• Asian-Australasian Journal of Animal Sciences
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• v.25 no.5
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• pp.701-707
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• 2012

Immune stress is the loss of immune homeostasis caused by external forces. The purpose of this experiment was to investigate the effects of immune stress on the growth performance, small intestinal enzymes and peristalsis rate, and mRNA expression of nutrient transporters in broiler chickens. Four hundred and thirty-two 1-d-old broilers (Cobb500) were randomly assigned to four groups for treatment; each group included nine cages with 12 birds per cage. Group 1 = no vaccine (NV); Group 2 = conventional vaccine (CV); group 3 = lipopolysaccharide (LPS)+conventional vaccine (LPS); group 4 = cyclophosphamide (CYP)+conventional vaccine (CYP). The results demonstrated that immune stress by LPS and CYP reduced body weight gain (BWG), feed intake (FI), small intestine peristalsis rate and sIgA content in small intestinal digesta (p<0.05). However, the feed conversion ratio (FCR) remained unchanged during the feeding period. LPS and CYP increased intestinal enzyme activity, relative expression of SGLT-1, CaBP-D28k and L-FABP mRNAs (p<0.05). LPS and CYP injection had a negative effect on the growth performance of healthy broiler chickens. The present study demonstrated that NV and CV could improve growth performance while enzyme activity in small intestine and relative expression of nutrient transporter mRNA of NV and CV were decreased in the conditions of a controlled rational feeding environment. It is generally recommended that broilers only need to be vaccinated for the diseases to which they might be exposed.

• Journal of the Korean Applied Science and Technology
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• v.27 no.1
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• pp.76-86
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• 2010

This study was conducted to evaluate the effects of dietary Korean red pine bark extract as an antibiotic replacements on cholesterol, fatty acids and the shelf-life of chicken meat. To accomplish this, chickens were fed the optimal level of red pine bark extract that was found to replace antibiotics in the diet of broilers. A total of 180 male broilers(Ross strain 308) were divided into three treated groups, T1(control group), T2(8 ppm of avilamycin) and T3(65 ppm of red pine bark extract per kg diet). The lipid content was reduced by 24.67% and 20.49% in T3 group, while the cholesterol level also decreased significantly in the T3 group by 20.49% and 20.55% when compared to the T1 and T2 groups, respectively. In addition, the saturated fatty acid level was lower in the T3 group than in the T1 and T2 groups, while the unsaturated fatty acid level of the T3 group was significantly higher than those of the other groups. The TBARS value of chicken thigh muscle containing its skin on the 7th day of low temperature storage was significantly lower by 23.86% and 21.17% in the T3 group than in the T1 and T2 groups, respectively. Evaluation of the color of the meat revealed that the $L^*$value (lightness) and $b^*$value(yellowness) were higher in the T3 group than in the T1 and the T2 groups, but that the pH was significantly lower in the T3. Based on the results of this study, the addition of 65 ppm red pine bark extract to the diet of broilers should improve their meat quality with respect to the lipid contents and shelf-life when compared to the addition of antibiotics.

• Korean Journal of Veterinary Research
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• v.57 no.3
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• pp.159-167
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• 2017

The microbial community is known to have a key role during the rearing period of broilers. In this study, gut microbial composition and diversity were examined to evaluate the relationships between these factors and broiler growth performance. By applying 454-pyrosequencing of the V1-V3 regions of bacterial 16S rRNA genes, six fecal samples from four- and 28-day-old chickens from three broiler farms and 24 intestinal samples of broilers with heavy and light body weights were analyzed. Microbial composition assessment revealed Firmicutes to be the most prevalent phylum at farm A, while Proteobacteria were predominant at farms B and C. Fecal microbial richness and diversity indices gradually increased from four to 28 days at all three farms. Microbial diversity assessment revealed that small intestine microbial diversity was lower in heavy birds than in light birds. In light birds, the Firmicutes proportion was lower than that in heavy birds. In conclusion, each broiler farm revealed a specific microbial profile which varied with the age of the birds. The microbial communities appeared to affect growth performance; therefore, gut microbial profiles can be utilized to monitor growth performance at broiler farms.

• Food Science of Animal Resources
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• v.31 no.5
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• pp.684-692
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• 2011

The quality attributes of thigh meat from a certified meat-type commercial Korean native chicken (WoorimatdagTM, WM) and a commercial broiler (Ross, CB) raised under the same environmental conditions, were compared. One-d-old, mixedsex WM (200), and 200 broilers (Ross, CB) each were randomly assigned to floor pens (20 chickens per pen). The production stages (I, II, and III) were selected based on similar live weight. The crude fat contents of WM thigh meat were lower than those of CB. WM thigh meat contained higher stearic and arachidonic acid contents but lower palmitoleic and oleic acid contents compared to those of CB. The thigh meat color CIE $L^*$- and CIE $b^*$-values of WM were lower, but inosine-5'-monophosphate content was higher in WM than CB in whole production stages. WM thigh meat showed higher collagen content, hardness, springiness, gumminess, and chewiness than CB. In sensory evaluation, odor, taste, and overall acceptance were higher while color was lower in WM. Based on these results, it can be concluded that even if commercial broilers are raised under the same environmental conditions as WM, the unique quality attributes of WM thigh meat are distinctively unique.

• Preventive Nutrition and Food Science
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• v.15 no.2
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• pp.143-146
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• 2010

Organic zinc was included in the diet of broiler chickens to examine its effect on the skin characteristics and the expression level of skin proteins. Broiler chicks (Ross$\times$Ross) were fed a corn-wheat-soybean meal basal diet, either as control or containing an additional 80 ppm of zinc proteinate for 4 weeks, and then five broilers from each treatment were selected randomly, slaughtered, and their skin characteristics were examined. There were significant increases (p<0.05) in thigh skin epidermis and dermis thickness in the chicks fed organic zinc. Collagen content in the skin of broilers was also increased by the addition of organic zinc to the diet. 2D-gel electrophoresis patterns indicated that expression levels of the three proteins, glyoxylase 1, hypothetical protein, and dispersin B were affected by zinc feeding. These results suggest that adding organic zinc to the chicken's feed may contribute to decreased skin tearing.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.12
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• pp.1865-1873
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• 2007

An experiment was performed to evaluate the effects of dietary metabolizable energy (ME) and lysine on carcass characteristics and meat quality in Arbor Acres (AA) broilers from 1 to 56 days of age. A total of 2,970 1-d-old male broiler chicks were randomly allocated to nine dietary treatments (three ME levels in combination with three lysine levels), and dietary ME and lysine concentrations were formulated by varying corn, soybean meal, tallow, and L-lysine sulfate concentrations. Live body weight (BW), carcass weight (CW), dressing percent, breast muscle weight (BMW), yield of breast muscle, muscle color (CIE L*, a*, and b*), pH values 45 min and 24 h postmortem ($pH_{45}$, and $pH_{24}$), meat shear force value (SFV), and water loss rate (WLR) were evaluated. Results showed that live body weight and dressing percent increased (p<0.05) as dietary energy increased. Higher dietary lysine content improved breast muscle weight. Neither carcass weight nor yield of breast muscle was affected by dietary energy or lysine content. Higher ME increased the b* value (p = 0.067) and $pH_{24}$ value (p<0.05), whereas it decreased SFV (p<0.05) and WLR (p = 0.06). Only water loss rate was influenced (p<0.01) by dietary lysine, which was higher in broilers from the high lysine diet as compared to those from medium or low lysine diets. The $pH_{45}$ value and L* value of breast muscle were not affected by ME or lysine. Significant interaction of dietary ME and lysine was found on a* value of breast muscle. These results indicated that dietary ME and lysine had important effects on breast muscle growth and meat quality, however their effects were different. Different concentrations of dietary ME and lysine might be considered to improve meat quality.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.12
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• pp.1639-1644
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• 2010

An experiment was conducted to evaluate the effects of dietary acetyl-L-carnitine (ALC) on growth performance, carcass characteristics, meat quality and lipid metabolism in broilers. A total of 240 one-day-old male Arbor Acres broilers were randomly allocated to 4 dietary treatments (0, 300, 600, and 900 mg/kg dietary ALC supplementation, respectively). Compared with the control treatment, addition of ALC resulted in lower (linear effect, p<0.05) ADG and AFI. Abdominal fat percentage decreased (linear effect, p<0.05) as dietary ALC was increased, but there was no effect on dressing percentage, breast muscle percentage or thigh muscle percentage. Breast muscle pH value 24 h post-mortem increased (linear effect, p<0.05), but there were no significant differences among treatments. However, thigh muscle pH value increased (linear effect, p<0.05) as dietary ALC was increased. Breast and thigh muscle $a^*$ values increased (linear effect, p<0.05), and breast and thigh muscle $b^*$ values decreased (linear effect, p<0.05) with increased ALC in the diet. In addition, breast and thigh muscle shear force value decreased (linear effect, p<0.05) as dietary ALC was increased. Total cholesterol, triglyceride, low-density lipoprotein cholesterol and lipoprotein lipase decreased (linear effect, p<0.05) and free fatty acid and lipase in serum increased (linear effect, p<0.05) with increased ALC in diets.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.8
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• pp.1159-1168
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• 2012

The experiment was carried out to investigate the effects of Alisma canaliculatum with probiotics (ACP) on the growth performance, meat composition, oxidative stability, and fatty acid composition of broiler meat. Sixteen probiotic strains were tested for their levels of acid, bile, and heat tolerance. Among them, Lactobacillus acidophilus KCTC 3111, Enterococcus faecium KCTC 2022, Bacillus subtilis KCTC 3239, and Saccharomyces cerevisiae KCTC 7928 were selected for use in ACP. Exactly 140 Ross broiler chicks were assigned to four dietary treatments in five replications for 5 wks in a completely randomized design. The dietary treatments were NC (Negative control; basal diet), PC (Positive control; basal diet with 0.005% Chlortetracycline), ACP-0.5% (basal diet with 0.5% ACP powder), and ACP-1% (basal diet with 1% ACP powder). According to the results, body weight of the broilers increased, and feed conversion ratio improved in the ACP-0.5% group compared to the NC group (p<0.05). Crude protein content of breast meat was higher (p<0.05) in the ACP-0.5% group, whereas crude fat content of thigh meat was lower (p<0.05) in the supplemented groups. Breast meat absolute and relative weights were both higher (p<0.05) in the ACP groups compared to the control group. Further, ACP diets increased gizzard and decreased large intestine relative weights, whereas kidney relative weight decreased upon the addition of a higher level (1%) of ACP (p<0.05). Thiobarbituric acid reactive substances values of breast and thigh meats were reduced (p<0.05) by ACP supplementation compared to control. Regarding the fatty acid composition of breast meat, arachidonic acid, docosahexaenoic acid, PUFA, and n6 fatty acid levels decreased (p<0.05) in the ACP groups, whereas the levels of linoleic acid, PUFA, PUFA/SFA, and n6 fatty acid in thigh meat decreased (p<0.05) by ACP and PC diets. It can be suggested based on the study results that ACP-0.5% diet could be an effective feed additive for broilers.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.1
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• pp.97-102
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• 2008

Four hundred and forty 1-day-old Arbor Acre broilers were fed commercial starter diets with 0, 250, 750 and 2,250 mg/kg of an alpha-amylase preparation from 1 to 21 days of age to investigate the effects of an exogenous enzyme on growth performance, activities of digestive enzymes in the pancreas and anterior intestinal contents and pancreatic amylase mRNA expression. Body weight gain (BWG) and average daily gain (ADG) increased linearly (p<0.01) with increasing levels of supplementary amylase but feed conversion ratio (FCR) was not affected. There was a negative quadratic change of protease and amylase in the small intestinal contents with the increase of supplementary amylase level. The activity of intestinal trypsin was also increased (p<0.05). Lipase was unaffected by amylase supplementation (p>0.05). The pancreatic protease, trypsin, and lipase were not affected by exogenous amylase levels. Consistent with the tendency for a linear depression of amylase activity, pancreatic ${\alpha}$-amylase mRNA was down-regulated by dietary amylase supplementation. The present study suggested that oral administration of exogenous amylase affected activities of intestinal enzymes and the production of pancreatic digestive enzymes in a dose-dependent manner.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.6
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• pp.895-902
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• 2012

The Korean native chickens (Woorimotdak$^{TM}$, KNC) and commercial broilers (Ross, CB) show obvious differences in meat flavor after cooking. To understand the contribution of protein and peptide for meat flavor, 2-dimensional (2-D) gel electrophoresis and matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) mass spectrometry was performed. A total of 16 protein spots were differentially expressed in the breast and thigh meat between the two breeds. A total of seven protein spots were represented by different levels between KNC and CB for breast meat. Among them three protein spots (TU39149, TU40162 and TU39598) showed increases in their expressions in KNC while other four protein spots (BU40125, BU40119, BU40029 and BU39904) showed increases in CB. All nine protein spots that were represented by different levels between KNC and CB for thigh meat showed increases in their expression in KNC. Phosphoglucomutase 1 (PGM 1), myosin heavy chain (MyHC), heat shock protein B1 (HSP27), cytochrome c reductase (Enzyme Q), Glyoxylase 1, DNA methyltransferase 3B (DNA MTase 3) were identified as the main protein spots by MALDI-TOF mass spectrometry. These results can provide valuable basic information for understanding the molecular mechanism responsible for breed specific differences in meat quality, especially the meat flavour.