• Asian-Australasian Journal of Animal Sciences
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• v.19 no.8
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• pp.1197-1205
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• 2006

This experiment was conducted to compare the effects of feeding DL-2-hydroxy-4-(methylthio)butanoic acid (HMTBA) and DL-methionine (DLM) supplemented corn-soybean-cottonseed meal diets on growth performance, carcass composition, and muscle color of broilers. The trial was designed as a $2{\times}3{\times}2$ factorial experiment, including two methionine (Met) sources (HMTBA and DLM), three equimolar graded levels of Met supplementation (i.e., 0.08, 0.16, and 0.24% in the starter diet and 0.07, 0.14, and 0.21% in the grower and finisher diets, respectively), and two sexes (male and female). Additionally, one basal diet for each sex was formulated to be limiting in Met to test the dosage response of increasing supplemental Met levels. Four hundred and twenty 10-d-old broilers were randomly allotted to 14 treatments (seven each for males and females), with five replicate pens per treatment and six chicks per pen. There was no difference (p>0.05) between the two Met sources in growth performance and muscle deposition of broilers throughout the whole experimental period (d 10 to 49). With the increasing Met supplementation levels, average daily gain was increased (quadratic; p<0.01) during the starter, grower, and overall phases, average daily feed intake was increased (quadratic; p<0.01) during the starter phase, and feed:gain ratio was decreased (quadratic; p<0.05) during the grower and overall phases. At the end of finisher phase, Met supplementation increased breast muscle content (quadratic; p<0.01) and thigh muscle content (linear; p<0.05), and decreased abdominal fat content (quadratic; p<0.02). Compared to the broiler fed DLM, broilers fed HMTBA had superior breast and thigh muscle coloration (p<0.01). Male broilers had higher weight gain and feed intake and better feed conversion than female broilers (p<0.01). The fat content of thigh muscle in female broilers was higher than that of male broilers (p<0.03). The best fit comparison of HMTBA vs. DLM was determined by Schwarz Bayesian Criteria index, which indicated that the average relative bioefficacy of HMTBA vs. DLM was 120% with 95% confidence limit 67 to 172%. These results indicated that Met supplementation improved growth performance and carcass quality of broilers fed corn-soybean-cottonseed meal diets irrespective of Met sources. Compared to DLM, HMTBA has the same molar bioefficacy on improving the growth performance and carcass quality of broilers; however, HMTBA fed birds had superior meat color to DLM fed birds.

• Journal of Animal Science and Technology
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• v.62 no.5
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• pp.614-627
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• 2020

During the course of this trial, our team assessed the influence of protease upon the growth performance, the nutrient digestibility, and the expression of growth-related genes and amino acid transporters within the liver, muscle, and small intestines of broilers. During the first step, our team allocated 600 broilers into four dietary treatments for a period of 35 days in order to measure the growth performance and nutrient digestibility of the broilers selected. The separate treatments contained 10 replicates (15 birds per replicate). The treatments were composed of: 1) CON, basal diet; 2) T1, basal diet + 0.03% protease; 3) T2, basal diet + 0.06% protease; and 4) T3, basal diet + 0.09% protease. Next, the broiler chick sample tissue was harvested from the CON and T3 groups in order to conduct gene expression analysis following the feeding trials the broilers underwent. Our team discovered that the broilers fed protease diets possessed increased body weight and an average daily gain, but conversely, had lower feed conversion ratios when their dietary protease levels increased from 0% to 0.09% (p < 0.05). Additionally, significant linear improvements were identified among the nutrient digestibility of dry matter, crude protein, energy, and amino acids within broilers supplied with protease diets when contrasted and compared with broilers supplied with the basal diet (p < 0.05). In addition, the gene expression of the genes IGF1, IGF2, GH, and LEP in the liver, and the genes MYOD1 and MYOG in the breast muscles, was significantly increased after broilers were fed with a protease diet as compared to broilers that subsisted on a basal diet (p < 0.05). Protease supplementation also raised the expression levels within these amino acid transporters: SCL6A19, SLC7A1, SLC7A7, SLC7A2, SLC7A6, SLC7A9, and SLC15A1, located in the small intestine, when compared to the basal diet (p < 0.05). Our results suggest that protease supplementation in their diet improved the growth performance of broilers via an increase in the expression growth-related genes within broiler liver and muscle tissue. In addition, protease supplementation enhanced broiler digestibility via the upregulation of amino acid transporter expression within the small intestine.

• Korean Journal of Poultry Science
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• v.45 no.3
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• pp.147-154
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• 2018

A total of 90 one-day-old male broilers (Ross 308) were randomly assigned to one of the three dietary treatments, each consisting of six replicates (5 broilers/cage). The dietary treatments were 1) control (CON: fresh clean water with no supplement); 2) low dose [LD: CON + 1.56% extractions from the wooden chips (EWC)] and 3) high dose (HD: CON + 12.5% EWC). Drinking water supplemented with EWC was provided using specifically designed individual nipple drinker units. Average daily water intake (ADWI), average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) were measured weekly for 21 days. One broiler from each cage was euthanized for measuring the visceral organ weights and collecting ileal tissue samples for ileal architecture analysis on day 21. Broilers assigned to the LD and HD watery groups showed higher ADWI than that in broilers consumed CON on day 7 (P<0.05). The broilers subjected to HD treatment showed a deeper crypt depth (P<0.05) than that in broilers subjected to LD and CON on day 21. Therefore, broilers consumed HD showed a lower (P<0.05) villus height:crypt depth ratio than that broilers consumed CON on day 21. Broilers provided drinking water containing any of the tested concentrations of EWC showed no effect (P > 0.05) on growth performance, ileal villus height, and visceral organ weights as compared with those in the CON from hatch to 21 days. In conclusion, broilers fed HD showed reduction in villus height:crypt depth ratio without impairing growth performance and visceral organ weights for the experimental period.

• Korean Journal of Poultry Science
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• v.47 no.2
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• pp.75-82
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• 2020

This study intended to investigate the growth performance and meat quality traits in broilers fed different regimens of NaCl over a period of 35 days. Seven hundred and fifty 1-day-old chicks (Cobb 500) were randomly assigned to five NaCl feeding regimens to obtain three replicates for each regimen. Broilers in CON group were provided with concentrations of 0.35% NaCl for the duration of the experimental period. The other groups were provided with two concentrations of NaCl (0.45% and 0.55%) under two durations, namely: 1) 1~28 d: 0.45% or 0.55% NaCl for 28 days then CON; and 2) 1~35 d: 0.45% or 0.55% NaCl for 35 days. Broilers fed 0.55% NaCl for 1~35 d showed improved (P<0.05) growth performance compared with broilers fed the CON regimen. Moreover, higher water holding capacity of breast meat was shown by the broilers fed 0.55% NaCl for 1~28 d when compared with that in broilers fed the CON diet (P<0.05). Broilers fed 0.45% NaCl showed an increase (P<0.05) in the lightness of the meat over CON diet and the 0.55% NaCl diet. In addition, broilers offered CON had the highest redness value and highest crude ash content in the breast meat (P<0.05). Feeding 0.45% NaCl for 1~35 d and 0.55% NaCl for 1~28 d resulted in a higher (P<0.05) protein content in breast meat. In conclusion, broilers fed diets with 0.55% NaCl for 1~35 d showed improved growth performance as well as water holding capacity and protein content of the breast meat.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.5
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• pp.665-673
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• 2012

A balance trial experiment was carried out to evaluate the potential relationship between an enzymatically hydrolyzed yeast (EHY) and yeast culture combined with a live Bacillus subtilis (Bs) on the productive parameters, ileal digestibility, retention of nutrient and energy and villus morphology in broilers. Seventy two 28 d old, Ross B308 male broilers were assigned to a factorial combination of 2 levels of EHY (0 and 1 kg/ton of feed) and 2 levels of Bs (0 and 125 g/ton of feed). The experiment lasted 2 weeks. Several treatment interactions were observed. EHY-fed broilers showed the lowest feed intake and feed conversion ratio whereas Bs-fed broilers showed the highest feed intake and intermediate feed conversion ratio (EHY and BS interaction, p<0.05). Also, EHY-fed broilers had greater ileal digestibility of dry matter (EHY and BS interaction, p<0.01) and energy (EHY and BS interaction, p<0.05) but these responses were counterbalanced by the combination of EHY and Bs. The thickness of the mucosa was similar between the control and EHY-fed broilers, but was lowest when Bs was added alone (EHY and BS interaction, p<0.01). The thickness of the villus was greater in EHY plus Bs-fed broilers, intermediate for the control and lower for Bs or EHY-fed broilers (EHY and BS interaction, p<0.05). The area of the villus was greater in the control and EHY plus Bs-fed broilers (EHY and BS interaction, p<0.05). In addition, EHY-fed broilers showed greater breast yield and nitrogen retention (p<0.01) and ashes digestibility (p<0.05). On the other hand, Bs-fed broilers had greater carcass and breast weight, nitrogen retention, energy excretion and villus height (p<0.05). In summary, EHY and Bs enhanced some growth, carcass and nutrient retention responses, but did not show any synergic relationship in these responses. Opposite to this, the results suggest that the positive effect of EHY on the feed conversion and digestibility of nutrients were counterbalanced by the addition of Bs.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.4
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• pp.560-563
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• 2004

The study was undertaken to evaluate the effect of naked neck gene on mortality, cell mediated and humoral immune response in white plumage broiler population. The mortality of homozygous naked neck (Na/Na) broilers (11.71%) was comparatively lower than that of heterozygous naked neck (Na/na) (12.28%) and normally feathered (na/na) (13.59%) broilers. The humoral immune response was measured against (1% v/v) sheep red blood cells (SRBC) for total haemagglutinin (HA) antibody, 2-mercaptoethanol resistance (MER) or (IgG) antibody and 2-mercaptoethanol sensitive (MES) or (IgM) antibody titre on 7 days post-immunization. The titre was expressed as log2 of the highest dilution which shows complete haemagglutination. Total HA titers of Na/Na and Na/na (11.05$\pm$0.53 and 11.09$\pm$0.38) were comparatively higher than that of na/na (10.26$\pm$0.42). The MES antibody titre of Na/Na (8.50$\pm$0.53) and Na/na (7.63$\pm$0.45) broilers were significantly higher as compared to na/na (6.11$\pm$0.32) broilers. The MER titre of na/na genetic group (4.15$\pm$0.42) was significantly higher than Na/Na (2.55$\pm$0.37) and comparatively higher than Na/na (3.45$\pm$0.38) broilers. In vivo cell response to phytohaemagglutinin-P (PHA-P), measured as Foot Index (FI) in mm expressed significantly higher response in Na/na (0.473$\pm$0.05) and Na/Na (0.413$\pm$0.04) broilers as compared to na/na (0.304$\pm$0.03) broilers. The result of present study suggested that white plumage naked neck broilers had better immune response as compared to normally feathered broilers.

• Korean Journal of Agricultural Science
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• v.46 no.2
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• pp.351-359
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• 2019

The purpose of this study was to compare the growth performance, nutrient digestibility, fecal microflora, blood profiles and meat quality of broilers, Korean native chickens and white semi broilers under identical feeding conditions. Sixty 1-d chicks of each type were randomly placed into 12 pens per cage (5 chicks per cage) and fed commercial diets for 28, 49, and 28 days, respectively. The broilers showed a significantly higher (p < 0.05) growth performance from 0 to 4 weeks compared with the other types. Korean native chickens had a significantly higher (p < 0.05) digestibility of dry matter and nitrogen than that of the other species. The blood glucose was significantly higher in the Korean native chickens compared to the other species, and the blood cholesterol was significantly lower. The Lactobacillus content in Korean native chickens was significantly higher (p < 0.05) compared to the other species, and the E. coli content in the broilers was significantly higher (p < 0.05) than in the Korean native chickens and white semi broilers. In terms of meat quality, the breast meat of the broilers had a high water content and pH level. The breast meat of the white semi broilers had a significantly lower (p < 0.05) shear force than that of the other species. In conclusion, there was an interspecific physiological difference due to the age and body weight of the chickens. The broilers had a higher growth performance and meat quality compared to the Korean native chickens and white semi broilers.

• Journal of Animal Science and Technology
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• v.64 no.1
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• pp.84-96
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• 2022

The current study was conducted to evaluate the effect of calcium-enriched fatty acid supplementation on the growth performance, blood metabolites, intestinal morphology, carcass traits, and nutrient digestibility of broilers subjected to chronic heat stress. A total of 210 one-day-old broiler chicks (40.12 ± 0.25 g) were randomly allocated to one of five dietary treatments, to obtain six replicates per treatment. Broilers were subjected to chronic heat stress from day 21 to day 35, post-hatching, at 34℃ for 9 h per day. The body weight (BW) and feed intake of the experimental broilers were recorded weekly, and the average daily gain (ADG) and feed conversion ratio (FCR) were calculated accordingly. Rectal temperature was measured to compare the basal body temperatures between individuals, and blood samples were collected on days 21 and 35 to evaluate basal body temperature, serum total cholesterol, and the triglyceride content of the broilers. On days 21 and 35, one broiler from each cage (n=6) was euthanized to measure carcass trait parameters, nutrient digestibility in digesta, and intestinal morphology. On days 14, 28, and 35, the broilers fed 2.0% calcium-enriched fatty acids had higher BW (p < 0.05) than those fed the other diets. However, no differences (p > 0.05) were found in the average daily feed intake (ADFI) between dietary treatments over the 35 experimental days. On the other hand, on day 21, post-hatching, the broilers fed the 2.0% calcium-enriched fatty acid diet had improved (p < 0.05) dietary feed efficiencies compared to the other treatments. On day 28, the broilers fed the 5.0% of calcium-enriched fatty acid diet also had higher (p < 0.05) dietary feed efficiencies than those fed with the other dietary treatments. No effects (p > 0.05) on carcass weight, nutrient digestibility, intestinal morphology, or blood parameters were found between broilers fed with dietary treatments. This study demonstrated that the inclusion of an additive, containing 2.0% calcium-enriched fatty acid, to broiler diet could ameliorate the negative growth performance of broilers; and no interaction (p > 0.05) was observed between the calcium-enriched fatty acid and nutrient digestibility, digestive anatomy, blood metabolism, and carcass traits of broilers subjected to chronic heat stress conditions for 35 days post-hatching.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.1
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• pp.140-146
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• 2014

This experiment aimed to evaluate the effects of different housing systems on behavioral activities, welfare and meat quality of fast-growing broilers. Two hundred broilers were allocated into two housing systems: indoor housing vs indoor with outdoor access. Their general behavior (feeding, drinking, fighting, standing, lying, walking, investigating, dust-bathing and preening) was observed, and tonic immobility, fluctuating asymmetry of legs and wings were measured, and meat quality was analyzed. The results showed that the indoor-housed broilers with outdoor access had significant higher standing, walking, investigating, dust-bathing and preening than those indoor only. However, farming system was not found to significantly affect their feeding, drinking and fighting activities (p>0.05). The value of FA of tibia length of the broilers with outdoor access was significantly lower than that of the indoor-housed birds ($1.57{\pm}1.30$ vs $2.76{\pm}1.40$, p<0.05), while no difference was found for the value of FA in tibia diameter and wing length (p>0.05). TI of the broilers with outdoor access was 165.5 that was significantly higher than that (147.2) of the indoor birds (p<0.05). However, death rate in the outdoor run groups was significantly higher than that of the indoor ones ($2.0{\pm}0.81$ vs $4.0{\pm}0.82$, p<0.05). Meat quality was not affected by the two farming systems. It can be concluded that the results of this study may suggest that the indoor housing with outdoor access provides enriched environment for broilers and facilitates the expression of natural behaviors of the broilers but resulted in poorer performance and higher death rate.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.2
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• pp.239-247
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• 2003

Two experiments were conducted with broilers to investigate the feasibility of microbial phytase replacing partial inorganic phosphorus supplementation and the synergistic effects of xylanase (320 FTU/kg) supplementation alone or in combination with phytase (750 U/kg) replacing 0.08% dietary inorganic phosphorus, on the growth performance and utilization of nutrients in broilers fed wheat-based diets. In Experiment 1, 540 broilers were fed five diets for 6 weeks. Diets C0 and C1 were corn-based diets and 0.08% inorganic P supplementation was replaced with 750 U phytase/kg feed in Diet C1. Diets W0, W1 and W2 were wheat-based diets supplemented with microbial phytase 0, 750, 750 U/kg feed and 0, 0.08% and 0.16% dietary inorganic P were replaced, respectively. In Experiment 2, 432 broilers were divided into four treatments to determine the synergistic effects of supplemental xylanase and phytase replacing 0.08% inorganic P. Four experimental diets were arranged according to a $2{\times}2$ factorial design. The results indicated that addition of phytase increased the digestibility of phytic P by 31.0 to 55%, dramatically decreased the excretion of phytic P and total P by 31.6 to 55.0% and 13.8 to 32.9%, respectively (p<0.01). It is feasible to completely replace 0.08% inorganic phosphorus supplementation with microbial phytase 750 U/kg in corn- or wheat-based diets for broilers. Addition of xylanase alone or in combination with phytase replacing 0.08% dietary inorganic P, increased body weight gain and feed utilization efficiency of broilers fed wheat-based diets (p<0.10) and decreased overall mortality (p<0.10). In the groups of birds supplementing xylanase 320 FTU/kg feed, a marked elevation of the dietary AME was observed (p<0.05). Addition of phytase replacing 0.08% dietary inorganic phosphorus, concurrently with xylanase supplementation had additive effects on the apparent digestibility of dietary phytic P and overall feed conversion ratio (p<0.05).