• Korean Journal of Food Science and Technology
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• v.9 no.4
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• pp.264-270
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• 1977

In order to investigate the effect of dietary fatty acids on lipids metabolism in adipose pads and superficial pectoral muscle of chicks, the present, experiment was carried out using signle comb White Leghorn male chicks fed a fat-free diet and diets containing margaric, stearic or linoleic acids. Total lipids of tissues were extracted with a chlorofrom-methanol solution. The lipid components were fractionated by thin layer chromatography and the fatty acid distribution of lipid fractions was determined by gas liquid chromatography. The neck adipose pads contained 34-62% total lipids, in which triglycerides, were dominant, being 97-98%. Margaric, stearic and linoleic acids were distributed at a relatively high rate in the adipose tissue when the corresponding acids were fed, and margaric acid feeding lowered palmitoleic acid distribution and linoleic acid feeding elevated stearic acid distribution. The wet superficial pectoral muscle contained 1.3-1.7% total lipids, of which 77-79% was phospholipids and 11-13% was free cholesterol. When margaric acid was fed, margaric and heptadecenoic acids appeared in the muscle lipids. When linoleic acid was fed, this acid was significantly highly distributed in every muscle lipid fractions, whereas, when stearic acid fed no elevation of stearic acid distribution was observed. In the muscle phospholipids, oleic acid was significantly highly distributed in the stearic acid fed chicks, and the linoleic acid feeding signigicantly lowered the distribution value of palmitic and oleic acids, but elevated the distribution value of stearic acid. And the linoleic acid feeding lowered the distribution value of eicosatrienoic acid and elevated the distribution value of arachidonic acid.

• Korean Journal of Poultry Science
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• v.10 no.2
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• pp.75-81
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• 1983

The records on 787 white Leghorn hens from two different strains, A and K were wed in this study to find out the pattern of increase in egg weight with age and the optimum age of early selection for maximizing the genetic gain. The pattern of increase in egg weight with age in two lines which was expressed on graph showed that the amount of increase was larger in the early part of the laying year and it decreased gradually. Regression equations suggested that egg weight increased linearly with age at the rate of 0.46 gram per week for line A and 0.83 gram for line K. And in the regression analyses of each period mean egg weight on annual mean egg weight, the coefficients of EW 30 that is mean egg weight from 29 weeks of age to 32 weeks of age were 0.86 for line A, 0.88 for line K, and those were the highest figures among the all regression coefficients of each mean egg weight on annual mean egg weight. In estimating the relative selection efficiency of each period mean egg weight on annual mean egg weight in EW 46, selection on EW 34 for line A and on EW 30 for line K was the most efficient for improving egg weight. These results suggested that one periods from 29 weeks of age to 36 weeks of age could be used for the best predictable time for improving annual mean egg weight.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.5
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• pp.601-605
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• 2005

Three lines of White Leghorn (WL) chickens (IWJ, IWG and IWC) maintained at Central Avian Research Institute, Izatnagar (UP), were used for chorioallantoic membrane (CAM) and liver tumour (LT) assay. Eleven-day-old embryos of each line were partitioned into three groups and inoculated with 0.2 ml of subgroup A, subgroup C and an equal mixture of subgroup A and C Rous sarcoma virus (RSV). Subgroup virus receptor on the cell surface membrane for subgroup A is coded for by tumour virus a (tva) locus and for subgroup C by tumour virus c (tvc) locus. The random association of the genes at the tva and tvc loci in IWJ and IWC line was assessed and the $x^2$-values for phenotypic classes were found to be significant, indicating the linkage between the tva and tvc loci. The linkage value was estimated to be 0.09 on pooled sex and pooled line basis. On the basis of four subclass tumour phenotypes a 4-allele model was proposed for tva locus having $a^{s1}$, $a^{s2}$, $a^{r1}$ and $a^{r2}$ alleles and the frequencies were calculated as 0.47, 0.13, 0.13 and 0.27 for IWJ line, 0.31, 0.33, 0.14 and 0.22 for IWG line and 0.44, 0.11, 0.21 and 0.24 for IWC line, respectively. Similarly, for tvc locus the frequencies of four alleles i.e. $c^{s1}$, $c^{s2}$, $c^{r1}$ and $c^{r2}$ were calculated as 0.42, 0.20, 0.21 and 0.17 for IWJ line, 0.42, 0.17, 0.27 and 0.14 for IWG line and 0.30, 0.21, 0.16 and 0.33 for IWC line, respectively. The $x^2$-values for all classes of observations were not significant (p>0.05), indicating a good fit to the 4-allele model for the occurrence of 4-subclass tumour phenotypes for tva and tvc loci. On the basis of the 2-allele model both tva and tvc locus carries three genotypes each. But, on the basis of the 4-allele model tva and tvc locus carries 10 genotypes each. The interaction between A-resistance and C-resistance (both CAM and LT death) was ascertained by taking the 10 genotypes of tva locus and 3 genotypes of tvc locus by pooling the lines and partitioning the observations into 3 classes. The $x^2$-values for the genotypic classes of CAM (-) LT (+) and CAM (-) LT (-) phenotypes to mixed virus (A+C) infection were found to be highly significant (p<0.01), indicating increased resistance, which indicates the joint segregation of $a^r$ and $c^r$ genes, suggesting the existence of close linkage between the tva and tvc loci. Therefore, an indirect selection approach using subgroup C viruses can be employed to generate stocks resistant to subgroup A LLV, obviating contamination with the most common agent causing LL in field condition.

• Korean Journal of Veterinary Research
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• v.37 no.3
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• pp.569-576
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• 1997

Fowl typhoid(FT) caused by Salmonella gallinarum is an infectious, egg-transmitted disease and characterized by swollen bronze liver, greenish-yellow diarrhea and high mortality in growing and adult chickens. Since 1992 the outbreak of FT has been increased. Several problems have been occurred such as absence of appropriate vaccines and lack of useful therapeutic methods. In these studies we investigated the pathogenicity of S gallinarum isolated in chickens. To compare the pathogenicity among the species of chickens, all chickens were challenged intramuscularly or orally with $1{\times}10^7$ CFU of S gallinarum. The brown-colored layers were more susceptible and white leghone chickens were more resistant than other species. In the brown layer chickens orally challenged, lethal doses ($LD_{50}$) of the isolates were inoculated at 1 day, 2 weeks, 4 weeks and 8 weeks old chickens with amount of $10^{4.2}$, $10^{4.7}$, $10^{7.0}$ and $10^{7.6}$ CFU, respectively. The chickens which were intramuscularly challenged with the less amount than $10^2$ CFU showed higher mortality than that of the chickens orally inoculated with same dose. Also, we investigated the recovery rates of bacteria from various organs of survival chickens which were challenged orally with $5{\times}l0^7$ CFU of S gallinarum. The bacteria was more frequently and isolated earlier from the liver and spleen than from any other ogans. In the pathogenicity test, the white-leghorn chickens which were known as resistant-strain against Salmonella were artificially immunosuppressed using bursectomy and/or dexamethasone treatment. Mortality of chickens with both bursectomized and treated with dexamethasone was higher(90%) than that of the control group(10%), the bursectomized chickens(10%) and the dexamethasone only treated group(20%). It was suggested that the protective mechanism in chickens against S gallinarum may be required both the functions of B-cells and T-cells.

• Korean Journal of Poultry Science
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• v.37 no.2
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• pp.117-123
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• 2010

This work was carried out to investigate the effect of the induced molting with low-protein and energy diet on the postmolt performance of layers. Eighty White Leghorn layers (61-old-wk) with over 80% egg production were used for 12 weeks in this work. Treatments were non-molt control (CO), fasting treatment for 10 days (FW), molt treatment with low-protein and low-energy molting diet for 3 weeks (LO), and molt treatment with standard molting diet for 3 weeks (ST) as 4 treatments (2 replications/treatment and 10 birds/replication). Body weight (BW) loss was 26.5% of initial BW at 2 week in FW treatment, and was 17.3% and 14.2% in both LO and ST treatments (P<0.05). Layers in molting treatments were fed with commercial layer diet after completion of molting since BW of layers was recovered for 7 weeks. Heart weight ratio was shown as 0.47, 0.43, 0.46 and 0.46% at CO, FW, LO and ST treatments, respectively, and liver weight ration of body weight was shown as 2.56, 1.30, 1.47 and 1.52%, respectively. Thus, those of molting treatments decreased compared to non-molt control (P<0.05). Oviduct weight ratio were shown as 3.95, 1.17, 1.54 and 1.67%, respectively, and similar with the results of liver (P<0.05). Feed intake decreased at LO and ST treatments during molting period and increased from the 5th week compared to control. Egg production decreased at 1 week in molt treatment and stopped at 2 week in FW, 3 week in LO, and 4 week in ST treatments. The birds started to lay egg at 4 week in FW and at 5 week in LO and ST treatments. Egg production was recovered until 50% at 6 week in FW and was recovered as 66.1 and 71.6% at 8 week in LO and ST treatment, respectively. Egg weights were similar among all treatments. Eggshell thicknesses were 0.41, 0.47, 0.46 and 0.46 mm at CO, FW, LO and ST treatment, respectively, but the higher in molt treatments than control (P<0.05). Eggshell breaking strength was 3.83 and 3.81 kg/$cm^2$ in FW and LO treatment, respectively, and high compared to control. However, eggshell breaking strengths were 3.54 and 3.78 kg/$cm^2$ and were not statistically different. Haugh units were 75.6, 81.1, 80.6 and 79.9 in 4 treatments and high in molt treatment. Finally, dietary low-protein and low-energy may induce molt as few effect on performance of layers.

• Korean Journal of Poultry Science
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• v.15 no.3
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• pp.211-218
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• 1988

Data on egg number from time of first lay to 71 week of age were obtained from samples of single comb white leghorn breeder and brown layer breeder populations which were raised at manny breeding Co. These data were used to estimate the heritabilities of age at sexual maturity, early egg number, residual egg number and annual egg number. Also, the genetic correlation coefficients between these traits were estimated and selection efficiencies of each segment in early part record were estimated by use of the heritabilities and generic correlations. The estimated heritabilities and standard errors in two lines(W and B) were $0.30\pm0.07$ and $0.33\pm0.08$ at early records, $0.19\pm0.06$ and $0.18\pm$0.05 at residual records and $0.37\pm0.09$ and $0.49\pm0.10$ at time of first lay. Those at annual records were $0.24\pm0.06$ equally. The estimated correlation coefficients and standard errors between early record and annual record were $0.76\pm0.08$ and $0.77\pm0.07$. Those between early record and residual record were $0.46\pm0.15$ and $0.39\pm0.16$ respectively. At improving annual egg production per year, selection based on early part record(SM to 40 week of age) would be 69% more efficient than on annual record in line W and 80% more efficient than on annual record in line B. But, if it were considered that egg weight decreased due to sexual maturity and cost for data collection, use of selected segment from 35~40week of age in line W and from 31~40 week of age in line B would be desired in spite of a. small loss in relative selection efficiency. The generation interval would not be shortened.

• Korean Journal of Poultry Science
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• v.17 no.3
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• pp.167-177
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• 1990

In order to investigate an effect of the feed restriction on the laying performance, 208 White Leghorn strain layer of 36 week-old were divided to 4 groups of 52 birds each and raised for 1 week of previous feeding and for the subsequent 3 weeks of experimental restricted feeding. The egg production, daily egg mass and feed efficiency of four groups of birds fed daily 100g, 95g, 90f and 85g of a commercial diet, respectively, which were compared with those of the original 2879 birds fed l13g of diet per day as control. During 3 weeks of experimental restricted feeding, period, daily body weight nam was decreased linearly as the degree of restriction increased in birds fed 100, 95, 90 and 85g of diet. Hen day egg production, egg weight and daily egg mass was linearly related to the diet intake level. then feed intake(x, g day$^{-1}$ ) showed a positive regression equations with the henday egg production(y, % ), egg weight(y, g egg$^{-1}$ ) and egg mass(y, g bird$^{-1}$ ) as y＝38.75＋0.3753$\times$(r＝0.503, n＝15), y＝48.2＋0.08868$\times$(r＝0.835, n＝ 15) and y＝15.69＋0.2786$\times$(r＝0.597, n＝15), respectively. Feed efficiency was increased to a plateau in birds fed 95g of diet. The estimated energy utilization for egg production was reached to a plateau in birds fed 95g of diet and the highst protein utilization was shown in birds fed 90g of diet anions birds fed graded levels of diet. And the feed restriction did not affect on the egg shell contents, while protein contents of egg were shown a trend to be increased and lipids and cholesterol contents of eggs was decreased according to the diet intake lowered. The results suggested that the improved feed efficiencies of birds restricted under 16% of diet(above 95g of diet) will be due to increased energy and protein utilization for egg production and feed restriction above 16% will be aboided. In the range from 113g to 95g of diet feeding, the crude profit was increased as the feed restricted in the case of egg price 600 won kg$^{-1}$ and feed price 200 won kg$^{-1}$ .

• Korean Journal of Poultry Science
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• v.47 no.2
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• pp.95-105
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• 2020

This study presents the production characteristics and physiological characteristics of five Korean native chicken (KNC) breeds consisting of Hwanggalsaek Jaeraejong (HJ), Korean Rhode Island Red (KR), Korean White Leghorn (KL), Korean Brown Cornish (KC), and Korean Ogye (KO). We investigated their production performances, vitalities, and stress responses. We measured the survival rate, body weight, age at first egg-laying, hen-day egg production, egg weight, amount of telomeric DNA, heterophil-lymphocyte ratio (H/L ratio), and heat shock protein (HSP)-70, HSP-90α and HSP-90β gene expression levels for 493 KNCs. The survival rate was highest in KR, and lowest in KO. Body weights were steadily high in the order of KC, KR, HJ, KO and KL. Average hen-day egg production was highest in KL, and lowest in KC. While the amount of telomeric DNA was highest in KR, and lowest in KC. Furthermore, both the H/L ratio and the HSP-90β gene expression level were highest in KC, and lowest in KR. These results indicated that the KR breed was highly resistant to stress, whereas KC was more susceptible to stress. Taken together, it is considered that with improvements the KC breed would be more suited to be used as a Korean broiler breed while KL would be more appropriately used as a Korean layer breed. In addition, it is considered that the KR breed is appropriate to be used as a maternal chicken breeder based on good production capacity and excellent robustness, while the HJ breed is desirable to be improved as a high-quality Korean meat breed based on its excellent meat quality.

• Korean Journal of Poultry Science
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• v.13 no.1
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• pp.1-14
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• 1986

The subject of this study was to obtain some genetic information for developing superior layer chickens. Heterosis and combining ability effects were estimated with 5,759 progenies of full diallel crosses of 6 strains in White Leghorn. Fertility, hatchability, brooder-house viability, rearing- house viability, laying-house viability, age at 1st egg laying, body weight at 1st egg laying, average egg weight, hen-day egg production, hen-housed egg production, and feed conversion were investigated and analyzed into heterosis effect, general combining ability, specific combining ability and reciprocal effect by Grilling's model I. The results obtained were summarized as follows; 1. The general performance of each traits was 94.76% in fertility, 74.05% in hatchability, 97.47% in brooder-house viability, 99.72% in rearing-house viability, 93.81% in laying-house viability, 150 day in the age at 1st egg laying, 1,505g in the body weight at 1st egg laying, 60.08g in average egg weight, 77.11% in hen-day egg production, 269.8 eggs in hen-housed egg Production, and 2.44 in feed conversion. 2. The heterosis effects were estimated to -0.66%, 9.58%, 0.26%, 1.83%, -3.87%, 3.63%, 0.96%, 4.23%, 6.4%, and -0.8%, in fertility, hatchability, brooder-house viability, laying-house viability, the age at 1st egg laying, the body weight at 1st egg laying, average egg weight, hen-day egg Production, hen-housed egg production and feed conversion, respectively. 3. The results obtained from analysis of combining ability were as follows ; 1) Estimates of general combining ability, specific combining ability and reciprocal effects were not high in fertility. It was considered that fertility was mainly affected by environmental factors. In the hatchability, the general combining ability was more important than specific combining ability and reciprocal effects, and the superior strains were K and V which the additive genetic effects were very high. 2) In the brooder-house viability and laying-house viability, specific combining ability and reciprocal effects appeared to be important and the combinations of K${\times}$A and A${\times}$K were very superior. 3) In the feed conversion and average egg weight, general combining ability was more important compared with specific combining ability and reciprocal effects. On the basis of combining ability the superior strains were F, K and B in feed conversion, F and B in the average egg weight. 4) General combining ability, specific combining ability and reciprocal effects were important in the age at 1st egg laying and the combination of V ${\times}$F, F${\times}$K and B${\times}$F were very useful on the basis of these effects. In the body weight at 1st egg laying, general combining ability was more important than specific combining ability and reciprocal effects, relatively. The K, F and E strains were recommended to develop the light strain in the body weight at 1st egg laying. 5) General combining ability, specific combining ability and reciprocal effects were important in the hen-day egg production and hen-housed egg production. The combinations of F${\times}$K, A${\times}$K, and K${\times}$A were proper for developing these traits. 4. In general, high general combining ability effects were estimated for hatchability, body weight at 1st egg laying, average egg weight, hen-day egg production, hen-housed egg production, and feed conversion and high specific combining ability effects for brooder-house viability, laying house viability, age at 1st egg laying, hen-day egg production and hen-housed egg production, and high reciprocal effects for the age at 1st egg laying.