• Korean Journal of Agricultural Science
• /
• v.34 no.1
• /
• pp.53-60
• /
• 2007

A layer feeding trial was conducted for 10 weeks to investigate the effects of the addition of corn distillers dried grains with solubles (DDGS) to layer diets on the laying performance, egg qualities, and yolk fatty acid composition. Nine hundred Hyline Brown layers, 24 weeks of age,were randomly allotted to 20 replicate laying cages, 45 birds per replicate. There were four diet treatments (0, 10, 15, and 20% DDGS), and five replicates per treatment. All experimental diets were prepared to contain iso-protein (17%) and iso-calorie (TMEn 2,780 kcal/kg). The use of DDGS up to 20% level in layer diets did not exert any influence on feed intake, laying rate, total egg mass, mean egg weight, and feed conversion ratio. DDGS did not exert any influence in weight of egg, breaking strength, and color of eggshell. The albumen height and Haugh unit was not influenced by DDGS addition. The yolk color was significantly increased by DDGS supplementation. As the DDGS level increased, the oleic acid content decreased, and the linoleic acid increased (P<0.05). The degree of saturation of yolk fatty acids was not affected by dietary DDGS. The inclusion of DDGS up to 20% in layer diets resulted in the decrease of feed cost per kg without any effect in the laying performance. In conclusion, the use of DDGS up to 20% level in layer diets could replace corn and soybean meal without any harmful effect on the laying performances.

• Asian-Australasian Journal of Animal Sciences
• /
• v.30 no.2
• /
• pp.206-210
• /
• 2017

Objective: A study was conducted to test six threonine (Thr) levels (0.39%, 0.44%, 0.49%, 0.54%, 0.59%, and 0.64%) to estimate the optimal dietary Thr requirements for Longyan laying ducks from 17 to 45 wk of age. Methods: Nine hundred Longyan ducks aged 17 wk were assigned randomly to the six dietary treatments, where each treatment comprised six replicate pens with 25 ducks per pen. Results: Increasing the Thr level enhanced egg production, egg weight, egg mass, and the feed conversion ratio (FCR) (linearly or quadratically; p<0.05). The Haugh unit score, yolk color, albumen height, and the weight, percentage, thickness, and breaking strength of the eggshell did not response to increases in the Thr levels, but the albumen weight and its proportion increased significantly (p<0.05), whereas the yolk weight and its proportion decreased significantly as the Thr levels increased. Conclusion: According to a regression model, the optimal Thr requirement for egg production, egg mass, and FCR in Longyan ducks is 0.57%, while 0.58% is the optimal level for egg weight from 17 to 45 wk of age.

• Korean Journal of Poultry Science
• /
• v.35 no.2
• /
• pp.171-176
• /
• 2008

Animal welfare advocates, claim that the induced molting by fasting be avoided. This study was conducted to evaluate the effect of molting induced by various feeding methods on productivity and egg quality in laying hens. We used 400 flocks of 60-week-old leghorn laying hens in four treatments(five replicates of 20 hens each): fasting method (C), feeding single corn grain diet (T1), feeding single wheat bran diet (T2) and feeding single alfalfa meal diet (T3). As the result of the experiment, egg production and daily egg mass significantly decreased only in T1 compared with the control during the $1{\sim}4th$ week after the secondary egg laying (P<0.05). Although the amount of feed intake was significantly less in T1 group during the $1{\sim}4th$ week compared to the control, no significant difference was detected during the total period (P>0.05). In addition, no significant difference of feed conversion was observed between treatment groups. In terms of egg quality, the egg shell thickness was significantly improved in T1 group than the control group by feeding only corn at the 10th and 14th week after the secondary egg laying (P<0.05), but the significant decrease was observed at the corn (T1) and wheat bran (T2) fed treatment groups than the control group at the 26th week of the experiment (P<0.05). The eggshell strength and haugh unit did not show any difference by the molting methods. Egg yolk color was significantly decreased in T1 and T2 group than the control group at the 6th week (P<0.05). However, T1 and T2 group resulted to show significantly high egg yolk color at the 18th week of the experiment (P<0.05). As the result of the experiment, no large difference was observed in the productivity by the feeding molting method and by the fasting induced molting method. In addition, the single diet fed feeding induced molting method by using alfalfa revealed to show more satisfactory trend than the corn or wheat bran single diet fed feeding induced molting methods even if no statistically significant difference was found in terms of egg productivity.

• Korean Journal of Poultry Science
• /
• v.25 no.3
• /
• pp.119-128
• /
• 1998

On account of the recent improvement in performance of brown layers, the market share taken by brown layers has increased to about 50% in the world and to almost 100% in Korea. There are several other reasons why the industry has moved from white to brown, such as : brown layers are used to be more robust, more docile and easier to manage ; e brown layers are easier to sex at the hatchery ; brown layers lay less second grade eggs, due to a better shell Quality ; brown eggs seem to be more attractive than white ; and a clear consumer preference, thus a better price per egg. More recently, however, the trend towards brown eggs has been slowing down. The main reasons for this lie in that white layers can still produce an egg at a lower cost and that white eggs have better de-shelling properties, easier candling and higher yolk and solid content of the liquid egg which are benefits for egg processing industry. Although the performance of the brown layers is still improving, there are increasing opinions in the poultry industry that the market portion of white layers should be increased based on the following reasons, such as : shell color has no effect on the nutritive value of eggs ; . brown layers consume more feed ; the percentage of meat spots is significantly higher in brown eggs than in white eggs ; . brown layers are less efficient in the second cycle of production than in the first ; white layers are more resistant to the disease of fowl typhoid. In order to increase the market share of white layers in Korea, it may be needed to enlighten the consumers not to prefer the brown and large eggs and to inform the excellencies of white eggs widely.

• Food Science of Animal Resources
• /
• v.38 no.3
• /
• pp.487-497
• /
• 2018

Controlling of microorganisms in the industrial process is important for production and distribution of hatching and table eggs. In the previous study, we reported that chlorine dioxide ($ClO_2$) gas of a proper concentration and humidity can significantly reduce the load of Salmonella spp. on eggshells. In this study, we compared microbial reduction efficacy on egg's surface using hatching eggs and table eggs, internal quality of table eggs, and hatchability after both the conventional method (washing and UV expose, fumigation with formalin) and $ClO_2$ gas disinfection. Application of 40 ppm $ClO_2$ gas to the table and hatching eggs, respectively, reduced the aerobic plate count (APC) with no statistical difference compared with the conventional methods. Additionally, we didn't observed that any significant difference in albumin height, Haugh unit (HU), and yolk color, this result confirms that 40 ppm $ClO_2$ had no effect on the internal quality of the table eggs, when comparing with the UV treatment method. The hatchability of hatching eggs was not statistical different between formaldehyde fumigation and 80 ppm $ClO_2$ gas treatment, though the value was decreased at high concentration of 160 ppm $ClO_2$ gas. From these results, we recommend that $ClO_2$ gas can be used as a safe disinfectant to effectively control egg surface microorganisms without affecting egg quality.

• Korean Journal of Poultry Science
• /
• v.32 no.1
• /
• pp.9-14
• /
• 2005

This study was conducted to investigate the effects of Bacillus subtilis on the egg qualify, blood characteristics and fecal $NH_3-N$ in laying hens. A total of two hundred fifty two laying hens were randomly allocated into three treatments with seven replications for six weeks. Dietary treatments included 1) CON (control; basal diet), 2) BS0.2(control + $0.2\%$ Bacillus subtilis) and 3) BS0.4 (control +$0.4\%$ Bacillus subtilis). For overall Period, hen-day egg production tended to increase by the Bacillus subtilis $0.4\%$ in the diets, but was no significant difference. Egg weight, egg shell breaking strength, egg shell thickness, Haugh Unit, yolk color unit and egg yolk index were not affected by treatments. Difference of egg weight and egg shell breaking strength in the BS0.2 treatment tended to increase without significant difference. Difference of egg yolk index in laying hens fed Bacillus subtilis was increased (P<0.05). The concentrations of red blood cell (RBC) and white blood cell (WBC) were not significant difference. $NH_3-N$ concentration in feces with BS0.4 treatment was significantly (P<0.05) lower than control. In conclusion, dietary Bacillus subtilis could decrease fecal $NH_3-N$.

• Development and Reproduction
• /
• v.20 no.2
• /
• pp.109-118
• /
• 2016

This study monitored the morphological development of embryo, larvae and juvenile yellowtail kingfish, Seriola lalandi, for their aquaculture. The fertilized eggs obtained by natural spawning were spherical shape and buoyant. Fertilized eggs were transparent and had one oil globule in the yolk, with an egg diameter of $1.35{\pm}0.04mm$ and an oil globule diameter of $0.32{\pm}0.02mm$. The fertilized eggs hatched 67-75 h after fertilization in water at $20{\pm}0.5^{\circ}C$. The total length (TL) of the hatched larvae was $3.62{\pm}0.16mm$. During hatching, the larvae, with their mouth and anus not yet opened. The yolk was completely absorbed 3 days after hatching (DAH), while the TL of post-larvae was $4.72{\pm}0.07mm$. At 40 DAH, the juveniles had grown to $30.44{\pm}4.07mm$ in TL, body depth increased, the body color changed to a black, yellow, and light gray-blue color, and 3-4 vertical stripes appeared. At 45 DAH, the juveniles were $38.67{\pm}5.65mm$ in TL and $10.10{\pm}0.94mm$ in body depth. The fish were green with a light orange color, with 7 faint green-brown stripes on the sides of their body. At 87 DAH, the juveniles had grown to 236.11 mm in TL, 217.68 mm in fork length, and 136.5 g in weight. The fish resembled their adult form, with a light yellow-green body color, loss of the pattern on the sides of their body, and a yellow coloration at the tip of the caudal fin.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.3
• /
• pp.421-427
• /
• 2009

A mixture of three dietary medicinal herb extracts (MHE, mulberry leaf:Japanese honeysuckle:goldthread = 48.5: 48.5:3.0) was prepared as an additive of hen's feed. One hundred-eight, 28-wk-old Lohmann Brown hens were assigned randomly with three levels of MHE in the diet (0, 0.3, and 1%). Hens were fed for 6 wks and eggs were collected in the 6th week, and stored at $4^{\circ}C$ for 14 days to investigate the effect of MHE on the quality and oxidative stability of eggs. Internal quality of the egg including weight, shell color, albumen height, yolk color, shell weight, shell thickness, and Haugh units was not different among the dietary treatments. The oxidation stability of raw and cooked egg was determined by 2-thiobarbituric acid reactive substances (TBARS) value, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and 2,2'-azinobis(3-ethylbenzonthianoline-6-sulfonic acid) ($ABTS^{+}$) radical reducing ability. Results indicated that TBARS value at day 0 and $ABTS^{+}$ radical reducing ability of eggs from hens fed MHE were higher than from the control group. However, DPPH radical scavenging activity showed no difference in both raw and cooked samples. Results of the present study indicate that dietary MHE may slightly enhance the oxidative stability of eggs.

• Korean Journal of Poultry Science
• /
• v.33 no.3
• /
• pp.189-194
• /
• 2006

This study was conducted to investigate the effects of natural mineral complex supplementation on egg production and characteristic in laying hens. A total of two hundred forty laying hens were randomly allocated into four treatments with ten replications for six weeks. Dietary treatments included 1) CON (control, basal diet) 2) M0.5 (basal diet + 3% chitosan + 0.5% natural mineral complex), 3) M1.0 (basal diet + 3% chitosan + 1.0% natural mineral complek) and 4) M1.5 (basal diet + 3% chitosan + 1.5% natural mineral complex). In the egg production, the M1.5 treatment was significantly higher than other treatments(P<0.05). However, egg weight was significantly higher in M0.5 treatment than CON and M1.0 treatments(P<0.05). Egg shell breaking strength was higher in M1.5 treatment than M0.5 treatment. Egg shell thickness was the highest in M1.5 treatment compared to other treatments(P<0.05). The hens 134 M0.5 diet were improved egg yolk color compared to those fed other diets(P<0.05). The Haugh unit, CON and M1.0 treatments showed significantly different results compared to those of M1.5 treatment(P<0.05). The M1.5 treatment had higher Ca and Fe concentration in blood and higher K concentration in yolk than CON(P<0.05). In conclusion, supplementation of natural mineral complex in laying hen diets influenced on egg production, egg shell qualify and mineral concentration in blood and yolk.

• Korean Journal of Poultry Science
• /
• v.31 no.4
• /
• pp.237-244
• /
• 2004

This study was conducted to investigate the effects of dietary Animunin Powder$^{?}$ on the egg quality characteristics, blood components and nutrient digestibility in laying hens. A total of two hundred seventy laying hens were randomly allocated into three treaments with fifteen replications for eight weeks. Dietary treaments included 1) Control (CON), 2) Control + $0.1\%$ Animunin Powder$^{?}$ (AM1), 3) Control + $0.2\%$ Animunin Powder$^{?}$ (AM2). During the period of 0~4weeks, the birds fed the AM1 diet had an improved egg production compared to the birds fed the CON (P<0.05). During the period of 4~8weeks the birds fed AM1 diet showed a statistically improved egg production compared to the CON (P<0.05). However, no significant differences were founded in the egg weight. During the period of $4\~8$ weeks the hens fed the AM2 diet had improved egg yolk color compared to the hens fed CON and AM1 diets (P<0.05). In the Haugh unit for the period of $0~4$$weeks, the AM2 treatment showed significantly improved results compared to the CON (P<0.05). Average egg shell breaking showed no significant differences through the experiment period, but in the period of $4\~8$weeks the AM2 treatment tended to be improved compared to the CON and AM1 treatment (P<0.05). There was no significant differences in egg shell thickness. In the serum cholesterol, the AM1 and AM2 treatments were significantly lower than the CON (P<0.05). The concentration of RBC and WBC in the AM treatments tended to increase but there were no significant differences. For the differences of lymphocytes between the end and initiation of the experiment, the hens fed the AM1 treatment were significantly different compared to the hens fed the CON and AM2 treatment (P<0.05). During the period of the experiment, the hens fed the AM1 diet were tended to show higher DM digestibility than the hens fed the CON and AM2 diet, but it was not statistically different. In conclusion, dieatry fed of Animunin Powder$^{?}$ could improve egg production, egg yolk color, and haugh unit.