• Korean Journal of Poultry Science
• /
• v.35 no.1
• /
• pp.63-69
• /
• 2008

The objective of this study was to investigate the effect of restricted feeding to laying performance and egg quality in brown layers. A total of 1,080 brown layer chicks were divided into three treatments; conventional feeding (ad libitum) and two restricted feedings (80% of conventional diet) for 70 weeks. One of restricted feeding started from six to eighteen weeks of age, and the other started from twelve to eighteen weeks of age. Diets were formulated by NRC (1994) recommendation. Overall laying performance and feed intake were the highest in $6{\sim}18 wk$ restricted group. But there was no significant difference among treatment group (P>0.05). Feed intake was higher in $6{\sim}18 wk$ restricted group during maximum production (P<0.05), but there was no difference between treatments after the peak. Egg quality tended to decreased by aging, but there was no significant difference among the treatments (P>0.05). The result of present study indicated that restricted feeding in rearing period of layers is beneficial to improve egg productivity and to reduce feed cost.

• Korean Journal of Poultry Science
• /
• v.30 no.4
• /
• pp.229-233
• /
• 2003

A study was conducted to investigate the effects of different BW control methods during rearing on laying performance of broiler breeder pullets. D-old 540 female breeder chicks (Arbor Acres) were assigned to three treatments consisted of standard BW (Control), 110% of standard BW at 12 wk of age (T1), and 90% of standard BW at 12 wk of age (T2), with three replicates of 60 birds per replicate (pen) for each treatment. At 20 wk of age, all birds from three treatments reached the BW reqired in the Arbor Acres Manual. There were no significant differences in egg production, egg weight and viability during laying period(p>0.05). However, total egg production rates were improved in T2 and T3. Average egg weight was the highest in T1 among all treatments. Fertility and hatchability were similar among treatments, but T2 tended to be higher than other treatments at 37 and 53 wk of age. No significant difference was found in hatchability among three treatments. The number of hatching egg of T2 reached 168 per year, showing higher number of eggs than did the other treatments. The number of hatched chicks in T2 was 131, which was also higher than the other treatments, but the difference was not significant. It appears that the laying performance of broiler breeder hens could be improved when their BW at 12 wk of age are kept at 90% of standard BW, and reach the standard BW at 20 week of age.

• Korean Journal of Poultry Science
• /
• v.37 no.1
• /
• pp.63-68
• /
• 2010

This experiment was conducted to investigate the effects of dietary supplementation of fermented apple pomace (FAP) and cinnamon on laying performance, egg quality and blood characteristics in laying hens. A total of two hundred 57-wk-old Hy-Line laying hens were divided into five groups with 4 replicates of 10 birds each; control, 0.1% probiotics, 1.0% fermented apple pomace 1.0%, 0.1% cinnamon and 1.0% fermented apple pomace with 1.0% cinnamon. Chickens fed the diets containing 1.0% of fermented apple pomace showed higher egg production than the chickens fed the other diets. No synergic effect on laying performance was found when fermented apple pomace and cinnamon were added to the diets in laying hens. There was no significant major differences in egg quality and serum blood biochemical profiles. These results suggest the possibility that fermentation of apple pomace could be used as the alternative of antibiotic growth promoters.

• Preventive Nutrition and Food Science
• /
• v.8 no.3
• /
• pp.294-300
• /
• 2003

The chicken egg provides a perfectly packaged, portion controlled, highly nutritious food containing vital nutrients essential for maintaining human health. However, concern by health professionals over the possible association of diets high in fat and cholesterol to chronic diseases has led to a decrease in egg consumption. Several different strategies have been adopted by the poultry food industry to enhance the nutritional value of eggs. The major emphasis has been focused on the modification of polyunsaturated fatty acid composition and fat soluble vitamins. This review briefly describes the composition, lipid nutrient content and the positive health effects of egg lipid nutrients.

• Proceedings of the KSAR Conference
• /
• 2002.06a
• /
• pp.17-17
• /
• 2002

There are considerable reports that the expression of insulin-like growth factor-Ⅰ (IGF-Ⅰ) is related to ovarian regulation and oviductal development in poultry. Korean Native Ogol Chicken (KNOC) have been inbred to keep a pure line so that there has been limitation in the improvement of egg productivity by genetic studies. Therefore, this study was conducted to investigate the early egg productivity of KNOC pre-selected by IGF-Ⅰ expression. (omitted)

• Korean Journal of Poultry Science
• /
• v.45 no.2
• /
• pp.119-124
• /
• 2018

This study was conducted to assess the effect of dietary addition of Germanium (Ge) on performance, egg quality, serum biochemical properties and yolk fatty acid composition in laying hens. At 74 weeks of age, a total of 360 Hy-line brown commercial layers were divided into four treatments with five replicates per treatment. Four dietary levels of Ge (0, 1, 2 and 4%) were added to the basal diets (ME: 2,750 kcal/kg, CP: 16%) and fed corresponding diet for a period of 12 weeks. The effects of these treatments on production performance and egg quality were measured three times at four week intervals, and at the end of the experiment, blood and egg yolk fatty acid were analyzed. The results showed that production performance parameters including egg production rate, feed intake, egg weight, egg mass and feed conversion ratio were non-significant, but dietary addition of 2% Ge tended to increase egg production rate. Eggshell strength was found to be significantly higher in Ge supplemented groups than in the control group (P<0.05), and eggshell thickness was also trended to be improved in Ge treated groups. In serum, triglyceride content was significantly greater (P<0.05), and the highest total cholesterol was found in hens of the control group as compared with that of the Ge supplemented groups. The yolk fatty acid composition including polyunsaturated fatty acid, unsaturated fatty acid and saturated fatty acid were not affected among the treatments but addition of 2 or 4% Ge in basal diet had significantly (P<0.05) increased monounsaturated fatty acid. Therefore, supplementation of Ge in laying hens diet has positive effects on egg quality and triglyceride in serum.

• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.8
• /
• pp.1217-1223
• /
• 2020

Objective: Eggshells with a uniform color and intensity are important for egg production because many consumers assess the quality of an egg according to the shell color. In the present study, we evaluated the influence of dominant effects on the variations in eggshell color after 32 weeks in a crossbred population. Methods: This study was conducted using 7,878 eggshell records from 2,626 hens. Heritability was estimated using a univariate animal model, which included inbreeding coefficients as a fixed effect and animal additive genetic, dominant genetic, and residuals as random effects. Genetic correlations were obtained using a bivariate animal model. The optimal diagnostic criteria identified in this study were: L^🟉 value (lightness) using a dominance model, and a^🟉 (redness), and b^🟉 (yellowness) value using an additive model. Results: The estimated heritabilities were 0.65 for shell lightness, 0.42 for redness, and 0.60 for yellowness. The dominance heritability was 0.23 for lightness. The estimated genetic correlations were 0.61 between lightness and redness, -0.84 between lightness and yellowness, and -0.39 between redness and yellowness. Conclusion: These results indicate that dominant genetic effects could help to explain the phenotypic variance in eggshell color, especially based on data from blue-shelled chickens. Considering the dominant genetic variation identified for shell color, this variation should be employed to produce blue eggs for commercial purposes using a planned mating system.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2002.11a
• /
• pp.130-132
• /
• 2002

This experiment was conducted to investigate the influence of different dietary ME and CP on post-molt performance of spent laying hens. Four hundred and thirty two, ISA brown after molt induction were fed 6 experimental diets containing 3 ME(2,750, 2,800, 2,850 kcal/kg) and 2 CP(15, 17%) levels in factorial design. The influence of ME and CP were measured on body weight, egg production, egg weight and feed intake throughout 24 weeks of production. Egg mass and FCR were calculated for the entire experimental period body weight remained less in hens receiving 2,800 kcal/kg. ME and showed the highest egg Production coupled with 15% CP. Feed intake decreased with the increasing level of ME and CP. As the results of this experiment, 2,800 kcal/kg ME can be used to maintain the low body weight and to obtain higher egg production with 15% CP in induced molting hens.

• Korean Journal of Veterinary Service
• /
• v.26 no.1
• /
• pp.51-56
• /
• 2003

Avian pneumoviros(APV), also known as avian rhinotracheitis virus(ARTV), affects both turkeys and chickens and is known to be the primary causative agent of turkey rhinotracheitis (TRT). The aim of this study was to establish the presence or absence of antibodies to avian pneumovirus in the commercial poultry population of Korea. For this purpose, chicken serum samples were obtained and tested by an enzyme-linked immunosorbent assay (ELISA). The tested serum was collected in laying hens with reduction of egg production or normal in Gyeongbuk province. A total of 184 sera representing 42 different poultry farms of the Gyeongbuk region of Korea were included in this study. Laying hens of 16 different farms with reduction of egg production and laying hens of 26 different farms with clinically healthy at the time of serum sampling were considered positive to antibody against APV. In the farms with reduction of egg production, positive farm to antibody against avian pneumovirus were 11 of 16 different farms(68.8%) and positive sera were 47(58.8%) of 80 different serum. In the farms with clinically healthy flock, positive farm to antibody against avian pneumovirus were 12(46.2%) of 26 different farms and positive serum sample were 39(37.5%) of 104 different sera. According to the results tested to 42 different farms in 14 city, 8 of 14 city have flocks with antibody positive laying hens against APV, 1 of 14 city have antibody suspicious and 5 of 14 city shown antibody negative, respectively.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2002.11a
• /
• pp.92-93
• /
• 2002

In order to study the effect of krill meal on the performance of layer, egg production, feed efficiency, and astaxanthin levels and fatty acid composition in egg yolk was investigated. During 12 weeks of experimental feeding period, dietary krill did not affected the performance of layer. The bird fed krill diet showed a decreased trend of feed consumption. Egg Yolk from birds fed the krill diet contained more astaxanthin and eicosapentaenoic acid(C20：5) and docosahexaenoic acid (C22：6). The results indicated the further research may be required on the reasons for the decreased feed intake.