• Korean Journal of Poultry Science
• /
• v.27 no.1
• /
• pp.19-23
• /
• 2000

The effects of microbial phutase on laying performance and phosphorus utilization were examined at different levels of dietary nonphosphorus(NPP) in 320 23-week-old Hy-line brown hens for 12weeks. Diets were formulated 0.275%(T1), 0.220%(T2), 0.165%(T3) of NPP levels, and supplemental microbial phytase was 300DPU/kg diet constantly. Conventional diet(C) was formulated 0.275% NPP level without microbial phytase. Egg production and egg mass were higher in T2 than the others (p<0.05), and average egg weight was higher in T1 than the other (p<0.05). Egg productivity was tended to increase with supplemental phytase compared to conventional diet. Daily feed intake a hen also increased in T2 (p<0.05). Feed conversion ratio was improved slightly without significant difference. Eggshell breaking strength and thickness were not different significantly among the treatments. Haugh unit and yolk color were also not different. Calcium and phosphorus retention in body increased in T2 (p<0.05), but dry matter and nitrogen retention were not different significantly. Differences in nitrogen and calcium excretions were not found among the treatments. But phosphorus excretion decreased in order of dietary phosphorus levels with supplement phytase compared to C (p<0.05). Tibial ash, calcium and phosphorus were similar among the treatments. In conclusion, supplemental microbial phytase in laying diet may help to utilize phytase phosphorus, and could decrease NPP intake.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.8
• /
• pp.1043-1048
• /
• 2010

This study investigated the effects of Fe-soy proteinate (Fe-SP) and magnesium oxide (MgO) dietary supplements on eggshell quality in laying hens. A total of 800 26-wk-old Hy-Line Brown hens were assigned to four dietary treatments: control (C), Fe-SP 100 (100 ppm Fe-soy proteinate), MgO (3 g MgO/kg diet), and Fe-SP 100+MgO. Each treatment had five replicates of 40 hens. The FT-IR (Fourier transform infrared) and XRD (X-ray diffraction) spectra of Fe-soy proteinate were different from those of $FeSO_4$ and soy digest. There were no significant differences among treatments in hen-day egg production, hen-house egg production, broken and soft egg rate, feed intake, or feed conversion. The MgO and Fe-SP 100+MgO treatments showed significantly (p<0.05) higher egg weights than the control group. Eggshell strength and thickness were significantly (p<0.05) higher in the MgO supplemented groups. The lightness and yellowness of the eggshells decreased, and the redness increased significantly in the Fe-SP treated groups. There were no significant differences among treatments in leukocyte level, but hemoglobin (Hb) concentrations were higher with Fe-SP treatments. In conclusion, supplementation with Fe-SP significantly affects eggshell color and hemoglobin concentration, whereas MgO supplementation increases eggshell strength and thickness. Egg weight and egg shell quality can be improved by supplementation of 100 ppm Fe in the form of Fe-SP and 3 g MgO/kg diet.

• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.10
• /
• pp.1447-1455
• /
• 2011

Sixty four, 30-week-old, Lohmann Brown-Lite laying hens were randomly allocated to one of four treatments with eight replicates per treatment and two hens per replicate for a 10 week study. The control diet was a high energy (11.81 MJ/kg) diet and the moderate energy (11.39 MJ/kg) diets were formulated dropping the level of animal fat. The three moderate energy diets were fed either unsupplemented (0.0%) or supplemented with 0.05 or 0.10% glycine. There were no significant differences (p>0.05) in hen-day egg production, egg weight, feed intake or feed conversion between birds fed the unsupplemented moderate energy and high energy diets. Significant differences were detected concerning egg components and quality measurements as assessed by albumen percentage (p = 0.02), yolk weight (p = 0.02), yolk percentage (p<0.01), yolk to albumen ratio (p<0.01) and yolk color (p = 0.01) between birds fed the unsupplemented moderate and high energy diets. Glycine supplementation of the moderate energy diet linearly increased (p<0.01) egg weight and feed intake with no significant (p>0.05) effects on egg production or feed conversion. Glycine supplementation significantly increased egg content (p<0.01), albumen weight (p<0.01) and percentage (p<0.01) as well as yolk weight (p<0.01) while yolk percentage (p = 0.04), yolk to albumen ratio (p = 0.01) and egg shell percentage (p<0.01) were linearly decreased. Supplementation with glycine produced a tendency (p = 0.09) towards an increase in the percentage of large eggs (63-72.9 g) produced with a concomitant decrease in the percentage of small (below 53 g) eggs (p = 0.09). The overall results of this study indicate that glycine supplementation of laying hen rations has the potential to increase egg production and weight. These increases appeared to be mediated through increases in feed intake and the ileal digestibility of fat and energy.

• Korean Journal of Agricultural Science
• /
• v.46 no.4
• /
• pp.991-997
• /
• 2019

This study was conducted to investigate the laying period performance of two crossbred Korean native chicken (KNC) grand parent stock (GPS) layer during 20 to 40 weeks. A total of 351 20-week-old KNC GPS were allocated in a completely randomized design to give 4 birds per each cage. The chickens were fed commercial diets [i.e., week 20 - 32, crude protein (CP) 18.0% and metabolizable energy (ME) 2,850 kcal/kg; week 32 - 40, CP 17.0% and ME 2,800 kcal/kg)] and fresh water during the whole experiment period ad libitum basis. Body weight, age of sexual maturity, egg weight, hen-day egg production (HDP) and feed conversion ratio (FCR) were measured during the experiment period (week 20 - 40). The results show no significant difference in the Body weight, age of sexual maturity, egg weight, and hen-day egg production (HDP) except for egg weight. 1B had a higher egg weight on week 36 only. We expect that the reason why most factors showed no significant difference is the lack of nutrients caused by limited feeding which follows the standard feeding system for the grand-parent stock. These results provide basic information for laying data in 2-way crossbred Korean native chickens.

• Korean Journal of Poultry Science
• /
• v.27 no.3
• /
• pp.235-242
• /
• 2000

A feeding trial was carried out effect of supplemental Lactobacillus on productivity, egg quality and intestinal microflora in 320 21 weeks - old laying hens for 12 week. Supplemented Lactobacillus strains were Lactobacillus amylovorus LLA7(LA), Lactobacillus crispatus LLA9(LC) and Lactobacillus vaginalis LLA11(LV). Three strains mixed to basal diet which containing 2,800㎉/kg ME, 16% CP with none, LA, LC, LV, LA+LC, LA+LV, LC+LV and LC+LC+LV. Supplemental level was 10(sup)7 cfu/g diet. Egg production was tended to increase with adding Lactobacilus, but not difference significantly. Average egg weight was heavier in adding Lactobacillrs compared to the none, and heaviest in LA+LV, LC+LV(P〈0.05). In periodic observation, the gap of egg weight with adding Lactobacillus or not was severe persisting laying periods. The diet containg MC or LV was better than LA, which means the difference by Lactobacillus strains for egg weight. Daily egg mass also increased in adding Lactobacillus about 1.1 to 2.3 g/hen, but not difference significantly. Feed intake and feed conversion were not difference regardless Lactobacillus strains and laying periods. Haugh unit improved with adding Lactobacillus. Cecal Lactobacillus spp. was increased with adding Lactobacillus(P〈0.05), didn't observed E. coli depression. In summary, supplemental Lactobacillus could improve for egg production, egg weight, egg mass and egg white. And those of effect expect much beneficial with mixing Lactobacillus which established well as single strain.

• Asian-Australasian Journal of Animal Sciences
• /
• v.30 no.3
• /
• pp.417-423
• /
• 2017

Objective: This experiment investigated the effects of dietary supplementation with conjugated linoleic acid (CLA) on the serum components, laying hen productivity, lipid composition of egg yolk, egg flavor and egg quality. Methods: Healthy 28-week-old Hy-Line white laying hens (n = 480) were divided randomly into 4 groups, 6 replicates/group, 20 birds/replicate. The 30-day experimental diets included 0% (control), 0.4%, 0.8%, and 1.6% CLA. Some serum indices of the birds, and egg production, quality, fatty acid composition, egg quality were measured. Results: The dietary supplementation with 0.4%, 0.8%, and 1.6% CLA did not significantly affect the laying rate and feed intake, as well as calcium ion and phosphorus ion concentration in serum (p>0.05). However, the CLA had significantly increased the strength of eggshell, decreased the odor, flavor, and taste of egg yolk, deepened the color of egg yolk, increased saturated fatty acids and polyunsaturated fatty acids, and reduced the monounsaturated fatty acids (p<0.05). On the other hand, the dietary supplementation with 1.6% CLA had significant effects on feed/gain, and improved serum hormones. Dietary supplementation with 0.4% and 0.8% CLA can significantly enhance the activity of alkaline phosphates. Conclusion: CLA has no effect on production performance, but does enhance the lipid content of the egg yolk and the strength of the eggshell.

• Korean Journal of Poultry Science
• /
• v.28 no.1
• /
• pp.1-6
• /
• 2001

Two experiments were carried out to evaluate the effects of adding phytase on nutrient availability and serum Ca and P level and to determine the effects of phytase on laying performance and egg quality in laying hens. In Exp. 1, twenty four laying hens(1.9kg average body weight and 78.4% egg production) were allotted to four treatments. Treatments included 1) corn-soybean meal based-control diet and 2), 3) and 4) control diet with phytase 200, 400 and 600 unit/kg, respectively. There were no significant effects of treatments on dry matter and nitrogen digestibility(P〉0.05). Ash, Ca and P digestibility in layer fed diet with phytase were greater than those in layer fed control diet(P〈0.05). Laying hens fed diets with phytase 200 and 400 unit retained more Ca than those fed other treatments (P〈0.05). No statistical difference was found for Ca exsretion(P〉0.05). P retention was greater for laying hens fed diet phytase 600 unit than other treaments(P〈0.05). P level in serum was higher for laying hens fed diets with phytase 400 and 600 unit than for laying hens fed other treatments. In Exp. 2, three hundred, IAS Brown layer, 40-week-old, divided into two treatment groups(control vs phytase supplementation without inorganic phosphate in the diets) with five replications per treatment and 30 layers per replication were fed the diets for 6 weeks. Egg production, egg weight and eggshell breaking strength and thickness were not different significantly(P〉0.05). In conclusion, phytase supplementation can be used to increase P utilization and retention in laying hens. Also, phytase supplementation was effective to spare inorganic phosphate in laying hen diets without any adverse effects on production performances.

• Korean Journal of Poultry Science
• /
• v.31 no.1
• /
• pp.37-44
• /
• 2004

It has been recognized that the hen, like its mammalian counterparts, provides young chicks with antibodies as protection against hostile invaders. This system facilitates the transfer of specific antibodies from serum to egg yolk, and provides a supply of antibodies called immunoglobulin Y(IgY) to the developing embryo and the hatched chick. The protection against pathogens that the relatively immune-incompetent newly hatched chick has, is through transmission of antibodies from the mother via the egg. Egg yolk, therefore, can be loaded with a large amount of IgY against pathogens which can immobilize the existing or invading pathogens during the embryo development or in day-old chicks. Thus, the immunization of laying hens to various pathogens results in production of different antigen-specific IgY in eggs. Egg yolk contains 8∼20 mg of jmmunoglobulins (IgY) per ml or 136∼340 mg per yolk suggesting that more than 30 g of IgY can be obtained from one immunized hen in a year. By immunizing laying hens with antigens and collecting IgY from egg yolk, low cost antibodies at less than $10 per g compared to more than $20,000 per g of mammalian IgG can be obtained. This IgY technology opens new potential market applications in medicine, public health, veterinary medicine and food safety. A broader use of IgY technology could be applied as biological or diagnostic tool, nutraceutical or functional food development, oral-supplementation for prophylaxis, and as pathogen-specific antimicrobial agents for infectious disease control. This paper has emphasized that when IgY-loaded chicken eggs are produced and consumed, the specific antibody binds, immobilizes and consequently reduces or inhibits the growth or colony forming abilities of microbial pathogens. This concept could serve as an alternative agent to replace the use of antibiotics, since today, more and more antibiotics are less effective in the treatment of infections, due to the emergence of drug-resistant bacteria.

• Korean Journal of Agricultural Science
• /
• v.45 no.4
• /
• pp.687-694
• /
• 2018

This study was conducted to investigate the laying performance of six strains of Korean domestic chickens (KDC 1A, 2A, 3A, 1B, 2B and 3B). A total of 288 20-week-old KDC hens were allocated in a completely randomized design to give 12 replicates per each strain (4 chickens per pen). The chickens were fed commercial diets (i.e., week 20 - 32, crude protein [CP] 18.0% and metabolizable energy [ME] 2,850 kcal/kg; week 32 - 40, CP 17.0% and ME 2,800 kcal/kg) ad libitum together with fresh water during the 20-week experiment. Body weight, age of sexual maturity, egg weight, hen-day egg production (HDP) and feed conversion ratio (FCR) were measured during the experiment period (week 20 - 40). Our results show that strain 3B had an improved (p < 0.05) HDP and FCR compared with the other strains on week 24 - 28. However, strain 3A had an improved (p < 0.05) HDP and FCR compared to the other strains on week 28 - 40. Similarly, strain 3A had a higher egg weight (p < 0.05) compared to the other strains on week 28, 32 and 40. In conclusion, the higher laying performance of strain 3A indicates its potential in the development of a KDC strain with improved commercial laying performance.

• 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.