• Korean Journal of Poultry Science
• /
• v.14 no.1
• /
• pp.1-8
• /
• 1987

Three experiments were conducted to investigate effects of dietary energy and protein levels on performance of laying hens. A total of 360 hens each of 352-day old Manina Brown (Exp.1), 280-day old Brown Warren (Exp.2) or 3174ay old Brown Warren (Exp.3) was divided into 20 pens of 18 birds. Each pen was assigned to one of the four dietary treatments with 5 replications according to a 2${\times}$2 factorial design, consisting of all possible cominations of two levels of metabolizable energy (2,500 and 2,800 kcal/kg of diet) and two levels of crude Protein (13 and 16%). All hens were housed two birds per cage. Exp.1 and 2 were conducted for four weeks and hens were fed experimental diets ad libitum, and Exp.3 lasted two weeks and feed consumption was restricted to 130g/hen/day. In Exp.1 and 2, increasing either energy or protein level in the diet numberically improved egg production. However, in Exp. 3, where feed consumption was restricted, egg Production was affected significantly 〈0.05) by the energy levies and numerically by the protein levels. Neither protein nor energy level influenced egg weight in Exp. 1 and 2, but in Exp. 3 the higher level of energy improved egg weight numerically, In all three experiments increasing either protein or energy level increased egg mass. Higher levels of either protein and energy tended to decrease feed consumption and improve feed conversion rate numerically. It should also be noted that the higher level of energy improved egg mass produced per unit intake of protein and the higher level of Protein improved egg mass produced per unit intake of energy.

• Korean Journal of Poultry Science
• /
• v.42 no.2
• /
• pp.181-189
• /
• 2015

The objective of this study was to investigate the effect of dietary supplementation of vitamin C and Sea buckthorn on the performance, blood biochemistry and meat quality in old laying hens. A total 200 Hy-Line Brown laying hens (101 weeks old) were randomly allotted to 1 of 5 dietary treatments : (1) Basal : basal diet, (2) Vit. C : basal diet + 0.1% vitamin C, (3) SB 0.1 : basal diet + 0.1% Sea buckthorn, (4) SB 0.5 : basal diet + 0.5% Sea buckthorn, and (5) SB 1.0 : basal diet + 1.0% Sea buckthorn. Each treatment was replicated 4 times with 10 birds units were arranged according to randomized block design. Feeding trial lasted 4 weeks under 16L:8D lighting regimen. The diets were fed to hens on an ad libitum basis for 4 weeks. Result indicated that during feeding trial of the experiment, hen-day egg production and feed conversion ratio were not significantly influenced by treatments. However, feed intake was significantly (P<0.05) higher in Vit. C and SB treated groups than the basal during 1 wks and 3 wks. Egg weight was significantly (P<0.05) higher in basal and Vit. C than the SB 1.0 treatment. There were no differences in carcass yield during feeding trials. However, partial ratio (breast and neck) was significantly (P<0.05) higher in SB 0.5 than other treatment. There were no differences in the level of leukocytes and erythrocytes. There were no significant differences on proximate analysis (DM, crude protein, crude fat, and crude ash), meat color, water holding capacity, cooking loss, and fatty acids concentrations. In conclusion, dietary supplementation of vitamin C and Sea buckthorn to the diet of old laying hens might be a potential ingredient for increasing partial weight (breast) in old laying hens.

• Journal of Mushroom
• /
• v.12 no.4
• /
• pp.350-356
• /
• 2014

This study was conducted to evaluate the feeding value of the spent mushroom (Hypsizygus marmoreus) substrates (SMS) in laying hens (Hy-Line Brown). The fresh spent mushroom (Hypsizygus marmoreus) substrates collected from the Namkyung farm were fermented with Bacillus subtilis EJ3 for 2 weeks. A total of twenty-four laying hens were fed corn-soy based experimental diets containing 0% (T0), 5% (T1), 10% (T2) and 15%(T3) fermented SMS for 12 weeks. There were no significant differences among the treatments in egg production, egg weight, egg mass, feed conversion and viability during the experimental period. Feed intake was significantly lowered in T0 (118.3 g) than T1 (121.9 g), T2 (120.3 g) and T3 (122.4 g). There were no significant differences among the treatments eggshell breaking strength, thickness and haugh unit, whereas the yolk color of T1, T2 and T3 were significantly heavy than T0. The palatability of boiled meat was significantly better in the T3 laying hens than in the T0 laying hens. In conclusion, fermented SMS can be used as resource of feed in laying hen feed at 5.0-15% level without effect on performance and egg qualify.

• Korean Journal of Poultry Science
• /
• v.35 no.2
• /
• pp.115-121
• /
• 2008

The study was conducted to evaluate the effects of dietary microbial phytase on egg productivity, egg quality, phosphorus utilization and nutrient digestibility in laying hens. The animals used in the experiment were a total of 120 Hy-Line Brown laying hens (32 weeks old). Dietary treatments included 1) CON (basal diet), 2) LP (low phosphorus diet) 3) NP (low phosphorus diet + 0.03% normal microbial phytase) and 4) CP (low phosphorus diet + 0.03% coated microbial phytase). Six laying hens were allotted to a block (pen) with five replicated. Through the whole period of experiment, egg production was significantly increased in CON and CP treatments compared to LP treatment (P<0.05). CON, CP and NP treatments significantly increased their egg shell breaking strength and egg shell thickness compared to LP treatment (P<0.05). CON, CP and NP treatments resulted higher yolk color and Haugh unit than LP treatment (P<0.05). Calcium and inorganic phosphorus contents in blood were higher in CP treatment compared to LP treatment (P<0.05). Dry matter digestibility and nitrogen digestibility were greater in CP treatment than CON, LP and NP treatments (P<0.05). Crude ash was increased in CON, CP and NP treatments compared to LP treatment (P<0.05). Calcium digestibility and phosphorus digestibility were significantly improved in CP and NP treatments than CON and LP treatments (P<0.05). Calcium retention of CON, CP and NP treatments were higher than LP treatment (P<0.05). Phosphorus retention was increased in CP and NP treatments compared to CON and LP treatments (P<0.05). LP treatment significantly increased their nitrogen, calcium excretion compared to CON, CP and NP treatments (P<0.05). Phosphorus excretion was decreased in LP, CP and NP treatments compared to CON treatment (P<0.05). In conclusion, CP treatment improved egg production, egg quality, inorganic calcium and phosphorus in blood, calcium and phosphorus retention and nutrient digestibility and decreased nitrogen and calcium excretion in laying hens.

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.11
• /
• pp.1766-1772
• /
• 2018

Objective: This experiment was to investigate the effect of increasing levels of apparent metabolizable energy ($AME_n$) on the laying performance, egg quality, blood parameters, blood biochemistry, intestinal morphology, and apparent total tract digestibility (ATTD) of energy and nutrients in diets fed to laying hens. Methods: A total of three-hundred twenty 33-week-old Hy-Line Brown laying hens (Gallus domesticus) were evenly assigned to four experimental diets of 2,750, 2,850, 2,950, and 3,050 kcal $AME_n/kg$ in pens with floors covered with deep litter of rice hulls. There were four replicates of each treatment, each consisting of 20 birds in a pen. Results: $AME_n$ intake was increased (linear, p<0.05) with inclusion level of $AME_n$ in diets increased. Feed intake and feed conversion ratio were improved (linear, p<0.01), but hen-day egg production tended to be increased with an increasing level of $AME_n$ in diets. During the experiment, leukocyte concentration and blood biochemistry (total cholesterol, triglyceride, glucose, total protein, calcium, asparate aminotransferase, and alanine transferase were not influenced by increasing level of $AME_n$ in diets. Gross energy and ether extract were increased (linear, p<0.01) as the inclusion level of $AME_n$ in diets increased. Conclusion: Laying hens fed high $AME_n$ diet (i.e., 3,050 kcal/kg in the current experiment) tended to overconsume energy with a positive effect on feed intake, feed conversion ratio, nutrient digestibility, and intestinal morphology but not on egg production and egg mass.

• Animal Bioscience
• /
• v.35 no.11
• /
• pp.1744-1751
• /
• 2022

Objective: The present study aimed to investigate the effect of xylo-oligosaccharides (XOS) administration on egg production, reproductive hormones, serum lipids and adipokines of hens at the late cycle of reproduction. Methods: Four treatments included control (basal diet) and XOS addition at 2.0 (XOS-2), 4.0 (XOS-4), or 6.0 (XOS-6) g/kg of diet using 288 commercial Hy-Line brown hens from 73 to 84 wk of age. Egg production, body fat deposition, reproductive tract and hormones, lipid metabolism and adipokines were determined. Results: At 84 wk, compared to the control, XOS supplementation at the three doses increased (p<0.001) egg-laying rates by 13.2% averagely, which led to a higher egg mass by 131 g/hen throughout the whole trial period. Abdominal fat and skinfold of XOS treatments were decreased (p<0.001) by 26.1% and 18.6%, respectively; large follicles and ovary weight were increased (p<0.001) by 0.73 follicle/hen and 18.6%, respectively. For serum parameters, cholesterol and triglyceride were decreased (p<0.001) by 17.5% and 29.2%, respectively; luteinizing hormone, follicle-stimulating hormone, and progesterone were increased (p≤0.001) by 16%, 31%, 29%, respectively; adiponectin and visfatin were increased (p<0.001) by 34% and 44%, respectively; but chemerin and leptin were decreased (p≤0.001) by 22% and 14%, respectively. With the increased XOS doses, linear decreases (p<0.05) were found on abdominal skinfold and serum triglyceride. Conclusion: The obtained data indicate that XOS can be used as an additive to improve fecundity by beneficially modulating fat deposition, lipid metabolism, reproductive hormones, and adipokines of hens at the late cycle of reproduction.

• Korean Journal of Poultry Science
• /
• v.39 no.1
• /
• pp.63-70
• /
• 2012

This study was conducted to determine the possible use of Red Ginseng marc as stress inhibiter in thermal stress (temperature humidity index 86) and lipopolysaccharide (LPS) - exposed laying hens by investigating their effects on laying performance, blood biochemical parameters, immunoglobulin concentration and serum superoxide dismutase (SOD) like ability. A total of forty-five 52-wk-old laying hens (ISA Brown) were divided into 3 treatment groups with 5 replicates of 3 birds in each group. NC (negative control, no immune substances), PC (positive control, ${\beta}$-glucan 25 ppm) and RGM (Red Ginseng Marc 3%) were added in feed with respective substance. Egg production in RGM was significantly increased in comparison with NC groups for 8 weeks (P<0.05). On blood biochemical parameters, effects of ambient temperature is definite by showing significant difference in aspartate aminotransferase and others (P<0.05), but RGM both before and after thermal stimulation have no significant difference in comparison with other groups. And for 3 weeks after thermal stimulation, laying performance was also not significantly different among treatments. Immunoglobulin M content and SOD like activities after challenge with LPS were higher in the RGM and PC than NC (P<0.05). In conclusion, although ineffective as inhibiter in thermal stress, dietary supplementation of Red Ginseng marc improved SOD like activity and immune system by regulating immunoglobulin content in laying hens. These findings have laid the foundation for future studies of immunomodulation in laying hens fed Red Ginseng Marc and of evaluation of heat stress inhibitor.

• Korean Journal of Poultry Science
• /
• v.39 no.1
• /
• pp.27-32
• /
• 2012

This experiment was conducted to investigate the dietary effects of turmeric powder (TP) on laying performances, egg qualities and its transfer into eggs. A total of two hundred, 60-wk-old, Lohmann Brown layers were divided into 4 groups, placed in to 5 replicates per group (10 layers each) and fed each one of four diets containing 0% TP (control), 0.10, 0.25 or 0.50% TP, respectively, for 7 wks. Egg production in the all groups fed diets containing TP were significantly higher than that in control (P<0.05). No differences in feed intakes, egg and eggshell qualities were observed among the treatments, but Roche color fan number (yolk color) in group fed diet with 0.5% TP was significantly higher than in control (P<0.05). In the groups fed diets containing TP, Haugh units after 2 wk of storage were significantly higher than that of control (P<0.05). The curcumin content of egg yolk in the groups fed diet containing 0.50% TP was significantly higher than those in the other groups (P<0.05). The cholesterol levels of egg yolk were not influenced by dietary TP. It was concluded that dietary TP was effective in improving laying performance and internal egg qualities. TP can be also used as a feed additive for the production of value-enhanced eggs with increased yolk color and curcumin content.

• Korean Journal of Agricultural Science
• /
• v.50 no.2
• /
• pp.249-256
• /
• 2023

The purpose of this experiment was to determine the influence of providing laying hens with extra feed on egg production and egg quality parameters. A total of 480 laying hens (38-weeks old), were divided into five treatment groups (eight replicate cages/treatment and 12 layer/replicate) according to their starting body weight (1.98 ± 0.05 kg) in this four-week feeding trial. Five different feed allowances of the same diet (105, 110, 115, 120, and 125 g·day^-1·bird^-1) were assigned to layers. Daily inspections of remaining feed (around 0.1g) and layer mortality (0%) showed no harmful impact of supplying extra feed to layers. Providing 120 and 125 g of feed per day to layers resulted in the highest final body weight, large-egg ratio, and improved yolk color among all treatment groups. Layers receiving 125 g of feed daily had the highest egg weight, but the highest egg production ratio was observed in layers receiving 110 g of feed/day. The additional supply of feed did not have a negative impact on the productive performance or egg quality of the layers. The provision of 125 g feed per day led to an improvement of large-egg ratio, egg weight, and yolk color, but likely led to obesity of the layers, which manifested as an increase in body weight and a decline in the egg production ratio. We concluded that 110 grams of feed was the proper quantity after taking into consideration the significance of the health of the laying hen to the overall production performance.

• Korean Journal of Poultry Science
• /
• v.37 no.3
• /
• pp.215-219
• /
• 2010

The applicability of electronic nose was tested to detect lipid peroxidation in chickens and to measure antioxidant effect of astaxanthin in chicken carcasses. Two sources of astaxanthin were fed to 62-wk-old spent laying hens to improve meat quality: natural astaxanthin (NA) from the red yeast, Phaffia rhodozyma, and synthetic astaxanthin (SA) from chemical synthesis. One hundred forty four ISA Brown laying hens were used in a 6-wk feeding trial. Three treatments consisted of the basal diet (control), SA (100 mg astaxanthin/kg basal diet) and NA (50 mg astaxanthin/kg basal diet). The astaxanthin levels of SA and NA were set to give a similar degree of skin pigmentation. After 6-wk feeding of astaxanthin, the skins from NA and SA were discriminated from the control by electronic nose. However, electronic nose failed to distinguish between SA and NA skins after 6-wk feeding. The astaxanthin level differences between skins of SA and NA were not remarkable during the 6-wk trial. The lipid peroxide formation in skin was significantly decreased by SA but not by NA. The antioxidation effect of SA was detected by electronic nose because SA skin was discriminated from others. NA was a better pigmentation agent than SA, but the reverse was true in antioxidation. Electronic nose is applicable for detecting astaxanthin in chicken, and meat off-flavor caused by lipid peroxidation during storage.