• Asian-Australasian Journal of Animal Sciences
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• v.31 no.11
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• pp.1807-1817
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• 2018

Objective: This study aimed at investigating white striping (WS) and wooden breast (WB) cases in breast meat collected from commercial broilers. Methods: A total of 183 breast samples were collected from male Ross 308 broilers slaughtered at the age of 6 weeks (n = 100) and 7 weeks (n = 83). The breasts were subjected to meat defect inspection, meat quality determination and histology evaluation. Results: Of 183, 4 breasts from 6-week-old broilers were classified as non-defective while the others exhibited the WS lesion. Among the 6-week-old birds, the defective samples from the medium size birds (carcass weight ${\leq}2.5kg$) showed mild to moderate WS degree with no altered meat quality. Some of the breasts from the 6-week-old birds with carcass weight above 2.5 kg exhibited WB in accompanied with the WS condition. Besides of a reduction of protein content, increases in collagen matter and pH values in the defective samples (p<0.05), no other impaired quality indices were detected within this group. All 7-week-old broilers yielded carcasses weighing above 2.5 kg and showed abnormal characteristics with progressive severity. The breasts affected with severe WS and WB showed the greatest cook loss, hardness, springiness and chewiness (p<0.05). Development of WB induced significantly increased drip loss in the samples (p<0.05). Histology indicated necrotic events in the defective myofibers. Based on logistic regression, increasing percent breast weight by one unit enhanced the chance of WS and WB development with advanced severity by 50.9% and 61.0%, respectively. Delayed slaughter age from 6 to 7 weeks increased the likelihood of obtaining increased WS severity by 56.3%. Conclusion: Cases of WS and WB defects in Southeast Asia have been revealed. Despite few cases of the severe WS and WB, such abnormal conditions significantly impaired technological properties and nutritional quality of broiler breasts.

• Korean Journal of Organic Agriculture
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• v.18 no.3
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• pp.347-361
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• 2010

This study was carried out to investigate the effects of wormwood (Artemisia sp.) addition on the growth performance, nutrients utilization and abdominal fat deposition of broiler chickens. Two hundred twenty five and two-day old Arboracre strain male commercial broiler chicks were distributed to 5 treatments with wormwood supplementation levels; C(O%), $T_1$ (1%), $T_2$ (3%), $T_3$ (5%), and $T_4$ (10%) and with 3 replications each with 5 birds for five weeks. Body weight gain during the experiment was improved in $T_1$ (1723.0g) compared with that of $T_3$ (1557.7g) and $T_4$ (1450.7g) (P<0.05). Feed intake was significantly (P<0.05) increased as the levels of wormwood addition increased (C: 2653.8g, T1: 2852.0, $T_2$: 2900.3, $T_3$: 2900.7g, T4: 2954.7g). Feed conversion rate (feed/gain) was significantly (P<0.05) increased as the levels of wormwood addition increased (C: 1.55, $T_1$: 1.66, $T_2$: 1.70, $T_3$: 1.86, $T_4$: 2.04). The days reaching to 2.0kg of body weight were expected to be 43.2 days in control, whereas those of group T1 were reduced to 42.6 days by 0.6 day from control. Nutrient utilization and abdominal fat deposition in the experiment were significantly decreased (P<0.05) and small intestine contents in the broilers was significantly increased (P<0.05) as the levels of wormwood addition increased. Therefore, although there was no significant improvement for the performance of broiler chickens with the dietary supplementation of wormwood meal, less than 1% addition of wormwood to broiler diets might have beneficial for human health by reducing the abdominal fat deposition of the broiler chicknens.

• Korean Journal of Poultry Science
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• v.42 no.3
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• pp.247-256
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• 2015

There are approximately 1,500 broiler farms in Korea, each raising 55,000 birds. Ninety-five percent of the farms are contracted with Integration Company. According to the Korean broiler performance index, broilers in Korea are marketed at 32 days with 1.52 kg of body weight. In contrast, the market age and body weight of broilers are 47 days/2.8 kg in the United States and 42 days/2.5 kg in Europe. Because of the younger market age of the Korean broiler, the pre-starter feed is important. Chicks exhibit poor absorption of dietary nutrients up to 7 days after hatching due to an immature digestive system and low enzyme secretion rate and activity. At the beginning of hatching, chicks obtain their nutrients from the egg yolk sac. It is highly recommended that chicks, after consuming the nutrients in the egg yolk sac, are given supplemented pre-starter feed to increase early growth rates and improve the performance of broiler production. Pre-starter nutrient requirements are not expressed in NRC, so Korean feeding standards for poultry and commercial breeding companies determine the nutrient requirements of pre-starter broiler chickens. Three approaches are followed to formulate specially designed pre-starter feeds for broiler chicks: (i) selective use of raw materials, (ii) proper standards of nutrient supply, and (iii) application of feed additives such as exogenous enzymes. In the selection of raw materials, those with high digestibility can be used. The absorption rate of carbohydrates in grains can be increased through feed processing at high temperature and high pressure. Soy proteins and fish meal can also be added as protein sources. As an energy source, vegetable oils are preferred over animal fats because of the former's high digestibility. It is suggested that the levels of proteins and amino acids are higher in pre-starter feed than in starter feed. With regard to energy, the sources of energy are more important than the levels of energy in feed. Feed additives such as exogenous enzymes can be used to improve nutrient digestibility. In addition, organic acids and plant extracts can be used as alternatives to animal growth promoters to stimulate immunity and prevent diseases. The growth performance of broilers is affected by various factors, such as management and disease control, in addition to the nutritional strategy; however, nutritional strategies play an important role in improving the productivity of broilers. Therefore, nutritional strategies, along with management and disease control, are required for improving the productivity of broilers in Korea.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.5
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• pp.695-701
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• 2016

This study was conducted to observe antioxidant enzyme activity, iron content and lipid oxidation of Korean native chickens and other poultry. The breast and thigh meat of three Korean native chicken breeds including Woorimatdak, Hyunin black and Yeonsan ogye, and three commercial poultry breeds including the broiler, White Leghorn and Pekin duck (Anasplatyrhyncos domesticus) were studied. The analyses of the antioxidant enzymes activity, iron content and lipid oxidation were performed in raw and cooked samples. The activity of catalase (CAT) in the thigh meat was higher than that of the breast meat of three Korean native chickens and the broiler, respectively. The activity of glutathione peroxidase (GPx) in the uncooked thigh meat of three Korean native chickens was higher than that of the breasts. The breast meat of Woorimatdak and Pekin duck had higher superoxide dismutase (SOD) activity than the others, while only the thigh meat of Pekin duck had the highest activity. Cooking inactivated CAT and decreased the activity of GPx and SOD. The thigh meat of Woorimatdak, White Leghorn, Yeonsan ogye and Hyunin black contained more total iron than the breast meat of those breeds. The heme-iron lost during cooking ranged from 3.2% to 14.8%. It is noted that the thigh meat had higher thiobarbituric acid reactive substances values than the breast in all chicken breeds. Though Woorimatdak showed higher antioxidant enzyme activity and lower released-iron percentage among Korean native chickens, no differences were found on lipid oxidation. We confirm that the dark meat of poultry exhibited higher antioxidant enzyme activity and contained more iron than the white meat.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.11
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• pp.1593-1599
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• 2014

This study consisted of two experiments, conducted to assess the impact of phase at which vegetable protein (VP) diets are introduced to broiler chicks, and preference of birds for diets based on soybean or canola meal (CM). Two hundred and ten day-old Cobb 500 chicks were randomly distributed into five dietary groups in the main experiment. One group was fed on animal protein (AP) diet all through to 21 days of age; two other groups were started on AP diet for 7 days and then switched to diets containing soybean meal (AP-SBM) or AP-CM, while two other diets (SBM-AP and CM-AP) were started on one of the VP diets for 7 days and then switched to AP diet. A sub-experiment on thirty birds raised on a commercial diet to 7 days was used in a feed selection test to quantify the preference of birds for the diets containing mainly CM or SBM. Chicks were reared under similar care and management conditions and the diets were iso-caloric and iso-nitrogenous. Results of the main experiment showed that chicks on CM-AP diet ate more (p<0.05) than those on the other diets up to day 7. Body weight gain was highest (p<0.001) on the AP-SBM diet while birds on the CM-AP diet weighed the least at 7 d. Feed intake, body weight gain, feed conversion ratio, mortality, bone growth, visceral organ development, and activities of digestive enzymes were similar between the groups from hatch to 21 days of age. Results of the second sub-experiment showed that chicks preferred the CM-based diets to the SBM-based diets at 8 to 14 d (p<0.001) and 15 to 21 d (p<0.01) when given a choice. Overall, the birds were not affected by the nature of the starter diet although they tended to prefer the canola to soybean diets.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.2
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• pp.247-251
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• 2015

This experiment was carried out to investigate effects of onion extract on growth performance, meat quality and blood profiles of White mini broilers. Total of 600 one-d-old male White mini broiler chicks were divided into four groups and fed control diets (non-medicated commercial diet or antibiotics medicated) or experimental diets (non-medicated diets containing 0.3% or 0.5% onion extract) for 5 wks. The final body weight (BW) and weight gain of the group fed non-medicated control diet were lower than those of medicated control group (p<0.01). The chicks fed diet with 0.3% or 0.5% onion extract showed a similar BW to that of medicated control group. The relative weight of various organs, such as liver, spleen, bursa of Fabricius, abdominal fat, and the activities of serum enzymes were not affected by dietary treatments. There were no significant differences in meat color among groups. Whereas, groups fed diets containing onion extract had slightly lower cooking loss and higher shear force value, but not significantly. The concentrations of serum free cholesterol and triacylglycerol in groups fed diet containing onion extract were significantly decreased compared with those of controls (p<0.01). In conclusion, the onion extracts exerted a growth-promoting effect when added in White mini broiler diets, reflecting potential alternative substances to replace antibiotics.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.12
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• pp.1686-1695
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• 2015

Molecular marker selection has been an acceptable tool in the acceleration of the genetic response of desired traits to improve production performance in chickens. The crossbreds from commercial parent stock (PS) broilers with four Thai synthetic breeds; Kaen Thong (KT), Khai Mook Esarn (KM), Soi Nin (SN), and Soi Pet (SP) were used to study the association among chicken growth hormones (cGH) and the insulin-like growth factor (IGF-I) genes for growth and carcass traits; for the purpose of developing a suitable terminal breeding program for Thai broilers. A total of 408 chickens of four Thai broiler lines were genotyped, using polymerase chain reaction-restriction fragment length polymorphism methods. The cGH gene was significantly associated with body weight at hatching; at 4, 6, 8, 10 weeks of age and with average daily gain (ADG); during 2 to 4, 4 to 6, 0 to 6, 0 to 8, and 0 to 10 weeks of age in $PS{\times}KM$ chickens. For $PS{\times}KT$ populations, cGH gene showed significant association with body weight at hatching, and ADG; during 8 to 10 weeks of age. The single nucleotide polymorphism variant confirmed that allele G has positive effects for body weight and ADG. Within carcass traits, cGH revealed a tentative association within the dressing percentage. For the IGF-I gene polymorphism, there were significant associations with body weight at hatching; at 2, 4, and 6 weeks of age and ADG; during 0 to 2, 4 to 6, and 0 to 6 weeks of age; in all of four Thai broiler populations. There were tentative associations of the IGF-I gene within the percentages of breast muscles and wings. Thus, cGH gene may be used as a candidate gene, to improve growth traits of Thai broilers.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1282-1287
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• 2011

The objective of this study was to assess the effect of xylanase on net energy for production, performance, nutrient digestion and gut microflora of broilers fed corn/soy-based diet. Eighty-four day-old male broiler chicks were allocated to two groups receiving two treatments, respectively. Each treatment had six replicate cages with seven broilers per cage. The diets were based on corn and soybean. The treatments were: i) basal diet reduced in apparent metabolizable energy (-0.63 MJ/kg compared to commercial diet specifications); ii) basal diet supplemented xylanase at 4,000 u/kg feed. The experiment used the auto-control, open circuit respiration calorimetry apparatus to examine the heat production and net energy for production. The results revealed that xylanase supplementation did not affect growth performance and diet AME value, but increased $NE_p$ value by 18.2% (p<0.05) and decreased daily heat production per $kg^{0.75}$ by 31.7% (p<0.05). There was no effect (p>0.05) of xylanase supplementation on the ileal digestibility of N and hemicelluloses, but the ileum digestibility of energy was increased by 2% by xylanase supplementation (p<0.05). Xylanase supplementation increased (p<0.05) the count of lactobacillus and bifidobacterial in the caecum.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.9
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• pp.1221-1225
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• 2005

The peroxisome proliferator-activated receptors (PPARs) are members of a superfamily of nuclear hormone receptors. Lots of studies in rodents and humans have shown that PPARs were involved in lipid metabolism and adipocyte differentiation. The main objective of this work was to detect the single nucleotide polymorphisms (SNPs) in whole coding regions of peroxisome proliferator-activated receptor alpha (PPAR-$\alpha$) and gamma (PPAR-$\gamma$) genes with approach of single strand conformation polymorphism (SSCP) in the chicken population of Arber Acres broiler, Hyline layer and three Chinese native breeds (Shiqiza, Beijing You, Bai'r). Two SNPs of C1029T and C297T were found in chicken PPAR-$\alpha$ and PPAR-$\gamma$ genes respectively and each SNP found three genotypes in the experimental populations. The results showed that the distribution frequency of 3 genotypes in Arber Acres broiler, Hyline layer and Chinese native breeds had significant differences on the PPAR-$\alpha$ and PPAR-$\gamma$ gene respectively (p<0.01). Furthermore, in the PPAR-$\alpha$ gene, the results of least square estimation for genotypes and body composition traits showed the BB genotype birds had higher abdominal fat weight (AFW) and percentage of abdominal fat (AFP) than AA genotype birds (p<0.05). From these we conjecture the PPAR-$\alpha$ and PPAR-$\gamma$ genes were suffered intensive selection during the long term commercial breeding and the PPAR-$\alpha$ gene may be a major gene or linked to the major genes that impact chicken fat metabolism and the SNPs could be used in molecular assistant selection (MAS) as a genetic marker for the chicken fatness traits.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.8
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• pp.1246-1250
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• 1999

Rabbits (48) of Soviet chinchilla (24) and White giant (24) were fed from 6 weeks to 12 weeks of age intensively on either of four isonitrogenous - isocaloric diets containing 0 ($D_1$), 5($D_2$), 10($D_3$) and 20($D_4$) percent raw neem seed kernel cake (NSKC), respectively as per NRC (1977) requirements in a Randomized block design and slaughtered at the end to find out differences in their carcass traits due to NSKC feeding. Dietary treatment had no significant effect on weight of edibles and inedibles and their percentages and dressing percentage in terms of carcass, carcass with pluck and carcass with pluck and head. Similarly, the meat-bone ratio of various primal cuts and overall carcass, yield of edibles per unit of inedibles and eye muscle area were not influenced due to the dietary variations. Chemical composition of fresh meat, and organoleptic evaluation of cooked meat with and without salt did not vary significantly due to incorporation of NSKC in the diets. The rabbits fed 20% NSKC ($D_4$) though consumed more (p<0.05) DM and DE per kg meat production, the intake of crude protein and total digestible nutrients was similar with other dietary treatments. Feed cost per unit meat production was, however, lower on 5 and 10% NSKC containing diets by 7.75 and 12.56%, respectively, as compared to deoiled ground nut cake containing control diet. It appears that NSKC could be used as a wholesome vegetable protein supplement upto 10% in diet of rabbits without any adverse effect on commercial carcass traits.