Tissues Of Broiler Chickens Research Articles

Identification of key genes and molecular mechanisms associated with low egg production of broiler breeder hens in ad libitum

BackgroundOverfeeding reduces laying performance in broiler breeder hens, which is associated with obesity, hepatic steatosis and systemic inflammation. To unravel the underlying mechanisms governing the effect of feeding regimes on energy metabolism and egg production, a transcriptomics approach was carried out for screening differentially expressed genes (DEGs) in ovary, liver and adipose tissues of broiler chickens under ad libitum and restricted feeding.ResultsIt showed that 289, 388 and 204 DEGs were identified in the adipose, liver and ovary, respectively. These DEGs were significantly enriched in phagosome pathway, lipid transport, activity and nutrient reservoir activity in ovary; steroid hormone biosynthesis and metabolism of xenobiotics by cytochrome P450 pathways in adipose tissue; and the metabolic pathways, peroxisome proliferator-activated receptor (PPAR) and Jak-STAT signaling pathway in liver. Estrogen receptor 1, identified as one of important hubs by constructing PPI network, was up-regulated in ad libitum group, which would make more apolipoproteins be transferred to ovary.ConclusionsHigh expression of VTGs, APOB, CYBB and CTSS in ovary would induce excess lipid deposit, oxidative stress and potential damage to ovulation. Our results contribute to understanding effects of feeding regimes on metabolic regulation during egg production of broiler breeder hens and also provide new evidence of metabolic regulation from integrated multi-tissue processes.

Pharmacokinetics and relative bioavailability of tiamulin in broiler chicken as influenced by different routes of administration.

The bioavailability and pharmacokinetic disposition of tiamulin in broiler chicken were investigated after administration through the crop, drinking water, and feed at 40mg/kg body weight. Residues of tiamulin in tissues of broiler chicken were also assessed. Plasma and tissue concentrations of tiamulin were analyzed by reverse-phase high-performance liquid chromatography (HPLC) method. Plasma concentration-time data were described by the non-compartmental model for all three routes, and pharmacokinetic parameters were calculated. There were no significant differences (p>0.05) in pharmacokinetic parameters and mean plasma concentrations of tiamulin between three routes tested (crop, water, and feed), indicating equal efficacy. Tiamulin residues in edible tissues (muscles, skin, and fat) were lower than the advocated maximum residue limit (MRL of 0.1µg/g and that of liver was 1µg/g) on the 3rd day. No traces were found on the 5th day after drug administration. This indicated that the withdrawal period (less than 5days) is very short, which makes it safer. This study shows that tiamulin can be used with equal efficacy through all routes of administration in broiler chicken (crop, water, and feed).

Supplementation of selenomethionine at different ages and levels on meat quality, tissue deposition, and selenium retention in broiler chickens

The aim of the present study was to verify the effect of selenomethionine (SM) supplementation in the diet of chickens on performance, carcass yield, apparent retention, meat quality, and selenium (Se) deposition in tissues. In the first experiment, 2,100 day-old male chicks from the Hubbard Flex strain were randomly distributed in 84 plots with 12 treatments and 7 replicates. The treatments consisted of SM (1,600ppm) supplementation at levels of 0.3 and 0.5ppm in substitution of sodium selenite (45.7%) in different preslaughter phases. In the second experiment, 224 day-old male chicks from Hubbard Flex strain were randomly distributed in 28 metabolic cages. Poultry were distributed in 4 treatments with 7 replicates (8 poultry) in the experimental period from 1 to 21 D and experimental plot with 4 poultry aged from 22 to 42 D. Treatments consisted of 4 SM addition levels (0.3, 0.4, 0.5, and 0.6ppm). In both experiments, the performance (1 to 21 and 1 to 42 D), carcass yield and cuts, apparent retention of Se (33 to 35 D), physical and chemical characteristics of the breast meat were evaluated: objective color, drip loss (DL), cooking loss (CL), pH, peroxide value, and Se deposition in tissues. In experiment I, it was found that SM at 0.3ppm improved the weight gain and feed conversion of 1 to 42 D. The use of SM at 0.5ppm resulted in lower DL and CL. The highest Se deposition in muscles was obtained using the SM at 0.5ppm of 1 to 42 D. Using the SM at 0.5ppm, only in the last week there was a deposition similar to the use of SM at 0.3ppm of 1 to 42 D. In experiment II, it can be observed that increased SM levels provided lower DL and lower pH values. Se deposition in tissues of broiler chickens increased linearly at the SM level from 0.3 to 0.6ppm.

Implementation and Validation of an Analytical Method for Lincomycin Determination in Feathers and Edible Tissues of Broiler Chickens by Liquid Chromatography Tandem Mass Spectrometry.

Recent studies have detected different antimicrobial residues in broiler chicken feathers, where they persisted for longer periods of time and at greater concentrations than in edible tissues. However, until today, lincomycin behaviour in this nonedible tissue has not been assessed yet. Considering this, an analytical methodology to detect and quantify this antibiotic concentration in feathers, muscle, and liver tissues from broiler chickens was implemented and in-house validated. The methodology will allow the determination of the bioaccumulation of this highly persistent antibiotic in feathers of treated birds. For this purpose, 98% lincomycin and 95% lincomycin D3 standards were used. Methanol was selected as the extraction solvent, and Chromabond® Florisil® cartridges were used for the clean-up stage. The separation of analytes was performed through the analytical column SunFire C18 with a running time of 4 minutes, and the instrumental analysis was performed through an LC-MS/MS, with a liquid chromatograph Agilent® 1290 Infinity, coupled to an AB SCIEX® API 5500 mass spectrometer. An internal protocol for an in-house validation was designed based on recommendations from Commission Decision 2002/657/EC and the Guidance document on the estimation of limit of detection and limit of quantification for measurements in the field of contaminants in feed and food. The average retention time for lincomycin was 2.255 min (for quantifier ion, 126.0). The calibration curves showed a coefficient of determination (r2) greater than 0.99 for all matrices, while recovery levels ranged between 98% and 101%. The limit of detection (LOD) calculated was of 19, 22, and 10 μg·kg−1, and the limit of quantification (LOQ) was of 62, 73, and 34 μg·kg−1 in feathers, muscle, and liver, respectively. This method detects lincomycin in the studied matrices, confidently and accurately, as it is required for designing analytical studies of drug residues in edible and nonedible tissues, such as feathers.

Gene expression of AvBD6-10 in broiler chickens is independent of AvBD6, 9, and 10 peptide potency

The Avian β-defensin (AvBD) gene cluster contains fourteen genes; within this, two groups (AvBD6/7 and AvBD8 -10) encode charged peptides of >+5 (AvBD6/7), indicative of potent microbial killing activities, and ≤+4 (AvBD8-10), suggestive of reduced antimicrobial activities. Chicken broiler gut tissues are constantly exposed to microbes in the form of commensal bacteria. This study examined whether tissue expression patterns of AvBD6-10 reflected microbial exposure and the encoded peptides a functional antimicrobial hierarchy.Gut AvBD6-10 gene expression was observed in hatch to day 21 birds, although the AvBD8-10 profiles were eclipsed by those detected in the liver and kidney tissues. In vitro challenges of chicken CHCC-OU2 cells using the gut commensal Lactobacillus johnsonii (104 CFU) did not significantly affect AvBD8-10 gene expression patterns, although upregulation (P < 0.05) of IL-Iβ gene expression was observed. Similarly, in response to Bacteriodes doreii, IL-Iβ and IL-6 gene upregulation were detected (P < 0.05), but AvBD10 gene expression remained unaffected. These data suggested that AvBD8-10 gene expression was not induced by commensal gut bacteria.Bacterial time-kill assays employing recombinant (r)AvBD6, 9 and 10 peptides (0.5μM - 12μM), indicated an antimicrobial hierarchy, linked to charge, of AvBD6 > AvBD9 > AvBD10 against Escherichia coli, but AvBD10 > AvBD9 > AvBD6 using Enterococcus faecalis. rAvBD10, selected due to its reduced cationic charge was, using CHCC-OU2 cells, investigated for cell proliferation and wound healing properties, but none were observed.These data suggest that in healthy broiler chicken tissues AvBD6/7 and AvBD8-10 gene expression profiles are independent of the in vitro antimicrobial hierarchies of the encoded AvBD6, 9 and 10 peptides.

Вплив цитратів наночастинок мікроелементів на інтенсивність протеїнового обміну в тканинах курчат-бройлерів та їх продуктивність

Вплив цитратів наночастинок мікроелементів на інтенсивність протеїнового обміну в тканинах курчат-бройлерів та їх продуктивність

Liquid Chromatography-Tandem Mass Spectrometry Determination and Depletion Profile of Chlortetracycline, Doxycycline, and Oxytetracycline in Broiler Chicken Muscle After Oral Administration

A simple and fast method based on liquid chromatography–electrospray ionization-tandem mass spectrometry (LC–ESI-MS/MS) was developed and validated for determination of tetracyclines in broiler chicken muscle. Sample preparation was performed using extraction with acetonitrile, followed by low-temperature purification (at − 20 °C) and further concentration. The chromatographic analysis was carried out using a Zorbax SB-C18 column with gradient elution using water and methanol both acidified with 0.025 M of formic acid. Mass spectrometry with electrospray ionization was operated in positive polarity using selected reaction monitoring (SRM) analysis mode, achieving the requirements of four identification points for each compound. Demeclocycline was used as internal standard. The method validation was done according to the criteria of Commission Decision 2002/657/EC. Parameters such as recovery, matrix effects, selectivity/specificity, linearity, precision (intra- and inter-day precision), accuracy, limits of detection (LOD) and quantification (LOQ), decision limit (CCα), detection capability (CCβ), and robustness were determined. Intra-day precision values were within the range 2.2–5.8% and inter-day precision was less than 10% for all analytes. Accuracy ranged from 98.2 to 103.2%. The method was successfully applied for depletion studies of chlortetracycline, doxycycline, and oxytetracycline in broiler chicken tissues after multiple oral administrations. After the depletion studies, the present study support more prudent use of CTC, DOX, and OTC for treatment of chickens and suggest a dose of 60 mg kg−1 body weight for CTC and OTC and 20 mg kg−1 body weight for DOX, orally administrated for five consecutive days.

A HPTLC-Fluorescent Densitometry Assay for Simultaneous Detection of Enrofloxacin and Ciprofloxacin in Broiler Chicken Tissues

A high-performance thin-layer chromatographic (HPTLC) method was developed and validated according to the protocol on Validation of Analytical Procedures: methodology, Veterinary International Cooperation on Harmonization for simultaneous determination of enrofloxacin and ciprofloxacin in broiler chicken tissues viz. liver, kidney, muscle-breast, muscle-thigh, and skin. Chromatography was performed on thin-layer chromatography (TLC) silica gel 60F254, aluminum sheets (10 × 10 cm) by Camag Linomat-5 applicator. The isolation of enrofloxacin and ciprofloxacin was attained by two development stages, initially with diethyl ether followed by dichloromethane/methanol/aqueous ammonia/acetonitrile (2:3:2:3) as mobile phase. The developed TLC plates were exposed to hydrochloric acid fumes and fluorescent densitometric evaluation was performed at 366 nm using Camag TLC Scanner-3 with WinCAT 1.4.4 software. The RF value was 0.60 and 0.44 for enrofloxacin and ciprofloxacin, respectively. The detection limits were 2 and 3 ng/band for enrofloxacin and ciprofloxacin, respectively, and 5 ng/band as limit of quantification for both the compounds. Enrofloxacin and ciprofloxacin showed wide linear range from 2 to 110 ng/band and 3 to 110 ng/band with high correlation coefficient values of 0.99997 and 0.99990 for peak area, respectively. An exemplary precision was observed for individual compounds. The percent recovery for ciprofloxacin was 82.0–86.8% when compared to enrofloxacin 83.4–90.3%. The observed results were within the acceptable values as a function of the analyte concentration, suggested by the Association of Official Analytical Chemists peer-verified methods program. The present validated HPTLC method can be used as screening technique for antibiotics residue monitoring program in broiler chicken tissues to promulgate food safety.

Development of a UPLC-FLD Method for Detection of Aflatoxin B1 and M1 in Animal Tissue to Study the Effect of Curcumin on Mycotoxin Clearance Rates.

Aflatoxin B1 (AFB1) and its metabolite aflatoxin M1 (AFM1) are well-known carcinogens for humans and animals health. In this study, an ultra-high performance liquid chromatography linked with fluorescence detection (UPLC-FLD) method was optimized and validated. In addition, we investigated for the first time, the influence of curcumin on residue depletion of AFB1 and AFM1 in liver, kidney, and muscle tissues of broiler chickens and estimated a necessary clearance time required for AFB1 and AFM1 residues. The results showed that the average recoveries of AFB1 varied in liver, kidney, and muscles between 82.32–85.56, 85.34–88.45, and 84.88–89.73% respectively, while the average recoveries of AFM1 in liver, kidney, and muscles varied between 92.17–95.03, 94.12–97.21, and 95.32–98.51%, respectively. The detection limit of aflatoxin B1 was 0.008 ng/ml, while for aflatoxin M1 was 0.003 ng/ml. The limit of quantification (LOQ) for AFB1 and AFM1 was 0.02 and 0.01 ng/ml, respectively. Clearance time for AFB1 and AFM1 residues were analyzed in two experimental groups of broilers. One group fed with dietary AFB1 (5.0 mg/kg feed) and other with curcumin+AFB1 diet (curcumin; 300 mg/kg feed, AFB1; 5.0 mg/kg feed). AFB1 and AFM1 residues clearance time was calculated based on LOQ using withdrawal time calculation software (WT1.4). Clearance time analyzed for AFB1 ranged from 11 to 19 days and for AFM1 ranged from 10 to 12 days at 95% confidence level. Interestingly, curcumin supplementation in the diet reduced the clearance time of AFM1 in liver and kidney but not in muscle tissues. Conclusively, the developed method can be appropriately used for the quality control testing of commercial broiler-meat processing companies, food manufacturers, and quality control laboratories.

LC-MS/MS based method development for the analysis of florfenicol and its application to estimate relative distribution in various tissues of broiler chicken.

Florfenicol, a broad spectrum bacteriostatic antibiotic belonging to amphenicol class, is widely used in poultry and livestock for the treatment of various infections. The major metabolite of florfenicol in different animal species is florfenicol amine which is exploited as the marker residue for the determination of florfenicol. Analysis of florfenicol merely by solvent extraction cannot determine the accurate amount of the drug present in incurred tissues (muscle, liver and kidney) of treated birds, as indicated by this study. Thus the methods solely based on solvent extraction may lead to false negative results. A reliable LC-MS/MS based confirmatory method for the analysis of florfenicol and its metabolites in chicken muscle was developed and validated according to the European Union Commission Decision 2002/657/EC. The method was based on acid hydrolysis to liberate non-extractable residues having presumably been covalently bound to tissues, and to convert all the florfenicol residues as well as its metabolites into florfenicol amine. The amine was subsequently recovered with ethyl acetate at pH 10.5, defatted and further cleaned up with dispersive solid phase extraction (dSPE). The LC separation was achieved on reverse phase C-18 column with isocratic elution using acetonitrile/water mobile phase and the analysis was performed on linear ion trap mass spectrometer. Calibration curve was obtained over a concentration range of 25-600μg/kg for chicken muscles. The accuracy values ranged from 84 to 101.4% and the precision values for within day and between days ranged from 1.2-11.7%, respectively. Limit of detection (LOD), limit of quantification (LOD), CCα and CCβ values were 0.98, 3.2, 113 and 126μg/kg, respectively. The developed method was highly robust and was further applied to estimate the relative distribution of solvent-extractable against solvent-non-extractable florfenicol drug residues in muscle, liver and kidney samples of broiler chicken after 5days of oral dosing.

Determination of the residue levels of nicarbazin and combination nicarbazin-narasin in broiler chickens after oral administration.

The depletion times of the anticoccidial nicarbazin administered individually and of nicarbazin and narasin administered in combination were evaluated by determining the presence and levels of 4,4'-dinitrocarbanilide (DNC), the marker residue for nicarbazin, and narasin residues in the muscle tissues of broiler chickens subjected to a pharmacological treatment. A high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was used. The results showed the presence of all anticoccidial residues; however, the DNC levels were higher when the nicarbazin was administered individually than when it was used in association with narasin throughout the experimental period. After six days of withdrawal, the DNC level following nicarbazin administration alone was lower than the maximum residue level (MRL) of 200 μg kg-1. However, when the nicarbazin was co-administered with narasin, the concentrations of DNC were lower than the MRL after four days of withdrawal. These results may be justified because the dosage of nicarbazin, when administrated individually, is greater than when it is used in combination with narasin. The levels of narasin were lower than the MRL of 15 μg kg-1 throughout the evaluation period. It was concluded that nicarbazin is rapidly metabolized from the broiler muscles up to six days of withdrawal since the DNC levels were lower than the maximum residue level (MRL) and the concentrations of narasin were lower than the MRL throughout the evaluation period.

Assessment of 28 trace elements and 17 amino acid levels in muscular tissues of broiler chicken (Gallus gallus) suffering from arsenic trioxide

The contents of 28 trace elements, 17 amino acid were evaluated in muscular tissues (wings, crureus and pectoralis) of chickens in response to arsenic trioxide (As2O3). A total of 200 one-day-old male Hy-line chickens were fed either a commercial diet (C-group) or an As2O3 supplement diet containing 7.5mg/kg (L-group), 15mg/kg (M-group) or 30mg/kg (H-group) As2O3 for 90 days. The elements content was analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Under As2O3 exposure, the concentration of As were elevated 8.87–15.76 fold, 7.93–15.63 fold and 5.94–12.45 fold in wings, crureus and pectoralis compared to the corresponding C-group, respectively. 19 element levels (lithium (Li), magnesium (Mg), aluminum (Al), silicon (Si), kalium (K), vanadium (V), chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), selenium (Se), strontium (Sr), molybdenum (Mo), cadmium (Cd), tin (Sn), antimony (Sb), barium (Ba), mercury (Hg) and lead (Pb), 9 element levels (K, Co, Ni, Cu, As, Se, Sr, Sn, Ba and Hg) and 4 element levels (Mn, cobalt (Co), As, Sr and Ba) were significantly increased (P < 0.05) in wing, crureus and pectoralis, respectively. 2 element levels (sodium (Na) and zinc (Zn)), 5 element levels (Li, Na, Si, titanium (Ti and Cr), 13 element levels (Li, Na, Mg, K, V, Cr, iron (Fe), Cu, Zn, Mo, Sn, Hg and Pb) were significantly decreased (P < 0.05) in wing muscle, crureus and pectoralis, respectively. Additionally, in crureus and pectoralis, the content of total amino acids (TAA) was no significant alterations in L and M-group and then increased approximately 10.2% and 7.6% in H-group, respectively (P < 0.05). In wings, the level of total amino acids increased approximately 10% in L-group, whereas it showed unchanged in M and H-group compared to the corresponding C-group. We also observed that significantly increased levels of proline, cysteine, aspartic acid, methionine along with decrease in the tyrosine levels in muscular tissues compared to the corresponding C-group. In conclusion, the residual of As in the muscular tissues of chickens were dose-dependent and disrupts trace element homeostasis, amino acids level in muscular tissues of chickens under As2O3 exposure. Additionally, the response (trace elements and amino acids) were different in wing, thigh and pectoral of chick under As2O3 exposure. This study provided references for further study of heavy metal poisoning and may be helpful to understanding the toxicological mechanism of As2O3 exposure in muscular tissues of chickens.

Quantification of enrofloxacin residues in broiler chicken tissues using competitive enzyme-linked immunosorbent assay

Irrational use of antimicrobial agents’ results in their accumulation in poultry eggs, meat and other byproducts. Less is known regarding antimicrobial residues in broiler meat, specifically for Jhang, Punjab, Pakistan. Thus, the main purpose of this research was to evaluate the prevalence of enrofloxacin residues in broiler chickens tissue. A total of 90 samples of chickens’ tissue were collected randomly from different local meat shops of Jhang city and were analyzed using competitive colorimetric enzyme-linked immunosorbent assay kit. Out of 90 samples analyzed, 53% of the breast muscle and 62% of the liver tissues samples contained residues of enrofloxacin higher than maximum residue limits. Median concentration of enrofloxacin residues in breast muscle and liver tissue was 103 ng/g and 1409 ng/g respectively. Quantification of antibiotic residues distribution in chickens’ tissues revealed that the difference between breast muscle and liver tissue was non-significant. Results of study revealed that broiler chickens being sold in Jhang city contained the enrofloxacin residues and may exposethe consumers to their deleterious effects.

Determination of Oxytetracycline and 4-Epi-Oxytetracycline Residues in Feathers and Edible Tissues of Broiler Chickens Using Liquid Chromatography Coupled with Tandem Mass Spectrometry

Antibiotics have been widely used in poultry production for the treatment of bacterial diseases. However, drug residues can remain in products derived from animals after the cessation of the drug therapies. Feathers, in particular, have shown an affinity for antibiotics such as tetracycline, suggesting the persistence of these drugs in nonedible tissue. After the birds are slaughtered, feathers are ground into feather meals, which are used as organic fertilizer or an ingredient in animal diets, thereby entering into the food chain and becoming a potential risk for public health. To evaluate the depletion of oxytetracycline (OTC) and its metabolite 4-epi-oxytetracycline (4-epi-OTC) in the muscles, liver, and feathers, 64 broiler chickens, bred under controlled conditions, were treated orally with a commercial formulation of 10% OTC for 7 days. The analytes were quantified using liquid chromatography-tandem mass spectrometry. OTC and 4-epi-OTC were found in the feathers for 46 days, whereas they were found in the muscle and liver for only 12 and 6 days, respectively. These results prove that the analytes remain in feathers in higher concentrations than they do in edible tissues after treatment with tetracyclines. Thus, feather meals represent a potential source of antimicrobial residue contamination in the food chain.

Study on the abuse of amantadine in tissues of broiler chickens by HPLC-MS/MS.

To evaluate the residual target tissues for better monitoring of amantadine abuse in broiler chickens, 22-day-old commercial Arbor Acres broiler chickens were, respectively, fed with 10, 20, and 40mg/kg of amantadine for five consecutive days. Plasma, breast, and liver tissue samples from the chickens were collected 0, 4, 16, 24, 48, 96, 144, and 312h after amantadine withdrawal. The high-performance liquid chromatography-tandem mass spectrometry method was used to detect the concentrations of amantadine. The highest concentration was found in the chicken liver and it took the longest time for amantadine to vanish by metabolism. In the high-dose group, amantadine residues were still detected 312h after amantadine withdrawal. As the amantadine dose increased, amantadine residues in the chicken liver were more slowly to disappear than in other tissues. Even if approximately the same concentration of amantadine residues was found in chicken breast and plasma samples, it took a shorter time before the residues were eliminated. In the medium- and high-dose groups, the concentrations of amantadine residues in chicken liver samples were substantially higher than those in chicken breast and plasma samples, and it took more time to eliminate them. Therefore, the chicken liver can be used as a target tissue to detect illegal use of amantadine.

Deposition of Dietary Bioactive Fatty Acids in Tissues of Broiler Chickens.

This study examined the deposition of dietary bioactive fatty acids (FAs), including medium-chain and essential FAs, in tissues of broiler chickens. Six hundred newly hatched chicks were allotted to 4 treatments, 6 replicates of 25 chicks per treatment. The chicks were fed diets containing 0%, 1.6%, 4.0%, or 6.4% medium-chain triglycerides (MCTs) for 36 d. The abdominal fat deposition, fat content, and FA composition of breast meat, thigh meat, and abdominal fat were measured. The accumulation rate (AR) of bioactive FAs in the tissues was estimated as the slope of the linear regression between the FA composition of tissues and diets. Results showed that a diet containing 6.4% MCTs reduced the abdominal fat deposition and fat content of thigh meat (P<0.05). Essential FAs had higher AR than did medium-chain FAs. The AR of C10:0 was higher than that of C8:0. Moreover, C6:0 could not be detected in the tissues of broiler chickens. In conclusion, essential, but not medium-chain, FAs could efficiently deposit in tissues of broiler chickens.

Prevalence of Clostridium perfringens type A isolates in different tissues of broiler chickens

Prevalence of Clostridium perfringens type A isolates in different tissues of broiler chickens

Performance and carbon turnover in fast- and slow-growing broilers submitted to cyclic heat stress and fed on high-protein diets

Two experiments were conducted to test the hypothesis that when using similar protein/amino acid diets and environment temperature conditions, the performance and carbon turnover in muscle and liver tissues, as measured by the incorporation of stable isotopes (13C/12C), must be different between fast-growing Cobb 500® and slow-growing Label Rouge broilers.For both experiments (Cobb and Label Rouge), 21-d-old birds were distributed in a completely randomised, 3 × 3 factorial design; three environmental temperatures (cyclic heat stress ad libitum, 22°C ad libitum, and 22°C restricted) and three crude protein concentrations (189.1, 210 and 220 g/kg CP) were used.The Cobb 500® had better performance with higher concentrations of crude protein. Cyclic heat stress (a temperature factor), negatively affected this genetic strain’s performance. For the Label Rouge birds, the crude protein concentrations in the diet presented inconsistent results and cyclic heat stress did not affect the performance.The carbon turnover rate was affected in the Cobb 500® strain, with a high protein content reducing carbon turnover in the evaluated tissues (liver and muscles). Feed intake had a greater impact on carbon turnover rates than cyclic heat stress. The Label Rouge birds were not affected by the evaluated factors, suggesting that genetic improvement has a leading role on tissue carbon turnover.There is a genetic influence on carbon turnover in the liver and muscle tissues of broiler chickens. In addition, genetically fast-growing broilers are more susceptible to variations in diet composition and environmental temperature than less rapidly growing animals.

Effects of feed supplementation with various zinc sources on mineral concentration and selected antioxidant indices in tissues and plasma of broiler chickens

The aim of this study was to compare the effects of organic dietary zinc (Zn) sources and zinc sulphate on mineral deposition, activity of total superoxide dismutase (SOD) and copper/zinc SOD in tissues of broiler chickens. The performance indicators and lipid peroxidation by measuring the contents of thiobarbituric acid reactive substances (TBARS) in tissues and plasma were also evaluated. Broilers were assigned to 4 treatment groups, each replicated × 6, with 9 birds per replicate. The control group was fed conventional basal diet (BD); the three other groups received identical BD supplemented with 120 mg Zn/kg in the form of zinc sulphate, zinc chelate of glycine hydrate (Zn-Gly), and zinc proteinate (Zn-Pro), respectively. After 5 weeks of dietary treatment, feed supplementation with Zn sulphate resulted in significantly higher average daily weight gain and final body weight, as well as improved feed conversion ratio compared to the Zn-Gly group. Intake of Zn-Pro significantly increased SOD activity (P &lt; 0.05) in erythrocytes and lipid peroxidation (P &lt; 0.01) in plasma. Activities of total SOD and Cu/Zn SOD in liver and kidney were not affected by Zn supplementation. Addition of Zn supplements to broiler diets did not influence concentrations of zinc, manganese and copper in plasma, liver, kidney or breast muscle, with the exception of Zn deposition in the liver being significantly higher (P &lt; 0.05) in the Zn-Pro supplemented group. Results of our study show that organic zinc sources have effects comparable to inorganic zinc sulphate in broilers fed diets containing a higher Zn content.

Selenium Deficiency Mainly Influences Antioxidant Selenoproteins Expression in Broiler Immune Organs.

Selenoprotein has many functions in chicken, and the expression of selenoproteins is closely associated with the selenium (Se) level. However, little is known about the expression patterns of selenoproteins in chicken immune organs. Here, we investigated the effect of dietary Se deficiency on the expressions of 23 selenoproteins in broiler immune organs. In this study, 150 broilers were randomly divided into two groups (75 chickens per group). The chickens were maintained either on a diet supplemented with Se through the addition of 0.2mg/kg of Se (C group) via sodium selenite or on a Se-deficient granulated diet (L group) until the broilers exhibited an onset of exudative diathesis (ED). Following euthanasia, the samples from the immune tissues (including the spleen, thymus, and bursa of Fabricius) were quickly collected, and the messenger RNA (mRNA) expression levels of 23 selenoproteins were examined by real-time quantitative PCR and analyzed using principal component analysis. The results showed that Se deficiency decreased the mRNA levels of 23 selenoproteins in the thymus, spleen, and bursa of the Fabricius tissues of broiler chickens. Furthermore, we found that among 23 selenoproteins, the mRNA levels of Dio1 in the thymus, Txnrd2 in the spleen, and Txnrd3 in the bursa of Fabricius decreased significantly (90.9%, 83.3%, and 96.8%, respectively). In addition, the principal component analysis (PCA) results suggested that Se deficiency mainly influenced the expression of antioxidative selenoproteins, especially glutathione peroxidases (Gpxs), thioredoxin reductases (Txnrds), and iodothyronine deiodinases (Dios) in chicken immune organs. The results of this study are valuable for understanding the relevance of selenoprotein activity in vivo.