• Korean Journal of Poultry Science
• /
• v.40 no.1
• /
• pp.67-73
• /
• 2013

With an increasing concern on laying hen welfare, barn system has appeared as one of the alternatives to replace the conventional cage. This study was conducted to compare the early laying performance and egg quality at the barn system with those at the conventional cage. A total of 288 shaver-579 brown layers were used for 9 weeks ($21^{st}$ to $30^{th}$ weeks of age) feeding study. Feed consumption and egg weight were significantly (P<0.01) higher at barn than at cage. However, there were no significant differences between two housing systems on hen day egg production (HDEP), egg mass, body weight, feed efficiency and livability. In case of egg quality parameters, shell thickness, albumen height and Haugh unit were significantly (P<0.05) different between two systems. Haugh unit and albumen height were significantly higher in eggs produced at cage (88.97 and 8.16 mm) compared than those produced at barn (83.11 and 6.87 mm), whereas shell thickness was thicker in eggs produced at barn than those produced at cage. Shape index, breaking strength, blood spots and yolk index data were not influenced significantly by the types of housing system. To implement welfare bestowing production, this study showed that the barn system can replace the conventional cage without serious sacrifices on starting phase egg production. In addition, this study suggested that the barn system need to be optimized in view of daily feed consumption.

• Korean Journal of Poultry Science
• /
• v.36 no.4
• /
• pp.311-316
• /
• 2009

The study was conducted to evaluate the effects of dietary acid hydrolysates of cocoon on laying performance, egg quality, blood level of immune substance and cholesterol in laying hens. The animals used in the experiment were a total of 240 Hy-Line Brown laying hens (41 weeks old). Dietary treatments included 1) CON (basal diet), 2) SP1 (basal diet + acid hydrolysates of cocoon 0.05%), 3) SP2 (basal diet + acid hydrolysates of cocoon 0.1%) and 4) SP3(basal diet + acid hydrolysates of cocoon 0.2%) twelve laying hens were allotted to a block (pen) with five replicated. Through the whole period of experiment, egg production, egg weight, egg shell breaking strength and egg shell thickness were no significant difference. However, acid hydrolysates of cocoon treatments (SP1, SP2, SP3) significantly increase their egg yolk height and Haugh unit compared to control (P<0.05). IgG and WBC (white blood cell) contents in blood were higher in SP1, SP2, SP3 treatment compared to control (P<0.05). However, albumin and total protein content in blood were no significant difference. Phospholipid, HDL-cholesterol, LDL-cholesterol and total cholesterol contents in serum were higher in SP1, SP2, SP3 treatment compared to control (P<0.05). In conclusion, supplement dietary acid hydrolysates of cocoon improved egg yolk height, Haugh unit, and blood level of phospholipid, HDL-cholesterol, LDL-cholesterol, total cholesterol in laying hen.

• Journal of Animal Science and Technology
• /
• v.54 no.1
• /
• pp.43-49
• /
• 2012

This study was carried out to investigate the effects of age of laying hens and grade of shell abnormality on internal egg quality. At each week, 1,000 eggs were randomly selected from 21,000 eggs laid by Hy-Line hens (100,000 birds) aged from 56 to 62 wk. The samples were divided into normal and externally abnormal eggs by an official egg grader. Then, egg quality including egg weight, egg white height, Haugh unit and yolk color was evaluated from each normal and abnormal eggs. The production rate of externally normal and abnormal eggs was 81.22 and 18.78%, respectively. No difference found in the production rate by the increase of hen's age, but Haugh unit of eggs from hens of 60-wk-old was higher (p<0.05) than that of 56-wk-old. When the same age groups were compared, egg white height and Haugh unit were lower in eggs which were externally abnormal. When the grade of abnormality increased, egg white height and Haugh unit were decreased further (p<0.05). Among the externally abnormal eggs, malformation showed the lowest Haugh unit. In conclusion, the shell abnormality of eggs laid by hens aged 56 to 62 wk was closely related with internal egg quality. Therefore, the grading external egg quality in the present egg grading system is directly related with the internal egg freshness.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.5
• /
• pp.694-699
• /
• 2009

The present study was conducted to evaluate the effect of chilled drinking water on the productivity of laying hens under constant high ambient temperature. A total of seventy-two, 123-day-old Hy-line brown layers was divided into two equal groups. The first group (UDWG) was given unchilled water ($23.0{\pm}2.5^{\circ}C$) as a control, and the second group (CDWG) was given chilled water ($16.0{\pm}0.5^{\circ}C$). The laying hens were kept at $30^{\circ}C$ constant temperature with 50% relative humidity and were exposed to 17 h of light per day. Feed intake, egg production, egg quality (egg weight, shell weight, shell thickness, egg color, yolk color, and Haugh unit), and blood samples were collected and analyzed. The results showed that the feed intake of CDWG laying hens was significantly higher (11.64%) than the UDWG counterparts (p<0.01). Egg production of CDWG was also significantly higher (11.27%) than the UDWG counterparts (p<0.001). Furthermore, we observed that the CDWG laying hens had significantly higher (11.72%) levels (p<0.10) of blood calcium, with a corresponding value of 21.92 mg/dl compared to the UDWG hens (19.62 mg/dl). The higher calcium concentration in the CDWG animals may contribute to increased egg production. The CDWG laying hens also contained higher (12.53%) phosphorus concentrations in blood compared to the UDWG (4.22 mg/dl vs. 3.75 mg/dl), although not statistically different (p>0.10). Egg weight and egg quality were not affected by chilled drinking water. In conclusion, providing chilled drinking for laying hens under high ambient temperature improved feed intake and egg production.

• Korean Journal of Poultry Science
• /
• v.32 no.4
• /
• pp.269-273
• /
• 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.

• Korean Journal of Poultry Science
• /
• v.29 no.1
• /
• pp.7-12
• /
• 2002

This study was conducted to investigate the effects of feeding germanium colloid(GC) on the egg quality and immune response in 1aying hens. One hundred forty four layers, 32-wk-old ISA Brown, were used in a 40-d experimental assay with a 7-d adjustment Period. Dietary treatments included 1) control (basal diet; CON), 2) 0.5ppm GC (basal diet + 0.Sppm germanium), 3) 1.0ppm GC (basal diet + 1.0 ppm germanium) . For overall Period, hen-day e99 Production tended to be increased as the concentration of GC in the diets was increased with significant difference (linear effect, p<0.01) . Laying hens fed 0.5ppm GC diet were significantly (P<0.01) lower in egg shell breaking strength than laying hens fed CON or 1.0 ppm GC diets. Egg shell thickness and yolk color were not influenced by GC supplementation. Laying hens fed 1.0ppm GC diet were h19her in egg yolk Index than laying hens fed CON and 0.5ppm GC diets with significant difference (quadratic effect, p<0.02) . As adding level of germanium colloid increased in the diets, the total serum cholesterol and triglyceride tended to be decreased. However, the effect of GC supplementation did not show significant in the levers of total serum cholesterol and triglyceride. Also, HDL- and LDL+VLDL-cholesterol in serum were not statistically different among the treatments. Red blood cell and white blood cell count in blood tended to be increased as the concentration of GC in the diets was increased with significant difference (P<0.01) . Hematocrit concentration in blood was successfully Increased by supplementation of GC (P<0.01) . In conclusion, although egg quality was not influenced by GC supplementation, supplementing GC Improved Immune status in laying hens.

• Korean Journal of Poultry Science
• /
• v.30 no.1
• /
• pp.61-66
• /
• 2003

This study was conducted to investigate the effects of dietary germanium biotite supplementation on egg quality and fecal noxious gas content in laying hens. One hundred and forty-four 40-wk-old, ISA Brown layers were used in this experiment. Dietary treatments were 1) CON(control diet), 2) GB0.5(control diet + 0.5% germanium biotite), 3) GB1.0 (control diet + 1.0% germanium biotite) and 4) GB1.5(control diet + 1.5% germanium biotite). Hen-day egg Production and egg shell breaking strength were not influenced by germanium biotite supplementation. However, egg weight decrease as the level of germanium biotite supplementation increased in the diets increased(Cubic effect, p<0.02). Eggshell thickness, yolk color and yolk index were not influenced by garmanium biotite supplementation. Serum triglyceride concentration as dietary germanium biotite increased (linear effect P<0.02; quadratic effect, p<0.05). Dietary supplementation of germanium biotite reduced fecal NH$_3$-N concentration (P<0.01), propionic acid(P<0.01), butyric acid( P<0.05) and acetic aicd(P<0.01) concentrations in the feces. In conclusion, the results of this experiment indicated that dietary germanium biotite supplementation did not affect egg shell quality, but reduced fecal NH$_3$-N concentration.

• Korean Journal of Poultry Science
• /
• v.51 no.2
• /
• pp.27-37
• /
• 2024

The poultry plays a crucial role in the animal industry, providing humans with efficient, high-quality animal protein. The rapid growth and short generational intervals of broilers offer significant benefits compared to other economic animals. This growth and increased muscle mass in modern commercial broilers result from advancements in breeding. However, the high productivity of contemporary broilers indicates they are approaching their physiological limits, with excessive fat accumulation becoming a significant industry issue. This not only reduces lean meat yield and feed efficiency but also negatively impacts consumers, especially due to problematic abdominal fat, which consumes more energy than lean meat production. Laying hens, reared for extended periods, maintain high productivity, producing a substantial number of eggs. This productivity in laying hens, akin to broilers, stems from genetic selection and breeding. For egg production, laying hens require physiological support for necessary nutrients. In this context, yolk fat accumulation is a critical physiological process. Lipoproteins, essential in avian lipid metabolism, are vital for yolk and body fat accumulation. Understanding these lipoproteins and their metabolism is key to developing healthier, more productive animals, offering economic benefits to farmers and improved nutritional quality to consumers. This review focuses on the physiological aspects of dietary fat transport, fatty acid biosynthesis in the liver, fat accumulation in the abdomen and muscles, and lipid deposition in egg yolks in chickens. It also highlights recent research trends in the regulation of fat metabolism in poultry.

• Korean Journal of Poultry Science
• /
• v.35 no.2
• /
• pp.131-136
• /
• 2008

This study was conducted to investigate the effects of dietary conjugated linoleic acid (CLA) and oil containing unsaturated fatty acid supplementation on egg production and quality in laying hens. Two hundred-eighty eight, 36 week old ISA brown commercial layer, were employed in a 5 week feeding trial. Dietary treatments are 1) BO (basal diet + 1% soybean oil + 1% oat), 2) BS (basal diet + 1% safflower oil + 1% oat), 3) BF (basal diet + 1% free fatty acid + 1% oat), 4) CD (basal diet + 1% CLA containing diglyceride + 1% oat), 5) CT (basal diet + 1% CLA containing triglyceride + 1% oat) and 6) CP (basal diet + 1% CLA by-product + 1% soybean oil). For overall period, hen-day egg production was not significant among treatments (P>0.05). Egg shell breaking strength at 3 weeks in CP treatment was significantly lower than BS, BF, CD and CT treatments (P<0.05) and that at 4 weeks in BO and CP treatments was significantly lower than others (P<0.05). Egg shell thickness at 3 and 4 weeks in CP treatment was significantly lower than BS, BF, CD and CT treatments (P<0.05). Egg weight at 3 and 4 weeks in CP treatment was significantly lower than others (P<0.05). Yolk height at 4 weeks in BF and CT treatments was significantly highest compared to BO, CD and CP treatments (P<0.05) and among BO, CD and CP treatments, that in BO and CD treatments was significantly higher than CP treatment (P<0.05). At 4 weeks, yolk color in CP treatment was significantly higher than BO and BS treatments (P<0.05). Haugh unit at 3 and 4 weeks in BO and CP treatments was significantly lower than others (P<0.05). In conclusion, supplementing CLA and oil containing unsaturated fatty acid for laying hens improved egg shell breaking strength, egg shell thickness, egg weight, yolk height, yolk color and haugh unit.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.7
• /
• pp.1015-1019
• /
• 2003

A 50 day feeding trial was conducted with White Leghorn (WL) laying hens, 42 weeks old, to determine if feeding of varying levels of aflatoxin (AF), ochratoxin A (OA) or their combinations has any effect on their performance and egg quality parameters. Feeding of $T_4$, $T_7$, $T_8$, $T_9$ and $T_10$ caused significant reduction in feed intake of hens. Hen day egg productions were significantly reduced at all the levels of toxins except 0.5 ppm of AF. Maximum reduction in egg production was noticed at 2 and 4 ppm of AF and OA, respectively. Average body weight and egg weight were not affected by toxin feeding. The feed efficiency in terms of net feed efficiency and feed consumed per dozen egg produced was significantly reduced at higher levels of both the toxins and their combinations. Feed consumption for production of 1 kg egg mass remained uninfluenced due to aflatoxin feeding whereas significant increase in the value of the same was noticed at 4 ppm level of OA and combination of 1 and 2 ppm of AF and 2 and 4 ppm of OA ($T_9$ and $T_10$), respectively. Various levels of OA (1-4 ppm) and all the combination of two toxins ($T_8$, $T_9$ and $T_10$) significantly altered the shape index of eggs in laying hens. The shell thickness was significantly reduced by higher level of AF (2 ppm), OA (2 and 4 ppm) and their combination. Albumen index, Haugh Unit and yolk index remained unchanged due to incorporation of toxins in the diet. It is concluded that AF, OA either singly or in combination at higher levels could depress the performance in terms of egg production and feed efficiency significantly. The egg quality parameters i.e. shape index and shell thickness were also significantly affected.