• Animal Bioscience
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• v.36 no.7
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• pp.1075-1082
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• 2023

Objective: Animal feed companies and researchers are currently embarking on quests for feed additives that could combat the pathogens while promoting growth as well as maintaining quality products. The current study aimed to evaluate the effects of onion extracts on growth performance, carcass quality, and bone morphometrics of broiler chickens. Methods: A total number of 200 one-day-old unsexed Ross 308 broiler chicks were assigned to 5 treatment groups, replicated 4 times. Each replicate (pens) held 10 chickens in a completely randomized design. The experimental diets were then randomly allotted to the pens which act as experimental units. The isoenergetic and isonitrogenous diets were formulated by including onion extracts at 0, 5, 10, 15, or 25 g/kg in a complete broiler diet. Feed intake, and body weight, were recorded then used to calculate feed conversion ratio. At the end of the experiment (42 days), four chickens from each pen were randomly selected for slaughter for carcass, bone morphology and sensory evaluation. Results: Results showed that onion extract supplementation did not affect (p>0.05) growth performances and meat sensory evaluation. However, there was a significantly increased (p<0.05) meat shear force in groups receiving onion extracts dietary treatments. Furthermore, onion extracts improved (p<0.05) bone morphology of broiler chickens in terms of weight, diameter, calcium, and phosphorous contents. Conclusion: In conclusion, onion extracts can be safely included in a commercial broiler diet as a growth promoter without causing adverse effects on growth performance traits and carcass quality in chickens. Onion extract supplementation improved tibia bone growth and strength in broiler chickens.

• Animal Bioscience
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• v.37 no.1
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• pp.16-27
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• 2024

Objective: The objective of this study was to investigate the effect of heat stress on the growth traits and genetic parameters of Thai native chickens. Methods: A total of 16,487 records for growth traits of Thai native chickens between 2017 and 2022 were used in this study. Data included the body weight at birth, body weight at 4, 8, and 12 weeks of age (BW0, BW4, BW8, BW12), average daily gain during 0 to 4, 4 to 8, and 8 to 12 weeks of age (ADG0-4, ADG4-8, ADG8-12), absolute growth rate at birth, at 4, 8, and 12 weeks of age (AGR0, AGR4, AGR8, AGR12). The repeatability test day model used the reaction-norm procedure to analyze the threshold point of heat stress, rate of decline of growth traits, and genetic parameters. Results: At temperature and humidity index (THI) of 76, Thai native chickens began to lose their growth traits, which was the onset of heat stress in this study. The estimated heritability, genetic correlation between animal and heat stress effect, and correlations between the intercept and slope of the permanent environmental effects were 0.27, -0.85, and -0.83 for BW, 0.17, -0.81, and -0.95 for ADG, 0.25, -0.61, and -0.83 for AGR, respectively. Male chickens are more affected by heat stress than female chickens with a greater reduction of BW, ADG, and AGR, values equal to -9.30, -0.23, -15.21 (in males) and -6.04, -0.21, -10.10 (in females) gram per 1 level increase of THI from the THI of 76. Conclusion: The influence of thermal stress had a strong effect on the decline in growth traits and genetic parameters in Thai native chickens. This study indicated that genetic models used in conjunction with THI data are an effective method for the analysis and assessment of the effects of heat stress on the growth traits and genetics of native chickens.

• The Journal of the Korean dental association
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• v.10 no.6
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• pp.369-372
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• 1972

This study was investigated that effects of steroid hormones on serum sodium and potassium concentration in parathyroidectomized chickens. The results are as followings; 1) Serum sodium and potassium concentration in SHAM-controls were unchanged. 2) In parathyroidectomized chickens, serum potassium level increased more than that of control and serum sodium level appeared no change in each group. 3) In group of administration of cortisone in parathyroidectomized chickens, serum potassium level increased generally more than that of control and serum sodium level appeared no change in each group. 4) In group of administration of testosterone in parathyroidectomized chickens, serum potassium level increased generally more than that of control and serum sodium level revealed no change in each group.

• Parasites, Hosts and Diseases
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• v.56 no.6
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• pp.597-602
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• 2018

Histomonas meleagridis is a facultative anaerobic parasite, which can cause a common poultry disease known as histomoniasis. The species and age of the birds impacts on the susceptibility, with turkey being the most susceptible species. Chickens are less susceptible to H. meleagridis than turkeys and usually serve as reservoir hosts. Here, the diagnosis of an outbreak of histomoniasis in backyard Sanhuang chickens is described. The primary diagnosis was made based on clinical symptoms, general changes at necropsy, histopathology, and the isolation and cultivation of parasites. The pathogen was further confirmed by cloning, PCR identification, and animal inoculation tests. A strain of H. meleagridis, named HM-JSYZ-C, with a higher pathogenicity level in chickens was obtained. The study lays a foundation for further investigations into H. meleagridis and histomoniasis in chickens.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1309-1314
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• 2004

The red carotenoid, astaxanthin was studied to improve the meat quality of broiler chickens. Astaxanthin pigmented chickens and delayed oxidation of lipid in them. Two sources of astaxanthin were used to pigment broiler chickens in a five-wk feeding trial: biological astaxanthin (BA) from the red yeast, Xanthophyllomyces dendrorhous, and chemical astaxanthin (CA) from chemical synthesis. The concentrations of CA (45 mg/kg feed) and BA (22.5 mg/kg feed) were set to give similar levels of pigmentation. The colorimetric values (a and b) of breast muscles were significantly changed by astaxanthin (p${\leq}$0.01). Absorption and accumulation of BA were higher than those of CA, probably due to the high contents of lipids in the yeast (17%). Lipid peroxide formation in skin was significantly decreased by astaxanthin (p${\leq}$0.05). This result indicated that the production of lipid peroxides in the carcasses of broiler chickens during storage could be delayed by astaxanthin. Therefore, astaxanthin could be used as an antioxidant as well as a colorant for broiler chickens.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.3
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• pp.346-350
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• 2001

The present study was designed to evaluate the usefulness of Sauropus. androgynus leaf (SAL) meal on reducing fat accumulation in broiler chickens. Eighty unsexed broiler chickens were allocated to four treatment groups with five replicates of four chickens each. SAL meal supplementation had no effect on body, leg, back, breast, wing, liver and heart weights, carcass protein, moisture and ash contents (p>0.05). Broilers fed diets supplemented with 30 g of SAL meal had lower feed intake with better feed conversion ratio (p<0.05) than did the control chickens. SAL supplementation at all levels significantly reduced fat accumulation in abdomen region, and liver (p<0.01), and in carcass (p<0.05). Higher SAL supplementation resulted in lower fat accumulation in the carcass ($r^{2}=0.94$; p<0.01), abdomen ($r^{2}=0.99$; p<0.01) and liver ($r^{2}=0.98$; p<0.01). The current study showed that a 30 g supplementation of SAL meal to the broiler diet was effective to improve feed conversion ratio without reducing body weight. SAL meal supplementation to the diet reduce fat accumulation in broiler chickens.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.5
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• pp.603-609
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• 2011

Telomeres are special structures at the ends of eukaryotic chromosomes. Vertebrate telomeres consist of tandem repeats of conserved TTAGGG sequence and associated proteins. Birds are interesting models for molecular studies on aging and cellular senescence because of their slow aging rates and longer life spans for their body size. In this longitudinal study, we explored the possibility of using telomeres as an age-marker to predict age in Single Comb White Leghorn layer chickens. We quantified the relative amount of telomeric DNA in isolated peripheral blood lymphocytes by the Quantitative Fluorescence in situ Hybridization technique on interphase nuclei (IQ FISH) using telomere-specific DNA probes. We found that the amount of telomeric DNA (ATD) reduced significantly with an increase in chronological age of the chicken. Especially, the telomere shortening rates are greatly increased in growing individuals compared to laying and old-aged individuals. Therefore, using the ATD values obtained by IQ FISH we established the possibility of age prediction in chickens based on the telomere theory of aging. By regression analysis of the ATD values at each age interval, we formulated an equation to predict the age of chickens. In conclusion, the telomeric DNA values by IQ FISH analyses can be used as an effective age-marker in predicting the chronological age of chickens. The study has implications in the breeding and population genetics of poultry, especially the reproductive potential.

• Korean Journal of Veterinary Service
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• v.20 no.1
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• pp.19-26
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• 1997

The present study was conducted to investigate the general epidemiological situations with 18-pullorum infected chickens from Kyongbuk provinces during the period from June 1995 to January 1996. On the Salmonella pullorum isolation tests by rectal swab culture method from infected chickens (386-samples), any Salmonella spp was not isolated from infected live-birds. But 2-S pullorum were isolated of 2-dead chickens(33.3% ) from 6-dead chickens which were positively reacted by serological tests. On the other hand, we could not isolated any Salmonella spp. in any parts of egg-contents ; egg-shell, egg-white and egg-yolks with 25-infected bird eggs. On the tests of antibiogram, 2-S pullorum strains were highly sensitive to GM, AM, SXT, CZ, K, FIM, ENR, C, AN, N, NN, LIN＋SP, CF, TE and PB, respectively and intermediate sensitive to the CB, CFP, CL, S, P and XNL. But 2-strains were resistant to CC, DP, E, L, OX, TLA and TyLO. In the serological tests, pullorum antibody titers of 18-infected birds was from 2.76 to 9.18 with average by the microplate test. During the 6-months, pullorum antibody average titers were not changed generally. To validate the effects of the antimicrobial agent treatments to the serological antibody titers, infected 6-chickens was medicated with 0.5%-futazolidone. The titer of premeditated birds was average 4.26 but after medication with furazolidone, the titers of treated 6-birds was average 4.08.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.12
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• pp.1758-1763
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• 2000

The effect of tu-chung (Eucommia ulmoides, Oliver) leaf meal on reducing lipid accumulation in chickens fed 1% cholesterol containing diet was studied. Forty male White Leghorn chickens aged 56 days were weighed and divided into four groups of ten chickens, and fed diets with or without 1% dietary cholesterol which were supplemented with 0 and 5% tu-chung. Tu-chung supplementation to the diet without cholesterol increased acetyl-CoA carboxylase (p<0.01) but decreased 3-hydroxy-3-methylglutaryl-CoA reductase activities (p<0.01) with no effect on fatty acid synthetase activities. However, its supplementation to the diet with cholesterol had no effect on these three enzyme activities as compared with the cholesterol containing diet without tu-chung. Tu-chung supplementation to the diet without cholesterol increased hepatic triglyceride (p<0.01), whereas its supplementation to the diet with cholesterol decreased it (p<0.01). Tu-chung supplementation to the diet with cholesterol decreased plasma cholesterol ester, free cholesterol, phospholipids (p<0.05) and triglyceride (p<0.01) as compared with the cholesterol containing diet without tu-chung. Supplementation of tu-chung to the diet without cholesterol decreased plasma free cholesterol (p<0.05). It is concluded that tu-chung leaf meal reduced an increase in lipid accumulation in chickens stimulated by 1% cholesterol feeding.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.4
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• pp.559-563
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• 2001

The effects of feeding a mannan oligosaccharide (Bio-Mos) from 0 to 3 g/kg diet and vaccination program on 1- to 35-day performance (growth and feed efficiency), metabolizable energy, nitrogen utilization and carcass composition of meat chickens were investigated. A general vaccination program was used against IB, IBD and ND with half of the birds per diet receiving a booster dose of IB and ND vaccines at 12 days of age. Dietary supplementation of Bio-Mos (BM) did not influence body weight gain, feed efficiency and nutrient utilization. The highest dietary BM (3 versus 1.5 or 0 g/kg) increased carcass abdominal fat and reduced the proportion of drumstick in the carcass of meat chickens. The booster dose reduced the performance of birds. It was concluded that the addition of BM to the diet of chickens did not significantly influence the performance and nutrient utilization of meat chickens.