• Korean Journal of Poultry Science
• /
• v.43 no.4
• /
• pp.253-261
• /
• 2016

Egg quality is a very important factor for both consumers and producers. Factors affecting egg quality include strain and age of hens; egg storage temperature, time, and humidity; laying season; and feeding. This study aimed to determine the effect of hen age and egg storage time on egg quality. A total of 700 eggs obtained from Hyline Brown commercial layers were used for this experiment, and they were separated into two hen age groups (30 vs. 60 weeks) with eight treatments and four storage times (day 0, 10, 20, and 30). The egg weight; shell color, thickness, and density; albumen height; Haugh unit (HU); yolk color; and the yolk and albumen pH and viscosity were measured for the egg quality assessment. The results showed that the age of the hen and egg storage time significantly affected almost all parameters of the internal and external egg quality. The shell thickness, albumen height, HU, yolk color, pH of yolk and albumen, and yolk viscosity significantly decreased with increasing hen age. The egg shell color was significantly lighter in eggs from 60-week-old hens than in those from 30 weeks-old hens. The egg weight; shell weight, thickness, and density; albumen height, HU; and albumen viscosity significantly decreased, but the yolk color and pH of the yolk and albumen increased with increasing egg storage time. The interaction effects between the storage time and hen age were significant in shell thickness, albumen height, yolk color, and yolk and albumen pH and viscosity. The eggs obtained from 60-week-old hens showed significantly lower shell thickness, albumen height, and HU values, which are considered typical egg quality measurements, than values of eggs from 30-week-old hens. Therefore, increasing hen age and egg storage time caused the deterioration of egg quality. In conclusion, this study demonstrated that hen age is the major factor affecting the quality of fresh eggs, whereas the storage time is the determinant factor affecting the quality of stored eggs.

• Asian-Australasian Journal of Animal Sciences
• /
• v.2 no.2
• /
• pp.67-75
• /
• 1989

Studies were conducted to compare the utilization of dietary calcium between brown laying Tsaiya duck and Leghorn hen. Birds were fed corn-soybean diets containing 1.0, 2.0, 3.0, 4.0 and 5.0% calcium, respectively, with five birds per treatment. The metabolizability of calcium was determined by the indicator method. Experiments were conducted three times each at the age of 27, 31 and 36 weeks. Results appeared that duck eggs were heavier with better shell quality in comparison with hen eggs. Ducks fed 1% calcium diet resulted in severely depressed egg production (19%), but not for hens which still had 56% egg production. The metabolizability of calcium for hens was significantly higher than that for ducks (P<0.05) when both were fed diets containing 1 or 2% calcium. As the dietary calcium level was increased to 3 to 5%, there was no significant difference in calcium metabolizability between ducks and hens. When the dietary calcium was between 2 to 5%, the ducks retained more calcium than did the hens. Plasma calcium content for both hens and ducks fed 1% calcium diet was about the same. When the amount of the dietary calcium was increased to 2-5%, the plasma calcium level of ducks was approximately 7-10 mg/dl higher than that of hens. The calcium content in the egg shell of duck was significantly higher than that of hens, too. As the dietary calcium level was increased, there was a decreased magnesium content in the eggshell of hens, but not for ducks. The magnesium level in the eggshell was higher in hens than that in ducks. It is concluded that ducks could retain significantly more calcium and maintain higher plasma calcium level which might be the reason for larger eggs with better shell quality by ducks.

• Asian-Australasian Journal of Animal Sciences
• /
• v.3 no.2
• /
• pp.121-123
• /
• 1990

A CRD experiment with unequal numbers of hens were assigned at random to three treatment groups, 1) separation of chicks from hen at 21 days after hatching 2) separation of chicks from hen at 7 days and 3) hens were allowed to brood the chicks(no separation) up to 10 weeks of age, to determine the productive and reproductive performance of hens and their chicks. The mean cycle length (one hatch to another) was 72.8 days for the 7-day group as compared with 87.7 days and 83.4 days for the 21-day and the no separation groups, respectively (p<.0l). The broody period was 28.5 days for the 7-day group compared with 43.9 and 42.6 days for the 21 days and the no separation groups, respectively (p<.0l). The end of the broody period to the start of lay varied from 8.0 to 8.7 days. The number of eggs laid per clutch were 12.3 for the 21-day group, compared with 11.5 and 10.1 for the 7-day and no separation groups, respectively (p<.05). This is due to the longer (p<.05) clutch length of the 21-day group as compared with the 7-day and no separation groups, respectively. The chicks separated from the hens at 21 and 7 days were heavier (p<.01) than the chicks not separated from the hens. Mortalities were highest (p<.05) for chicks separated at 7 days as compared with chicks separated at 21 days and those not separated. We concluded that separating chicks at 7 days from the hen gave the shortest cycle length and broody period, separating the chicks at 21 days gave the longest clutch length and the maximum number of eggs, separating the chicks at 21 and 7 days resulted in heavier chicks and separating the chicks at 7 days resulted in the highest mortality.

• Korean Journal of Veterinary Service
• /
• v.29 no.1
• /
• pp.65-70
• /
• 2006

In order to detection of the intestinal parasites, fecal samples were taken from broiler (n=290), parent stock (n=168) and laying hen (n=114) in Jeonbuk province. The prevalence and identification of intestinal parasites were determined by the fecal examination using the floatation method and microscopical examination, respectively. The detection rate of parasite-eggs from 3 flocks (total=572) was 44.9%. In the breed and type of breeding, infection rate of parasite-eggs was detected 65.5% as broiler (floor breeding, 290 chickens), 20.2% as parent stock (floor breeding, 168 chickens) and 28.9% as laying hen (cage breeding, 114 chickens), in order. In the concern of mixed infection such as single and double, the rate were 40.7% and 4.2%, respectively. Six kinds of infective eggs were isolated 257 fecal sample from 3 flock. They were classified 74.7% as Eimeria spp, 18.1% as Ascaridia galli and 6.0% as Capillaria spp and 0.4% as Heteratkis gallinarum, Railleina spp or Trichostrongylus spp, single or in combination.

• Korean Journal of Veterinary Service
• /
• v.16 no.1
• /
• pp.82-89
• /
• 1993

In order to detection of the intestinal parasites, fecal samples were taken from broiler (n=262), laying hen(n=244), parent stock(n=207) and native stock(n=287) in Chonbuk province. The prevalence and identification of intestinal parasites were determined by the fecal examination using the floatation and /or sedimentation methods and microscopical examination, respectively. The results were obtained as follows : 1. The detection rate of parasite-eggs from 4 flocks(total=1,000) was 65.7%. 2. In the breed and type of breeding, infection rate of parasite-eggs was detected 84.0％ as native stock (floor breeding, 241 chicken), 79.7％ as parent stock (floor breeding, 165 chickens), 73.3% as broiler(floor breeding, 192 chicken) and 24.2% as laying hen(cage breeding, 59 chicken), in order. 3. In the concern of mixed infection such as single, double and triple, the rate was 55.1%, 8.7% and 1.9%, respectively. 4. Ten kinds of infective eggs were isolated from 657 fecal sample of 4 flock. They were classified 51.l% as Eimeria spp., 12.7% as Ascaridia galli, 5.1% as Capillaria spp., 4.1% as Strongyloides avium, 2.3% as Heterakis gallinarum, 0.5% as Hymenolepis spp., 0.3% as Railleina spp. and 0.2% as Syngamus spp., Trichostrongilus spp., or Choanoteania spp., single or in combination.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.29 no.6
• /
• pp.1030-1034
• /
• 2000

The ovalbumin, a most sensitive egg white protein to irradiation was purified from irradiated hen's eggs. Eggs were irradiated in their shells to 0~7 kGy. To investigate for a practical use in identifying of irradiated eggs, competitive ELISA using ovalbumin was peformed. The binding activity of ovalbumin to anti-ovalbumin IgG was reduced in a dose-dependent manner by irradiating up to 7 kGy, and consider-ably lowered after irradiating at 7 kGy. The concentration of 50% inhibition of ovalbumin to IgG was increased to 1.5~3.7 times in an irradiation dose-dependent relationship. SDS-PAGE of ovalbumin showed that the partial breakdown of ovalbumin was induced by irradiation. The lowering of binding activity was probably due to the partial breakdown of ovalbumin by irradiation. These results demonstrated that the ELISA should be quite useful and effective methods for the identification of irradiated eggs.

• Korean Journal of Poultry Science
• /
• v.14 no.2
• /
• pp.113-123
• /
• 1987

This study was carried out to investigate the effects of age of hen and oviposition time on egg weight, egg shell quality and e88 shape index in White Leghorn laying hens. The data were collected from 150 laying hens for about 4 months from September 1, 1986 to January 6, 1987. The results obtained from this study were summarized as follows; The percentage of the eggs produced before noon was decreased and that of the eggs produced after noon was increased as the hen gets older. Egg weight was increased rapidly to 270 days of age but after 270 days of age the rate of egg weight increase was slowly downed. The egg shell thickness became thinner and egg shell breaking strength was reduced and egg shape index was increased as the hen gets older. The egg weight was decreased as the oviposition time was proceeded and the regression coefficients of egg weight on oviposition time were -0.6788--0.4170, which means that the egg weight was decreased 0.4170-0.6788g per one hour delay of oviposition time. Egg shell thickness was increased 0. 0.00377-0.00643mm and egg shell breaking strength improved 0.0287-0.034kg/$\textrm{cm}^2$ per one hour delay of oviposition time. But it seems that there was no relationship between the oviposition time and the egg shape index.

• Animal Bioscience
• /
• v.35 no.9
• /
• pp.1408-1417
• /
• 2022

Objective: The objective of this study was to determine whether dietary black soldier fly (Hermetia illucens, HI) larvae oil (HILO) could serve as an alternative fat source to soybean oil (SBO) in laying hen diets. Methods: We randomly assigned 25-week-old Hy-line Brown laying hens (n = 144) to receive (n = 6 hens/group; eight replicates) a control or an experimental diet in which SBO was replaced with 50% (50HILO) or 100% HILO (100HILO). Results: Dietary HILO did not negatively affect body weight or productive performance during the study. The eggs also had similar quality parameters, proximate composition, and cholesterol levels. However, the yolk color index was significantly higher (p<0.01) in the 100HILO than in the other groups. Dietary HILO significantly altered the composition of fatty acids (FAs) in abdominal fat and eggs. Total saturated fatty acids (SFAs) and total polyunsaturated FAs (PUFAs) were significantly increased and decreased in the 50HILO and 100HILO groups, respectively, compared with those in the control group (p<0.001 and p<0.0001, respectively). Specifically, the medium-chain FAs lauric and myristic acids were remarkably increased in the abdominal fat of laying hens fed HILO (p<0.0001), whereas only myristic acid increased in eggs (p<0.0001). Undesirable heavy metal (aluminum, fluorine, arsenic, lead, mercury, and cadmium) concentrations were below permissible limits in eggs. Conclusion: We considered that HILO could be an alternative dietary fat to SBO for laying hens with maintained productive performance and good egg quality.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.14 no.2
• /
• pp.91-100
• /
• 2006

Effects of the supplement of earthworm cast produced from the feeding of organic wastes and earthworm on the productivity and nutritional constituents of functional eggs were investigated. Compared with control experiments, the case supplemented with earthworm cast showed high ratios in egg production, selection and the reserved feed. According to the experiment with earthworm, both the number of jumbo eggs and the quantity of reserved feed were increased. Therefore, the nutritional effect of earthworm in the feed was positive. The optimum percentage of earthworm cast in the feed was 10%: the average laying increased to 96.8, which was a 5% increase; the ratio of the large eggs increased by 5% although the ratio of jumbo eggs and of extra large eggs decreased by 5% and 1.1%, respectively; the average reserved feed was 662.5g. Also, Beauveria bassiana was inoculated into the feed as valuable microorganisms to prevent the growth of pathogen and to obtain essential amino acid. With the inoculatio of B. bassiana KACC 40039, the average laying was 0.82/hen and with B. bassiana HYB, it was 0.77/hen. Those numbers were three to eight percentage over the control. As for the effect of inoculation of B. bassiana in the feed on the production of broken eggs, B. bassiana KACC 40039 produced no broken eggs. Analysis of nutritional contents of eggs showed the increase in protein content and decrease in lipid content when compared with the control. According to these results, increase in the income of farmers can be expected.

• Korean Journal of Poultry Science
• /
• v.26 no.4
• /
• pp.247-252
• /
• 1999

This experiment was carried out to investigate the effects of the laying hens on the immune response against bovine serum albumin(BSA) in egg yolk. Total 45 laying hens were divided into three groups according to breeds (White Leghorn, ISA Brown, Native hen). They were fed the experimental diet for 12 weeks. Immune response were examind in egg yolk from three groups of hens injected with BSA. The results obtained from this work were summaried as follows : 1. The weight of egg yolk and the percentage of hen-day production in the ISA Brown hens are greater than those in the Native hens and the White Leghons. 2. IgY concentrations in eggs from hens immunized with BSA were not different among the breeds laying hens. 3. The anti-BSA antibody activities determined by enzyme linked immunosorbent assay (ELISA) in the egg yolk were similar between the White-Leghorn and ISA Brown hens, but Native hens tended to decrease in 20∼50 days respectively. Therefore, the weight of egg yolk and the percentage of hen-day production in the ISA Brown hens are greater than those in the Native hens and the White Leghons will be as important factors for an efficient production of IgY.