• Asian-Australasian Journal of Animal Sciences
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• v.17 no.11
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• pp.1553-1561
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• 2004

Two feeding trials were conducted with 128 pullets from 4 to 20 weeks of age and 96 laying hens from 23 to 63 weeks of age to evaluate the effects of scavenging and type of protein supplement on the feed intake and performance of improved pullets and laying hens. The experiments had a completely randomized design with four dietary treatments and four replicates. Treatments were: Control (Cont), scavenging but with access to a balanced concentrate at night; confinement (CF) and given the control feed ad libitum; scavenging and supplemented at night with the control feed, but with soybean meal replaced by cassava leaf meal (CLM); scavenging and supplemented at night with the control feed, but with fishmeal replaced y soybean meal (SBM). The mean daily dry matter (DMI), metabolizable energy (MEI) and crude protein intakes (CPI) of the pullets and laying hens, respectively, were 28%, and 18% higher for the confinement treatment (CF) compared to the scavenging treatments (p<0.001). The DMI, MEI and CPI of the pullets were not significantly different among scavenging treatments (p>0.05), but for the layers DMI, MEI and CPI were significantly higher for the CLM and SBM treatments compared to the Cont treatment (p<0.001). In the growing period, the average daily weight gain (ADG), supplement feed conversion ratio (FCR) and supplement feed cost/kg eggs (FCS) were not significantly different for CF compared to Cont, and among scavenging treatments (p>0.05). In the laying period, the hen-day production was significantly lower, and supplement FCR and FCS significantly higher for the CF compared to the scavenging treatments (p<0.001). Egg weight, and yolk, albumen and shell percentage and shape index were not significantly different among the scavenging treatments (p>0.05). However, shell and yolk percentages were significantly lower for the CF compared to the Cont treatment (p<0.01). Mortality was significantly higher for the CF compared to the scavenging treatments for pullets, and was significantly lower for the CF compared to scavenging treatments for laying hens (p<0.001). It was concluded that scavenging pullets and layers were getting around 28% and 18%, respectively, of their nutrient requirements from scavenging activities, resulting in correspondingly lower supplement feed conversion ratios and feed costs. Daily gains of the pullets were not affected by scavenging or protein supplement, but egg production and mortality were lower for the confined hens.

• Korean Journal of Poultry Science
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• v.32 no.1
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• pp.9-14
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• 2005

This study was conducted to investigate the effects of Bacillus subtilis on the egg qualify, blood characteristics and fecal $NH_3-N$ in laying hens. A total of two hundred fifty two laying hens were randomly allocated into three treatments with seven replications for six weeks. Dietary treatments included 1) CON (control; basal diet), 2) BS0.2(control + $0.2\%$ Bacillus subtilis) and 3) BS0.4 (control +$0.4\%$ Bacillus subtilis). For overall Period, hen-day egg production tended to increase by the Bacillus subtilis $0.4\%$ in the diets, but was no significant difference. Egg weight, egg shell breaking strength, egg shell thickness, Haugh Unit, yolk color unit and egg yolk index were not affected by treatments. Difference of egg weight and egg shell breaking strength in the BS0.2 treatment tended to increase without significant difference. Difference of egg yolk index in laying hens fed Bacillus subtilis was increased (P<0.05). The concentrations of red blood cell (RBC) and white blood cell (WBC) were not significant difference. $NH_3-N$ concentration in feces with BS0.4 treatment was significantly (P<0.05) lower than control. In conclusion, dietary Bacillus subtilis could decrease fecal $NH_3-N$.

• Korean Journal of Poultry Science
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• v.37 no.1
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• pp.51-62
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• 2010

This study was conducted to investigate the effects of dietary supplementation of multiple probiotics on the performance, small intestinal microflora and immune response in laying hens and broilers. In Exp.1, a total of 800, 82 wk old Hy-line Brown$^{(R)}$ laying hens were assigned to one of the following five dietary treatment; Control, Antibiotics (avilamycin 6 ppm), Probiotics; PB-M (Micro-ferm$^{(R)}$ 0.2%), PB-L (Lacto-sacc$^{(R)}$ 0.1%), PB-Y (Y University probiotics 0.2%). Each treatment was replicated eight times with 20 birds in each replicate and two birds were housed in each cage. Twenty birds units were arranged according to completely randomized block design. Feeding trial lasted 6 wk under 16 h lighting regimen. The Exp. 2, was conducted with a total of 1,000 broilers chicks (Ross$^{(R)}$). They were divided into five treatments, same as those of Exp. 1. Birds were fed starter (0~3 wk) and grower (4~5 wk) diets. Each treatment was replicated four times with 50 birds per pen comprising of deep litter. In Exp. 1, egg production parameters, such as hen-day and hen-house egg production, egg weight, broken and soft shell egg production, feed intake and feed conversion were not significantly different among treatments. However, strength and thickness of eggshell were significantly (P<0.05) different. Among the probiotics, PB-Y showed the highest strength and thickness of eggshell. Eggshell color, egg yolk color and Haugh unit were not significantly influenced. In Exp. 2, overall weight gain (0~5 wk) and mortality were not significantly different among treatments. However, weight gain of birds from PB-Y treatment during starter (0~3 wk) was significantly lower than the birds from Control and Antibiotic treatment. During the whole period (0~5 wk), birds from Antibiotics treatment had higher feed intake and Production Index (PI) and lower feed conversion than birds from Control treatment. Probiotics treatments were not significantly different from the Control on feed intake and feed conversion. In Exp.1, there were significant (P<0.05) differences in leukocytes parameters, such as white blood cell (WBC), hetrophil (HE), lymphocytes (LY), monocyte (MO), eosinophil (EO) and stress index (SI; HE/LY) in the blood of layers. Birds from Antibiotics and probiotics treatments tended to increase these parameters. In Exp. 2, however, only SI was significantly (P<0.05) decreased in Antibiotics treatments. Concentration of serum immunoglobulin (IgG) were higher (P<0.05) in PB-M and PB-Y treatments when compared with Control treatment in Exp. 1. The population of E. coli significantly (P<0.05) decreased in birds from Antibiotics, PB-L and PB-Y treatments when compared with birds from Control treatment in Exp. 1. Metalbolizability of crude fat decreased significantly (P<0.05) in birds from probiotic treatments in Exp. 2. It was concluded that the response of probiotics on the productivity of layers and broilers were different. Probiotics increased strength and thickness of eggshell in layers, and decreased feed conversion and increased PI in broilers. Leukocytes and IgG tended to increase by supplementation of antibiotics and probiotics in layers. Intestinal E. coli tended to decrease in layers. Digestibility of crude fat of diet decreased in probiotics treatments broilers. Parameters of blood and microbial were more sensitive in layers than broilers.

• Korean Journal of Poultry Science
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• v.19 no.4
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• pp.177-185
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• 1992

This study was carried out to investigate the relationship between frequency of soft and broken eggs and the economic traits for colored laying hens using the data sampled 7 times in Korea from 1985 to 1991. In addition, the correlation coefficients of frequency of soft and broken eggs on the economic traits for colored laying hens in order to decrease the frequency of soft and broken eggs were studied. The results obtained were summarized as follows ： 1. For colored laying hens, mean of the sexual maturity(SM) was 163.6 days, hen-day egg Production(HDEP) was 79.49％, hen-housed egg Production(HHEP) was 272.9 eggs, egg weight (EW) was 62.69g and the frequency of soft and broken eggs was 1.363％ during 18∼72wks. For white laying hens, SM was 157.2 days, HDEP was 77.87％, HHEP was 265.1 eggs, EW was 60. 26g and the frequency of soft and broken eggs (FSBE) was 1.174％ during 18∼72wks. 2. Statistical significances were observed in laying viability, SM, HDEP, FR, BW and FSBE during 18 ∼72wks and 18 ∼78wks by year for colored laying hens. 3. Sexual maturity was shortened from 168.5 days to 155.9 days. FSBE decreased from 1.4∼l.69％ to 0.94∼o.89％ during 18∼72wks, and HDEP was increased from 74.5∼75.1％ to 77.8∼80.6％, HHEP was increased to 302.0∼304.6 eggs and FSBE was increased from 1.54∼2.02％ to 0.98％ during 18∼78wks in colored laying hens. 4. Estimate of correlation coefficients between FSBE and trait of SM, EW, 72 wks BW were 0.3985, 0.1072, 0.4225, and those of HDEP, HHEP, FR were -0.5662, -2896, -0.245 during 18∼72wks In colored laying hens, respectively. 5. Estimate of correlation coefficients between FSBE and traits of SM, EW, 78wks BW were 0.3791, 0.1171, 0.4609, and those of HDEP, HHEP, FR were -0.5041, -0.2372, -0.2421 during 18∼78wks in colored laying hens, respectively.

• Korean Journal of Poultry Science
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• v.47 no.3
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• pp.189-197
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• 2020

This study was conducted to compare the production performance and stress response of chickens kept in the conventional cages and floor pens. 491 female White Leghorns were used in this study, and their production characteristics and stress response indicators were analyzed from 34 to 43 weeks of age. The results showed that there was no significant difference in survival rate, hen-day egg production, and body weight between the chickens kept in the conventional cages and those kept in the floor pens. The chickens kept in the conventional cages had a significantly higher egg weight and egg quality compared with those kept in the floor pens (P<0.01). The amount of telomeric DNA in lymphocytes was significantly higher in the chickens kept in floor pens than in those kept in conventional cages (P<0.05). The heterophil-lymphocyte ratio, HSP-90β gene expression level, and DNA damage rate significantly increased in chickens kept in the conventional cages, as compared to the chickens kept in floor pens (P<0.01). In conclusion, there seems to be no difference in the production performance between chickens kept in conventional cages and those kept in floor pens. Furthermore, chickens kept in conventional cages had higher stress response values than those kept in floor pens for all stress response indicators. Therefore, conventional cage types are considered to be a more stressful environment for chickens than floor pens, regardless of the production performance of the chickens.

• Korean Journal of Poultry Science
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• v.35 no.1
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• pp.71-78
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• 2008

This study was conducted to investigate the effects of dietary supplementation of herbs and plant extracts (PE) on the performance, small intestinal microflora and immune response in laying hens. A total of 1,440 Hy-Line Brown laying hens of 67 wks old were assigned to one of the following 9 dietary treatments : T1 : Control (C), T2 : C + Avilamycine 6 ppm, T3 : C + Herb $Mix^{(R)}$ 0.2%, T4 : C + Biostrong $510^{(R)}$ 0.02%, T5 : C + $APEX^{(R)}$ 0.02%, T6 : C + $Digestarom^{(R)}$ 0.02%, T7 : C + $Phellozyme^{(R)}$ 0.1%, T8 : C + $Galicin^{(R)}$ 0.05%, T9 : C + CRINA $Poultry^{(R)}$ 0.05%. Each treatment was replicated 8 times with twenty birds housed in 2 bird cages. Twenty bird units were arranged according to completely randomized block design. Feeding trial lasted 6 wks under 16 hours lighting regimen. Hen-day egg production was not significantly different among the treatments, but that of supplemented groups tended to be higher than the control. There were significant differences among treatments in feed intake and feed conversion ratio. Feed intake was higher in the supplemented groups than the control. Feed conversion ratio was higher in T8 than other treatments. Egg shell color index and egg yolk color index were significantly different among treatments. Egg shell color was affected by supplements and egg yolk color index of T9 (PE-CRINA) was significantly higher than the control. Haugh unit was not significantly different among treatments. There were significant differences in leukocytes and erythrocytes parameters. The level of serum WBC and stress index (heterophil/lymphocyte) were higher in supplemented groups than the control. The level of RBC tended to be lower in the herb or PE groups than the control. The concentration of serum IgG was not significantly different among the treatments, but all those of the supplemented groups were higher than the control. The number of Lactobacilli spp. tended to increase and that of Cl. perfrigens decrease in the supplemented groups. The number of E. coli significantly decreased in the supplemented groups. The results of this experiment showed that feeding herbs and plant extracts to laying hens tended to improve the egg production and affect positively on the level of blood parameters and small intestinal microflora.

• Korean Journal of Poultry Science
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• v.42 no.3
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• pp.205-214
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• 2015

This study aimed to investigate the effects of reducing feed intake on performance and meat quality in old laying hens. A total of 200 Hy-Line Brown laying hens (100 weeks old) were randomly allotted to five dietary treatments: control (100% daily feed intake), 90%, 60%, 50%, and 20% daily feed intake. Each treatment was replicated four times with 10 birds per replication and two birds per cage. Ten-bird units were arranged according to a randomized block design. The feeding trial lasted for 4 weeks under a 16L:8D lighting regimen. The results indicated that the daily feed intake correlated with hen-day egg production and feed conversion ratios (P<0.05). The carcass yields and partial ratios were also correlated with daily feed intake (P<0.05). The levels of leukocytes (without basophils) were higher in the 50% and 20% daily feed intake groups than in the other groups. The concentrations of dry matter, crude ash, crude fat, and crude protein, water holding capacity, cooking loss, and fatty acids in the breast meat did not decrease as the daily feed intake decreased. In conclusion, reducing daily feed intake decreased laying performance and carcass yield but had no effect on breast meat quality.

• Journal of agriculture & life science
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• v.53 no.2
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• pp.121-129
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• 2019

This study carried out to determine control factors for the improvement of productivity of laying hens suffering heat stress during hot weather. A total of 48,451 ISA Brown layers were housed in a farm located in Gyeongsangnam-do, Republic of Korea. Five thermo-hydrometer loggers were installed inside the house to collect data of dry-bulb temperature and relative humidity. The experiment continued for 81 days when the summer season begins from 19th June to 7th September, 2018. This study analyzed the correlations among layers' production index and daily average, highest, and lowest temperature; daily average, highest, and lowest relative humidity; and daily average, minimum, and maximum THI. The result indicated that feed consumption, hen-day egg production, egg weight, and FCR decreased as the daily average, highest and lowest dry-bulb temperature and THI rise (p<0.01). On the other hand, water intake increased as the daily average, highest and lowest dry-bulb temperature and THI rise (p<0.001). The relative humidity was not considered to have direct correlations to the layers' production index (p>0.05). However, it was noticeable that the mortality did not have significant relations with daily average and highest temperature; THI; or daily average, highest and lowest relative humidity while it was relevant to the daily lowest temperature and THI (p<0.05). In conclusion, to enhance the productivity of laying hens in a hot climate, it is recommended that daily average, highest, and lowest dry-bulb temperature and THI are maintained as low as possible. Especially, the daily lowest temperature is needed to lower to 20℃, which is the lowest critical temperature for layers.

• Korean Journal of Poultry Science
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• v.31 no.1
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• pp.9-15
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• 2004

This study was conducted to evaluate the effects of dietary herbal plant mixture on the performance in laying hens under heat stress. One hundred ninety two 54-weeks-old ISA Brown commercial layers, were used in 56 d experimental assay. Dietary treatments included CON (control; basal diet), HPM0.05 (basal diet ＋ 0.05% herbal plant mixture), HPM0.1 (basal diet ＋ 0.1% herbal plant mixture), and HPM0.2 (basal diet ＋ 0.2% herbal plant mixture). For overall period, the hens fed with HPM0.1 and HPM0.2 diets showed lower in the hen day egg production than the hens fed with CON diet(P＜0.05). At the end of the experimental period, egg weight was heavier in HPM 0.1 treatment than in CON (P＜0.05). There were no significant differences among the treatments in egg shell breaking strength, egg shell thickness, Haugh unit, and yolk color unit. Total cholesterol concentration of yolk tended to decrease as the level of herbal plant mixture in the diet increased. Total protein of blood was higher in the hens fed with herbal plant mixture than in the hens fed with CON diet (P＜0.05). Albumin concentration of blood was increased in HPM0.05 and HPM0.1 treatments compared with CON(P＜0.05). Red blood cell (RBC) and white blood cell (WBC) concentrations in serum were increased in HPM0.1 and HPM0.2 treatments compared with CON treatment (P＜0.05). In conclusion, dietary herbal plant mixture in laying hens under heat stress adversely affected egg production but increased total protein, albumin, RBC and WBC in blood.

• Journal of Animal Science and Technology
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• v.57 no.5
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• pp.17.1-17.6
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• 2015

The present study investigated the nutritional and economic suitability of cashew reject meal (full fat and defatted) as replacement for groundnut cake (GNC) in the diets of laying chickens. A total of eighty four brown shavers at 25 weeks of age were randomly allotted into seven dietary treatments each containing 6 replicates of 2 birds each. The seven diets prepared included diet 1, a control with GNC at $220gkg^{-1}$ as main protein source in the diet. Diets 2, 3 and 4 consist of gradual replacement of GNC with defatted cashew reject meal (DCRM) at 50%, 75% and 100% on weight for weight basis respectively while diets 5, 6 and 7 consist of gradual inclusion of full fat cashew reject meal (FCRM) to replace 25%, 35% and 50% of GNC protein respectively. Each group was allotted a diet in a completely randomized design in a study that lasted eight weeks during which records of the chemical constituent of the test ingredients, performance characteristics, egg quality traits and economic indicators were measured. Results showed that the crude protein were 22.10 and 35.4% for FCRM and DCRM respectively. Gross energy of DCRM was 5035 kcal/kg compared to GNC, 4752 kcal/kg. Result of aflatoxin $B_1$ revealed moderate level between 10 and $17{\mu}g/Kg$ in DCRM and GNC samples respectively. Birds on control gained 10 g, while those on DCRM and FCRM gained about 35 g and 120 g respectively. Feed intake declined (P < 0.05) with increased level of FCRM. Hen day production was highest in birds fed DCRM, followed by control and lowest value (P < 0.05) was recorded for FCRM. No significant change (P > 0.05) was observed for egg weight and shell thickness. Fat deposition and cholesterol content increased (P > 0.05) with increasing level of FCRM. The cost of feed per kilogram decreased gradually with increased inclusion level of CRM. The prediction equation showed the relative worth of DCRM compared to GNC was 92.3% whereas the actual market price of GNC triples that of DCRM. It was recommended that GNC could be completely replaced by DCRM in layer's diets in regions where this by product is abundant. However, FCRM should be cautiously used in diets of laying chickens.