• Korean Journal of Poultry Science
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• v.33 no.3
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• pp.189-194
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• 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
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• v.32 no.4
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• pp.269-273
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• 2005

The wild ginseng culture by-products(WGCB) was added to the laying hens diets. A total of 420 Lohmann Brown laying hens were alloted to five levels of drinking water containing WGCB 0, 0.4, 0.8 1.6, $3.2\%$with seven replications and fed com-soybean meal based diets contained ME 2,800 kcal/kg, CP $16\%$. Laying Performance, egg quality, egg yolk fatty acid and cholesterol concentration were measured. Egg Production and daily e99 mass were significantly lower(p<0.05) in birds fed the WGCB $3.2\%$ compared with no WGCB group, but showed no significant effect in other treatments. Feed efficiency of birds fed $0.4\%$ WGCB showed the lowest of all treatments(p<0.05). Eggshell thickness was increased(p<0.05) by WGCB supplementation, whereas eggshell breaking strength, haugh unit and yolk color index were not affected. No significant change in yolk fatty acids and cholesterol were observed by the addition of WGCB.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.8
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• pp.1080-1088
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• 2013

Our previous results showed that kisspeptin-10 (Kp-10) injections via intraperitoneal (i.p.) once daily for three weeks notably promoted the egg laying rate in quails. In order to investigate the mechanism behind the effects of Kp-10 on enhancing the egg laying rate in birds, this study focused on the alternations of lipids synthesis in liver after Kp-10 injections. 75 female quails (22 d of age) were allocated to three groups randomly, and subjected to 0 (control, Con), 10 nmol (low dosage, L) and 100 nmol (high dosage, H) Kp-10 injections via i.p. once daily for three weeks, respectively. At d 52, quails were sacrificed and sampled for further analyses. Serum $E_2$ concentration was increased by Kp-10 injections, and reached statistical significance in H group. Serum triglyceride (TG) concentrations were increased by 46.7% in L group and 36.8% in H group, respectively, but did not reach statistical significance, and TG contents in liver were significantly elevated by Kp-10 injections in a dose-dependent manner. Serum total cholesterol (Tch) concentrations significantly decreased in H group, while in H group the hepatic Tch content was markedly increased. The level of non-esterified fatty acid (NEFA), apolipoprotein A1 and B (apoA1 and apoB) were not altered by Kp-10 injections. The genes expression of sterol regulatory element binding protein-1 (SREBP-1), fatty acid synthetase (FAS), apolipoprotein VLDL-II (apoVLDL-II), cholesterol $7{\alpha}$-hydroxylase (CYP7A1) and vitellogenin II (VTG-II) were significantly up-regulated by high but not low dosage of Kp-10 injection compared to the control group. However, the expression of SREBP-2, acetyl-CoA carboxylase ($ACC_{\alpha}$), malic enzyme (ME), stearoyl-CoA (${\Delta}9$) desaturase 1 (SCD1), apolipoprotein A1 (apoA1), fatty acid binding protein 2 (FABP2), 3-hydroxyl-3-methyl glutaryl-coenzyme A reductases (HMGCR), estrogen receptor ${\alpha}$, ${\beta}$($ER{\alpha}$ and ${\beta}$) mRNA were not affected by Kp-10 treatment. In line with hepatic mRNA abundance, hepatic SREBP1 protein content was significantly higher in H group. Although the mRNA expression was not altered, the content of $ER{\alpha}$ protein in liver was also significantly increased in H group. However, SREBP-2 protein content in liver was not changed by Kp-10 treatment. In conclusion, exogenous Kp-10 consecutive injections during juvenile stage significantly advanced the tempo of egg laying in quails, which was associated with the significant elevation in hepatic lipids synthesis and transport.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.255-263
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• 2004

Two experiments were conducted to evaluate the feeding values of sesame oil meal (SOM) and to investigate the effects of its dietary supplementation on egg production in laying hens. In experiment I, the values of true metabolizable energy (TME), nitrogen corrected true metabolizable energy (TMEn) and true amino acid availability (TAAA) were determined by force-feeding 16 ISA-Brown roosters and collecting the total excreta from the birds, The TME and TMEn of SOM were 2.30 and 1.99 kcal/g, respectively, and the average TAAA of 15 amino acids was $76.93\%$. In experiment 2, a total of ninety, 48 weeks old ISA-Brown layer were randomly divided into 9 groups of 10 birds each and assigned to three experimental diets containing 0, 5 and $10\%$ SOM for 4 weeks (30 birds per treatment). The inclusion of SOM into laying hen diets at the 5 and $10\%$ level did not affect production and quality of egg. The C18:3 $\omega$3 content of egg yolks in the $10\%$ SOM group was higher than the other groups, but not significantly. There were no adverse effects on blood parameters in layers fed treated diets containing $5\%$ or $10\%$ SOM, The results indicate that SOM can be used for layers diet up to $10\%$ without any significant negative effects on egg production and quality.

• Food Science of Animal Resources
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• v.34 no.2
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• pp.172-177
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• 2014

Two experiments were conducted to investigate the dietary effects of conventional or lutein fortified chlorella on lutein absorptions, the tissue distributions and the changes in lutein content of eggs in laying hens. In Exp 1, a total of one hundred and fifty, 70 wk-old Hy-Line brown layers were divided into three groups with five replicates and fed with each experiment diet (control diet, diet with 1% conventional chlorella or lutein fortified chlorella) for 2 wk, respectively. The egg production in groups fed diets containing both chlorella powders were higher than that of the control group (p<0.01). With chlorella supplementations, the yolk color significantly increased, although there were no significant differences in the eggshell qualities. The lutein contents of serum, liver and growing oocytes were greatly increased by feeding conventional or lutein fortified chlorella (p<0.01). In Exp. 2, a total of ninety 60 wk-old Hy-Line brown layers were assigned into three groups with three replicates per group (10 birds per replicate). The birds were fed with one of three experimental diets (0, 0.1 or 0.2% lutein fortified chlorella) for 2 wk, respectively. The egg production was not affected by dietary treatments. The egg weight in the group fed with diet containing 0.2% of lutein fortified chlorella was higher than that of the control (p<0.05). As the dietary chlorella levels increased, the daily egg mass linearly increased, although not significantly. The yolk colors in groups fed diets containing lutein fortified chlorella were dramatically increased as compared to the control (p<0.001). The lutein in chicken eggs significantly increased when fed with 0.2% of lutein fortified chlorella (p<0.01). These results suggested that the dietary lutein derived from chlorella was readily absorbed into the serum and absorbed by the liver with growing oocyte for commercial laying hens. Particularly, the lutein fortified chlorella was a valuable natural source for the production of lutein enriched chicken eggs.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.10
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• pp.1495-1499
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• 2017

Objective: This study aimed to investigate the effects of enrichment resources (a perch, dustbath, and nest) layout in furnished laying-hen cages (FC) on exterior quality of eggs. Methods: One hundred and sixty-eight (168) Hy-Line Brown laying hens at 16 weeks of age were randomly distributed to four treatments: small furnished cages (SFC), medium furnished cages type I (MFC-I), medium furnished cages type II (MFC-II), and medium furnished cages type III (MFC-III). Each treatment had 4 replicates or cages with 6 hens for SFC (24 birds for each SFC) and 12 hen/cage for MFC-I, -II, and -III (48 birds for each MFC-I, -II and -III). Following a 2-week acclimation, data collection started at 18 weeks of age and continued till 52 weeks of age. Dirtiness of egg surface or cracked shell as indicators of the exterior egg quality were recorded each week. Results: The results showed that the proportion of cracked or dirty eggs was significantly affected by the FC type (p<0.01) in that the highest proportion of cracked or dirty eggs was found in MFC-I and the lowest proportion of dirty eggs in SFC. The results of this showed that furnished cage types affected both dirty eggs and cracked eggs (p<0.01). The results also indicated that not nest but dustbath lead to more dirty eggs. Only MFC-I had higher dirty eggs at nest than other FC (p<0.01). The results of dirty eggs in MFC-I and MFC-II compared with SFC and MFC-III seemed suggest that a low position of dustbath led to more dirty eggs. Conclusion: SFC design affected exterior egg quality and the low position of dustbath in FC resulted in higher proportion of dirty eggs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.2
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• pp.294-300
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• 2010

This experiment was conducted to investigate the effects of Opuntia humifusa (OPH) extracts and methyl sulfonyl methane (MSM) supplementations on the laying productivity, egg quality and sensory characteristics of eggs in hens. Six hundred forty, 35-wk-old Lohmann brown, laying hens were randomly divided into four groups: 1) water (control), 0.12% OPH extract, 0.1% MSM, and 0.12% OPH extract+0.1% MSM. They were mixed into the feed and given for 5 weeks. Egg production rates, egg weight, feed demand ratio were not significantly different among the groups. However, OPH or MSM decreased broken egg rates by increasing thickness and firmness of egg shell but they did not show the additive effects. In addition, OPH or MSM enhanced Haugh unit, an indicator of freshness of egg, and viscosity of egg white and egg yolk. OPH or MSM maintained the freshness of eggs better the control during their storage for 10 day at $4^{\circ}C$. However, OPH+MSM did not show additive effects in their freshness. Sensory test revealed that OPH or MSM decreased fishy taste and greasy flavor and they improved texture. Overall OPH or MSM enhanced the preference of eggs. In conclusion, the supplementation of either OPH or MSM enhances egg freshness and egg quality in laying hens but they should not be supplemented together due to no additive effects.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.10
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• pp.1606-1611
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• 2007

The experiment was conducted to investigate the effects of dihydropyridine on laying performance and fat metabolism of laying hens. Five hundred and forty laying hens, 40 weeks old, were randomly allotted to three groups, each of which included four replicates of 45 hens. The groups were given a basal corn-soybean meal diet supplemented with 0, 150 mg/kg and 300 mg/kg dihydropyridine. Results showed that compared with the control group (0 mg/kg dihydropyridine), supplements of 150 and 300 mg/kg dihydropyridine increased egg production rate by 9.39% (p<0.01) and 12.97% (p<0.01), increased mean egg weight by 3% (p>0.05) and 4.8% (p>0.05), and improved feed efficiency by 9.54% (p<0.05) and 7.25% (p<0.05), respectively; The addition of 150 and 300 mg/kg dihydropyridine decreased percentage of abdominal fat by 35.4% (p<0.05) and 46.9% (p<0.05), decreased liver fat content by 32.4% (p<0.05) and 10.5% (p<0.05), increased HSL activity of abdominal fat by 39.64% (p<0.05) and 48.48% (p<0.05), increased HSL activity of liver by 9.4% (p>0.05) and 47.34% (p<0.05) and increased the content of cAMP in adenohypophysis by 14.67% (p<0.05) and 10.91% (p<0.05), respectively; The inclusion of 150 mg/kg dihydropyridine increased liver superoxide dismutase activity by 69.61% (p<0.05), and increased hepatic apoB concentration by 53.96% (p<0.05); The supplementation of 150 or 300 mg/kg dihydropyridine decreased malondialdehyde concentration of hepatic mitochondria by 30.90% (p<0.01) and 10.39% (p<0.05), respectively; Supplemented dihydropyridine had no significant effects on TG, Ch HDL-C and VLDL-C concentrations in serum; addition of 150 or 300 mg/kg dihydropyridine increased T3 levels in serum by 15.34% (p<0.05) and 11.88% (p<0.05) and decreased insulin concentration by 40.44% (p<0.05) and 54.37% (p<0.05), respectively. The results demonstrated that adding dihydropyridine had the tendency of improving very low density lipoprotein receptor (VLDLR) content in the ovary. It was concluded that dihydropyridine could improve laying performance and regulate the fat metabolism of laying hens and that 150 mg/kg dihydropyridine is the optimum dose for laying birds in practical conditions.

• Korean Journal of Poultry Science
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• v.13 no.2
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• pp.173-178
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• 1986

Data on egg production, egg weight and egg mass were obtained from a sample of the Synthetic White Leghorn population which was raised at Poultry Breeding Farm, Seoul National University. Egg mass was not measured directly, but was calculated from the egg numbers and the average egg weight for same period. Phenotypic means, components of variance and covariance, heritabilities and genetic correlations were computed. Egg mass was estimated to be a lowly heritable trait (0.204-0.270). High heritability estimates were found for age at sexual maturity and egg weight. Genetic correlation estimates were high and positive between egg mass and egg number(combined estimates 0.711). Egg mass and egg weight were moderately correlated genetically (0.431). Genetic correlation estimates was -0.280 between egg number and age at sexual maturity, but was 0.524 between egg weight and age at sexual maturity. Results show that selection for total egg mass based on record from a single period will not be satisfactory unless the single period chosen is one in the latter part of the laying year.

• Korean Journal of Poultry Science
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• v.44 no.2
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• pp.67-73
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• 2017

The purpose of our study was to determine the effects of varying levels of energy, protein, and amino acids on the performances of laying hens. A total of 240 Hy-Line Brown laying hens at 36 weeks of age were used in this 4-week feeding trial. The hens were randomly allocated to five treatment diets, with eight replications of six hens in each replicate cage. The treatment diets were as follows: A- basal diet + 18% crude protein, metabolizable energy 2,800 kcal, total (methionine + cysteine) 0.65%; B- basal diet + 17% crude protein, metabolizable energy 2,700 kcal, total (methionine + cysteine) 0.59%; C- basal diet + 16.5% crude protein, metabolizable energy 2,700 kcal, total (methionine + cysteine) 0.59%; D- basal diet + 16.5% crude protein, metabolizable energy 2,700 kcal, total (methionine + cysteine) 0.54%; and E- basal diet + 16% crude protein, metabolizable energy 2,680 kcal, total (methionine + cysteine) 0.54%. The study results revealed that the hen-day egg production of hens that were fed with low-energy diets (B, C, and D) was comparable with that of hens fed with high-energy diet A, whereas average daily feed intake in hens fed treatment diet D and E was significantly higher (P<0.05) than that in hens fed treatment diet A. Overall, the eggshell thickness was unaffected by any of the treatment diets. Egg weight was comparable among the treatment diets, except for treatment diet E. Haugh unit improved with decreasing levels of dietary energy, protein, and methionine + cysteine in the diet. We can summarize that laying hens fed with low dietary energy and low crude protein treatment diets B, C, and D had satisfactory performance compared with those fed with high-energy treatment diet A. This indicates that there is the potential to reduce feed costs by formulating diets with lower energy and low protein levels.