• Korean Journal of Poultry Science
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• v.8 no.2
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• pp.55-68
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• 1981

Calcium and phosphorus are not only indispensable for the bone formation and body fluids equilibrium but also are major components of egg shell. It is nutritionally important, therefore, to investigate the metabolism of calcium and phosphorus and to search for optimum requirement of calcium and phosphorus and the availability of various sources of calcium an4 phosphorus by poultry. An attempt was made to review the nutrition of calcium and phosphorus in poultry diets. 1, Calcium and phosphorus have great interrelationship with vitamin D in their metabolisms. 2. Most of the plant-origin phosphorus are existing in phytic form and it leads to low availability when used in poultry rations, although calcium and phosphorus present in animal-origin or mineral supplements are highly available in general. 3. Calcium and phosphorus requirement from existing information indicated that 1.0% calcium and 0.7% phosphorus for broiler and egg-type chicks, and 3.5% calcium and 0.4% phosphorus for laying hen. 4. It has been recommended that calcium and phosphorus level should be increased when the feed intake was decreased or when the egg Production rate was higher or when the hens are old. 5. Mono-, ci-, tri-, calcium phosphate, calcium carbonate, bone meal, limestone and oyster shell u the most readily available among various sources of calcium phosphorus supplements. Soft rock phosphate, deflourinated phosphate and gypsum are somewhat inferior to the previous ones in bioavailability. 6. The effect of particle size of calcium supplements on egg shell quality and egg production rate is not yet clearly defined but recent works showed that oyster shell is more available when it was coarse and limestone is more available when it was fine in panicle. size. 7. Present data indicated that mixed feeding of oyster shell and limestone is superior to the single feeding of each on laying performance. 8. Significant interaction between phosphorus and sodium was observed, that is, excessive sodium decreased egg production in layer and body weight growth in broiler in the low phosphorus diets but increased them in the high phosphorus diets.

• Korean Journal of Poultry Science
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• v.18 no.2
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• pp.67-84
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• 1991

The purpose of this study was to investigate the effects of dietary protein levels on laying hen performance. The level of methionine and lysine were 0.32% and 0.64%, respectively and the levels of protein were 12%, 13%, 14% or 15%. Total 384 laying pullets of 22weeks age were reared from January 28, 1989 to March 23, 1990 for 60 weeks. The results obtained were summarized as follows : 1 Egg productions was highest at 15% of protein in phase I, 14% in phase II, and 13% in phase III, and there was significantly different egg Production among treatments during phase I and phase II (P＜0.05). 2. Egg weight was heaviest in 14% of protein treatment in three phases and they showed significantly different egg weight among different levels of protein in phase I (P＜0.01), phase II and III (P＜0.05) , but there was not significantly different between 14% and 15% of protein. 3. Daily egg mass tends to increase followed by increasing of protein level and showed signifiant differences among treatments in phase I and phase II (P＜0.01). 4. The 14% of protein treatment showed the highest daily feed intake and it showed significant difference in phase I and phase II (P＜0.01) , but there was no significant difference between 14% and 15% of protein. 5. Feed efficiency was improved significantly followed by increasing of protein level in phase I (P＜0.01) and phase II (P＜0.05), but there was no significant difference among treatments in phase III. 6. Viability tends to increase as increasing of protein level, but there was no significant difference among treatments. 7. Utilizabilities of dry matter, crude protein and ether extract of experimental diets were not different among treatments, but the utilizability of carbohydrate tends to increase as increasing of protein level (P＜0.05). 8. Eviscerated yield and abdominal fat accumulation was not difference among treatments. 9. Egg shell quality and chemical composition of egg content were not different among treatments. 10. The feed cost per kg egg mass showed the cheapest in 13% of protein treatment in all phase, but there were no significant differences among treatments.

• Korean Journal of Poultry Science
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• v.30 no.4
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• pp.229-233
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• 2003

A study was conducted to investigate the effects of different BW control methods during rearing on laying performance of broiler breeder pullets. D-old 540 female breeder chicks (Arbor Acres) were assigned to three treatments consisted of standard BW (Control), 110% of standard BW at 12 wk of age (T1), and 90% of standard BW at 12 wk of age (T2), with three replicates of 60 birds per replicate (pen) for each treatment. At 20 wk of age, all birds from three treatments reached the BW reqired in the Arbor Acres Manual. There were no significant differences in egg production, egg weight and viability during laying period(p>0.05). However, total egg production rates were improved in T2 and T3. Average egg weight was the highest in T1 among all treatments. Fertility and hatchability were similar among treatments, but T2 tended to be higher than other treatments at 37 and 53 wk of age. No significant difference was found in hatchability among three treatments. The number of hatching egg of T2 reached 168 per year, showing higher number of eggs than did the other treatments. The number of hatched chicks in T2 was 131, which was also higher than the other treatments, but the difference was not significant. It appears that the laying performance of broiler breeder hens could be improved when their BW at 12 wk of age are kept at 90% of standard BW, and reach the standard BW at 20 week of age.

• Food Science of Animal Resources
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• v.28 no.5
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• pp.645-650
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• 2008

The effects of various levels of dietary dried whole crop of kale (0.1%, 0.3%), dried peel of kale (0.3%), dried whole crop of Angelica keiskei (Koidz) (0.1%, 0.3%), and peel of Angelica keiskei (Koidz) (0.3%) in egg-laying performance were studied with 560 ISA brown layers for a period of 12 weeks. No significant differences were recognized between the treatments and control in egg production, feed intake and egg mass. The quality of egg and eggshell were not different among treatments but egg yolk color was improved in the both of whole crop and peel of kale and Angelica keiskei (Koidz). Vitamin and polyunsaturated fatty acid concentration of eggs increased in treatments compared to control but were not significantly different from controls. In conclusion, dried peel of kale and Angelica keiskei (Koidz) supplementation in laying hens diet improved egg yolk color, and improve vitamin concentration of chicken eggs.

• Korean Journal of Poultry Science
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• v.39 no.2
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• pp.157-161
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• 2012

The objective of this study was to evaluate the effects of feeding dried Thymus vulgaris powder (TVP) on the layer performance, egg quality and egg yolk fatty acid composition. Two hundred eighty eight, 35 weeks old Brown nicks were allocated in the cage for five TVP (0, 0.25, 0.5, 1.0 and 2.0%) diets with four replicates in each treatment. Each basal diet contained 16.0% CP and 2,800 kcal/kg ME and supplied to layers for 8 weeks. Egg production and egg weight were not statistically different but numerically increased in birds fed 2.0% TVP than other treatments. Egg mass was not consistent depending on the TVP addition levels in diets. Feed intake was significantly lower in TVP addition treatments than the control (p<0.05), however, feed conversion was not significantly differed among control and treatments (p<0.05). Dietary addition of 2.0% TVP showed high values on albumin height, Haugh unit and egg yolk color and they are 7.93, 86.79 and 7.20, respectively (p<0.05). Palmitic and arachidonic acids were remarkably lowered when 2.0% TVP added to basal diets and then fed to birds for 8 weeks, in contrast, significantly higher linolenic acid composition was determined in birds fed 2.0% TVP (p<0.05). As the results, the highest unsaturated fatty composition and UFA/SFA ratio were observed in 2.0% TVP treatment as compared to those of control and other treatments. Therefore, the results indicate that the Thymus vulgaris powder addition to basal diet tended to have positive effects on egg quality and egg yolk fatty acids composition, and the optimum addition of Thymus vulgaris powder may be 2.0%.

• Korean Journal of Poultry Science
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• v.34 no.4
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• pp.245-251
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• 2007

This study was conducted to investigate the effects of modification of a herbal recipe(Herb $Mix^{(R)}$) on the growth of pullet and laying performance of hens. The formula of Herb $Mix^{(R)}$, a mixture of Rehmannia glutinosa, Angelica gigas, Discorea japonica, Glycyrrhiza uralensis, Schisandra chinensis and Ligusticum jeholense, was modified in mixing ratio. A total of 1,120 pullets(Hy-Line Brown) of 14 wks old were assigned to seven treatments; control, Herb $Mix^{(R)}$(HM), R. glutinosa fortified HM, A. gigas fortified HM, D. japonica fortified HM, G. uralensis fortified HM, S. chinensis fortified HM, L. jeholense fortified HM and Flavomycin supplemented diet. Each treatment had 8 replicates of 20 birds each housed in 2 birds cages. Body weight at 10% egg production was significantly(P<0.05) influenced by treatments. Birds fed A. gigas fortified HM diet were heaviest followed by L. jeholense fortified HM, HM-original and D. japonica fortified HM, Flavomycin supplemented diet and R. glutinosa while those fed control diet were lightest. Also, age reaching 50% egg production and peak production was earliest in A. gigas fortified HM and latest in the control. Egg production, feed intake, feed conversion and egg weight were significantly influenced by treatments. Significant improvement in egg production and feed intake was shown in A. gigas fortified HM treatment. Feed conversion ratio was lowest in antibiotic(Flavomycin) treatment and egg weight was heaviest in L. jeholense fortified HM treatment. There were no significant differences among treatments in intestinal microflora but cfu of Cl. perfringnes and E. coli tended to be lower in HM treatments than the control. Among the leucocytes of blood, the HM treatments were lower than the control in counts of white blood cell and heterophils. It was concluded that modification of Herb $Mix^{(R)}$ fortifying with A. gigas, D. japonica and L. jeholense significantly influence growth and laying performance of birds.

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

• Korean Journal of Poultry Science
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• v.23 no.1
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• pp.27-37
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• 1996

This experiment was carried out to study the effects of feeding split diets for a.m. and p.m. on laying hen performance and feed cost with 480 ISA Brown layers for three periods during 32∼36, 52∼56 and 72∼76 wk of age, respectively. The control group(C) was fed a conventional single diet throughout the day and split diet groups (T$_1$, T$_2$, T$_3$, T$_4$ and T$\_$5/) were offered high energy-high protein-low Ca diets, and low energy-low protein-high Ca diets in a.m. and p.m., respectively. In split diet groups, feed intake, ME and CP consumption, and feed cost were significantly reduced(P<0.05) compared to the C, while the hen-day egg production was significantly improved. However, the average egg weight was not influenced by the feeding system. Due to the reduced daily feed, ME, and CP intakes, and the improved egg production, the conversions of feed, ME, CP, and feed cost required per kg egg mass were also significantly improved (P<0.05) in splits diet groups. Among split diet groups, the T$_2$ group fed the diet devoid of Ca supplement from the conventional laying hen diet in a.m., and the diet containing the Ca supplement 2 times the conventional diet in p.m., was superior in conversion of nutrients and feed cost per kg egg mass to the other split diet groups. It was concluded that daily feed and nutrients cousumption and daily feed cost could be reduced 5∼6％ while hen-day egg production could be improved about 4％, so that about 10％ of the feed and nutrients and feed cost per kg egg mass could be spared by introducing the split diet feeding for a.m. and p.m. based on T$_2$ treatment in laying hens.

• Korean Journal of Poultry Science
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• v.30 no.2
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• pp.83-90
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• 2003

This study was conducted to determine the effects of stocking density on performance and physiological responses of egg-type breeder layers in cages. A total of 264 Hy-Line Brown egg-type breeder layers at the age of 32 weeks were divided into 4 groups with 3 replicates of 22 birds (20 females, 2 males) per replicate and assigned to four stocking density treatments with 22 birds per cage with different sizes (980, 735, 640 and 560 $\textrm{cm}^2$/bird). The birds were fed the same experimental diet ad libitum for 12 weeks, and laying performance, egg and eggshell qualities, fertility and hatchability were determined. At the end of the experimental period, 9 birds were selected in each treatment in order to measure the scores of plumage condition. Antibody titers to Newcastle disease and infectious bronchitis were also determined. No significant differences were observed in laying performances, eggshell strength, Haugh unit, fertility and hatchability among the treatments. In birds housed 640 $\textrm{cm}^2$ per bird, eggshell thickness were significantly lower (P<0.05) than those of the other groups from 7 to 12 weeks. There was no significant difference in antibody titers to Newcastle disease. In birds housed 980 $\textrm{cm}^2$ per bird, antibody titers to infectious bronchitis were significantly (P<0.05) higher than those of the other groups. With increase in the level of stocking density, the scores of plumage condition were also significantly decreased (P<0.01). This study demonstrated that moderate increment of stocking density did not resulted in reduction in laying-performances of egg-type breeder layers. However, it seemed that the higher stocking density might give more stress to the birds from physical stimuli and thus were harmful environment causing higher mortalities compared to the lower ones.

• Korean Journal of Poultry Science
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• v.46 no.1
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• pp.17-24
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• 2019

Chickens have been considered as well-defined animal bioreactor. The optimized ovalbumin promoter is essential for recombinant protein production in transgenic chicken. Here we try to compare the activity and identify the effect of estrogen on ovalbumin promoter according to each promoter length with estrogen response element (ERE) existence. We cloned two (2.8 and 5.5 kb) ovalbumin promoters that the 5.5 kb contained the ERE but the 2.8 kb did not, and these two promoters were cloned to pGL4.11 vector. Additionally, we constructed another pGL4.11 vector containing of the 4.4 kb (with ERE) ovalbumin promoter deleted with 1 kb between ERE region and the 2.8 kb promoter. For reporter assay, HeLa, MES-SA, LMH/2A, and cEF cells were transfected with all the pGL4.11 vectors. The comparative analysis showed that the mutated 4.4 kb promoter has more potent activity than the 2.8 and 5.5 kb promoters in HeLa, MES-SA, and LMH/2A cells. However, there is no significant difference in cEFs. Also, these cells transfected with the mutated 4.4 kb promoter were treated with the $17{\beta}$-estradiol (0~3,000 nM) and HeLa, MES-SA, and LMH/2A cells showed estrogen responsibilities, but cEFs did not. Besides, the mutated 4.4 kb promoter has still higher activity than the 2.8 and 5.5 kb promoter, and there is no transcriptional induction effect in 2.8 kb promoter at 500 nM estrogen that is blood concentration of laying hens. Hence our study strongly suggested that the mutated 4.4 kb promoter is considered as one of the most efficient length for generating transgenic chicken.