• Journal of Animal Science and Technology
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• v.62 no.2
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• pp.159-173
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• 2020

A 4×2 factorial feeding trial was designed to investigate the effect of replacing soybean meal (SBM) with cottonseed meal (CSM) in wheat/sorghum/SBM-based diets fed with or without microbial enzymes in diets on the performance, visceral organ development and digestibility of nutrients of broiler chickens. Four graded levels of CSM - none (0%), low (4%, 8%, and 12%), medium (5%, 10%, and 15%), and high (6%, 12%, and 18%) of complete diets in starter, grower and finisher, respectively were fed with or without 100 mg/kg of xylanase and β-glucanase blend. Eight isocaloric and isonitrogenous diets were formulated using least-cost method to meet the nutrient specifications of Ross 308 male broilers. Each treatment was randomly assigned to 6 replicates (10 birds per replicate). There were CSM-enzyme interactions (p < 0.05) on feed intake (FI) and weight gain (WG) in the starter phase. Enzyme supplementation improved (p < 0.05) feed conversion ratio (FCR) in the grower and finisher phases, and increased WG in growing and finishing birds. CSM inclusion reduced (p < 0.05) the weight of gizzard and proventriculus in starter chicks, while these organs were bigger (p < 0.05) in the grower phase. The test ingredient decreased (p < 0.05) small intestinal weight in starter and grower birds. The CSM increased the absolute weight of thighs (p < 0.05) while breast meat was increased (p < 0.01) by enzyme addition. Starch digestibility was improved (p < 0.01) by enzyme inclusion and decreased (p < 0.01) by CSM. Enzyme supplementation improved (p < 0.05) the ileal digestibility of gross energy and protein. The results demonstrate that CSM can substitute up to 90% SBM in broiler chicken diets without compromising performance, and the nutritive value of CSM-containing diets can effectively be improved by enzyme supplementation.

• Animal Bioscience
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• v.34 no.12
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• pp.1951-1962
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• 2021

Objective: This study was conducted to evaluate single cell protein (SCP), produced from Methylococcus species, as a protein source on the growth performance, carcass traits and gut health of broiler chickens. Methods: Ten iso-nitrogenous and iso-caloric diets containing 0 (Control), 2.5%, 5%, 7.5%, and 10% SCP replacing either soybean meal (T₁ to T₅) or fish meal (T₆ to T₁₀) were formulated. Each diet prepared for starter (0 to 14 days), grower (15 to 21 days), and finisher (22 to 42 days) phases was offered to four replicates of 10 chicks each (n = 400). Growth performance at different phases and carcass characteristics and intestinal morphology on 42nd day of trial were measured. Results: Body weight gain in groups fed 2.5% and 5% SCP diets were comparable to control during different phases and cumulatively, however lower (p<0.01) in 7.5% and 10% SCP diets. Feed conversion ratio was better (p<0.01) in 2.5% and 5% SCP diets. Dressing percentage, abdominal fat percentage and meat:bone ratio were not affected (p>0.05) by SCP inclusion in the diets. However, breast percentage was higher (p<0.01) in 2.5% and 5% SCP groups and thigh percentage higher in 7.5% and 10% SCP groups. Total microbial count in duodenum, jejunum and ileum were not affected (p>0.05) by SCP inclusion up to 10% in diets. Duodenal villi length and crypt depth were highest (p<0.01) in group fed 5% SCP diets and lowest in group fed 10% SCP diets. Jejunal villi length and crypt depth as well as ileal villi length were lowest (p<0.01) in group fed 10% SCP diets. Body weight gain, feed consumption, feed conversion ratio and gut health were better (p<0.01) in broilers fed fish meal based diets compared to soybean meal based diets. Conclusion: It was concluded that inclusion of SCP up to 5% replacing soybean meal in broiler diets is beneficial in improving growth rate, breast yield and gut health status.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.509-516
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• 2021

This study investigated the effect of dietary supplementation with cysteamine hydrochloride (CSH) on the growth performance and nutrient digestibility of broilers. A total of 180 one-day-old male Ross broilers were allotted to one of the three treatment groups with three replications (20 birds per replication). The experimental groups were as follows: control group (basal diet), CSH-1 group (basal diet + 250 mg CSH/kg feed), and CSH-2 group (basal diet + 500 mg CSH/kg feed). During the grower period, feed intake, body weight, average daily gain, feed conversion ratio (FCR), and livability did not show any variation among the treatment groups. On the other hand, a comprehensive evaluation of the finisher period and the entire experiment period found that FCR was significantly improved in CSH-1 and CSH-2 groups as compared to the control group (p<0.05). The dietary supplementation of CSH did not affect the carcass and meat percent (breast and leg muscle). Although there was no significant difference, the digestibility of organic matter tended to be higher in the CSH-2 group than in the control group (p<0.1). This study suggests that a dietary supplement with 250-500 mg/kg CSH can be effective in improving FCR and the digestibility of organic matter in broilers.

• Journal of Animal Science and Technology
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• v.64 no.5
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• pp.985-996
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• 2022

This study investigated the effects of light intensity on growth performance, blood components, eye condition, and carcass characteristics of broiler chickens. Three hundred and fifty-two 1-day-old male chicks were assigned to one of four treatments (four repetitions per treatment, 22 birds per repetition) and reared in a floor pen for 5 weeks. From the second week, chicks were reared under four different levels of light intensity (5, 20, 35, and 50 lx) and the lighting duration was maintained at 18-hours light : 6-hours dark (18L : 6D). The feed intake and body weight were measured weekly. At 35 days of age, 12 birds per treatment were randomly selected for blood sampling, eye measurement, and carcass analysis. There were no significant differences in body weight gain, feed intake, and feed conversion ratio among treatments. Triglyceride levels in the serum were significantly higher in the 5 lx treatment, and creatinine was significantly lower in the 5 lx treatment (p < 0.05). The heterophil : lymphocyte ratios decreased significantly as light intensity increased (p < 0.05); however, other blood cell compositions were not affected by light intensity. Interleukin-6 content was significantly higher in the 5 lx treatment than in other treatments (p < 0.05), but the content of tumor necrosis factor-α was not significantly different among treatments. Serum corticosterone concentration was significantly higher at 5 lx than at 20, 35, and 50 lx (p < 0.05). The corneal diameter was the highest in 5 lx treatment (p < 0.05), and tended to increase as the light intensity decreased. Other eye parameters were not significantly different among treatments, but displayed a tendency to increase as the light intensity decreased. Carcass yield and part yields were not affected by light intensity. Meat quality parameters (pH, color, cooking loss, and water-holding capacity) did not show significant difference among the treatments. The results indicate that a light intensity of 5 lx may increase physiological stress or have a negative effect on broiler welfare, even if the performance and carcass characteristics are not affected. Therefore, a light intensity of 20 lx or above is recommended considering both the growth performance and welfare of broilers.

• Journal of Life Science
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• v.32 no.9
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• pp.706-711
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• 2022

Broiler chickens are exposed to various stresses throughout their lives, and those stresses affect their well-being and meat quality. Therefore, the farm breeding system is critical for reducing stress in broilers and improving animal welfare. This study was conducted to evaluate the difference between general farms and animal welfare farms and to evaluate feather corticosterone as an index for measuring stress. Samples of 28-day-old broilers (blood, feathers, and muscle) were collected from slaughter-houses, and corticosterone, along with HSP70, glycogen, and L-lactate, were extracted from feathers and serum as indicators of broiler stress levels and energy metabolism. The analysis results confirmed a significantly (p<0.01) higher feather cortisone level in the general farm group than in the welfare farm group, but no significance was detected for serum corticosterone. HSP70 levels did not differ in muscles and feathers. Glycogen levels were significantly higher in the general farm group than in the welfare farm group (p<0.01), but L-lactate levels showed no difference. Our results suggest that feather corticosterone can be used as an indicator to evaluate stress differences between general farms and animal welfare farms and that long-term stress can be assessed.

• Food Science of Animal Resources
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• v.31 no.5
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• pp.676-683
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• 2011

The aim of this study was to compare the physicochemical changes of hot-boned chicken breast and leg muscles. Chicken breast and leg muscles from 56 broilers were excised within a 15 min post-mortem (PM) and stored at $20^{\circ}C$. Physicochemical traits were determined at 0.5, 6, 12, and 24 h PM. The ultimate pH of leg muscle was higher than that of breast muscle (p<0.05). The content of glycogen in the breast muscle was relatively higher than that in the leg muscle until 6 h PM (p<0.05). R-values showing rigor mortis of breast and leg muscles were completed after or before 6 h PM. Breast muscle had less cooking loss than leg muscle (p<0.05). Drip loss did not significantly differ between breast and leg muscles with the exception of that at 6 h PM. The sarcomere length of leg muscle was relatively longer than that of breast muscle (p<0.05). The MFI of leg muscle was significantly lower than that of breast muscle (p<0.05). The shear force of leg muscle was lower than that of breast muscle at 6 and 12 h PM (p<0.05); however, that of both muscles did not significantly differ at 24 h PM.

• Korean Journal of Poultry Science
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• v.39 no.4
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• pp.305-310
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• 2012

This work was carried out to investigate performance and carcass yield of large-type broilers at different stocking densities. Treatments were T1 (9.1 birds/$m^2$), T2 (10.3 birds/$m^2$) and T3 (11.5 birds/$m^2$) by the stocking density. Four hundred eight 1-day-old Arbor Acre broiler chicks were used for six weeks (starter, 0~1 wks; earlier, 1~3 wks; finisher, 3~6 wks) and divided into 3 treatments (4 replications/treatment, 30, 34 or 38 birds/replication). Research indexes were rearing viability ratio, body weight, body weight gain, feed intake, feed conversion ratio, production efficiency factor and carcass ratio. Rearing viability ratio (%) was 89% or more for all treatments and there was no significant difference on weekly rearing viability ratio (%). Body weight of T2 was the greatest and that of T3 was the lowest at 1 weeks old (P<0.05). Body weight gain of T2 was the greatest and that of T3 was the lowest at 0~1 weeks old (P<0.05). However, body weight gain of T3 was the greatest and that of T1 was the lowest at 1~2 weeks old (P<0.05). Body weight gain of T2 was the greatest as 3,031 g among treatments at 0~6 weeks old (P<0.05). Feed intakes of T1, T2 and T3 were 1,417 g, 1,265 g and 1,355 g, respectively, and that of T1 was the greatest among treatments (P<0.05). There was no significant difference on body weight, body weight gain and feed intake. Feed conversion ratio of T1 was the greatest among treatments at 1~2 wks, 3~4 wks and 0~6 wks old (P<0.05). Production efficiency factors of T1, T2 and T3 were 363.5, 388.3 and 358.3, respectively, and there was no significant difference among treatments. Wing meat ratio of T1 was the higher compared to other treatments at the age of 4 wk (P<0.05). There was no significant difference on carcass ratio and partial meat ratio among treatments. Neck meat ratio of T2 was the lowest among treatments (P<0.05). This result may provide the standard data of different stocking densities for large-type broiler and the further research is needed.

• Korean Journal of Poultry Science
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• v.32 no.3
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• pp.171-177
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• 2005

Two experiments were carried out to investigate the effects of level and feeding period of dietary Monascus culture on the performance and cholesterol content of serum and meat in broilers and growing ducks.0.0(C), 0.5(T1), 1.0(T2) and $1.5\%(T3)$ of iwonascus culture which contained 0.5% monacolin-k was added to commercial broiler diets, respectively, and ffd during 2~6 weeks of age in Experiment 1. In Experilnent 2, commercial broiler diet added $1.0\%$ of Monascus culture was fed during $6\~6(C),\;4\~6(T1),\;2\~6(T2)\;and\;0\~6(T3)$ weeks of age, respectively. Three replicates of 16 day-old broilers and 10 day-old growing ducks each were randomly assigned to floor pen, respectively. In Experiment 1, as the level of dietary Monascus culture increased, body weight and feed intake of broilers significantly decreased (P<0.05), whereas those of growing ducks tended to increase without significant differences among treatments. Feed/gain ratio both in broilers and growing ducks showed a trend to increase. Cholesterol contents of serum both in broilers and growing ducks significantly decreased(P<0.05), and those of breast and thigh meat tended to decrease as the level of dietary Monascus culture increased. In Experiment 2, as the feeding period of dietary Monascus culture increased, body weight gain(P<0.05) and feed intake of broilers tended to decrease whereas those of growing ducks increased without significant differences anions treatments. Feed/gain ratio also increased without significant differences. Cholesterol contents of serum both in broilers and growing ducks significantly decreased(P<0.05), and those of breast and thigh meat tended to decrease as the feeding period of dietary Monascus culture increased without significant differences.

• Food Science of Animal Resources
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• v.28 no.4
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• pp.480-485
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• 2008

In this experiment, 5 treatments consisted of control, probiotics (0.2%; T1), illite (1.0%; T2), activated carbon (1.0%; T3), and hardwood vinegar (1.0%; T4) as diets of chicken were evaluated for 35 days through feeding of 200 male chickens (Arbor Acre Broiler). Thigh muscle from slaughtered chickens were analyzed on pH, volatile basic nitrogen (VBN), thiobarbituric acid reactive substance (TBARS), shear force, and meat color during 10 d of cold storage at $4{\pm}1^{\circ}C$. Groups of T3 and T4 showed higher pH levels compared to the control group, and T4 showed significantly higher value. Over the storage period, all treatment groups showed increase in pH (p<0.05). Values of VBN of T1, T3, and T4 were lower than those of the control group and T2 up to 7 d of storage (p<0.05), but there was no significance at 10 d of storage. Values of TBARS of T3 and T4 were lower than the control group, T1, and T2, while all treated groups showed rapid increase of TBARS values over storage period (p<0.05). Shear force did not show significant difference among treated groups, but it was decreased over storage. Lightness of meat color (L) in treated groups was higher than the control, and T4 showed the highest value during entire storage period (p<0.05). Yellowness levels (b) of T3 and T4 were higher than the control group. These results may suggest the improvement of chicken meat quality and shelf life via the addition 1% activated carbon and 1% hardwood vinegar into feed.

• Korean Journal of Poultry Science
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• v.48 no.1
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• pp.13-22
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• 2021

The present experiment was conducted to evaluate the effect of stocking density on the growth performance, immune status, and meat quality of broilers. In total, 385 one-day-old Ross 308 broilers were randomly assigned to one of four distinct stocking densities: 26 birds/㎡, 22 birds/㎡, 19 birds/㎡, and 16 birds/㎡. They were fed the diet ad libitum for 5 weeks. Immunoglobulin (Ig) and corticosterone levels were evaluated, and growth performance, blood parameters, and breast meat quality were determined. It was observed that the weight gain and feed intake of growers (21~35 d) and broilers (0~35 d) were significantly reduced as the stocking density increased (P<0.05). However, the feed intake of starters (0~21 d) significantly increased as the stocking density increased (P<0.05). There were no significant differences in the biochemical profiles among the four different stock densities. Furthermore, no significant differences were observed in the stress parameters: (heterophils / lymphocytes ratio and corticosterone), IgA, and IgM; however, IgG significantly increased with stocking density (P<0.05). The pH, water holding capacity, and cooking loss of the muscle were all unaffected by the stocking density, but the shear force (tenderness) increased slightly as the density increased. The findings of this study suggest that a lower stocking density (16 birds/㎡) significantly improved the shear force of breast meat and IgG in broilers.