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

• Korean Journal of Veterinary Service
• /
• v.41 no.1
• /
• pp.21-27
• /
• 2018

Fowl adenovirus (FAdV) and chicken anemia virus (CAV) have gained much importance as an immunosuppressive and economically important emerging pathogen of poultry. This study was carried out to investigate the prevalence of FAdV and CAV infection in chickens. The groups were divided into Korean native chickens, broiler, layer hens and broiler breeder and set up groups according to age. As results, 12.5% of the native chicken, 2.5% of broiler and 6.7% of layer chicken were positive, respectively by PCR for FAdV. Serological test showed that 84.8%, 79.0%, 97.7% and 96.1% of chickens were positive for antibody to FAdV in native chickens, broiler, layer hens and broiler breeder. The prevalence of CAV infection were 20.0%, 7.5%, 16.7% and 10.0%, based on CAV gene detection by PCR. In serological test of CAV, 40.6%, 35.9%, 84.8% and 73.9% of chickens were positive in that groups.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.7
• /
• pp.1048-1053
• /
• 2009

The present study was conducted to determine the effects of chitosan on nitric oxide (NO) content and inducible nitric oxide synthase (iNOS) activity in serum, and relative expression of iNOS mRNA in the duodenum, jejunum, and ileum of broiler chickens. A total of 240 one-day-old Arbor Acre mixed-sex broiler chickens were randomly allotted to six dietary treatments with five replicates in each treatment and eight chickens in each replicate. The broiler chickens in the six treatments were fed the basal diet supplemented with 0 (control), 0.05, 0.2, 0.5, 1.0 or 2.0 g/kg chitosan. The trial lasted for 42 days. The results showed that dietary chitosan enhanced NO content and iNOS activity in serum as well as iNOS mRNA expression in the duodenum and ileum of broiler chickens in a quadratic dose-dependent manner (p<0.05), and improved jejunum iNOS mRNA expression in a quadratic dose-dependent manner (p<0.10) with increasing addition of chitosan. Chicks fed a diet containing 0.5-1.0 g/kg chitosan had higher NO content and iNOS activity in serum as well as small-intestinal iNOS mRNA expression compared with birds given the control diet, but positive effects of chitosan tended to be suppressed when addition of chitosan in the diet was increased to 2.0 g/kg. These results implied that there was a threshold level of chitosan inclusion beyond which progressive reductions in serum NO content and small intestinal iNOS expression occured, and the regulation of chitosan on immune functions in chickens is probably associated with activated expression of iNOS and NO secretion.

• Animal Bioscience
• /
• v.35 no.12
• /
• pp.1904-1910
• /
• 2022

Objective: This study aimed to investigate the effects of corticotropin-releasing factor (CRF) on the feed intake of broiler chickens and explore its influencing mechanism. Methods: The study included two trials. In trial 1, 32 male broiler chickens (Arbor Acres, Gallus gallus domesticus) were given ventricle buried tubes, and they were allowed to recover for 3 days. At 8:00 AM, intracerebroventricular (ICV) injection with CRF or normal saline was performed in 10-day-old broiler chickens, which were divided into the 5, 10, and 20 ㎍ and control (normal saline) groups according to the dose of CRF injection. In trial 2, chickens were divided into the 10 ㎍ and control group (physiological saline) to repeat trial 1. Results: Results of trial 1 showed that the cumulative amount of feed intake in the 10 or 20 ㎍ groups was considerably lower than that of the control group after ICV injection with CRF. The lowest amount of feed intake was obtained with the addition of 10 ㎍ of CRF. In trial 2, the expression of ghrelin in the hypothalamus injected with 10 ㎍ of CRF increased significantly, but the expression of ghrelin in various sections of the small intestine considerably decreased. The expression of CRF receptor subtypes 1 (CRFR1) in the hypothalamus and some parts of the small intestine remarkably increased, and the expression of CRF receptor subtypes 2 (CRFR2) increased only in the duodenum, whereas the expression of growth hormone secretagogue receptor (GHSR-1α) in the jejunum and ileum increased considerably after ICV injection of 10 ㎍ of CRF. Conclusion: The CRF at 10 ㎍ increased ghrelin expression in the hypothalamus and CRFR1 expression in the small intestine, and this phenomenon was related to the suppressed feed intake of broiler chickens.

• Food Science of Animal Resources
• /
• v.31 no.2
• /
• pp.207-214
• /
• 2011

The influence of supplementing diets with various levels of organic zinc (OZ) on the performance, meat quality attributes, and sensory properties of broiler chickens was investigated. A total of 3,200 1-d-old female broiler chicks were randomly allotted to 16 floor pens (replicates) with 200 birds per pen. A corn-wheat-soybean meal basal diet (control) was formulated and 20 ppm OZ (20 OZ), 40 ppm OZ (40 OZ), or 80 ppm OZ (80 OZ) was added to the basal diet to form four dietary treatments with four replicates per treatment. Live performance of broiler chickens, meat quality, and sensory properties were evaluated. The results showed no significant difference among the treatments for live performance of broiler chickens. Significant increases (p<0.05) in thigh skin epidermis and dermis thickness were shown in the OZ supplementation groups; however, no effect of OZ on the thickness of back skin epidermis or dermis was found. Dietary OZ levels did not affect the pH of breast and thigh meat or the water holding capacity (WHC) of thigh meat, but the WHC of breast meat increased significantly (p<0.05) when birds were fed 40 OZ and 80 OZ. Results of a sensory analysis showed no differences among the dietary treatments. In conclusion, dietary OZ did not affect live performance or sensory properties of broiler chickens but did increase the WHC of breast meat and thickness of skin layers; thus, improving carcass quality in broiler chickens.

• Journal of Animal Science and Technology
• /
• v.62 no.6
• /
• pp.884-892
• /
• 2020

Corticosterone is known as a biological stress index in many species including birds. Feather corticosterone concentration (FCC) has increasingly been used as a measure for chronic stress status in broiler chickens. As sample preparation is the first step of analytical process, different techniques of feather matrix disruption need to be validated for obtaining better result in analysing corticosterone extraction. The current study was a validation of pulverizing the feather by bead beater (BB) and surgical scissors (SS) processing prior to corticosterone extraction in feather of broiler chickens. The type of feather processing prior to the hormone extraction may alter the final output. Thereby, finding a standard method according to laboratory facilities is pivotal. This study carried out to determine the effects of feather pulverization methods on the extraction amount of corticosterone in broiler chickens. Feathers were sampled from four weeks old Ross 308 broiler chickens (n = 12 birds). All broiler chickens were kept under the same environmental condition and had access to feed and water. Feather samples were assigned to one of the following processing methods 1) using a BB for pulverizing and 2) using a SS for chopping into tiny pieces. Each sample was duplicated into two wells during enzyme immunoassay (EIA) analysis to improve the accuracy of the obtained data. The results showed lower standard errors and constant output of FCC by using the BB method compared with the SS method. Overall comparison of FCC showed a significantly higher (p < 0.001) amount of the FCC in the BB compared with the SS. Overall, using the BB method is recommended over the SS method for feather processing due to the ability to homogenize a large number of samples simultaneously, ease of use and greater extraction of feather corticosterone.

• Animal Bioscience
• /
• v.36 no.11
• /
• pp.1632-1646
• /
• 2023

Objective: The objective of the present study was to investigate the effect of dietary betaine (BT) supplementation on the hepatic transcriptome profiles in broiler chickens raised under heat stress (HS) conditions. Methods: A total of 180 (21-d-old) Ross 308 male broiler chicks were allotted to 1 of 3 treatment groups with 6 replicated cages in a completely randomized design. One group was kept under thermoneutral conditions at all times and was fed a basal diet (PC). Other 2 groups were exposed to a cyclic heat stress condition. One of the 2 groups under heat stress conditions was fed the basal diet as a negative control (NC), whereas the other group was fed the basal diet supplemented with 0.2% BT. All chickens were provided with diets and water ad libitum for 21 d. Following the experiment, the liver samples were collected for RNA sequencing analysis. Results: Broiler chickens in NC and BT group had decreased (p<0.05) growth performance. In the transcriptome analysis, the number of differentially expressed genes were identified in the liver by HS conditions and dietary BT supplementation. In the comparison between NC and PC treatments, genes related to energy and nucleic acid metabolism, amino acid metabolism, and immune system were altered by HS, which support the reason why heat-stressed poultry had decreased growth performance. In the comparison between NC and BT treatments, genes related to lipid metabolism, carbohydrate metabolism, and immune system were differently expressed under HS conditions. Conclusion: HS negatively impacts various physiological processes, including DNA replication, metabolism of amino acids, lipids, and carbohydrates, and cell cycle progression in broiler chickens. Dietary BT supplementation, however, offers potential counteractive effects by modulating liver function, facilitating gluconeogenesis, and enhancing immune systems. These findings provide a basis for understanding molecular responses by HS and the possible benefits of dietary BT supplementation in broiler chickens exposed to HS.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.10
• /
• pp.1445-1450
• /
• 2005

This experiment was conducted to evaluate the effect of feed withdrawal (F) and heat acclimatization (A) on malebroiler and -layer chickens responses to acute heat stress (AHS) at four weeks of age. Totals of ninety male chicks of broiler or layer type were randomly allocated into 30 pens of grower batteries with raised wire floors. Chicks were subjected to F and A three times a week through the first three weeks of age. At each time, feed withdrawal and heat acclimatization (T = $35^{\circ}C$) lasted for six and four hours, respectively. Feed consumption (FC), body weight (BW), and feed conversion ratio (FCR) were recorded weekly for broiler type chickens only. At four weeks of age, all groups of chickens were exposed to AHS (T = $39{\pm}1^{\circ}C$) for three hours. Before and after AHS challenge, body temperature (Tb), heterophil (H), and lymphocyte (L) counts were recorded, and H/L ratio was calculated. Antibody (Ab) response to sheep red blood cells (SRBC) was assessed from all treatments without being exposed to AHS. Group F of broiler-type chickens weighed less (p<0.05) compared to control group. Also, both A and F groups of broiler-type chickens consumed less (p<0.05) feed when compared to control group. Acute heat stress elevated Tb of all treatment groups, however the increase was more profound (p<0.001) in broiler chicks. Broiler chicks of both A and F groups showed a tendency to have higher (p = 0.08) Tb when compared to control group. Acute heat stress elevated (p<0.001) H/L ratio in both types of chickens. Broiler chicks maintained higher (p<0.001) H/L ratio. Both F and A groups reduced (p<0.01) the level of elevation in H/L ratio compared to control groups of both types of chickens. Neither A nor F group affected the Ab production in response to SRBC. However, there was a tendency towards higher Ab responses in F group when compared to other groups in both types of chickens. Results of the present study demonstrate that previous history of feed withdrawal or episodes of heat exposures improved chicks'physiological withstanding of AHS and a tendency to improved humoral immune response.

• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.11
• /
• pp.1592-1597
• /
• 2013

Type of dietary direct-fed microbials (DFMs) or poultry litter could directly influence the composition of gut microbiota. Gut microbiota plays an important role in shaping the developing immune system and maintaining the homeostasis of the mature immune system in mammal and chickens. The present study was carried out to investigate the interaction among litter, DFMs and immunity in broiler chickens exposed to a field-simulated environment. Immune status of broiler chickens was assessed by serum antibodies against Eimeria spp. and Clostridium spp. and intestinal cytokine mRNA expression. The current experimental design had a $3{\times}2$ factorial arrangement of treatments with three types of litter, i.e., fresh litter or used litter that was obtained from a farm with no disease outbreak (used litter) or a farm with history of a gangrenous dermatitis outbreak (GD litter), and two dietary treatments with or without DFMs. It was found that either DFM addition or type of litter significantly affected anticoccidial antibody levels of broiler chickens at d 42. In general, dietary DFMs increased the anticoccidial antibodies in the fresh-litter raised chickens, but lowered the levels in the GD-litter raised chickens. Serum antibodies against Clostridium perfringens ${\alpha}$-toxin were significantly (p<0.05) higher in chickens raised on GD litter compared with those raised on fresh litter. Cytokine mRNA expression was significantly (p<0.05) altered by either the type of litter or DFMs. Of interest, dietary DFMs lowered interferon-${\gamma}$, interleukin 1beta, and CXCLi2 cytokine mRNA expression in chickens raised on fresh litter but increased them in GD-litter raised chickens. In conclusion, dietary DFMs modulate various immune parameters of broiler chickens, but the DFM-mediated effects were dependent upon the type of litter on which chickens were raised.

• Asian-Australasian Journal of Animal Sciences
• /
• v.32 no.6
• /
• pp.904-911
• /
• 2019

Objective: The study was conducted to evaluate the effects of night light regimen on growth performance, antioxidant status and health of Lingnan Yellow broiler chickens from 1 to 21 days of age. Methods: A completely randomized factorial design involved 2 photoperiods (constant lighting [CL], 24 L:0 D and intermittent lighting [INL], 17 L:3 D:1 L:3 D)${\times}2$ light intensities (10 lx and 30 lx). A total of one thousand six hundred and eighty 1-d-old Lingnan Yellow broiler chicks were randomly divided into 4 treatments with 6 replicates (70 birds per replicate). The experiment lasted for 21 d. Results: Photoperiods and light intensities had no effect on average daily gain, feed conversion ratio, and mortality of the broiler chickens (p>0.05). The INL had a significant effect on average daily feed intake (p<0.05) of broiler chickens compared with CL. Photoperiod and light intensity had an interactive effect on melatonin (MT) concentration (p<0.05). At CL, reducing light intensity increased MT concentration; INL birds had higher MT but MT concentration was not affected by light intensity. There was an interactive effect on glutathione peroxidase (GPx) and catalase (CAT) in serum and total antioxidant capability (T-AOC) in liver between photoperiod and light intensity. With the decrease of light intensity, the activities of GPx and CAT in serum and T-AOC in liver increased in CL group (p<0.05). Broiler chickens reared under INL had better antioxidant status and 10 lx treatments had higher activities of CAT in serum than 30 lx (p<0.05). Different photoperiods and light intensities had no effect on malondialdehyde. There was an interaction between photoperiod and light intensity on serum creatine kinase (CK) concentration (p<0.05). At CL, the elevated light intensity resulted in an increase in CK content; INL birds had lower CK concentration especially in low light intensity group. Besides, INL and low light intensity significantly reduced the concentration of serum corticosterone and heat shock protein 70 (p<0.05). Serum immunoglobulin M contents were increased in broiler chickens reared under the INL compared with CL group (p<0.05). Conclusion: Results above suggest that the night light regimen of INL and 10 lx could be beneficial to the broiler chickens from 1 to 21 days of age due to the better health status and electricity savings.