Influence of dietary lycopene on growth performance, antioxidant status, blood parameters and mortality in broiler chicken with cold-induced ascites.

The aim of this study was to determine the effects of dietary lycopene supplementation on growth performance and antioxidant status of broiler chickens exposed to cold environment to induce ascites. Three hundred male chickens were exposed full-day to cold stress (CT, 10°C) starting from day 15 of age until the end of experiment at day 42, while a positive control group (NT, 100 birds) was kept under normal temperature (23-25°C). The CT groups (three treatments and five replicates of 20 birds) were as follows: negative control (basal diet, CT) and CT + 200 or 400 mg lycopene per kg diet from 15 to 42 d of age. Results showed that CT without lycopene supplementation caused a reduction of feed intake and weight gain and increased the feed conversion ratio. Supplementation of lycopene during CT restored the performance to levels of the positive control, lowered the index of right ventricles/total ventricles and ascites mortality. Birds reared under CT had lower serum activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and higher malondialdehyde (MDA) concentration than birds reared under the NT environment. With lycopene supplementation, serum MDA level significantly decreased and the activity of SOD and GPx increased. Blood concentration of haematocrit, haemoglobin and red blood cells were decreased by the highest lycopene supplementation to a level comparable to NT. Moreover, increasing dietary lycopene level suppressed serum concentrations of cholesterol and enhanced high-density lipoproteins levels in blood. In conclusion, lycopene supplementation alleviates adverse effects of cold stress on performance through modulating activity of antioxidant enzymes in broiler chickens.

Use of immune repertoire sequencing to resolve discordant microscopic and immunochemical findings in a case of T cell-rich large B cell lymphoma in a young dog.

BACKGROUND: Lymphocytic neoplasms with frequent reactive lymphocytes are uncommonly reported in dogs, and can pose a diagnostic challenge. Different diagnostic modalities such as cytology, flow cytometry, histopathology, immunohistochemistry, and clonality testing, are sometimes required for a diagnosis. This report illustrates the value of using a multi-modal diagnostic approach to decipher a complex lymphocytic tumor, and introduces immune repertoire sequencing as a diagnostic adjunct. CASE PRESENTATION: A 10-month-old Great Dane was referred for marked ascites. Cytologic analysis of abdominal fluid and hepatic aspirates revealed a mixed lymphocyte population including numerous large lymphocytes, yielding a diagnosis of lymphoma. Flow cytometrically, abdominal fluid lymphocytes were highly positive for CD4, CD5, CD18, CD45, and MHC II, consistent with T cell lymphoma. Due to a rapidly deteriorating clinical condition, the dog was euthanized. Post mortem histologic evaluation showed effacement of the liver by aggregates of B cells surrounded by T cells, suggestive of hepatic T cell-rich large B cell lymphoma. Immune repertoire sequencing confirmed the presence of clonal B cells in the liver but not the abdominal fluid, whereas reactive T cells with shared, polyclonal immune repertoires were found in both locations. CONCLUSIONS: T cell-rich large B cell lymphoma is a rare neoplasm in dogs that may be challenging to diagnose and classify due to mixed lymphocyte populations. In this case, the results of histopathology, immunohistochemistry and immune repertoire sequencing were most consistent with a hepatic B cell neoplasm and reactive T cells exfoliating into the abdominal fluid. Immune repertoire sequencing was helpful in delineating neoplastic from reactive lymphocytes and characterizing repertoire overlap in both compartments. The potential pitfalls of equating atypical cytomorphology and monotypic marker expression in neoplasia are highlighted.

Identification and validation of quantitative trait loci for ascites syndrome in broiler chickens using whole genome resequencing.

BACKGROUND: Ascites syndrome is a hypertensive, multifactorial, multigene trait affecting meat-type chickens imposing significant economic losses on the broiler industry. A region containing the CPQ gene has been previously identified as significantly affecting ascites phenotype. The region was discovered through whole genome resequencing focused on chicken chromosome 2. The association was confirmed through further genotyping in multiple broiler populations. RESULTS: The whole genome resequencing analyses have now been extended to the current chicken genome assembly. DNA samples were pooled according to gender and phenotype and the pools subjected to next generation sequencing. Loci were identified as clusters of single nucleotide polymorphisms where frequencies of the polymorphisms differed between resistant and susceptible chickens. The chickens are an unselected line descended from a commercial elite broiler line. Regions identified were specific to one or both genders. The data identify a total of 28 regions as potential quantitative trait loci for ascites. The genes from these regions have been associated with hypertensive-related traits in human association studies. One region on chicken chromosome 28 contains the LRRTM4 gene. Additional genotyping for the LRRTM4 region demonstrates an epistatic interaction with the CPQ region for ascites phenotype. CONCLUSIONS: The 28 regions identified were not previously identified in a multi-generational genome wide association study using 60k Single Nucleotide Polymorphism panels. This work demonstrates the utility of whole genome resequencing as a cost effective, direct, and efficient method for identifying specific gene regions affecting complex traits. The approach is applicable to any organism with a genome assembly and requires no a priori assumptions.

Effect of a background Ca2+ entry pathway mediated by TRPC1 on myocardial damage of broilers with induced ascites syndrome.

Ascites syndrome (AS) in chickens is associated with profound vascular remodelling and increased pulmonary artery pressure as well as right ventricular hypertrophy. Classical transient receptor potential cation channels (TRPCs) are key regulators of cardiac hypertrophy that act via regulation of calcium influx in mammals. We investigated whether classical transient receptor potential channels in chickens with right ventricular hypertrophy still possess this mechanism for regulating Ca2+ flux. Intravenous injection of cellulose particles was successfully used to induce AS in chickens, and tissues were examined 22 days after treatment. The chickens in the test group showed cardiac hypertrophy with oedema of the cardiac muscle and disruption of myofilaments. The right-to-total ventricle weight ratio (RV/TV), the levels of serum aspartate aminotransferase (AST) and creatine kinase (CK) of the test group were significantly higher than in the control group. Intracellular calcium levels were significantly increased in cardiomyocytes from chickens in the test group. Gene expression of TRPC3, TRPC4, TRPC5, TRPC6 and TRPC7 in heart tissues from the test group showed no significant differences compared with controls. However, TRPC1 protein levels, as well as mRNA levels, were down-regulated in the heart muscle of AS chickens (P < 0.05). Although we observed an increase in calcium concentration, the expression of TRPC1 decreased in cardiac cells. We hypothesized that an increase in intracellular free calcium concentration could inversely regulate calcium channel expression. RESEARCH HIGHLIGHTS Intracellular Ca2+ levels were increased in the myocardium of AS broilers. Expression of TRPC1, which mediates calcium influx, was decreased in the myocardium of AS broilers. The relationship between intracellular Ca2+ levels and expression of TRPC1 requires further study.

Combined effects of guanidinoacetic acid, coenzyme Q10 and taurine on growth performance, gene expression and ascites mortality in broiler chickens.

High levels of guanidinoacetate acid (GAA) deteriorate growth response in broiler chickens. We propose using coenzyme Q10 , an antioxidant, and taurine (TAU), a methyl donor, to cope with the situation when high level of GAA included in diet. GAA was supplemented at 0 (control), 0.75, 1.5 and 2.25 g/kg in isoenergetic and isonitrogenous diets and fed to broilers (Cobb 500) from 1 to 40 days post-hatch. Three additional diets were prepared by adding CoQ10 (40 mg/kg), TAU (40 mg/kg) or their combination (both CoQ10 and TAU at 40 mg/kg) to the 2.25 g/kg GAA group. The experimental design used was a completely randomized design. While weight gain (p = 0.038) and feed conversion ratio (p = 0.024) improved when GAA added at 1.5 g/kg, higher supplementation (2.25 g/kg) deteriorated these responses. These responses, however, were significantly restored by using CoQ10 , TAU or their combination. Abdominal fat deposition was significantly decreased when TAU added to broiler diets by virtue of upregulating peroxisome proliferator-activated receptor alpha. Supplementing broiler diets with CoQ10 and TAU or their combination significantly decrease ascites mortality. In conclusion, CoQ10 and TAU have shown beneficial effects when high level of GAA included in broiler diets.

Recovery of Bacillus mycoides, B. pseudomycoides and Aeromonas hydrophila from common carp (Cyprinus carpio) and rainbow trout (Oncorhynchus mykiss) with gill disease.

During a 3-month period from June to the end of August 2016, ~5% mortalities were observed in a farm with rainbow trout (Oncorhynchus mykiss Walbaum) and one farm of common carp (Cyprinus carpio L.) in Bulgaria. The disease was manifested by gill ulcers/rot, asphyxiation and bloody ascites. Aeromonas hydrophila was isolated from the internal organs of all the diseased fish. Bacillus mycoides or B. pseudomycoides were recovered from the gill lesions on diseased carp and rainbow trout, respectively, with identification achieved by conventional phenotyping and by sequencing of the 16S rRNA gene. In vivo experiments confirmed that all three organisms were pathogenic to rainbow trout.

Mitochondrial biogenesis and PGC-1α gene expression in male broilers from ascites-susceptible and -resistant lines.

Ascites is a cardiovascular metabolic disease characterized by accumulation of fluid around the heart and in the abdominal cavity that eventually leads to death. This syndrome is the end-point result of a series of metabolic incidents that are generally caused by impaired oxygen availability. Mitochondria are the major sites of oxygen consumption, therefore major contributors to oxidative stress. Genetic, metabolic and dietary factors can influence variations in mitochondrial biogenesis (mitochondrial size, number and mass) that might have an effect on oxygen consumption and reactive oxygen species production. This study evaluated the effect of genotype on PGC-1α mRNA gene expression and mitochondrial biogenesis. These parameters were examined in male broiler chickens at 22 weeks of age from the SUS and RES lines divergently selected for ascites phenotype. From each line, five birds were sampled for right ventricle and breast muscle. Gene expression and mtDNA copy number were assessed by quantitative PCR. Results showed that birds from SUS had significantly higher PGC-1α mRNA gene (p = .033) and mitochondrial DNA copy number (p = .038) in breast muscle. There was no difference in right ventricle PGC-1α expression or mitochondrial DNA copy number between the two lines. These findings indicate that mitochondrial biogenesis and PGC-1α mRNA gene expression differ between male broiler chickens from RES and SUS lines in a tissue-specific manner.

Genetic parameters of body weight and ascites in broilers: effect of different incidence rates of ascites syndrome.

1. The objectives of the current study were to investigate the effect of incidence rate (5%, 10%, 20%, 30% and 50%) of ascites syndrome on the expression of genetic characteristics for body weight at 5 weeks of age (BW5) and AS and to compare different methods of genetic parameter estimation for these traits. 2. Based on stochastic simulation, a population with discrete generations was created in which random mating was used for 10 generations. Two methods of restricted maximum likelihood and Bayesian approach via Gibbs sampling were used for the estimation of genetic parameters. A bivariate model including maternal effects was used. The root mean square error for direct heritabilities was also calculated. 3. The results showed that when incidence rates of ascites increased from 5% to 30%, the heritability of AS increased from 0.013 and 0.005 to 0.110 and 0.162 for linear and threshold models, respectively. 4. Maternal effects were significant for both BW5 and AS. Genetic correlations were decreased by increasing incidence rates of ascites in the population from 0.678 and 0.587 at 5% level of ascites to 0.393 and -0.260 at 50% occurrence for linear and threshold models, respectively. 5. The RMSE of direct heritability from true values for BW5 was greater based on a linear-threshold model compared with the linear model of analysis (0.0092 vs. 0.0015). The RMSE of direct heritability from true values for AS was greater based on a linear-linear model (1.21 vs. 1.14). 6. In order to rank birds for ascites incidence, it is recommended to use a threshold model because it resulted in higher heritability estimates compared with the linear model and that BW5 could be one of the main components of selection goals.

The effect of acetylosalicylic acid and berberis on ascites syndrome parameters in broiler chickens.

One-hundred and thirty day-old broiler chickens were kept for 6 days and on the seventh day, 120 chickens were selected and randomly divided into 5 groups with 2 replicates. To cause ascites, an amount of 0.12% sodium was added to the drinking water of 4 groups of chickens. On the fourteenth day, the amount of sodium was increased to 0.24% and at the same time, treatment with acetylosalicylic acid and berberis was started. At the age of 14 and 21 days, random sample chickens from each replicate were necropsied and were examined in terms of the factors associated with ascites. The results showed that the ratio of the weight of the right ventricle (RV) to the weight of the total ventricles (TV) and all other factors on 14th day revealed no significant difference between the groups (p>0.05). On 21st day, the RV/TV ratio in the ascites control group was significantly higher than that in the control group (p<0.05). The RV/TV ratio in the groups receiving acetylosalicylic acid and berberis were lower than those in the ascites control group; however, this reduction was not significant (p>0.05). The rate of mortality in the groups receiving acetylosalicylic acid and berberis was lower than that in ascites control group. Considering the results obtained, it can be suggested that the treatment with acetylosalicylic acid and berberis is effective to prevent ascites.

Molecular diagnosis of Eimeria stiedae in hepatic tissue of experimentally infected rabbits.

The early detection of Eimeria stiedae in the hepatic tissue of experimentally infected rabbits was investigated using molecular assay. Forty 6-week-old male New Zealand rabbits were divided into two groups. Group A (30 animals) was infected with 2.5 × 10(4) sporulated oocysts of E. stiedae per animal on Day 0 and Group B (10 animals) was used as the uninfected controls. Three animals from Group A and one from Group B were sacrificed at 0, 3, 6, 9, 12, 15, 18, 21, 24 and 27 days post infection (PI). Gross and microscopic post-mortem findings were recorded. Polymerase chain reaction (PCR) of the E. stiedae internal transcribed spacer 1 genomic region was conducted on blood, liver tissue, and feces from the Group A experimentally infected animals. Macroscopically, the liver showed irregular yellowish white nodules pathognomonic to E. stiedae infection beginning on Day 15 PI. Hepatomegaly and ascites were obvious from Day 21-24 PI. The presence of different E. stiedae schizonts and gametocytes in the histopathological sections of the biliary epithelium were evident on Day 15 PI. The E. stiedae PCR was first positive in liver tissues on Day 12 and in fecal samples on Day 18 PI, but the blood samples were negative. In conclusion, the PCR can be used for early diagnosis and control of E. stiedae schizonts before shedding of the oocysts in feces.

Histopathological studies of the heart in three lines of broiler chickens.

The aim of this study was to analyse the morphological lesion pattern of the heart of broiler chickens (Cobb 500, Hubbard F15 and Ross 308) during fattening with no clinical signs of disease and to determine the most susceptible period for the occurrence of morphological lesions. The most frequently diagnosed lesions in each genetic line were degeneration of the fibres with vacuolation, congestion of cardiac muscle, oedema and vacuolisation of the Purkinje cells. The highest numbers of morphological lesions were observed on d 38, 31 and 10 of life. The lesions were most numerous in the septum, followed by the left and right ventricles. Ischaemic cardiomyocytes were also most numerous on d 38 of life and in the left ventricle. Overload of cardiac muscle, prolonged hypoxia and increasing body weight on d 38 are the likely reasons for the largest number of lesions and ischaemic fibres, which may lead to heart failure.

The suitability of some blood gas and biochemical parameters as diagnostic tools or early indicators of ascites syndrome in broiler sire lines.

In recent few years, there have been some attempts to find a reliable indicator trait as a selection criterion against susceptibility to ascites syndrome (AS). Blood parameters were of great interest as they could be measured in live animals without implementing an ascites-inducing challenge (AIC). In this work, the suitability of some blood parameters was evaluated for diagnosing AS-susceptible chicks in later steps of the disease in trial 1 as well as their early predictive ability in trial 2. In the first trial, one hundred 1-day-old chicks from two pure broiler lines namely S1 and S2 and, in the second trial, 226 1-day-old chicks from line S2 were subjected to AIC. Saline drinking water (1200 mg/l) and lower-than-standard ambient temperatures were the implemented AICs in trials 1 and 2 respectively. The blood parameters including pH, partial pressure of O2 (pO2 ), partial pressure of CO2 (pCO2 ), bicarbonate ion concentration (BIC), percentage of haematocrit (HCT) and saturated haemoglobin (SaO2 ) were measured twice per each bird at days 28 and 35 in trial 1 and once in trial 2 at day 21. The results of the first trial revealed that in line S2 some of the blood parameters differed significantly between the ascitic and non-ascitic groups following exposure to AIC. In this line, the incidence of AS was accompanied by a lower pO2 , SaO2 and BIC, while with higher pCO2 and HCT values. In the second trial, however, although almost all of the parameters showed meaningful differences between the ascitic and non-ascitic broilers, only mean difference of BIC parameter was statistically significant. The general conclusion of this study is that the blood parameters can somewhat have diagnostic ability in the condition in which the AIC is already present, whereas the results did not approve their usefulness as early predictors of AS.

Molecular characterization of Acanthamoeba strains isolated from domestic dogs in Tenerife, Canary Islands, Spain.

The present study describes two cases of Acanthamoeba infections (keratitis and ascites/peritonitis) in small breed domestic dogs in Tenerife, Canary Islands, Spain. In both cases, amoebic trophozoites were observed under the inverted microscope and isolated from the infected tissues and/or fluids, without detecting the presence of other viral, fungal or bacterial pathogens. Amoebae were isolated using 2 % non-nutrient agar plates and axenified for further biochemical and molecular analyses. Osmotolerance and thermotolerance assays revealed that both isolates were able to grow up to 37 °C and 1 M of mannitol and were thus considered as potentially pathogenic. Moreover, the strains were classified as highly cytotoxic as they cause more than 75 % of toxicity when incubated with two eukaryotic cell lines. In order to classify the strains at the molecular level, the diagnostic fragment 3 (DF3) region of the 18S rDNA of Acanthamoeba was amplified and sequenced, revealing that both isolates belonged to genotype T4. In both cases, owners of the animals did not allow any further studies or follow-up and therefore the current status of these animals is unknown. Furthermore, the isolation of these pathogenic amoebae should raise awareness with the veterinary community locally and worldwide.

Acute and chronic eggshell temperature manipulations during hatching term influence hatchability, broiler performance, and ascites incidence.

The aim of the current study was to determine how a control temperature and acute and chronic high eggshell temperatures during the last three days of incubation, can affect hatchability, chick quality, and organ development on day of hatch as well as broiler performance and ascites incidence in later life. The eggshell temperature manipulations were applied during hatching term (days 19 to 21) as follows: control EST (37.3 to 38.0°C), acute high eggshell temperature manipulations (38.4- to 39.0°C for three hours daily) and chronic high eggshell temperature manipulations (38.4 to 39.0°C). The lowest hatchability and the highest cull chick rate were in the chronic high eggshell temperature manipulations group. Lower chick quality parameters correlated with lower chick weights and heavier residual yolk sac weights that were in the chronic high eggshell temperature manipulations group depending on hatch time. The live weights on the 1(st) day of the growing period were higher in the control and acute high eggshell temperature manipulations groups than the chronic high eggshell temperature manipulations group. At 6 wk of age, live weights of broilers were the highest in the control than in the acute and chronic high eggshell temperature manipulations groups. The total mortality was 2.5, 9.2, and 13.3%, the mortality due to ascites was 2.1, 8.3, and 12.9% in the control, acute ,and chronic high eggshell temperature manipulations groups, respectively. The right ventricular/total ventricular ratios for the control, acute and chronic high eggshell temperature manipulations groups were 0.22, 0.28, and 0.30%, respectively. In conclusion, short-term and long-term higher temperatures during the hatching term affect embryo development, incubation results, broiler performance, and ascites incidence. Although the acute high eggshell temperature manipulations did not affect the chick quality parameters at hatch, it negatively affected incubation results and broiler performance, especially mortality due to ascites.

The effects of increasing levels of dietary garlic bulb on growth performance, systolic blood pressure, hematology, and ascites syndrome in broiler chickens.

The effects of dietary garlic bulb were studied separately on hematological parameters, ascites incidence, and growth performance of an ascites susceptible broiler hybrid under both standard temperature conditions ( STC: ) and cold temperature conditions ( CTC: ). A total of 336 one-day-old male broiler chickens were allocated to 4 experimental groups with 4 replicates of 21 birds each under STC. In addition, the same grouping with another 336 birds was used for CTC. Under CTC, the birds were exposed to cold temperatures for induction of ascites. Experimental groups were defined by the inclusion of 0 (control), 5, 10 or 15 g/kg garlic bulbs in the diets under both STC and CTC. Growth performance, systolic blood pressure (as a measure of systemic arterial blood pressure), physiological and biochemical parameters, as well as ascites indices (right ventricle [ RV: ], total ventricle [ TV: ] weights, and RV/TV: ) were evaluated. Systolic blood pressure was determined using an indirect method with a sphygmomanometer, a pediatric cuff, and a Doppler device. The final body weight decreased quadratically (P = 0.003), with increasing garlic bulb levels in the diets under STC. The feed conversion ratio showed no significant differences among all groups under both STC and CTC. No significant differences were observed in total mortality and ascites-related mortality in all groups under STC, although total mortality (L: P = 0.01; Q: P = 0.001) and ascites-related mortality (L: P = 0.007; Q: P = 0.001) were significantly different among the diets under CTC. Under STC, the systolic blood pressure, packed cell volume, hemoglobin, RV, TV, and RV/TV did not vary significantly among the diets. However, red blood cell count and erythrocyte osmotic fragility decreased linearly (P < 0.005) with increasing garlic bulb levels in the diets under STC. Under CTC, the systolic blood pressure, packed cell volume, red blood cell count, and erythrocyte osmotic fragility decreased (P < 0.05) with increasing garlic levels. It is concluded that the inclusion of 5 g/kg garlic bulb in susceptible broiler chicken diets has a systemic anti-hypertensive effect and could decrease ascites incidence without impairing broiler chicken performance.

Incidence of ascites syndrome and related hematological response in short-term feed-restricted broilers raised at low ambient temperature.

Ascites is a major cause of mortality and morbidity in modern broiler production. Reduction of early growth, followed by compensatory gain, seems a practical and viable method to minimize losses caused by ascites. An experiment was conducted to determine if early feed restriction can reduce the incidence of ascites in broilers exposed to cool temperatures. Ross 308 cockerels (N=180) were assigned to 5 diet treatments and 2 temperature regimes, with 3 replicate pens of 6 birds per treatment and temperature. A standard grower diet was diluted by adding rice hulls at 0, 15, 30, 45, and 60% by weight from 7 to 14 d of age. On d 21 through 42, the temperature was maintained at 20 to 25°C (thermoneutral), or at 11 to 15°C (cool). Broilers exposed to cool temperatures developed higher right ventricle (RV) to total ventricle (TV) and RV to BW ratios, increased plasma triiodothyronine (T3) and thyroxine (T4) concentrations, and elevated blood values for hemoglobin concentration, mean cell volume, and hematocrit (P<0.05) but did not develop clinical ascites. Diluting the feed with rice hulls from d 7 to 14 resulted in proportional reductions in BW by d 14 (P<0.001) that tended to persist through d 28 (P=0.005), after which compensatory growth eliminated all differences in BW between diet treatment groups by d 35 (P=0.099) and d 42 (P>0.1). Exposure to cool temperatures increased key indices of ascites susceptibility, and these preascitic changes were partially prevented by diluting the feed to reduce growth performance.

Diagnostic exercise: ascites, abdominal masses, and diffuse peritoneal nodules in a rat.

A 1.4-year-old virgin female brown-hooded fancy rat presented for abdominal distention, jaundice, and dyspnea. At physical examination, a firm mass was palpable in the caudoventral abdomen as well as multiple small nodular masses associated with the abdominal viscera. At necropsy, in addition to a large mass replacing the left ovary and myriad nodules studding the peritoneal surface, there was 31 ml of abdominal effusion. By cytology, the abdominal fluid contained numerous pleomorphic vacuolated tumor cells surrounding globular pale eosinophilic to amphophilic acellular material that was strongly periodic acid-Schiff positive. Histologically, the tumor was biphasic with abundant acellular hyaline matrix that was also periodic acid-Schiff positive.

A quantitative trait locus for ascites on chromosome 9 in broiler chicken lines.

A genome-wide SNP survey was used to identify chromosomal regions that showed linkage disequilibrium with respect to ascites susceptibility and ventricular hypertrophy in an F2 cross between previously described ascites-resistant and -susceptible lines. Variable number tandem repeats were used to obtain genotype data to further characterize these regions. A region on chromosome 9 (12 to 13 Mbp in 2011 assembly) shows association with ascites in the ascites lines and in several commercial broiler breeder lines with a significant sex effect. There are 2 candidate genes, AGTR1 (an angiotensin II type 1 receptor) and UTS2D (urotensin 2 domain containing), in this region that have been associated with hypertension and hypoxic response in mammals.

Effects of low ambient temperatures and dietary vitamin C supplement on growth performance, blood parameters, and antioxidant capacity of 21-day-old broilers.

The study was conducted to determine the effects of low ambient temperature (LAT) and a vitamin C (VC) dietary supplement on the growth performance, blood parameters, and antioxidant capacity of 21-d-old broilers. A total of 400 one-day-old male Cobb broilers were assigned to 1 of 4 treatments as follows: 1) LAT and a basal diet; 2) LAT and a basal diet supplemented with 1,000 mg of VC/kg (LAT + VC); 3) normal ambient temperature (NAT) and a basal diet; 4) NAT and a basal diet supplemented with 1,000 mg of VC/kg (NAT + VC). All birds were fed to 21 d of age. Broilers in groups 1 and 2 were raised at 24 to 26°C during 1 to 7 d, and at 9 to 11°C during 8 to 21 d, whereas groups 3 and 4 were raised at 29 to 31°C during 1 to 7 d and at 24 to 26°C during 8 to 21 d. The LAT increased the feed conversion ratio during the whole experimental period (P < 0.01), whereas it increased heart index at 21 d (P < 0.05) and hematocrit and hemoglobin level at 14 d (P < 0.05). Supplementing the diet with VC increased hematocrit, hemoglobin, and red blood cell count at 21 d (P < 0.05). At 21 d, LAT conditions decreased total antioxidant capacity in the serum, liver, and lungs (P < 0.05), and it also increased the levels of VC in the serum and liver, the amount of protein carbonylation in liver and lungs, and the malondialdehyde level in the lungs (P < 0.05). The addition of VC tended to increase the total antioxidant capacity level in serum (P < 0.1). Low ambient temperature resulted in oxidative stress for broilers that were fed from 1 to 21 d of age, whereas no significant effect was found on the antioxidant activity by dietary VC supplementation.

The effect of peroxisome proliferator-activated receptor gamma (PPARγ) as a mediator of dietary fatty acids and thiazolidinedione in pulmonary arterial hypertension induced by cold stress of broilers.

The objective of this experiment was to evaluate the effects of dietary fish oil and pioglitazone as peroxisome proliferators-activated receptor gamma (PPARγ) activating ligands on the reduction of cold-induced ascites in broiler chickens. A total of 480 one-day-old (Ross 308) male chicks were randomly allocated to four treatment groups with eight replicates of 15 birds each. The following treatments were used: 1) ambient temperature (negative control), with basal diet; 2) cold-induced ascites (positive control), with basal diet; 3) cold-induced ascites, with basal diet +10 mg/kg/day pioglitazone and 4) cold-induced ascites, with basal diet +1% of fish oil. When compared with the positive control, body weight gain was higher (P ≤ 0.05) for broilers fed diets containing fish oil and pioglitazone at 28, 42, and 0-42 d. Broilers under cold-induced ascites had the highest blood pressure at 21 and 42 d, while fish oil and pioglitazone treatment reduced the blood pressure (P ≤ 0.05). Red blood cells, white blood cells, hematocrit, erythrocyte osmotic fragility, bursa of Fabricius and spleen weights were improved (P ≤ 0.05) for chickens fed fish oil diets and pioglitazone compared to the cold-induced ascites (positive control). Exposure to cold temperature resulted in an increase in plasma T3 and T3/T4 ratio and decline in plasma T4 (P ≤ 0.05). In conclusion, PPARγ agonist pioglitazone and fish oil as source of omega-3 polyunsaturated fatty acid could be used as a strategy to reduce the negative effects of pulmonary arterial hypertension and ascites in broiler chickens.