• Asian-Australasian Journal of Animal Sciences
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• v.32 no.6
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• pp.849-855
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• 2019

Objective: This study was conducted to compare growth performance, nutrient digestibility and meat quality of broilers fed a genetically modified organism (GMO) diet or a non-GMO diet. Methods: A total of 840 broilers with an initial body weight of 43.03 g per chick were randomly allocated into 1 of the following 2 dietary treatments lasted for 32 days (15 broilers per pen with 28 replicates per treatment): i) Trt 1, GMO maize-soybean meal based diet; ii) Trt 2, non-GMO maize soybean meal based diet. Both diets were maize-soybean meal diets. The GMO qualitative analysis, proximate analysis and amino acid analysis of the feed ingredient samples were carried out. Diets were formulated based on a nutrient matrix derived from analysis results. Growth performance was measured on day 0, 7, 17, and 32. And all other response criteria were measured on day 32. Results: The analysis results showed that the total Lys, Met, Thr of non-GMO grains were lower than that of GMO grains, the protein content of GMO soybean meal was higher than that of non-GMO soybean meal. Feed intake and feed conversion rate (FCR) were greater (p<0.05) in broilers provided with non-GMO diet than that of the GMO group from d 17 to 32. A decrease in FCR was observed in birds fed the GMO diet through the entire experiment (p<0.05). No significant impacts on blood profile, meat quality and nutrient digestibility were found in response to dietary treatments throughout the experimental period (p>0.05). Conclusion: These results indicated that non-GMO diet showed a negative effect on growth performance but nutrient digestibility, blood profile, carcass weight and meat quality were not affected by non-GMO diets.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.5
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• pp.700-705
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• 2009

This study was conducted to evaluate the effects of Ligustrum lucidum (LL) on growth performance, antioxidation, and meat quality in broilers. 270 birds (1 d old) were allotted to 3 treatments with 6 replicates per treatment. The feeding program included a starter diet from d 1 to 21 of age and a grower diet from d 22 to 42 of age. The birds were given a basal corn-soybean meal diet supplemented with 0 (the control), 5 or 10 g of LL/kg, respectively. The results showed that in the starter, grower and overall phase, broilers fed with 5 or 10 g of LL/kg had better (p<0.01) average daily gain, but there were no differences in feed: gain between treatments. In the starter and overall phase, average daily feed intake of LL groups was greater (p<0.05) than that of the control, but this difference was not observed in the grower phase. Supplementation of LL significantly increased (p<0.05) superoxide dismutase activity and total antioxidant capability in serum of chickens. In breast muscle, birds fed 5 g of LL/kg had an increase (p<0.05) in superoxide dismutase activity. The LL supplementation significantly decreased (p<0.05) malondialdehyde contents. Adding 5 or 10 g of LL/kg to the diet significantly increased pH value and reduced drip loss of meat (p<0.05). The results of this study indicated that dietary LL could improve growth performance, increase pH value and reduce drip loss of meat by decreasing lipid peroxidation and by improving antioxidative status in broilers.

• Journal of Animal Science and Technology
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• v.62 no.4
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• pp.468-474
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• 2020

The study was to determine the effects of diverse concentrations of T-2 toxin in broiler diet. Three hundred 1-day-old chicks with initial body weight of 46 ± 0.52 g were chosen and randomly assigned into five dietary treatments with 5 replicate cages and 12 broilers per cage for 42 d feeding trial. Dietary treatments were prepared with basal diets containing 0 (T₁), 50 (T₂), 100 (T₃), 150 (T₄), 200 (T₅) ppb T2-toxin. Significant results were observed in the decreased intake of feed, feed conversion ratio (FCR), body weight gain (BWG), level of serum protein, cholesterol and hemoglobulin of broilers in increased concentration of the T-2 toxin in diet (150 and 200 ppb) groups than control. Also, observed that the uric acid, serum glutamic pyruvic transferase (SGPT), serum glutamic oxaloacetic transferase (SGOT) and Heterophil/Lymphocyte (H/L) ratio value were significantly higher (p < 0.05) in groups T₄ and T₅ than control. However, the BWG, feed intake and FCR, as well blood biochemical profiles of serum protein, cholesterol, hemoglobulin, uric acid, SGPT, SGOT and H/L ratio in groups T₂ and T₃ were statistically similar to control diet of broilers. It was concluded that the results showed that no adverse effects on growth performance and blood biochemical parameters in broilers feed with T-2 toxin (50 and 100 ppb) during the entire trial.

• Korean Journal of Poultry Science
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• v.44 no.3
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• pp.151-159
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• 2017

The experiment was carried out on 648 Ross 308 broilers ($40.4{\pm}0.2$ g; 1 d) chickens. It lasted for 28 days to evaluate the effects of phytogenic feed additive (PFA) on growth performance, nutrient digestibility, cecum microbiota, bone minerals contents, meat quality and internal organ weights. The chickens were haphazardly divided into any 1 of 6 dietary treatments (6 replicate pens/treatment; 18 broilers/pen). The experimental diets were: CON, control; T1, CON + 150 ppm PFA; T2, CP 0.5% reduced from basal diet; T3, T2 + 150 ppm PFA; T4, Ca 0.07% reduced + available P (aP) 0.065% reduced from basal diet; T5, T4 + 150 ppm PFA. Overall, broilers fed with T3 diet tended to have higher (P=0.08) body weight gain (BWG), and lower (P=0.05) feed conversion ratio (FCR) than T2 diet. The apparent total tract digestibility (ATTD) of P was lower (P=0.03) in T2 as compared to CON and it was higher (P=0.02) in T3 as compared to T2. There were no differences in meat quality, relative organ weight, and cecum microbiota (P>0.05). The supplementation of PFA showed trends in improvement in ash content in the bone of birds fed T1, T2 and T4 diets compared with CON. Likewise, the supplementation of PFA tended to increase (P=0.07) Ca content in the bone of birds fed T1 diet compared to CON. In conclusion, dietary supplementation with 150 ppm PFA could improve BWG in birds fed protein reduced diet, improve apparent total tract digestibility (ATTD) of P, and the bone Ca contents in broilers.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.1
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• pp.66-74
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• 2005

Three experiments were conducted to study the property of xylanase and the effects of xylanase in wheat-based diets on growth performance of broilers, respectively. Experiment 1 was performed in vitro to evaluate the effect of different pH and temperature on xylanase activity, and to evaluate the enzymic stability under different conditions. The results indicated that the optimum temperature and pH for xylanase activity were $50^{\circ}C$ and 4.5, respectively. The activity of enzyme solution was reduced rapidly after the treatment of water bath above $60^{\circ}C$ for 10 min. The enzyme was relatively stable at pH 3.5 to 8.0 and deteriorated when incubated at pH below 3.5. In Experiment 2, a total of 378 d-old male Arbor Acres broilers were randomly distributed to 7 different treatments with 6 replicates (9 birds) in each treatment. The treatments were as follows: (1) corn based diet (CS), (2) wheat based diet (WS), (3) WS+ 0.05% xylanase, (4) WS+0.15% xylanase, (5) WS+0.25% xylanase, (6) WS+0.35% xylanase, (7) WS+0.45% xylanase. The results showed that the body weight and feed/gain ratio of the broilers fed wheat-based diets have been significantly improved (p<0.05) compared to that fed corn-based diet in the first 3 wk. With regard to the wheat-based diets, the xylanase supplementation had a tendency to improve the growth performance in first 3 wk. After 3 wk, no significant difference (p>0.05) was found among all these different treatments. The supplementation of xylanase and the type of diets did not affect the feed intake but increased the concentration of triglyceride in serum. In Experiment 3, a total of 360 d-old male Arbor Acres broilers were assigned to 30 groups with 12 birds in each group randomly. These groups were then randomly distributed to 5 different treatments with 6 replicates within each treatment. The broilers of each treatment were fed one of the diets as follows: (1) Corn based diet, (2) White wheat based diet (WW) (3) White wheat based diet+0.25% xylanase, (4) Red wheat based diet, (5) Red wheat based diet+0.25% xylanase. The results showed that the body weight and feed/gain ratio had been significantly improved (p<0.05) by xylanase supplementation in the first 2 or 3 wk. The effect of xylanase in red wheat diet is a little higher than that used in white wheat diet. From the results of the present experiments, it can be concluded that the supplementation of Aspergillar xylanase can improve the performance of the broilers fed the wheat-based diet.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.10
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• pp.1475-1481
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• 2002

The study was conducted to evaluate the effect of early feed restriction on growth, fat accumulation and meat composition in unsexed broiler chickens. In experiment 1, three hundred and fifty one-day-old broiler chicks were divided into 7 groups. Each treatment group was represented by five replicates of ten broilers each. One group was fed ad libitum as the control group and the other six groups were fed 25% ad libitum (25% multiplied by amount of feed intake of ad libitum chicks at the previous day) for 4 or 6 days, 50% ad libitum for 4 or 6 days, and 75% ad libitum for 4 or 6 days. In experiment 2, five hundred broiler chicks were divided into 10 groups. Each treatment group was represented by five replicates of ten broilers each. One group was fed ad libitum as the control group. Three initial age at which broilers were restricted (2, 4 or 6 days of age) and three type of feed restriction (physical restriction, meal feeding and diet dilution) ($3{\times}3$) were examined. They were restricted feeding for 6 days. Experimental results showed that broilers fed 25% ad libitum for 4-6 days tended to reduce leg meat fat with lower abdominal fat (p<0.05) (experiment 1). Breast meat fat was significantly higher in restricted broilers (p<0.01). Plasma triglyceride was higher in broilers fed 75% ad libitum for 4-6 days. In experiment 2, abdominal fat was lower in restricted broilers (p<0.05). Breast meat fat was significantly higher (p<0.01), whereas leg meat fat was significantly lower (p<0.05) in restricted broilers. Plasma triglyceride was significantly higher in physical feed restriction for 4 days, meal feeding for 4 days and diet dilution for 6 days (p<0.05). In conclusion, to reduce fat accumulation in abdomen and leg meat, broilers should be fed 25% ad libitum for 6 days started at 4 days, or subjected to meal feeding (6 hours per day for 6 days) started at 6 days.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.3
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• pp.384-389
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• 2016

A total of 400, one day-old commercial broiler chicks were divided into five diet groups (negative control, positive control group with 55 ppm Zn-bacitracin, 15 ppm ${\beta}$-glucan, 30 ppm ${\beta}$-glucan, and 60 ppm ${\beta}$-glucan) and fed for six weeks. Ten broilers were allotted to each of 40 floor pens. Eight floor pens were randomly assigned to one of the 5 diets. Each diet was fed to the broilers for 6 weeks with free access to water and diet. The survival rate, growth rate, feed efficiency, and feed conversion rate of the broilers were calculated. At the end of the feeding trial, the birds were slaughtered, breast muscles deboned, and quality parameters of the breast meat during storage were determined. The high level of dietary ${\beta}$-glucan (60 ppm) showed better feed conversion ratio and survival rate than the negative control. The survival rate of 60 ppm ${\beta}$-glucan-treated group was the same as that of the antibiotic-treated group, which showed the highest survival rate among the treatments. There was no significant difference in carcass yield, water holding capacity, pH, color, and 2-thiobarbituric acid reactive substances values of chicken breast meat among the 5 treatment groups. Supplementation of 60 ppm ${\beta}$-glucan to broiler diet improved the survival rate and feed conversion rate of broilers to the same level as 55 ppm Zn-bacitracin group. The result indicated that use of ${\beta}$-glucan (60 ppm) can be a potential alternative to antibiotics to improve the survival and performance of broilers. However, dietary ${\beta}$-glucan showed no effects on the quality parameters of chicken breast meat.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.1
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• pp.69-74
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• 1996

There levels of dietary ME (3,000, 3,200 and 3,400 kcal/kg) and four levels of Total Sulphur Amino Acid (TSAA) (0.73, 0.83, 0.93 and 1.03%) were studied in the starter period (0-3 wks) of the broilers. Three levels of dietary ME (3,000, 3,200 and 3,400 kcal/kg) combined with four levels of TSAA (0.65, 0.72, 0.79 and 0.86%) were studied in the grower period (3-6 wks). The crude protein content of the diet of the starter period was 23% while the diet of the grower period was 20%. The performance data of the starter broilers indicated that the dietary energy levels had no significant effects on body weight gain, feed intake and feed:gain ratio. However, TSAA levels had a significant influence on the growth and feed parameters. The response pattern for the grower period was similar to the starter period. The present experiment showed that in the tropics the TSAA requirement for the starter period was between 0.83 to 0.93% which is similar to the values recommended by NRC while for the grower period the TSAA requirement was between 0.79 to 0.86% at all the three energy levels which is higher than the values recommended by NRC.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.4
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• pp.573-578
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• 2013

A total of 720 1-d-old male broilers (Arbor Acres) with the initial BW = $45{\pm}2$ g were used in a 32-d experiment. Birds were randomly allotted into 1 of 4 treatments according to a completely random block design. Dietary treatments included: i) CON (basal diet), ii) ANT (CON+0.5 g antibiotics/kg feed (bacitracin methylene disalicylate)), iii) BP1 (CON+0.25 bacteriophage/kg feed), and iv) BP2 (CON+0.5 g bacteriophage/kg feed). The BWG and FI were not affected by dietary treatments throughout the whole experiment, whereas BP2 treatment reduced (p<0.05) the feed conversion ratio compared with the CON treatment during 0 to 14 d. The birds fed bacteriophages at the level of 0.25 g/kg increased (p<0.05) the relative liver weight. The inclusion of antibiotic and bacteriophage significantly reduced (p<0.05) the Escherichia coli and Salmonella concentration in the excreta compared with the NC group. Broilers fed the BP2 treatment had higher (p<0.05) lactobacillus counts compared with those fed NC and PC treatments. In conclusion, dietary supplementation of 0.5 g/kg bacteriophages increased feed efficiency and liver weight without effects on the breast muscle properties; also pathogens were inhibited by addition of bacteriophages.

• Korean Journal of Poultry Science
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• v.51 no.2
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• pp.27-37
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• 2024

The poultry plays a crucial role in the animal industry, providing humans with efficient, high-quality animal protein. The rapid growth and short generational intervals of broilers offer significant benefits compared to other economic animals. This growth and increased muscle mass in modern commercial broilers result from advancements in breeding. However, the high productivity of contemporary broilers indicates they are approaching their physiological limits, with excessive fat accumulation becoming a significant industry issue. This not only reduces lean meat yield and feed efficiency but also negatively impacts consumers, especially due to problematic abdominal fat, which consumes more energy than lean meat production. Laying hens, reared for extended periods, maintain high productivity, producing a substantial number of eggs. This productivity in laying hens, akin to broilers, stems from genetic selection and breeding. For egg production, laying hens require physiological support for necessary nutrients. In this context, yolk fat accumulation is a critical physiological process. Lipoproteins, essential in avian lipid metabolism, are vital for yolk and body fat accumulation. Understanding these lipoproteins and their metabolism is key to developing healthier, more productive animals, offering economic benefits to farmers and improved nutritional quality to consumers. This review focuses on the physiological aspects of dietary fat transport, fatty acid biosynthesis in the liver, fat accumulation in the abdomen and muscles, and lipid deposition in egg yolks in chickens. It also highlights recent research trends in the regulation of fat metabolism in poultry.