molecular studies on aging and cellular senescence because of their slow aging rates and longer life spans for their body size. In this longitudinal study, we explored the possibility of using telomeres as an age-marker to predict age in Single Comb White Leghorn layer chickens. We quantified the relative amount of telomeric DNA in isolated peripheral blood lymphocytes by the Quantitative Fluorescence in situ Hybridization technique on interphase nuclei (IQ FISH) using telomere-specific DNA probes. We found that the amount of telomeric DNA (ATD) reduced significantly with an increase in chronological age of the chicken. Especially, the telomere shortening rates are greatly increased in growing individuals compared to laying and old-aged individuals. Therefore, using the ATD values obtained by IQ FISH we established the possibility of age prediction in chickens based on the telomere theory of aging. By regression analysis of the ATD values at each age interval, we formulated an equation to predict the age of chickens. In conclusion, the telomeric DNA values by IQ FISH analyses can be used as an effective age-marker in predicting the chronological age of chickens. The study has implications in the breeding and population genetics of poultry, especially the reproductive potential.

• Korean Journal of Poultry Science
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• v.23 no.4
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• pp.177-183
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• 1996

This study was conducted to analyze genetic characteristics of Korean Native Chicken three lines classified on the basis of the feather color and appearance (Red, Yellow, and Black) using DNA fingerprinting method. To estimate the genetic relatedness among breeds and similarities within breeds, we collected blood samples from Korean Native Chicken (KNC), Rhode Island Red (RIR), White Leghorn (WL), and Cornish(CN) and obtained genomic DNA from the blood of 10 individuals randomly selected within the breeds and lines. The genomic DNA samples were digested with restriction enzymes (Hinf J, Hae Ill) and hybridized with various probes (Jeffreys' probes 33.15, 33.6 and M13) after Southern transfer. Genetic similarities within breeds were characterized by band sharing (BS) value, estimated by the DFP band pattern between the pair of lanes. BS values within WL, RIR, and KNC were 0.82, 0.70 and 0.56, respectively. Relative genetic diversity (BS value) of KNC was higher than those two breeds (WL, RIR). Estimation of genetic similarity between KNC lines and control breed (RIR) was 0.32, whereas similarity within KNC lines (6 groups) was 0.50. In this analysis, KNC was showed to have a highly genetic diver-sity at the DNA level, and to be closer in genetic distance to RIR (0.67) than any other breeds.

• Korean Journal of Poultry Science
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• v.23 no.2
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• pp.61-69
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• 1996

Primordial germ cells (PGCs) were manipulated as part of the system to produce transgenic chickens. PGCs were isolated from the germinal crescent of developmental stage 6 to 8 donor emhryos of the Korean Native Ogol Chickens (KNOC). These PGCs were transfected with plasmid DNA containing the lac Z gene by liposome mediated transfection methods. The lac Z gene was transfected and expressed in the PGCs. These transfected PGCs were injected into the germinal crescent of White Leghorn embryos (stage 6 to 8). The injected transfected PGCs migrated via the circulatory system into the future gonad and expression observed in the gonads of 3 day old chick. Of the 47 embryos and 3 day old chickens, one positive PGCs gonad from sacrificed young chickens was detected by appearance of blue cells. Plasmid DNA with the foreign gene was incorporated into the population of germ cells in the gonad. These results demonstrate that PGCs can he transfected and then transferred for colonization into the gonad, and show the potential to ultimately manipulate the genetic material of the chicken gernline.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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• pp.1617-1621
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• 2002

Two hundred and sixteen single comb white egg layers of the White Leghorn hens of 24 weeks of age were randomly allocated to 12 groups with three replications of six hens in each. Hens were fed in a factorial arrangement 2${\times}3{\times}$2, on diets containing either 16 or 18% crude protein with 0, 3 or 6% fish meal, replacing groundnut meal with soybean meal. Soybean meal incorporation improved (p<0.05) egg production, feed intake, feed conversion efficiency and egg weights. Egg quality traits of specific gravity, shape index, albumen index, yolk index and shell thickness remained unchanged. Laying performance was significantly (p<0.05) better at 18% than on 16% dietary protein level. Use of fish meal linearly improved egg production and feed conversion efficiency on diets supplemented with groundnut meal and fish meal incorporation showed quadratic improvement on feed conversion efficiency with SBM diets at 16% dietary protein level. Therefore, use of soybean meal as substitute of groundnut meal is recommended in layer diets, at 16% dietary protein level and fish meal incorporation could be beneficial for layers.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.12
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• pp.1758-1763
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• 2000

The effect of tu-chung (Eucommia ulmoides, Oliver) leaf meal on reducing lipid accumulation in chickens fed 1% cholesterol containing diet was studied. Forty male White Leghorn chickens aged 56 days were weighed and divided into four groups of ten chickens, and fed diets with or without 1% dietary cholesterol which were supplemented with 0 and 5% tu-chung. Tu-chung supplementation to the diet without cholesterol increased acetyl-CoA carboxylase (p<0.01) but decreased 3-hydroxy-3-methylglutaryl-CoA reductase activities (p<0.01) with no effect on fatty acid synthetase activities. However, its supplementation to the diet with cholesterol had no effect on these three enzyme activities as compared with the cholesterol containing diet without tu-chung. Tu-chung supplementation to the diet without cholesterol increased hepatic triglyceride (p<0.01), whereas its supplementation to the diet with cholesterol decreased it (p<0.01). Tu-chung supplementation to the diet with cholesterol decreased plasma cholesterol ester, free cholesterol, phospholipids (p<0.05) and triglyceride (p<0.01) as compared with the cholesterol containing diet without tu-chung. Supplementation of tu-chung to the diet without cholesterol decreased plasma free cholesterol (p<0.05). It is concluded that tu-chung leaf meal reduced an increase in lipid accumulation in chickens stimulated by 1% cholesterol feeding.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.12
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• pp.1743-1749
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• 2000

An experiment was conducted to investigate the effect of supplementation of commercial phytase and ${\beta}-glucanase$ to wheat-soybean meal based layer diets. Control (17% CP) and reduced protein (13.5% CP) diets were compared with and without phytase and/or ${\beta}-glucanase$. Reducing dietary crude protein levels reduced the amount of N excreted by laying hens with no adverse affect on egg production or overall feed conversion ratio. There was, however, a slight reduction in average egg weight. When phytase was added to the control protein diets it was possible to reduce the level of dicalcium phosphate in the diet without a loss in performance and daily P output was reduced significantly. When phytase was added to the reduced protein diets, however, there was a dramatic loss in performance in the last four weeks of the study. Supplementation of ${\beta}-glucanase$ to wheat based layer diet did not appear to have beneficial affects in terms of laying performance and reducing nitrogen or phosphorus excretion. Combination of phytase and ${\beta}-glucanase$ had no positive effects on laying performance or reduction of DM, N and P.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.2
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• pp.243-248
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• 1993

The effect of dietary lipid factors (plant and animal oil, cholesterol and ${\beta}$-sitosterol) on the liver, serum, and egg yolk cholesterol levels of the laying hen was studied. Single Comb White Leghorn laying hens, at 28 weeks of age, were fed two basal diets containing 8.0% soybean oil or 8.0% fish oil, with or without supplemental cholesterol (1.0%), ${\beta}$-sitosterol (2.0%) or combinations of both. Restricting caloric intake resulted in significantly (p<.05) decreased egg production and the total amount of cholesterol excreted via the egg was significantly (p<.05) different among treatment groups. Cholesterol supplementation to the two basal diets resulted in a significant elevation of liver, serum and egg yolk cholesterol levels. The addition of ${\beta}$-sitosterol lowered the cholesterol levels in liver and serum, while increased in the egg yolk (SO + ST, FO + ST). The anticholesterogenic effect of dietary ${\beta}$-sitosterol was not clearly exhibited in this study.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.2
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• pp.235-242
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• 1993

In order to investigate the effects of dietary cellulose and protein levels on chick performance, four semi-purified diets were formulated so as to contain cellulose at levels of 5% (LC) and 20% (HC) in combination with 10% (LP) and 20% (HP) protein, and fed ad libitum to 1-week-old White Leghorn male chicks for 3 weeks. There were no significant differences in feed intake, body weight gain and feed efficiency between the LC-HP and HC-HP groups. All parameters were lower in the LP groups; the HC-LP group consumed very small amount of feed and lost body weight during the experiment. The retention rates of DM, ash, nitrogen and energy were higher in the HP than the LP groups. The triglyceride concentration of carcass was lower in the HC-LP group and that of liver was higher in the LC-LP group. The carcass total cholesterol level was higher in the HC-HP group. The relative weight of most digestive organs was higher in the HP group irrespective of the cellulose level. In conclusion, the chick performance was primarily influenced by dietary protein level, and when the chicks were fed inadequate levels of protein, the low cellulose level gave a better performance than the high cellulose level.