• Korean Journal of Agricultural Science
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• v.45 no.3
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• pp.485-492
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• 2018

Two experiments were conducted to investigate the effect of feeding a diet supplemented with swine hair protein (SHP) on the nutrient digestibility of Korean native chickens and their egg production as well as on egg quality. In experiment 1, twenty roosters of the Hanhyup-3 strain were assigned to an individual cage to give 10 replicates per treatment (i.e., 0 and 10% of SHP), and the nutrient digestibility in response to the SHP supplementation was measured. In experiment 2, fifty-four layers of the Hy-Line strain were assigned to an individual cage to give 27 replicates per treatment (i.e., 0 and 10% of SHP), and egg production and egg quality were measured. In experiment 1, no significant difference (p > 0.05) was found in the digestibility of crude protein, crude fat, nitrogen-free extract (NFE), and crude fiber in response to the diet supplemented with SHP. In experiment 2, although no significant difference (p > 0.05) was found with the dietary treatments, the 10% SHP supplemented diet decreased (p < 0.05) the feed intake of laying hens. However, the SHP supplemented diet did not affect (p > 0.05) the laying rate, egg weight and feed conversion ratio of those fed the diet. Eggshell thickness and yolk color decreased (p < 0.05); however, eggshell strength, eggshell color, albumen height and Haugh units increased (p < 0.05) by feeding layers a diet supplemented with SHP. In conclusion, the results suggest that 10% SHP supplemented in a poultry diet could be a useful protein source.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.217-224
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• 1992

The study was undertaken to determine the effect of dietary magnesium on the eggshell quality and other performance in laying Tsaiya ducks and Leghorn hens. Twenty-five Tsaiya ducks and 25 Leghorn hens were raised in individual cages. The basal diet was mainly consisted of corn starch and isolated soybean protein. At the beginning of the experiments, birds were fed for 10 days with the basal diet supplemented with 500 mg/kg Mg (1070 mg/kg in total by analysis) in order to allow the birds adapting to the new diet. Both Tsaiya ducks and Leghorn hens were then each randomly divided into five groups and each group of five birds were fed with the experimental diets containing 690, 1070, 1690, 2150 or 2380 mg/kg Mg, respectively for 21 days. Eggs were collected in order to measure eggshell quality, Mg and Ca content of the eggshell. At the end of the experiments, blood samples of all birds were taken from their brachial veins for measuring the concentration of Mg and Ca in the plasma. Experimental results appeared that the dietary Mg content did not significantly affect egg production, egg weight, eggshell breaking strength and thickness in both Tsaiya ducks and Leghorn hens. In Tsaiya ducks, however, the plasma Mg concentration was affected by the dietary Mg content, but the plasma Mg almost reached a plateau (4.66 mg/dl) as long as the dietary Mg level was over 1070 mg/kg. In Leghorn hens, the plasma Mg level was significantly increased from 1.66 mg/dl to 4.03 mg/dl when the dietary Mg content in the diet had been increased from 690 mg/kg to 2380 mg/kg, suggesting that the plasma Mg concentration seems to be directly influenced by the Mg absorbed in the intestine. In the Tsaiya ducks, however, the dietary Mg level did not significantly affect the eggshell Mg content (from 0.113% to 0.123%). Whereas, there was a negative correlation between the eggshell thickness and eggshell Mg content (r = -0.50, p<0.01), revealing that the increase in eggshell Mg content probably associated with the impairment of eggshell quality in Tsaiya ducks. In Leghorn hens, however, there was no significant correlation between eggshell quality and eggshell Mg content, although the Mg content in the eggshell was also increased from 0.279% to 0.427% when the dietary Mg had been elevated from 690 mg/kg to 2380 mg/kg.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.7
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• pp.994-998
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• 2017

Objective: An experiment was conducted to determine the effect of superdosing phytase on productive performance and egg quality in laying hens. Methods: A total of 200 42-wk-old Hy-Line Brown laying hens were allotted into 1 of 5 dietary treatments with 5 replicates consisting of 8 hens per replicate. The positive control (PC) and negative control diets (NC) were prepared based on the recommended P levels in layer diets. Supplemental phytase was added to the negative control diet at 10,000 (SD10), 20,000 (SD20), or 30,000 (SD30) fytase units (FTU)/kg. Productive performance was summarized for 6 weeks from 42 weeks to 47 weeks of age. Egg quality was assessed from 4 eggs per replicate randomly collected at the conclusion of the experiment. Results: The SD20 treatment had greater (p<0.05) hen-day egg production than PC, NC, and SD10 treatment groups. There was no difference in hen-day egg production between SD20 and SD30 treatment groups. However, SD30 treatment had greater (p<0.05) hen-day egg production than PC treatment, but showed no difference in hen-day egg production as compared to NC and SD10 treatment groups. However, egg weight, egg mass, feed intake, and feed conversion ratio were not affected by dietary treatments. Egg quality including eggshell strength, eggshell color, egg yolk color, and haugh unit was not influenced by dietary treatments. Conclusion: Superdosing level of 20,000 FTU/kg phytase in diets has a positive effect on egg production rate, but no beneficial effect on egg quality in laying hens.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.10
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• pp.1654-1659
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• 2018

Objective: This study was conducted to investigate the effects of dietary supplementation with fermented and non-fermented brown algae by-products on the laying performance, egg quality, relative organ weight, and blood profile of laying hens. Methods: Hy-Line Brown chickens (n = 180; 70-week-old) were randomly divided into 5 groups with 4 replicates per group (3 hens per cage, 4 cages per replicate), and fed with 5 experimental diets, namely the basal control diet (CON) or the control diet supplemented with 0.5% brown seaweed (BS), 0.5% seaweed fusiforme (SF), 0.5% fermented brown seaweed (FBS), or 0.5% fermented seaweed fusiforme (FSF), for 4 weeks. Results: Egg production rate and egg mass were greater in the BS group than in the other groups (p<0.05), and the SF and FSF groups had greater egg production than the control group (p<0.05). Egg weight was higher in the BS group than in the other groups (p<0.05). There were no differences in eggshell color, egg yolk color, eggshell strength, or eggshell thickness among the groups. There was no difference in Haugh units among the treatment groups, except for the FSF group, which had a significantly lower value (p<0.05). The non-fermented groups had greater relative organ weights, particularly the liver and cecum, than the other groups (p<0.05). Regarding blood profile, the supplemented-diet groups had higher albumin levels than the control group (p<0.05). The FBS group had higher total cholesterol and triglyceride levels than the other groups (p<0.05). The BS and FBS groups had higher glutamic pyruvic transaminase levels than the other groups (p<0.05). Conclusion: This study demonstrated that dietary brown algae supplementation can improve egg-laying performance; however, supplementation with fermented seaweeds had no positive effect on the egg-laying performance of hens.

• Korean Journal of Poultry Science
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• v.29 no.2
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• pp.135-140
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• 2002

An experiment was conducted to determine the effects of vitamin C supplementation on the performance and egg quality of layers. A total of 800 ISA Brown layers of 71 weeks old were assigned to one of the following diets containing 0, 3, 10, 50 or 100 ppm LG-vitamin C, 100ppm free ascorbic acid, 100 ppm Rovimix stay C-35 or 50 ppm LG-vitamin C supplemented with 100 ppm Zn methionine chelate. The feeding trial was conducted for flour weeks during the period of May to June when the average ambient temperature was $23.8^{\circ}C$ (5 :00 PM). Each treatment was replicated five times with 20 birds housed in 2 birds cage units. Vitamin C supplementation did not improve the overall performances (egg Production and egg Quality). Birds fed 100 ppm of LG vitamin C had the lowest egg Production while birds fed 100 ppm of Rovimix-35 had the lowest egg weight among birds fed different sources of vitamin C. Although supplementation of vitamin C over 50 ppm increased soft and broken egg Production, supplementation of 10 ppm LG vitamin C showed lowest soft and broken egg Production among all treatments. E99she11 thickness was highest in the treatment of 50 ppm LG vitamin C. In conclusion, supplementation of vitamin C at the level of 3 ~ 100 ppm did not significantly influence the laying performance and eggshell quality of laying hens under normal ambient(20 ~$26^{\circ}C$ ) condition.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.9
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• pp.1296-1302
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• 2009

Ninety six beak-trimmed 72 week-old Lohmann Brown hens were randomly divided into four equal groups. Each group comprised 4 replicates. Isoenergetic and isonitrogenous experimental diets contained low calcium (3.5%); optimum calcium (4.2%); low Ca (3.5% Ca)+1% Clinoptilolite (CLP); low Ca (3.5% Ca)+2% CLP. Data were collected biweekly and the experiment lasted 6 weeks. Egg production, feed consumption, feed conversion ratio, egg weight, tibia Ca, P, ash and eggshell thickness were not affected by addition of CLP to the diets (p>0.05). There were no significant differences in egg shell strength and ash when data were analyzed individually in measurement periods ($74^{th}$, $76^{th}$ and $78^{th}$ weeks). However, according to pooled data ($74^{th}$-$78^{th}$ weeks), eggshell strength was increased (p<0.05) only by 2% CLP supplementation versus low Ca (3.5%) diet, and shell ash was significantly increased by 2% CLP supplementation compared with the other diets. The damaged egg ratio on 1% and 2% CLP diets was significantly decreased between 76-78 weeks'data when compared with the low Ca diet. However; damaged egg ratio on the 2% CLP diet was significantly decreased when pooled data (74-78) were compared with no CLP diets. The differences in marketable egg ratio paralleled damaged egg ratio. The plasma calcium level at the end of experiment was increased on the 2% CLP diet when compared with the low Ca (3.5%) diet (p<0.05). Furthermore, at the end of the experiment a marked decrease of manure moisture was observed on both CLP diets (p<0.01). In conclusion, Clinoptilolite (2%) supplementation to layer diets tends to improve eggshell quality and manure dry matter (1% and 2% CLP) after six weeks.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.8
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• pp.1028-1033
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• 2010

The effects of delta-aminolevulinic acid (DALA) or chito-oligosaccharide (COS) in layer diets on production performance, egg quality and hematological characteristics were investigated in this 8-week trial. Two hundred and seventy 27-week-old (Hy-Line brown) layers were randomly assigned to 5 treatments with 9 replications per treatment. Dietary treatments were i) Control (basal diet); ii) DALA1 (basal diet+DALA 2 mg/kg); iii) DALA2 (basal diet+DALA 4 mg/kg); iv) COS1 (basal diet+COS 100 mg/kg) and v) COS2 (basal diet+COS 200 mg/kg). In this study, no significant difference was observed in feed intake and egg shell quality (eggshell breaking strength and egg shell thickness) among treatments. The inclusion of DALA increased egg production during the first 4 weeks. Egg weight was increased in both DALA (quadratic, p<0.05) and COS (linear, p<0.05) treatments compared with the control treatment. Laying hens fed the DALA treatment had an increased yolk color unit (quadratic, p<0.05) and haugh unit (linear, p<0.05) compared with the control group. Similarly, these characteristics were also affected by COS treatments, with both values being linearly increased (p<0.05) in COS treatments compared with the control treatment. Additionally, birds fed DALA treatments significantly increased (quadratic, p<0.05) the number of RBC, WBC and lymphocytes compared with the control treatment. Dietary DALA supplementation linearly increased (p<0.05) the serum iron concentration at the end of the 8th week. The inclusion of COS increased (linear, p<0.05) the concentration of RBC, WBC and lymphocytes compared with the control treatment. In conclusion, dietary DALA at the lower dosage (2 mg/kg) could exert better effects in laying hens than higher dosage (4 mg/kg). Birds fed DALA supplemented diet had an increased iron availability, egg weight, eggshell quality and immunity. Moreover, the inclusion of COS (200 mg/kg) can increase egg weight, eggshell quality and immunity in laying hens. Therefore, both the utilization of COS and DALA could be considered as a new strategy for optimizing egg quality and health condition of laying hens.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2001.11a
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• pp.58-60
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• 2001

Two experiments were conducted to study the effects of nutrient level and feeding method of split diets for a.m. and p.m. on laying hen performance. In both studies, ISA Brown layers were kept in laying hen cages and treatments were represented by three or four replicates each containing 25 or 34 birds. In Experiment 1, the control group(C) was fed a conventional single diet throughout the day and split diet groups(T1, T2 and T3) were offered high energy/protein - low Ca diet and low energy/protein - high Ca diets in a.m. and p.m., respectively. In split diet groups, ME and CP consumption, and feed cost required per day and per kg egg mass were significantly reduced(P＜0.05) compared to C group, while the hen-day egg production, average egg weight and daily feed intake were not different among treatments. In the second study, C and T1 groups were fed the diets same to the C and T2 groups in Experiment 1, respectively. And T2 group was fed the diet mixed with the split diets for a.m. in mash and p.m. in pellet used in T1 group. In T1 and T2 groups, daily feed intake and average egg weight were significantly reduced(P＜0.05), while the hen-day egg production was not influenced by the feeding system. Daily ME and CP consumption, and feed cost were reduced(P＜0.05) in T1 and T2, while the ME, CP and feed cost required per kg egg mass were not different to the C group. In both study, eggshell qualities were improved(P＜0.05) by split diet feeding. It was concluded the feed and nutrients consumption, feed cost per day or per kg egg mass could be spared by introducing split diets for a.m. and p.m., and the feeding method of mixed diet of split diets was also convenient and effective for sparing feed cost and improvement of eggshell quality.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.6
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• pp.840-846
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• 2015

The objective of this study was to investigate the effects of dietary corticosterone on egg quality. For 2 weeks hens received either control or experimental diet containing corticosterone at 30 mg/kg diet. Feed intake and egg production were monitored daily, and body weight measured weekly. Egg weights and egg quality were measured daily. Corticosterone treatment resulted in a remarkable increase in feed intake and sharp decrease in egg production compared with control (p<0.05) whereas body weight remained unchanged. Decreased albumen height, but no changes in egg weight, led to decreased Haugh unit (p<0.05). Corticosterone caused elevated eggshell thickness (p<0.05) without altering weight and strength, suggesting possible changes in shell structure. Yolk color and redness were increased by corticosterone (p<0.05) but lightness and yellowness were either not changed or inconsistent over the time period of measurements. Increased concentrations in plasma were also found for corticosterone, glucose, cholesterol, creatinine, uric acid, albumin, aspartate aminotransferase, creatine kinase, lactate dehydrogenase, total protein, and amylase (p<0.05), suggesting that corticosterone increased protein breakdown, renal dysfunctions and pancreatitis. Together, the current results imply that dietary corticosterone affects egg quality such as yolk colors and shell thickness, in addition to its effects on feed intake and egg production.

• Korean Journal of Poultry Science
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• v.50 no.2
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• pp.73-80
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• 2023

Vitamin D3 is an essential nutrient which plays an important role in calcium metabolism for eggshell formation, in calcium and phosphorus metabolism for bone mineralization, and in maintaining host immunity. Although there have been a great deal of studies investigating the role of vitamin D3 in eggshell quality and vitamin D3 contents in eggs, no attempts have been made to monitor the eggshell quality and vitamin D3 contents in eggs at farm level. Thus, this survey was conducted to measure eggshell quality and vitamin D3 contents in eggs laid from laying hens fed diets containing different levels of vitamin D3. Eggs from four commercial laying hen farms were sampled before and 1, 2, 3 and 5 weeks after provision of the vitamin D3-enriched diets added with the level of 16,500 IU and 29,000 IU. Dietary vitamin D3 did not affect the eggshell color and breaking strength, but increase the eggshell thickness. In addition, vitamin D3 contents in eggs were elevated as vitamin D3 in diets was increased. It is concluded that addition of dietary vitamin D3 into the diets of laying hens at the commercial laying hen farms could improve eggshell quality and vitamin D3 contents in eggs. It is expected that the prediction equation for egg vitamin D3 contents might be produced if more data on vitamin D3 contents in diets and eggs at the farms are to be analyzed.