Publications by authors named "Myunghwan Yu"

The experiment was conducted to estimate the matrix value of xylanase and the effect of dietary xylanase supplementation on growth performance, viscosity, digestibility, and carcass traits in broiler chickens. A total of 588 one-day-old Ross 308 broiler chicks were raised with a commercial diet until day 7 and seven-day-old chicks were randomly allotted to one of seven dietary treatments with twelve replicates. Diets were corn-soybean meat based with wheat added.

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The current study investigated the optimal standardized ileal digestible (SID) methionine (Met) requirement for the growth performance of white Pekin ducks from hatching to 21 days of age. A total of 288 one-day-old male white Pekin ducklings were initially weighed and randomly assigned to six dietary groups, with six replicates per group. Eight ducklings were housed in each floor cage, pre-littered with rice hulls.

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Objective: The study assessed the calcium (Ca) endogenous losses and digestibility in 45-week-old Hy-Line Brown laying hens fed diets incorporating different Ca-sourcing ingredients.

Methods: A total of 168 hens were randomly assigned to dietary treatments, with six replicates, and four hens were housed per cage. The seven diets included different Ca sources such as monocalcium phosphate (MCP), dicalcium phosphate (DCP), limestone, corn, soybean, wheat bran, and a Ca-free diet.

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The objective of this study is to investigate the effect of β-mannanase in energy and amino acid-deficient broiler diets on the growth performance, carcass yields, ileal nutrient digestibility, viscosity, intestinal morphology, and blood metabolites of broilers from hatch to day 35. A total of 168 one-day-old Ross 308 broiler chicks were randomly assigned to one of three dietary treatments in a completely randomized design, with each treatment having eight replicates and seven birds per cage. The treatments were as follows: i) positive control diet (PC) containing standard energy and amino acids; ii) negative control (NC) with 150 kcal/kg metabolizable energy (ME) and 4.

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The purpose of this study was to assess the optimal standardized ileal digestible (SID) lysine (Lys) requirement for male White Pekin ducklings with a specific focus on growth performance for the 3 weeks following hatching. A total of 384 one-day-old male White Pekin ducklings were allocated to six different dietary treatments, each containing varying levels of digestible Lys content ranging from 0.72% to 1.

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Laying hen responses to supplemental multiprotease on performance, egg quality, digestibility, gut histomorphology, nitrogen excretion, and economic performance of laying hens until 37 weeks of age were investigated. A total of 189 25-week-old Hy-Line Brown hens were housed in enriched cages (7 birds/cage) and randomly allocated to 1 of 3 diets with 9 replicates per treatment. Dietary treatments included: an adequate positive control- PC [met the breed and age standards for crude protein (CP) and amino acids (AA)]; negative control- NC (90 % CP and AA requirement); and NC supplemented with multiprotease - NCMP.

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The current study investigated the impact of using iron and plastic crates during summer transportation on production, physiological characteristics, and welfare of broiler chickens. A total of 160 Ross 308 male broilers were randomly selected from a battery-caged house at 35 days of age. Their average body weight was 1,866.

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The impact of crating density and prevailing weather conditions during transit on preslaughter losses, physiological characteristics, and meat quality in broilers was investigated. A total of 900 35-day-old Ross 308 male broilers with an average body weight of 1,860 ± 17.458 g (mean ± SEM) in summer and 1,864 ± 17.

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Article Synopsis
  • - The study investigates how different crate types (plastic vs. iron) affect the welfare and meat quality of broiler chickens during winter transport, noting that drug stress can impact meat yield and quality.
  • - A total of 175 male Ross 308 broilers were compared, with some transported in iron and plastic crates and a control group kept on the farm; results showed no differences in carcass traits, but the plastic crates were linked to lower stress indicators.
  • - Findings reveal that broilers in iron crates had higher stress levels (elevated cortisol, glucose, and lactate) compared to those in plastic crates or the control group, suggesting that plastic crates are better for welfare by reducing stress during transport.
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The impact of dietary non-starch polysaccharides (NSP) on performance and carcass traits of broilers fed wheat-bran substituted into corn-soybean meal-based diets supplemented with xylanase was investigated. A total of 280 (7-day-old) Ross 308 broilers were randomly allotted to one of five dietary treatments with 8 replicates, 7 chicks per pen. Treatments were; i) CON: Control diet, ii) CON-X (CON + 3,000 U/kg xylanase), iii) L-X: low NSP (2% wheat bran in CON + 3,000 U/kg xylanase), iv) M-X: medium NSP (4% wheat bran in CON + 3,000 U/kg xylanase), v) H-X: higher NSP (8% wheat bran in CON+ 3,000 U/kg xylanase).

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  • The study aimed to evaluate how phytase and multi-carbohydrase affect the growth, nutrient digestibility, and overall quality of broiler chickens fed phosphorus and energy-deficient diets.
  • A total of 288 Ross 308 broiler chicks were divided into six dietary treatment groups, including a positive control and various AP-deficient diets with or without enzyme supplements.
  • Results showed that enzyme-supplemented diets improved growth metrics like body weight and feed conversion rates, enhanced tibia mineralization, and increased leg meat yield, with the best results seen in the diet combining both phytase and multi-carbohydrase.
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  • Duck meat is a healthier option due to its higher unsaturated fats, iron, and protein, which can lower bad cholesterol and improve immunity.
  • The study examined the effects of different rice hull bedding depths (4 cm, 8 cm, 12 cm, and 16 cm) on the growth and meat quality of White Pekin ducks over 42 days.
  • Results showed that ducks with 16 cm bedding had the best growth performance and lowest fat in breast meat, and while bedding depth impacted some factors, it didn't significantly affect meat composition, footpad dermatitis, or mortality rates.
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  • The study focuses on Yellow Korean native chickens (KNC-Y), known for their excellent egg production, and aims to identify genetic traits linked to this performance through runs of homozygosity (ROH) analysis.
  • Using DNA samples from 675 KNC-Y chickens, researchers generated SNP data and found a total of 29,958 ROH fragments, with specific regions on various chromosomes linked to economic traits.
  • The analysis revealed 111 annotated genes, with the PTGS2 gene highlighted as significant for its influence on egg-laying performance in the KNC-Y population.
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Objective: The goal of the current study was to investigate the impact of various concentrations of xylanase in energy-deficient corn-based diets on the growth performance, carcass characteristics, nutrient digestibility, and digesta viscosity in broilers from 7 to 35 days of age.

Methods: A total of 280 seven-day-old Ross 308 broilers were randomly allocated to one of the five dietary treatments following a completely randomized design with 8 replicates and 7 birds per cage. The treatments were: i) positive control (PC, without xylanase); ii) NC-1 (80 kcal/kg ME reduced from PC); iii) NC-2 (100 kcal/kg ME reduced from PC); iv) NCX-1 (NC-1 + 2,000 U/kg xylanase); and v) NCX-2 (NC-2 + 3,000 U/kg xylanase).

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Objective: This study aimed to investigate the efficacy of Bacillus-based probiotics supplemented at two different levels to modulate the productive performance, egg quality, tibia traits, and specific cecal bacteria counts of Hy-Line Brown layers from 25 to 37 weeks of age.

Methods: A total of 216 twenty-five-week-old hens were randomly distributed into 3 experimental diets with 12 replicates of 6 birds per cage. Diets included basal diet supplemented with 0 (CON), 3×108 (PRO1), or 3×109 (PRO2) colony-forming unit (CFU) of the test probiotic containing Bacillus subtilis PB6, Bacillus subtilis FXA, and Bacillus licheniformis G3 per kilogram of feed.

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  • The study examined how the major histocompatibility complex (MHC) genes respond in broiler chickens infected with Eimeria.
  • RNA sequencing was used to compare gene expression in infected and uninfected chickens at different times post-infection, revealing 14 significant differentially expressed genes (DEGs) that were primarily related to immune responses.
  • Results indicated an initial upregulation of MHC-Y class I genes to activate the immune response followed by a downregulation, suggesting that Eimeria can suppress this immune reaction as infection progresses.
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This study was conducted to assess the effectiveness of phytase on the performance, carcass traits, nutrient digestibility, tibia characteristics, and inositol phosphorus (IP) degradation in broiler chickens. Additionally, the available phosphorus (AP) equivalency of phytase in AP-deficient diets was estimated for 35 days after hatching. A total of 336 one-day-old Ross 308 broiler chicks were allocated to one of seven dietary treatments with six replications with eight birds per cage.

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The digestibility of crude protein (CP) and amino acids (AA) in feedstuffs including corn, soybean meal (SBM), and corn distillers dried grains with solubles (DDGS) was investigated in White Pekin ducks. The test ingredients were the sole source of AA and CP. A nitrogen-free diet was also formulated for determining endogenous losses of AA and nitrogen.

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The effect of different commercially available bedding materials on the growth performance and carcass characteristics of ducks for 42 days was investigated. 336 one-day-old White-Pekin ducklings (60.48 ± 0.

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Coccidiosis caused by the species is a highly problematic disease in the chicken industry. Here, we used RNA sequencing to observe the time-dependent host responses of -infected chickens to examine the genes and biological functions associated with immunity to the parasite. Transcriptome analysis was performed at three time points: 4, 7, and 21 days post-infection (dpi).

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We aimed to compare the combinatorial effect of 3,4,5-trihydroxybenzoic acid (THB) and oregano extracts (OE) with THB alone on the growth performance and elimination of deleterious effects in coccidiosis-infected broilers. A total of 210 one-day-old broilers were randomly assigned to one of five dietary treatments, with six replicates each, for 35 days. Dietary treatments were: 1) non-challenged, non-treated (NC); 2) challenged, non-treated (PC); 3) PC+ Salinomycin (0.

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Objective: To investigate the physiological effects of exogenous emulsifiers in broiler chickens that were fed tallow-incorporated reduced-energy diets over 35 days.

Methods: A total of 256 Ross 308 one-day-old broilers (42.28±0.

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This study was conducted to evaluate the efficacy of a combination 3,4,5-trihydroxybenzoic acid (THB) and oregano extracts (i.e., Carvacrol and Thymol) at intake/dietary different levels on growth performance, intestinal health indicators, immune responses and fecal oocyst shedding in broiler chickens under challenged condition.

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