• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.681-685
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• 2009

L-carnitine promotes mitochondrial ${\beta}$-oxidation of long chain fatty acids and their subsequent transport across the inner mitochondrial membrane. Although the role of L-carnitine in fatty acid metabolism has been extensively studied, its role in live performance and carcass responses of commercial broilers is less understood. The objective of this research was to determine if Lcarnitine fed at various levels in diets differing in CP and amino acids impacted on live performance and carcass characteristics of commercial broilers. Two floor pen experiments were conducted to assess the effect of dietary L-carnitine in grower diets. In Exp. 1, Ross${\times}$Hubbard Ultra Yield broilers were placed in 48 floor pens (12 birds/pen) and fed common diets to d 14. A two (0 or 50 ppm Lcarnitine) by three (173, 187, and 202 g/kg CP) factorial arrangement of treatments was employed from 15 to 35 d of age (8 replications/treatment). An interaction (p<0.05) in carcass yield indicated that increasing CP (187 g/kg) resulted in improved yield in the presence of L-carnitine. Increasing CP from 173 to 202 g/kg increased (p<0.05) BW gain and decreased (p<0.05) feed conversion and percentage abdominal fat. Feeding dietary L-carnitine increased back-half carcass yield which was attributable to an increase (p<0.05) in thigh, but not drumstick, yield relative to carcass. In Exp. 2, $Ross{\times}Ross$ 708 broilers were fed common diets until 29 d. From 30 to 42 d of age, birds were fed one of seven diets: i) 200 g/kg CP, 0 ppm L-carnitine; ii) 200 g/kg CP, 40 ppm L-carnitine; iii) 180 g/kg CP, 0 ppm L-carnitine; iv) 180 g/kg CP, 10 ppm L-carnitine; v) 180 g/kg CP, 20 ppm L-carnitine; vi) 180 g/kg CP, 30 ppm L-carnitine; and vii) 180 g/kg CP, 40 ppm L-carnitine (6 replications of 12 birds each). BW gain, feed conversion, mortality (30 to 42 d), and carcass traits (42 d) were measured on all birds by pen. There were no treatment differences (p<0.05). However, the addition of 40 ppm L-carnitine in the 200 g CP/kg diet increased (p = 0.06) thigh yields relative to BW in comparison to birds fed diets without L-carnitine, which was further confirmed via a contrast analysis (0 vs. 40 ppm L-carnitine in the 200 and 180 g CP/kg diets; p<0.05). These results indicated that dietary L-carnitine may heighten metabolism in dark meat of commercial broilers resulting in increased relative thigh tissue accretion without compromising breast accretion.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.2
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• pp.233-240
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• 2013

The objective of this study was to investigate the effects of L-carnitine on growth performance, organ weight, biochemical parameters of blood, heart and liver, and ascites susceptibility of broilers at different ages reared under a low-temperature environment. A total of 420 1-d-old male Ross 308 broilers were randomly assigned to two dietary treatments with fifteen replicates of fourteen broilers each. Treatment diets consisted of L-carnitine supplementation at levels of 0 and 100 mg/kg. At 11-d of age, low temperature stress was used to increase ascites susceptibility. Blood, heart and liver samples were collected at different ages for analysis of boichemical parameters. The results showed that, there was no significant difference in growth performance with L-carnitine supplementation, but the mortality due to ascites was significantly decreased. Dietary L-carnitine supplementation significantly reduced heart index (HI) and ascites heart index (AHI) on d 21, lung index (LUI) on d 35 and liver index (LI) on d 42. The broilers fed diets containing L-carnitine had significantly lower red blood cell counts (RBC), hemoglobin (HGB) concentration and hematocrit (HCT) on d 42. Dietary L-carnitine supplementation significantly reduced malondialdehyde (MDA) content of heart tissue on d 21 and 35, and significantly increased total superoxide dismutase (T-SOD) and Glutathione peroxidase (GSH-Px) activity of the heart on d 21 and 42. L-carnitine supplementation significantly reduced serum triglyceride (TG) content on d 28 and 35 and serum glucose (GLU) on d 35 and 42, and significantly increased serum total protein (TP) and globulin (GLO) content on d 42. L-carnitine supplementation significantly enhanced liver succinodehydrogenase (SDH), malic dehydrogenase (MDH) and $Na^+$-$K^+$-ATPase activity on d 28, and tended to reduce the lactic acid (LD) level of liver on d 35 (p = 0.06). L-carnitine supplementation significantly reduced serum uric acid (UA) content on d 28, 35 and 42. Based on the current results, it can be concluded that dietary L-carnitine supplementation reduced organ index, red blood cell counts and hematocrit, enhanced antioxidative capacity of the heart, enhanced liver enzymes activity involved in tricarboxylic acid cycle, and reduced serum glucose and triglyceride. Therefore, it is suggested that L-carnitine can potentially reduce susceptibility and mortality due to ascites.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.5
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• pp.681-688
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• 2016

The present study was conducted to compare the supplementation of natural (D-${\alpha}$-tocopherol) and synthetic (DL-${\alpha}$-tocopherol acetate) vitamin E on the growth performance, meat quality, muscular antioxidant capacity and genes expression related to oxidative status of broilers. A total of 144 1 day-old Arbor Acres broiler chicks were randomly allocated into 3 groups with 6 replicates of 8 birds each. Birds were given a basal diet (control group), and basal diet supplemented with either 20 IU D-${\alpha}$-tocopherol or DL-${\alpha}$-tocopherol acetate for 42 days, respectively. The results indicated that treatments did not alter growth performance of broilers (p>0.05). Compared with the control group, concentration of ${\alpha}$-tocopherol in the breast muscle was increased by the supplementation of vitamin E (p<0.05). In the thigh, ${\alpha}$-tocopherol content was also enhanced by vitamin E inclusion, and this effect was more pronounced in the natural vitamin E group (p<0.05). Vitamin E supplementation increased the redness of breast (p<0.05). In the contrast, the inclusion of synthetic vitamin E decreased lightness of thigh (p<0.05). Dietary vitamin E inclusion reduced drip loss at 24 h of thigh muscle (p<0.05), and this effect was maintained for drip loss at 48 h in the natural vitamin E group (p<0.05). Broilers given diet supplemented with vitamin E showed decreased malondialdehyde (MDA) content in the breast (p<0.05). Additionally, natural rather than synthetic vitamin E reduced MDA accumulation in the thigh (p<0.05). Neither natural nor synthetic vitamin E supplementation altered muscular mRNA abundance of genes related to oxidative stress (p>0.05). It was concluded that vitamin E supplementation, especially the natural vitamin E, can enhance the retention of muscular ${\alpha}$-tocopherol, improve meat quality and muscular antioxidant capacity of broilers.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.6
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• pp.855-864
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• 2016

The objective of this study was to compare the physicochemical and nutritional properties of breast and thigh meat from commercial Chinese crossbred chickens (817 Crossbred chicken, 817C), imported commercial broilers (Arbor Acres broiler, AAB), and commercial spent hens (Hyline Brown, HLB). The crossbred chickens, commercial broilers and spent hens were slaughtered at their typical market ages of 45 d, 40 d, and 560 d, respectively. The results revealed that several different characteristic features for the three breeds. The meat of the 817C was darker than that of the other two genotypes. The 817C were also characterized by higher protein, lower intramuscular fat, and better texture attributes (cooking loss, pressing loss and Warner-Bratzler shear force [WBSF]) compared with AAB and HLB. The meat of the spent hens (i.e. HLB) was higher in WBSF and total collagen content than meat of the crossbred chickens and imported broilers. Furthermore, correlation analysis and principal component analysis revealed that there was a clear relationship among physicochemical properties of chicken meats. With regard to nutritional properties, it was found that 817C and HLB exhibited higher contents of essential amino acids and essential/non-essential amino acid ratios. In addition, 817C were noted to have highest content of microelements whereas AAB have highest content of potassium. Besides, 817C birds had particularly higher proportions of desirable fatty acids, essential fatty acids, polyunsaturated/saturated and (18:0+18:1)/16:0 ratios. The present study also revealed that there were significant differences on breast meat and thigh meat for the physicochemical and nutritional properties, regardless of chicken breeds. In conclusion, meat of crossbred chickens has some unique features and exhibited more advantages over commercial broilers and spent hens. Therefore, the current investigation would provide valuable information for the chicken meat product processing, and influence the consumption of different chicken meat.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.10
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• pp.1470-1476
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• 2016

Octacosanol, which has prominent physiological activities and functions, has been recognized as a potential growth promoter in animals. A total of 392 1-d-old male Arbor Acres broiler chicks with similar body weight were randomly distributed into four dietary groups of seven replicates with 14 birds each supplemented with 0, 12, 24, or 36 mg octacosanol (extracted from rice bran, purity >92%)/kg feed. The feeding trial lasted for six weeks and was divided into the starter (day 1 to 21) and the grower (day 22 to 42) phases. The results showed that the feed conversion ratio (FCR) was significantly improved in broilers fed a diet containing 24 mg/kg octacosanol compared with those fed the control diet in the overall phase (day 1 to 42, p = 0.042). The average daily gain and FCR both showed linear effects in response to dietary supplementation of octacosanol during the overall phase (p = 0.031 and 0.018, respectively). Broilers fed with 24 or 36 mg/kg octacosanol diet showed a higher eviscerated yield, which increased by 5.88% and 4.26% respectively, than those fed the control diet (p = 0.030). The breast muscle yield of broilers fed with 24 mg/kg octacosanol diet increased significantly by 12.15% compared with those fed the control diet (p = 0.047). Eviscerated and breast muscle yield increased linearly with the increase in dietary octacosanol supplementation (p = 0.013 and 0.021, respectively). Broilers fed with 24 or 36 mg/kg octacosanol diet had a greater (p = 0.021) $pH_{45min}$ value in the breast muscle, which was maintained linearly in response to dietary octacosanol supplementation (p = 0.003). There was a significant decrease (p = 0.007) in drip loss value between the octacosanol-added and the control groups. The drip loss showed linear (p = 0.004) and quadratic (p = 0.041) responses with dietary supplementation of octacosanol. These studies indicate that octacosanol is a potentially effective and safe feed additive which may improve feed efficiency and meat quality, and increase eviscerated and breast muscle yield, in broiler chicks. Dietary supplementation of octacosanol at 24 mg/kg diet is regarded as the recommended dosage in the broilers' diet.

• Korean Journal of Poultry Science
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• v.36 no.2
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• pp.157-163
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• 2009

This work was conducted to investigate the amount and major compositions of excreta from broilers. One hundred fifty 1-d-old male and female Ross broilers were used in this work and ten broilers were selected to measure excreta. Average amount of excreta per broiler was 85.4 g, and average moisture content was 76.9%. N, $P_2O_5$ and $K_2O$ in excreta were 1.19, 0.29 and 0.49%, respectively. pH, $BOD_5$, $COD_{mn}$, and SS were 7.80, 42,134 mg/L, 52,668 mg/L, and 106,669 mg/L, respectively. Pb in poultry excreta was 0.803 mg/kg and highly lowed compared with the standard contents (150 mg/kg). Cd was not founded in excreta. Hg was founded in excreta as 0.002 mg/kg, but it was low compared with the standard level (2 mg/kg).

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.8
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• pp.1123-1130
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• 2004

Two experiments were conducted to examine the effects of dietary inclusion of xylose on growth performance, nutrient digestibility and xylose absorption in the portal-drained viscera of broiler chicks. In Exp. 1, ninety male 14 day-old broilers were used to study the effects of different inclusion levels (0, 5, 10, 20 and 40%) of D-xylose in the semi-purified diets on the growth and nutrient digestibility of broilers. In Exp. 2, One hundred and eight male broilers, fed by precision feeding at 22 day-old, were used to investigate the absorption and transportation of dietary xylose in the portal-drained viscera of broiler. The results of Exp. 1 indicated that the growth of broilers was gradually decreased as the xylose level increased (p<0.01). With the xylose supplementation increased, the moisture in broiler excreta was gradually elevated (p<0.01), AME and the digestibilities of crude protein and ether extract were significantly reduced and the digestibilities of xylose and arabinose were also decreased (p<0.01). The results of Exp. 2 showed that the concentrations of ribose, xylose and galactose in serum were significantly influenced by different dietary levels of xylose (p<0.01), but there's no apparent difference among rhamnose, glucose and arabinose (p>0.05). The xylose concentration in serum was highest in Vena Cava, middle in Portal Vein and lowest in Ulnar Vein within 6 h after precision feeding. And then the xylose concentration in Portal Vein and Ulnar Vein were higher than that of Vena Cava. The concentration of ribose, xylose and galactose in serum were also significantly changed with time prolongation (p<0.01). The concentration of xylose in serum was highest in the 40% xylose treatment, middle in the 20% xylose group and lowest in the control group. The glycogen contents in liver and muscle were linearly decreased as the level of xylose increased (p<0.01). The higher the dietary level of xylose was, the lower digestibility of dietary xylose was (p<0.10). 40% xylose markedly decreased the digestibility of dietary glucose (p<0.01). In conclusion, high levels of xylose in the diets inhibited the growth and nutrient digestibility of broiler. The outputs of xylose from the hydrolyzation of wheat-based diet by xylanase should have no adverse effects on broiler performance.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.2
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• pp.267-271
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• 2012

An experiment was conducted to evaluate the effects of one alpha-hydroxycholecalciferol ($1{\alpha}$-OH $D_3$) on growth performance, tibia quality, and skin and meat color in broilers fed calcium (Ca)- and phosphorus (P)-deficient corn-soybean meal diets. A total of 288 male Ross broilers, at 21 days of age, were randomly assigned to three treatments with eight cages per treatment. Three levels of $1{\alpha}$-OH $D_3$ (0, 5, and 10 ${\mu}g$/kg) were added to a basal diet (0.50% Ca, 0.13% non-phytate phosphorus (NPP), and 0.35% total phosphorus (tP)) without vitamin $D_3$. As a result of this study, the addition of $1{\alpha}$-OH $D_3$ increased body weight gain (p<0.001), feed intake (p = 0.007), feed efficiency (p<0.001), tibia weight (p = 0.002), length (p<0.001), breaking-strength (p = 0.012), ash (p<0.001), Ca (p<0.001), and P content (p = 0.004). Dietary $1{\alpha}$-OH $D_3$ enhanced breast meat yellowness (p = 0.015) and the length and weight of the small intestine of the broilers. Moreover, $1{\alpha}$-OH $D_3$ decreased serum Ca concentration (p = 0.074) and breast meat redness (p = 0.010). These results indicate that the $1{\alpha}$-OH $D_3$ improves growth, tibia quality, and meat color in broilers fed Ca- and P-deficient corn-soybean meal diets.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.2
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• pp.250-257
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• 2011

An experiment was conducted to determine the effects of different mycotoxin adsorbents including esterified glucomannan (EGM), hydrated sodium calcium aluminosilicate (HSCAS) and compound mycotoxin adsorbent (CMA) on performance, blood parameters, and liver pathological changes in broilers fed mold-contaminated feed. Two hundred and forty 10-day-old broilers were randomly assigned to one of the five dietary treatments including: i) control diet; ii) mold-contaminated diet; iii) moldcontaminated diet+0.05% EGM; iv) mold-contaminated diet+0.2% HSCAS; v) mold-contaminated diet+0.1% CMA. At 35-days-old, blood and liver tissue samples were collected for analysis. 0.1% CMA improved ADG and ADFI during 10-42 d compared to the moldcontaminated group (p<0.05). The mold-contaminated diet increased total white blood cell (WBC) number, haemoglobin (Hgb) concentration, hematocrit (Hct) level, serum aspartate aminotransferase (AST) and ${\gamma}$-glutamyl transferase (GGT) activities, and decreased red blood cell (RBC) number and serum globulin (GLB) and urea nitrogen (BUN) concentrations (p<0.05). The three mycotoxin adsorbents alleviated the alteration of RBC, WBC, Hgb and AST caused by the mold-contaminated diet. Furthermore, 0.1% CMA increased GLB concentration and decreased Hct level and GGT activity (p<0.05). Liver superoxide dismutase (SOD) activity was reduced, and myeloperoxidase (MPO) activity was increased by the mold-contaminated diet (p<0.05). Both EGM and HSCAS prevented the increase of MPO activity (p<0.05). Liver lesion, including severe vacuolar degeneration of hepatocytes, was observed in chicks fed the mold-contaminated diet. 0.05% EGM prevented these effects except for biliary hyperplasia and mild vacuolar degeneration. 0.2% HSCAS showed medium vacuolar degeneration of hepatocytes. Liver of broilers fed 0.1% CMA revealed a mild vacuolar degeneration. These results indicate that a mold-contaminated diet results in adverse effects on blood parameters and liver morphology. 0.05% EGM and 0.2% HSCAS partially alleviated the adverse effects. However, 0.1% CMA almost completely ameliorated the adverse effects.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.9
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• pp.1444-1454
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• 2020

Objective: Cold stress induces oxidative damage and impairs energy status of broilers. N-acetylcysteine (NAC) exhibits antioxidant properties and modulates energy metabolism of animals. This study was conducted to investigate the effects of NAC on energy status and antioxidant capacity of heart and liver in the cold-stressed broilers. Methods: The experiment consisted of 4 treatments in a 2×2 factorial arrangement with two diets (basal diet or plus 0.1% NAC) and two ambient temperatures (thermoneutral [conventional ambient temperature] or cold stress [10℃±1℃ during days 15 to 42]). Results: No ascites were seen in cold-stressed broilers. NAC did not attenuate the impaired growth performance of stressed birds. However, NAC decreased plasma asparagine but increased aspartate levels in cold-stressed birds (p<0.05). NAC reduced hepatic adenosine triphosphate (ATP) but elevated adenosine diphosphate contents in unstressed birds (p<0.05). The hepatic ratio of adenosine monophosphate (AMP) to ATP was increased in birds fed NAC (p<0.05). NAC decreased plasma malondialdehyde (MDA) level and cardiac total superoxide dismutase (T-SOD) activity in unstressed birds, but increased hepatic activities of T-SOD, catalase and glutathione peroxidase in stressed birds (p<0.05). NAC down-regulated hepatic AMP-activated protein kinase but up-regulated cardiac heme-oxigenase mRNA expression in stressed birds, and decreased expression of hepatic peroxisome proliferator-activated receptor coactivator-1α as well as hypoxia-inducible factor-1α in liver and heart of birds. Conclusion: Dietary NAC did not affect energy status but enhanced the hepatic antioxidant capacity by increasing the activities of antioxidant enzymes in cold-stressed broilers.