Effect of RNA interference with HIF-1α on the growth of pulmonary artery endothelial cells in broiler chickens

Pulmonary artery remodeling is a characteristic feature of broiler ascites syndrome (BAS). Pulmonary artery endothelial cells (PAECs) regulated by HIF-1α play a critical role in pulmonary artery remodeling, but the underlying mechanisms of HIF-1α in BAS remain unclear. In this experiment, primary PAECs were cultured in vitro and were identified by coagulation factor VIII. After hypoxia and RNA interference, the mRNA and protein expression levels of HIF-1α and VEGF were determined by qPCR and Western blotting. The transcriptome profiles of PAECs were obtained by RNA sequencing. Our results showed that the positive rate of PAECs was more than 90%, hypoxia-induced promoted the proliferation and apoptosis of PAECs, and RNA interference significantly downregulated the expression of HIF-1α, inhibited the proliferation of PAECs, and promoted the apoptosis of PAECs. In addition, transcriptome sequencing analysis indicated that HIF-1α may regulate broiler ascites syndrome by mediating COL4A, vitronectin, vWF, ITGα8, and MKP-5 in the ECM, CAMs and MAPK pathways in PAECs. These studies lay the foundation for further exploration of the mechanisms of pulmonary artery remodeling, and HIF-1α may be a potentially effective gene for the prevention and treatment of BAS.

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.

Right congestive heart failure in domestic kitten (Felis domesticus) by dilation of the pulmonary veins and cardiomegali

Background

Congestive heart failure (CHF) is a pathological state characterized by the incapability of the heart to properly perform its essential function of delivering blood to meet the metabolic demands of the body.

Case Description

The present case report concerns a 3-month-old male domestic kitten, displaying symptoms including an enlarged abdomen, emaciation, dehydration, dyspnea, rhinorrhea, and infestation with scabies. This animal, weighing 0.7 kg displays a tabby bicolor pattern. The findings gleaned from the clinical evaluation revealed the presence of a murmur upon auscultation of the cardiac region. Upon conducting an ultrasound examination, it was determined that the abdominal cavity contained a fluid accumulation known as ascites.

Conclusion

The findings from the radiographic evaluation indicate that feline Hiro exhibits ascites alongside cardiomegaly, in conjunction with discernible vascular modifications characterized by both enlargements of the pulmonary arteries and veins.

Peroxisome proliferator-activated receptor gamma (PPARγ) activation: a potential treatment for ascites syndrome in broiler chickens

Ascites (serous fluid accumulation in the abdominal cavity) has been observed worldwide in fast growing broilers. Pulmonary vascular remodeling is an important pathological feature of broiler ascites syndrome. Peroxisome proliferators-activated receptor gamma (PPARγ) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) are expressed in pulmonary vascular endothelial cells and vascular smooth muscle cells (VSMC) where they participate in the regulation of normal pulmonary vascular function. The objective of the present study was to investigate the effects of omega-3 fatty acids (found in fish oil) and pioglitazone (PIO) as natural and synthetic PPARγ ligands supplementation on PPARγ and PGC-1α expression in the prevention of pulmonary arterial hypertension (PAH) syndrome in broiler chickens. The experiment was conducted with 4 treatment groups: 1) negative control, normal temperature conditions with basal diet; 2) positive control, low-temperature conditions with basal diet; 3) positive control + 10 mg PIO/kg of weight/d and 4) positive control + 1% FO. Each treatment had 5 replicates. Ascites heart index (RV/TV) was significantly (P < 0.05) reduced in chickens receiving FO (0.20) and PIO (0.21) compared to the positive control group (0.26). The addition of PIO in broilers under cold-induced ascites significantly increased the expression of PPARγ (9.44) and PGC-1α (5.81) genes in lung tissue compared to the negative control group (1.03, P < 0.05). Proliferative indexes of VSMC in pulmonary arteries such as PMT, PIT, and percentage wall thickness were significantly elevated in positive control group, indicating that pulmonary vascular remodeling occurred following VSMC proliferation in ascites. The vessel internal diameter was increased in FO and PIO groups. Based on these results, activation and expression of PPARγ and PGC-1α genes as a critical regulator of pulmonary artery smooth muscle cell using ligands, especially PIO, can be effective in reducing the incidence of PAH in broiler chickens.

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.

Further investigation of mitochondrial biogenesis and gene expression of key regulators in ascites- susceptible and ascites- resistant broiler research lines

We have extended our previous survey of the association of mitochondrial prevalence in particular tissues with ascites susceptibility in broilers. We previously reported that in breast muscle of 22 week old susceptible line male birds had significantly higher mtDNA copy number relative to nuclear copy number (mtDNA/nucDNA), compared to resistant line male birds. The higher copy number correlated with higher expression of PPARGC1A mRNA gene. Ascites is a significant metabolic disease associated with fast-growing meat-type chickens (broilers) and is a terminal result of pulmonary hypertension syndrome. We now report the mtDNA/nucDNA ratio in lung, liver, heart, thigh, and breast of both genders at 3, and 20 weeks old. At 3 weeks the mtDNA/nucDNA ratio is significantly higher in lung, breast, and thigh for susceptible line males compared to the resistant line males. Conversely, we see the opposite for lung and breast in females. At 20 weeks of age the differences between males from the two lines is lost for lung, and thigh. Although there is a significant reduction in the mtDNA/nucDNA ratio of breast from 3 weeks to 20 weeks in the susceptible line males, the susceptible males remain higher than resistant line males for this specific tissue. We assessed relative expression of five genes known to regulate mitochondrial biogenesis for lung, thigh and breast muscle from males and females of both lines with no consistent pattern to explain the marked gender and line differences for these tissues. Our results indicate clear sex differences in mitochondrial biogenesis establishing a strong association between the mtDNA quantity in a tissue-specific manner and correlated with ascites-phenotype. We propose that mtDNA/nucDNA levels could serve as a potential predictive marker in breeding programs to reduce ascites.

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.

Hemostatic Findings in Ascitic Fluid: A Cross-Sectional Study in 70 Dogs

BACKGROUND

Ascitic fluids of horses and humans have fibrinolytic activity, independent of the underlying mechanism of fluid formation.

OBJECTIVE

To determine whether coagulation and fibrinogenolytic/fibrinolytic activity (ie, low fibrinogen and increased fibrin-fibrinogen degradation products [FDPs], D-dimer, or both) occur in all types of ascitic fluid in dogs.

ANIMALS

A total of 70 client-owned dogs with ascites.

METHODS

In this cross-sectional study, dogs were categorized based on the pathophysiology of fluid formation into 4 groups: transudates due to decreased osmotic pressure, transudates due to increased hydrostatic pressure, exudates, and hemorrhagic ascites. Fibrinogen, FDPs, and D-dimer concentrations were measured and then compared in both ascitic fluid and plasma.

RESULTS

Ten dogs had transudates due to decreased colloid osmotic pressure, 18 had transudates due to increased hydrostatic pressure, 13 had exudates, and 29 had hemorrhagic ascites. Ascitic fibrinogen concentrations (n = 70) were significantly lower (median = 59 mg/dL; range: 59-122 mg/dL) than those in the plasma (median = 168 mg/dL, range: 59-879 mg/dL; P < .0001). Ascitic FDPs concentrations (n = 70) were significantly higher (<5 μg/mL: 3/70 dogs, ≥5 to <20 μg/mL: 11/70 dogs, ≥20 μg/mL: 56/70 dogs) than those in the plasma (<5 μg/mL: 17/70 dogs, ≥5 to <20 μg/mL: 28/70 dogs, ≥20 μg/mL: 25/70 dogs; P < .0001). Ascitic D-dimer concentrations (n = 70) were significantly higher (median = 3.98 μg/mL, range: 0.02-9.19) than those in the plasma (median = 0.11 μg/mL, range: 0.01-4.08; P < .0001). Analysis of the data for each of the 4 different types of ascites showed similar results to those of all the data analyzed together.

CONCLUSIONS AND CLINICAL IMPORTANCE

Ascitic fluid of dogs has evidence of coagulation activation and fibrinogenolytic/fibrinolytic activity and that this phenomenon occurs independent of the underlying mechanism that leads to the formation of ascites.

Mesothelioma in the Calf

Three cases of mesothelioma in calves are described. Two were full-term foetuses, the other was 3 months old. There was ascites in all three. The tumours formed multiple, discrete nodules on the parietal and visceral peritoneum, and in the older calf also on the pleura. Lymph nodes were unaffected. The tumours appear to arise from the superficial layers of the serosa, and are considered to be of multicentric origin.

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.

Premature parturition, edema, and ascites in an alpaca infected with Anaplasma phagocytophilum

An 8-year-old alpaca was presented for fever, anorexia, edema, ascites, and premature parturition. She was determined to have Anaplasma phagocytophilum infection based on positive blood polymerase chain reaction (PCR) and positive acute and convalescent serum titers. Antibiotics and supportive therapies were administered and the alpaca made a complete recovery.

The impact of L-NAME and L-arginine chronic toxicity induced lesions on ascites--pulmonary hypertension syndrome development in broiler chickens

The impact of L-arginine (LA), a precursor for synthesis of nitric oxide (NO), and N-omega-nitro-L-arginine methyl ester (L-NAME, LN), a non-selective inhibitor of the enzyme producing nitric oxide (nitric oxide synthase; NOS) chronic toxicity induced lesions on Ascites - Pulmonary hypertension syndrome (PHS) development was investigated in 140 one-day-old male broiler chickens (ROSS) during the first 5 weeks of life. Every second day the animals were treated intraperitoneally (ip) with L-NAME (10 mg/kg of body weight; BW), L-arginine (100 mg/kg BW), L-arginine and L-NAME in combination (100 mg/kg BW and 10 mg/kg BW respectively), and with physiological saline (0.90% w/v of NaCl; 0.5 mL/kg BW). Seven birds from each group were euthanized every week. The histopathological examination of the heart, the liver, the lungs, the blood vessels and the lymphoid organs, was performed. Also the organ index values were determined. At the end of the experiment the pre-ascitic condition or ascites - PHS was confirmed in five dead animals in the L-NAME-treated group. In the same group the edema was the most prominent histopathological change confirmed in the heart and in the lungs of the sacrificed chickens. In L-arginine-treated group the congestion and the haemorrhages were the striking changes in the same organs with the highest degree in the last two weeks of trial. While the focal disruption of myocardiofibriole and hepatocytes were predominant lesions in L-NAME-treated chickens (5th and 4th weeks, respectively), in L-NAME/L-arginine-treated group only the mild focal myocardial degeneration was seen. According to the most of the results of present investigation, it was concluded that the consecutive treatment with L-NAME provoked ascites - PHS, while L-arginine has protective effect in this animal model of disease.

Heritability of sudden death syndrome and its associated correlations to ascites and body weight in broilers

(1) Genetic parameters for the sudden death syndrome (SDS) were estimated in meat-type chickens. Data were collected over 11 generations of selection for body weight within two distinct breeds (Cornish and White Rock). (2) The animal model was used exclusively with linear methods (LM) to estimate genetic parameters. Heritability (h2) of SDS on the liability scale was 0.30 +/- 0.002 and 0.25 +/- 0.002 in the Cornish and White Rock breeds, respectively. (3) A positive genetic correlation (r(g)) with ascites (AS) was determined (approximately 0.3 +/- 0.006). However, it was not possible to estimate the rg of SDS with body weight because of the low prevalence of the defect trait studied (1.8% in the Cornish and 1-5% in the White Rock). (4) Heritability of SDS calculated using male records only was 0.45 +/- 0.009 and 0.35 +/- 0.009, and r(g) with body weight was 0.30 +/- 0.010 and 0.27 +/- 0.009, in the Cornish and White Rock breeds, respectively. (5) In conclusion, the heart defect investigated was heritable with a positive genetic correlation with AS and body weight.

Genetic parameters of ascites-related traits in broilers: correlations with feed efficiency and carcase traits

(1) Pulmonary hypertension syndrome followed by ascites is a metabolic disorder in broilers that occurs more often in fast-growing birds and at cool temperatures. (2) Knowledge of the genetic relationships among ascites-related traits and performance traits like carcase traits or feed efficiency traits is required to design breeding programmes that aim to improve the degree of resistance to ascites syndrome as well as production traits. The objective of this study was to estimate these genetic correlations. (3) Three different experiments were set up to measure ascites-related traits (4202 birds), feed efficiency traits (2166 birds) and carcase traits (2036 birds). The birds in different experiments originated from the same group of parents, which enabled the estimation of genetic correlations among different traits. (4) The genetic correlation of body weight (BW) measured under normal conditions and in the carcase experiment with the ascites indicator trait of right ventricle to total ventricle ratio (RV:TV) measured under cold conditions was 0.30. The estimated genetic correlation indicated that single-trait selecting for BW leads to an increase in occurrence of the ascites syndrome but that there are realistic opportunities of multi-trait selection of birds for improved BW and resistance to ascites. (5) Weak but positive genetic relationships were found between feed efficiency and ascites-related traits suggesting that more efficient birds tend to be slightly more susceptible to ascites. (6) The relatively low genetic correlation between BW measured in the carcase or in the feed efficiency experiments and BW measured in the ascites experiment (0.49) showed considerable genotype by environment interaction. (7) These results indicate that birds with high genetic potential for growth rate under normal temperature conditions have lower growth rate under cold-stress conditions due to ascites.

Prophylactic action of lipoic acid on oxidative stress and growth performance in broilers at risk of developing ascites syndrome

The objective of this study was to assess the effects of dietary supplementation with lipoic acid (LA) on broilers maintained at 2235 m above sea level with high risk to develop ascites syndrome (AS). A total of 2040 chicks were fed under commercial conditions with water and specific diets ad libitum during 7 weeks in two consecutive experiments. Mortality and indicators of performance and oxidative stress were compared weekly in broilers fed a basal diet plus 0, 10, 20, or 40 parts/10(6) LA. The effects of LA at 40 parts/10(6) were also studied during the initial 3 weeks or the last 4 weeks of the production cycle. Diets supplemented with 40 parts/10(6) of LA during 7 weeks significantly improved feed conversion, decreased general mortality and mortality attributable to AS, and lowered thiobarbituric acid reactive substances and hydroxyl radicals in liver, and increased total glutathione pool. Smaller doses or shorter periods of exposure to LA were partially effective. In conclusion, LA under our experimental conditions has a prophylactic action in broilers with high risk to develop AS due to oxygen availability limitation.

[Resolution of ascites after successful balloon dilatation of cortriatriatum dexter in a dog]

A 9-month-old male American Cocker Spaniel was examined for progressive abdominal distension, tachypnoea, and decreased appetite. Physical examination revealed signs of congestion in the caudal body half only (ascites, congested saphenic vein), and abdominocentesis yielded a modified transudate. Echocardiography revealed an abnormal membrane in the right atrium and cor triatriatum dexter was diagnosed; the diagnosis was confirmed by cardiac catheterization. Successful treatment consisted of balloon dilatation of the pinpoint opening in the abnormal membrane. The dog recovered well, with the ascites resolving within a week, and its further development was normal.

Isolation and characterization of virulent yellowtail ascites virus

Yellowtail ascites virus (YTAV) is the causative agent of ascites and deformity in fish and causes serious losses to the fish-farming industry of yellowtail fry and fingerling Seriola quinqueradiata in Japan. In 2006, cultured yellowtail died from ascites in Kochi, Japan. We isolated and characterized a virus from the diseased fish. Based on the pathogenicity, culture characteristics, morphological features, RT-PCR results targeting VP2/NS region, phylogeny based on the VP1 amino acid sequence, and immunochemical reactivity of structural proteins, the virus isolate was identified as YTAV (designated as YTAV-06). YTAV-06 was a more virulent isolate than YTAV Y-6, isolated originally from yellowtail with ascites. To our knowledge, this is the first report describing that YTAV isolates may vary in their virulence.

Increased calcium deposits and decreased Ca2+-ATPase in right ventricular myocardium of ascitic broiler chickens

Right ventricular hypertrophy and failure is an important step in the development of ascites syndrome (AS) in broiler chickens. Cytoplasmic calcium concentration is a major regulator of cardiac contractile function and various physiological processes in cardiac muscle cells. The purpose of this study was to measure the right ventricular pressure and investigate the precise ultrastructural location of Ca(2+) and Ca(2+)-ATPase in the right ventricular myocardium of chickens with AS induced by low ambient temperature. The results showed that the right ventricular diastolic pressure of ascitic broilers was significantly higher than that of control broilers (P < 0.01), and the maximum change ratio of right intraventricular pressure (RV +/- dp/dt(max)) of ascitic broilers was significantly lower than that of the controls (P < 0.01). Extensively increased calcium deposits were observed in the right ventricular myocardium of ascitic broilers, whereas in the age-matched control broilers, calcium deposits were much less. The Ca(2+)-ATPase reactive products were obviously found on the sarcoplasmic reticulum and mitochondrial membrane of the control right ventricular myocardium, but rarely observed in the ascitic broilers. The data suggest that in ascitic broilers there is the right ventricular diastolic dysfunction, in which the overload of intracellular calcium and the decreased Ca(2+)-ATPase activity might be the important factors.

Spontaneous peritoneal malignant mesothelioma in a geriatric japanese macaque (Macaca fuscata)

A 28.5-year-old female Japanese macaque (Macaca fuscata) was euthanatized because of abdominal distension due to severe ascites. Nodular lesions of varying sizes up to 5 mm in diameter were distributed diffusely on the surface of the omentum, mesentery and parietal peritoneum. No neoplastic masses were detected in any visceral organ. The nodules were composed of proliferation of mono- or multi-layered epithelial-like cells occasionally showing papillary growth and sheets of small round or polygonal cells. Signet ring-like cells and tubular structures were occasionally present. Neoplastic cells were strongly positive to cytokeratin, and occasionally to vimentin. Based on gross and histopathological findings, this tumor was diagnosed as an epithelial type of peritoneal malignant mesothelioma, the first reported case in the non-human primates.

Development of Ascites-Resistant and Ascites-Susceptible Broiler Lines

The rapid growth of modern broilers is associated with enhanced appetite and high metabolic rate and, consequently, high O(2) demand. Ascites syndrome (AS) develops in individuals that fail to fully supply the increasing demand for O(2) in their bodies under ascites-inducing conditions (AIC) such as high altitude or low temperatures. The tendency of broilers to develop AS is heritable, but efficacious selection against AS susceptibility (without affecting the normal expression of other important traits) requires identification of indirect selection criteria. In the present study, divergent AS-susceptible (AS-S) and AS-resistant (AS-R) lines were developed to confirm the heritability of AS and to facilitate future detection of criteria for indirect selection against AS susceptibility. The base population consisted of 85 sire families with a mean of 73 progeny per sire, reared in a commercial broiler house under low-challenge AIC (cold environment and pelleted feed). Chicks dying with AS manifestations were designated AS-susceptible, whereas the surviving birds were designated AS-resistant. By the end of the trial (d 48), AS mortality had accumulated to 17.2%, but AS incidence per family (%ASF) ranged from 0 to 49%, with a high heritability (0.57). Parents of 7 families with very high %ASF produced the first generation (S(1)) of the AS-S line, and parents of 7 families with very low %ASF produced the S(1) of the AS-R line. The S(1) males and females reproduced generation S(2) of the selected lines, whereas additional S(1) males were tested under high-challenge AIC (individual cages, cool wind, and pelleted feed). Progeny testing under this high-challenge AIC, followed by sib selection, was repeated in generations S(2) and S(3), resulting in a divergence of 86.6% in the incidence of AS between the AS-S (91.3%) and AS-R (4.7%) lines. The rapid genetic divergence, and family analysis of %ASF suggested that a single or few major genes are responsible for the difference between the 2 selected lines. These lines may facilitate more sensitive and effective genomic research aimed at detecting these genes or identifying the primary physiological cause of AS.

Evaluation of Growth Rate, Body Weight, Heart Rate, and Blood Parameters as Potential Indicators for Selection Against Susceptibility to the Ascites Syndrome in Young Broilers

The continuous selection for rapid growth has been accompanied by an increasing occurrence of ascites syndrome (AS), which develops in broilers failing to supply the increasing demand for O(2) in their bodies. Moderate heritability has been reported for AS in broiler populations, suggesting that selection against AS is feasible. However, direct selection based on AS mortality requires exposure of candidate birds to AS-inducing conditions (AIC), which hinder selection for performance traits. Noninvasive indicators of AS, expressed under standard husbandry, may facilitate the integration of selection against AS into breeding programs. This study was designed to look for differences in heart rate, hematocrit, O(2) saturation of hemoglobin in arterial blood (SaO(2)), BW, and weight gain, all measured at early ages under standard brooding conditions, between birds that later developed AS and those that remained healthy under AIC, and to estimate the heritability of these AS-related parameters and their genetic correlation with the tendency of broilers to develop AS. The experimental population was derived from a broiler dam line. Male progeny of 34 half-sib sire families were reared under standard brooding conditions to 19 d of age, then under an AIC protocol consisting of housing in individual cages, cool air high-speed ventilation, and growth enhancement using high-energy pelleted feed and 23 h/d of light. Birds were necropsied upon mortality or at the end of the trials and were recorded as being susceptible, with manifestations of AS (SUS), or resistant and healthy (RES). About 44% developed AS, confirming the efficacy of the novel AIC protocol. The SUS and RES chicks did not differ in BW and weight gain up to 19 d of age, suggesting that there was no association between AS susceptibility and rapid early growth. The SUS chicks exhibited lower SaO(2) and heart rate than the RES chicks. Moderate heritability was estimated for all traits, but only SaO(2) exhibited consistently significant genetic correlation (-0.5) with AS, suggesting that it may serve as an early indicator for selection against AS, albeit with a limited efficacy.

Effects of dietary L-carnitine and coenzyme Q10at different supplemental ages on growth performance and some immune response in ascites-susceptible broilers

Effects of dietary L-carnitine and coenzyme Q10 (CoQ10) at different supplemental ages on performance and some immune response were investigated in ascites-susceptible broilers. A 3 x 2 x 2 factorial design was used consisting of L-carnitine supplementation (0, 75, and 100 mg/kg), CoQ10 supplementation (0 and 40 mg/kg) and different supplemental ages (from day 1 on and from day 10 on). A total of 480 one-day-old Arbor Acre male broiler chicks were randomly allocated to 12 groups, every group had five replicates, each with eight birds. The birds were fed a corn-soybean based diet for six weeks. From day 10-21, all the birds were exposed to a low ambient temperature (12-15 degrees C) to increase the susceptibility to ascites. No significant effects were observed on growth performance by L-carnitine, CoQ10 supplementation, and different supplemental ages. Packed cell volume was significantly decreased by L-carnitine supplementation alone, and ascites heart index and ascites mortality were decreased by L-carnitine, CoQ10 supplementation alone, and L-carnitine + CoQ10 supplementation together (p < 0.05). Heart index of broilers was significantly improved by L-carnitine, CoQ10 supplementation alone during 0-3 week. Serum IgG content was improved by L-carnitine supplementation alone (p < 0.05), but lysozyme activity was increased by L-carnitine + CoQ10 supplementation together (p < 0.05). A significant L-carnitine by supplemental age interaction was observed in lysozyme activity. L-carnitine supplementation alone had no effects on the peripheral blood lymphocyte (PBL) proliferation in response to concanavalin A (ConA) and lipopolysaccharide, but supplemental CoQ10 alone and L-carnitine+ CoQ10 together decreased the PBL proliferation in response to ConA (p < 0.05). The present study suggested that L-carnitine + CoQ10 supplementation together had positive effects on some immune response of ascites-susceptible broilers, which might benefit for the reduction of broilers' susceptibility to ascites.

Echocardiographic characteristics of chickens with ascites syndrome

1. B- and M-mode echocardiography was used to compare cardiac function in broilers with spontaneous ascites syndrome with that of normal chickens. 2. Thirty ascitic chickens and 15 normal chickens aged three, 4, 5, and 6 weeks from the same flock (180 birds in total) were examined. They were restrained gently in a natural standing position, and echocardiographs were obtained from a 7.0-MHz linear transducer placed on the left pectoral apterium. Indices of cardiac structure and functioning were calculated from the echocardiographs, and some were normalised to body weight. Heart rate was also measured. 3. All cardiac structural indices in both ascitic and normal chickens increased with age. Compared with normal chickens, right ventricular diameter at the end of systole in ascitic chickens was greater at 4, 5 and 6 weeks of age. Ventricular septal thickness at the end of both systole and diastole was greater in ascitic chickens at 5 and 6 weeks. Left ventricular free wall thickness at the end of diastole was less in ascitic chickens at 3 weeks. However, all the structural indices decreased with age after normalisation with body weight. 4. The heart rate of ascitic chickens was lower at 4, 5 and 6 weeks. Normalised left ventricular fractional shortening was lower in ascitic chickens at 4, 5 and 6 weeks, as was normalised right ventricular fractional shortening. Incrassation of the ventricular septum (Delta T), which changed little in normal chickens, was less at 4, 5 and 6 weeks in ascitic chickens. Left ventricular fractional shortening, right ventricular fractional shortening and Delta T were all negatively correlated with ascites heart index at all ages. 5. Taken together the results suggest heart failure of both ventricle, but that right ventricular dysfunction is more extensive than left ventricular dysfunction. We suggest that secondary pulmonary hypertension would result in these ascitic chickens due to volume overload.

Segregation analysis of blood oxygen saturation in broilers suggests a major gene influence on ascites

1. Blood oxygen saturation (SaO) is a potential indicator trait for resistance to ascites in chickens. 2. The objective of the study was to investigate the genetic architecture of SaO in a meat-type chicken line reared in commercial conditions. 3. Data were collected over 15 generations of selection and were divided into two data sets on the basis of a change in recording age from 6 to 5 weeks of age, approximately halfway through the period. The resulting pedigrees comprised in excess of 90,000 birds each and, on average, 12% of these birds had SaO records. 4. Segregation analyses of SaO were carried out assuming a mixed inheritance model that included a major locus segregating in a polygenic background. 5. The analyses suggest that a major gene is involved in the genetic control of SaO in this line. The putative gene acts in a dominant fashion and has an additive effect of around 0.90 sigma(p), equivalent to a predicted difference in SaO between the two homozygous classes of more than 10%. The frequency of the allele that increases SaO changed from 0.53 to 0.65 from the first to the second set of data, consistent with selection on SaO scores. 6. Using estimated genotype probabilities at the putative major locus, we inferred that it acts in an overdominant fashion on body weight and fleshing score. If the low SaO allele leads to susceptibility to ascites, its combined effects are consistent with it being maintained in the population by a balance of natural selection on fitness nad artificial selection on growth and carcase traits. 7. Even with selection on both SaO and growth traits, the combined genotypic effects would make it difficult to remove the unfavourable low-SaO allele by means of traditional selection without the use of genetic markers.

Genetic parameters for blood oxygen saturation, body weight and breast conformation in 4 meat-type chicken lines

1. The objective of the study was to explore the genetic architecture of blood oxygen saturation (SaO) (an indicator trait, negatively correlated with ascites susceptibility), body weight (Weight) and fleshing score (Flesh, a measure of breast conformation) for 4 meat-type chicken lines reared in commercial conditions. 2. Genetic components, including heritabilities and genetic correlations, were estimated by Restricted Maximum likelihood for these traits measured at 6 weeks of age. 3. Data were collected over eight generations of selection and pedigrees comprised in excess of 130,000 birds. 4. Univariate analyses were performed to allow model definition and to obtain starting values for trivariate analyses. The basic model included a random animal effect and, in further models explored, a maternal environmental effect or a genetic maternal effect or both were fitted. Models were compared using likelihood ratio tests. 5. Estimated heritabilities for SaO ranged from 0.1 to 0.2, and there was no evidence of genetic maternal effects for SaO. The environmental maternal component was significant for one of the populations only. Estimated heritabilities for both Weight and Flesh were between 0.2 and 0.4, and there was evidence of environmental and genetic maternal effects for these traits in all populations. 6. Genetic correlations between SaO and Weight and between SaO and Flesh were low and negative. This suggests that, in principle, genetic selection to simultaneously increase SaO, and therefore decrease ascites susceptibility, and WEight and Flesh could be performed using traditional (marker-free) selection methods. We discuss how a putative interaction between ascites and production traits could jeopardise the success of such methods.

Generation of hydroxyl radicals during ascites experimentally induced in broilers

Increased metabolic rates, pulmonary hypertension and cardiac dysfunction are the most important features of the ascites syndrome in broiler chickens. However, the mechanism of cell injury causing the pathogenesis of the syndrome is not clearly understood. Our study aimed to examine the generation of hydroxyl radicals (OH*) in broiler chickens experiencing ascites. The hundred and fifty 1-d-old chickens were purchased from a local hatchery and reared in an open poultry house for 46 d. They were divided at random into three groups and ascites was induced in two groups by exposing them to low temperature or administration of triiodothyronine (T(3)). The third group served as control and was reared normally. Haematological, biochemical and pathological tests were used to determine the incidence of ascites: including total red blood cell (RBC), packed cell volume (PCV), release of alanine transaminase (ALT) and aspartate transaminase (AST) and ratio of right ventricular weight to total ventricular weight (RV/TV). A salicylate hydroxylation method was used to examine the generation of hydroxyl radicals (OH*) in treated groups. TWo hydroxylated salicylic acid metabolites, 2,3- and 2,5-dihydroxy benzoic acid (2,3- and 2,5-DHBA), were measured by HPLC to detect the generation of OH*. An ascites syndrome was observed in T(3) and low-temperature treated groups, as shown by necropsy changes and increases in f RBC, PCV, ALT, AST and the ratio of RV/TV. Concentrations of 2,3- and 2,5-DHBA were increased in groups experiencing ascites compared to control group. It is suggested that reactive oxygen species that is OH* ions, may be involved in the pathogenesis of the ascites syndrome in broiler chickens.

Exocrine pancreatic carcinoma and carcinomatosis with abdominal effusion containing mast cells in a ferret (Mustela putorius furo)

This case describes the clinical presentation and findings of exocrine pancreatic carcinoma in a 9-year-old female sprayed ferret (Mustela putorius furo). Transcoelomic metastasis and hemorrhagic abdominal effusion were secondary to the neoplasm. The finding of mast cells in abdominal effusion, with a leukocyte component composed primarily of lymphocytes and lesser numbers of neutrophils and macrophages, is an atypical finding, never before reported in ferrets.

Effects of dietary coenzyme Q10supplementation on hepatic mitochondrial function and the activities of respiratory chain-related enzymes in ascitic broiler chickens

1. One hundred and sixty 1-d-old Arbor Acre male broiler chicks were fed with maize-soybean based diets for 6 weeks in a 2 x 2 factorial experiment. The factors were CoQ10 supplementation (0 or 40 mg/kg) and Escherichia coli lipopolysaccharide (LPS) challenge (LPS or saline). 2. CoQ10 was supplemented from d 1. From d 18, the chickens received three weekly i.p. injections of LPS (1.0 mg/kg BW) or an equivalent amount of sterile saline as control. From d 10 on, all chickens were exposed to low ambient temperature (12 to 15 degrees C) to induce ascites. 3. The blood packed cell volume and ascites heart index of broiler chickens were reduced by dietary CoQ10 supplementation. Mitochondrial State 3 and State 4 respiration, respiratory control ratio and phosphate oxygen ratio were not changed, but H+/site stoichiometry of complex II + III was elevated by dietary CoQ10 supplementation. 4. Cytochrome c oxidase and H+-ATPase activity were increased by CoQ10 supplementation, whereas NADH cytochrome c reductase and succinate cytochrome c reductase were not influenced. Mitochondrial anti-ROS capability was increased and malondialdehyde content was decreased by CoQ10 supplementation. 5. The work suggested that dietary CoQ10 supplementation could reduce broiler chickens' susceptibility to ascites, which might be the result of improving hepatic mitochondrial function, some respiratory chain-related enzymes activities and mitochondrial antioxidative capability.

Early-age housing temperature affects subsequent broiler chicken performance

The influence of housing temperature in early life on subsequent growth and development of broiler chickens was investigated. Hatchlings were exposed to an ambient temperature of 34 degrees C (NT) or 28 degrees C (LT) on d 1. Both temperature regimes decreased with 1 degrees C per day for 5 d. At d 6 the ambient temperature of the LT group was increased to the same ambient temperature as the NT group. At d 29 all chickens were exposed to 10 degrees C for 7 d. Navel temperature was lower in the LT group than in the NT group from d 2 to 5. Body weight of the chickens was higher in the NT group than in the LT group and the difference between both groups increased in time. Temperature treatment during the early post-hatching period did not result in a long-term alternation in organ development, haematocrit value, energy and protein metabolism or the occurrence of ascites. Although not significantly, the course of metabolism suggested that early thermal treatment had long-term effects. Before cold treatment in week 5, the NT group showed higher values for energy and protein metabolism than the LT group, but during cold exposure, the opposite was found. We concluded that exposure of chickens to a moderate reduction in house temperatures during early post-hatching life seemed to have long-term negative effects on the performance of these chickens, but, on the other hand, it seemed that these chickens were better prepared to withstand cold challenge later in life.

A bivariate mixture model analysis of body weight and ascites traits in broilers

The objective of the present study was to use bivariate mixture models to study the relationships between body weight (BW) and ascites indicator traits. Existing data were used from an experiment in which birds were housed in 2 groups under different climate conditions. In the first group, BW, the ratio of right ventricular weight to total ventricular weight (RV:TV), and hematocrit value (HCT) were measured in 4,202 broilers under cold conditions; in the second group, the same traits were measured in 795 birds under normal temperature conditions. Cold-stress conditions were applied to identify individuals that were susceptible to ascites. The RV:TV and HCT were approximately normally distributed under normal temperature conditions, whereas the distributions of these traits were skewed under cold temperature conditions, suggesting different underlying distributions. Fitting a bivariate mixture model to the observations showed that there was only one homogeneous population for ascites traits under normal temperature conditions, whereas there was a mixture of (2) distributions under cold conditions. One distribution contained nonascitic birds and the other distribution contained ascitic birds. In the distribution of nonascitic birds, the inferred phenotypic correlations (phenotypic correlations with 2 distinguishing underlying distributions) of BW with RV:TV and HCT were close to zero (0.10 and -0.07, respectively), whereas in the distribution of ascitic birds, the inferred phenotypic correlations of BW with RV:TV and HCT were negative (-0.39 and -0.4, respectively). The negative inferred correlations of BW with RV:TV and HCT in the distribution of ascitic birds resulted in negative overall correlations (correlations without 2 distinguishing distributions) of BW with RV:TV (-0.30) and HCT (-0.37) under cold conditions. The present results indicate that the overall correlations between BW and ascites traits are dependent on the relative frequency of ascitic and nonascitic birds in the population.

The identification of matrix metalloproteinases and their tissue inhibitors in broiler chickens by immunohistochemistry

The aim of this study was to investigate the distribution of matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitor of matrix metalloproteinase (TIMP)-1 and TIMP-2 using immunohistochemistry in the ascites syndrome of broiler chickens in a salt-induced experimental model. The presence of the enzymes in the lung, heart, liver, kidney and brain was evaluated semi-quantitatively with the streptavidin-biotin-peroxidase (Strep-ABC) method using commercially available primary monoclonal antibodies. Immunostaining of MMP-2 and MMP-9 was more intense and extensive in ascitic broilers than in the controls, although a decrease was seen with increasing age both in normal and ascitic chickens. The presence of MMP-9 enzyme was negatively correlated with the presence of TIMP-1 enzyme. It is suggested that MMP-2 and MMP-9 enzymes might play a role in the permeability increase of vessel walls by the destruction of the basement membranes in the salt-induced experimental ascites syndrome in broiler chickens.

Effects of early feed restriction and cold temperature on lipid peroxidation, pulmonary vascular remodelling and ascites morbidity in broilers under normal and cold temperature

Two experiments were conducted to evaluate the effects of early feed restriction on lipid peroxidation, pulmonary vascular remodelling and ascites incidence in broilers under normal and low ambient temperature. In experiment 1, the restricted birds were fed 8h per day either from 7 to 14 d or from 7 to 21 d, while the controlled birds were fed ad libitum. In experiment 2, the restricted birds were fed 80 or 60% of the previous 24-h feed consumption of full-fed controls for 7 d from 7 to 14 d. On d 14, half of the birds in each treatment both in experiment 1 and experiment 2 were exposed to low ambient temperature to induce ascites. Body weight and feed conversion ratio were measured weekly. The incidences of ascites and other disease were recorded to determine ascites morbidity and total mortality. Blood samples were taken on d 14, 21, 28, 35 and 42 to measure the plasma malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). On d 42, samples were taken to determine the right/total ventricular weight ratio (RV/TV), vessel wall area/vessel total area ratio (WA/TA) and mean media thickness in pulmonary arterioles (mMTPA). Low-temperature treatment increased plasma MDA concentration. When broilers were exposed to a cool environment for 3 weeks, plasma SOD and GSH-Px activity were decreased compared with normal-temperature chicks. RV/TV, WA/TA and mMTPA on d 42 were increased in birds exposed to cold, consistent with the increased pulmonary hypertension and ascites morbidity. Early feed restriction markedly decreased plasma MDA concentration. The plasma SOD and GSH-Px activity of feed-restricted birds were markedly higher than those fed ad libitum on d 35 and d 42. All early feed restriction treatments reduced ascites morbidity and total mortality. On d 42, the RV/TV, WA/TA and mMTPA of feed-restricted broilers were lower than that of the ad libitum-fed broilers. The results suggested that early feed restriction alleviated the lipid peroxidation, promoted the activity of enzymatic antioxidant and inhibited pulmonary vascular remodelling. These changes might be associated with reduced ascites incidence.

Comparison of three lines of broiler breeders differing in ascites susceptibility or growth rate. 1. Relationship between acoustic resonance data and embryonic or hatching parameters

Ascites is a prevalent cardiovascular disease among modern broilers with negative impacts on production and animal welfare. The peak of mortality due to ascites occurs at the end of the growing period, but the etiology of this problem may start during embryonic development. A few recent reports have demonstrated that the signs of ascites susceptibility are manifested during the late stages of incubation. In the current study, we used a nondestructive method based on egg acoustic resonance parameters [resonant frequency (RF) and damping] to establish a relationship between embryo physiological events during early development in broiler eggs and susceptibility to ascites. The hatching eggs of 3 broiler lines differing in ascites susceptibility were used for this study: ascites-resistant dam line (DAR), ascites-sensitive dam line (DAS), and ascites-sensitive sire line (SASL). These lines were selected on the basis of fast growth, high breast meat yield, and ascites induction at low temperatures such that the order of ascites susceptibility in terms of mortality was SASL >> DAS > DAR. Eggs were incubated under standard conditions in forced-draft incubators. We measured egg weights at setting, albumen pH, Haugh units (HU) at setting, and embryo weights at d 11 and 18, at internal pipping (IP), and at hatch. The durations of IP, external pipping (EP), and hatching were also determined. At 2 hourly periods during incubation, egg RF and damping were also measured. There were differences in egg weights between DAR and SASL vs. DAS, but albumen HU, albumen pH, and the ratio of yolk weight to egg weight were similar. There were differences in RF, damping, embryonic growth rates, and hatching events. Changes in resonant frequency and damping, which certainly suggest eggshell differences among lines, were not totally related to variations in physiological events during early and late embryonic development. A comparison between DAR and DAS, between DAS and SASL, or DAR and SASL indicates that sensitivity to ascites and selection for rapid growth rate in ascites-sensitive lines have different effects on embryonic parameters. We concluded that the sensitivity of broiler breeders to ascites does not influence egg internal quality, but the occurrence of ascites sensitivity in broilers could not be reliably predicted by early in ovo acoustic resonance parameters and hatching events.

Comparison of three lines of broilers differing in ascites susceptibility or growth rate. 2. Egg weight loss, gas pressures, embryonic heat production, and physiological hormone levels

Ascites is a metabolic disorder that accounts for over 25% of overall mortality in the broiler industry. This disorder is manifested between wk 5 and 6 posthatch, but there are previous indications that predisposition may be identified during embryonic development. In this current study, we determined embryonic physiological and metabolic parameters that may be associated with ascites predisposition. For this purpose, we used broiler eggs from 3 lines that differed in ascites sensitivity. These included an ascites-sensitive dam line (DAS), an ascites-resistant dam line (DAR), and an ascites-sensitive sire line (SASL). Eggs were incubated for 21 d under standard conditions. The following parameters were measured during incubation: egg weights at setting, egg weight losses at 18 d, embryo body weights and embryo heart weights throughout development, air cell partial gas pressures (pCO2 and pO2) levels at d 18 and at internal pipping (IP); plasma triiodothyronine, thyroxine, and corticosterone levels at d 18, IP, and hatch; heat production from d 17 until hatch, hematocrit values at hatch, and posthatch growth rate to 7 d along with hematocrit values. The data obtained revealed that selection for ascites sensitivity or rapid growth rate had no consistent influence on some of these parameters such that they could be wholly associated with ascites sensitivity for predictive purposes. Whereas differences in embryonic developmental patterns were apparent throughout embryonic development, these differences in physiological and metabolic parameters may be due partly to genetic differences unrelated to ascites sensitivity.

Hypobaric hypoxia in ascites resistant and susceptible broiler genetic lines influences gut morphology

Genetic selection based on rapid growth rates, improved feed conversion, and increased body weights has led to a predisposition to ascites in broiler populations. Sire-family selection was applied to a commercial elite line to produce divergent lines of ascites-resistant (RES) and ascites-susceptible (SUS) broilers by the 8th generation. One objective of this research was to determine the effects of hypobaric hypoxia on gut morphology in these genetic lines. In two separate trials, pedigree broiler chickens were randomly assigned to cages in a hypobaric chamber (simulated 2,900 m above sea level) or a matching local altitude chamber (390 m above sea level). Ascites incidence was characterized by heart enlargement and fluid accumulation in the abdominal cavity. At the end of the study on d 42, all surviving birds were killed and evaluated for the presence of ascites and 2-cm sections from the duodenum and lower ileum were collected from 5 chickens per line, per altitude for each trial for morphometric analysis. At a high altitude, ascites incidence was lower in the RES line (20.9 and 3.7%) than in the SUS line (86.4 and 66.9%, Trials 1 and 2, respectively). No ascites was observed at a local altitude. Under hypoxic conditions, duodenum villus surface area was higher (P < 0.05) in the RES line (181.3 +/- 16.8 and 219 +/- 10.9 microm) compared with the SUS line (130.1 +/- 10.5 and 134.3 +/- 9.3 microm; Trials 1 and 2, respectively). No differences in ileum villus morphology were observed for any of the parameters measured. The reduced surface area in the duodenum of birds selected for ascites susceptibility suggests reduced enteric function and may provide clues as to why these birds have increased incidence of ascites.

Effect of prebiotic on gut development and ascites incidence of broilers reared in a hypoxic environment

Modern broilers have been genetically selected for an increased growth rate and improved feed conversion, but they are also more susceptible to ascites. Ascites occurs when there is an imbalance between available oxygen and the oxygen demand of the broiler. We hypothesized that promoting neonatal gut development with a prebiotic, such as Aspergillus meal (Prebiotic-AM), would enhance gut efficiency, decrease the oxygen demand of the gut, and reduce ascites incidence. In this study, we compared the effect of Prebiotic-AM on ascites incidence and gut development in commercial broilers reared at a local altitude (390 m above sea level) and a simulated high altitude (2,900 m above sea level). Half of the birds received a National Research Council recommended corn-soybean ration, and the other half received the same ration supplemented with 0.2% Prebiotic-AM. These 2 groups were further divided into a local altitude group and a simulated high altitude group for a total of 4 treatment combinations. Tissues were collected on d 1, 3, 7, 14, and 21 from the duodenum and lower ileum and placed in 10% buffered formalin for morphometric analysis. At a simulated high altitude, ascites incidence was 68% for birds fed the Prebiotic-AM supplement compared with 92% ascites incidence in birds given the control feed. The simulated high altitude decreased (P < 0.05) gut development, but prebiotic-treated birds reared in hypoxic conditions had similar gut development to control birds reared at local altitude. These data suggest that a feed ration supplemented with Prebiotic-AM may reduce the effect of hypoxia on broiler gut development and ascites incidence.

Differential expression of cardiac muscle mitochondrial matrix proteins in broilers from ascites-resistant and susceptible lines

Ascites is a metabolic disorder of modern broilers that is distinguished by cardiopulmonary insufficiency in the face of intense oxygen demands of rapidly growing tissues. Broilers with ascites exhibit sustained elevation of pulmonary arterial pressure and right ventricular hypertrophy, the end result of which is heart failure. It has been shown that mitochondrial function is impaired in broilers with ascites. In the current study, mitochondrial matrix protein levels were compared between ascites-resistant line broilers and ascites-susceptible line broilers with and without ascites using two-dimensional (2-D) gel electrophoresis. One hundred seventy-two protein spots were detected on the gels, and 9 of the spots were present at different levels in the 4 groups of broilers. These 9 protein spots were selected for identification by mass spectrometry. Two of the spots were found to contain single mitochondrial matrix proteins. Both mitochondrial matrix proteins, the dihydrolipoamide succinyltransferase component of the 2-oxoglutarate dehydrogenase complex and the alpha-subunit of mitochondrial trifunctional enzyme, were present at higher levels in ascites-resistant line broilers with ascites in the present study. The elevated levels of 2 key proteins in aerobic metabolism in ascites-resistant line broilers with ascites observed in the present study suggests that the mitochondria of broilers with this disease may respond inappropriately to hypoxia.

Anatomical parameters of cardiopulmonary system in three different lines of chickens: further evidence for involvement in ascites syndrome

The present study was designed to compare the anatomical parameters of the cardiopulmonary system in three different lines of chickens with different susceptibility to ascites syndrome. Eggs from three different genetic lines-commercial broiler and layer lines and one native to Iran--were incubated and hatched, and 1-day-old chicks used. The relative heart and lung weights, the volumes of the heart, lung and thorax cavity, the incidence of ascites, and the related physiological parameters in these chickens were followed. Lung weight as a percentage of body weight, the relative lung and heart volume, and the volumes of the thorax cavity, before and after removing heart and lung tissues, were lower in fast-growing broiler chickens compared with the layer and native chickens. Additionally, most of these parameters (e.g. relative lung weight, lung volume and thorax cavity) were significantly decreased with age in broiler chickens but were increased in layer and native chickens, which was concomitant with the incidence of ascites in broiler chickens. Our data indicate that all cardiopulmonary parameters investigated are extremely unfavourable to broiler chickens and suggest a reduction in gas exchange area in broilers, and therefore higher susceptibility to pulmonary hypertension and ascites.

Genetic parameters of ascites-related traits in broilers: effect of cold and normal temperature conditions

(1) Ascites syndrome is a growth-related disorder of broilers that occurs more often in fast-growing birds and at low temperatures. The objective of this study was to estimate genetic and phenotypic correlations among ascites-related traits measured either under cold or under normal temperature conditions, and to estimate genetic correlations between ascites-related traits measured under cold and normal conditions. (2) Several traits related to ascites were measured on more than 4000 chickens under cold conditions and on more than 700 chickens under normal conditions. (3) The heritability estimates for body weight (BW) measured under cold and normal conditions were 0.42 and 0.50, respectively, for haematocrit value 0.46 and 0.17, respectively, and for ratio of right to total ventricular weight 0.45 and 0.12, respectively. (4) The genetic correlation between BW and haematocrit value under cold conditions was -0.23 and between BW and ratio of right to total ventricular weight -0.27. Under normal conditions, however, these genetic correlations were 0.55 and 0.50, respectively. (5) These results demonstrate that the heritability estimates of ascites-related traits as well as genetic correlations between ascites-related traits and BW depend on the temperature conditions under which animals are kept. (6) Strong positive genetic correlations (around 0.8) were observed between total mortality, fluid in the abdomen and ratio of right to total ventricular weight under cold conditions. The genetic correlation between ratio of right to total ventricular weight under cold and normal conditions was 0.91. (7) These results suggest that the ratio of right to total ventricular weight measured under normal temperature conditions might serve as a good indicator trait for ascites.

Flow cytometric analysis of effusions in dogs and cats with the automated haematologyanalyser ADVIA 120

Samples were aspirated from 12 thoracic effusions, 10 abdominal effusions and four pericardial effusions in 17 dogs and nine cats. They were analysed cytometrically with the ADVIA 120 flow cytometer and the results were compared with the results of cytological examinations of May-Grünwald-Giemsa-stained smears. The conventional cytology revealed a purulent or pyogranulomatous inflammation in 12 of the animals, lymphoma in six, malignant histiocytosis in two, and an unspecified carcinoma in two; two animals had a chylous effusion, two had a modified transudate, and one dog had an idiopathic pericardial haemorrhage. The flow cytometric analysis was based on cellular volume, peroxidase staining intensity and the determination of nuclear lobularity, and made it possible to identify predominant cell lineages and cell debris, which were shown in characteristic cytograms. Inflammatory effusions, monocytic proliferation and lymphoma were easily detected, but carcinoma cells and mesothelial cells were classified as 'mononuclear blasts'.

Pathogenesis of Ascites in Broilers Raised at Low Altitude: Aetiological Considerations Based on Echocardiographic Findings

This study reports novel insight into the aetiology of pulmonary hypertension and ascites in broiler chickens. The scope of measurements was focused on anatomical and functional parameters, and blood flow patterns in leghorns (resistant to ascites), fast-growing broilers (susceptible to ascites), broilers developing ascites, and ascitic broilers evaluated in vivo using echocardiography, and further examined in the context of postmortem findings. Both, in vivo observed features and postmortem findings, showed clear differences between broilers and leghorns, and between normal and ascitic broilers. Abnormalities in the heart chamber geometry and blood flow patterns were detected upon echocardiographic examination in all ascitic broilers. Right and left atrio-ventricular (AV) valve regurgitation were common findings in ascitic broilers and some apparently normal broilers, with left AV valve insufficiency being a predominant feature with respect to degree and frequency of occurrence. Blood flow disturbances were not detected in leghorns. Left ventricular fractional shortening (functional parameter) was considerably reduced (P < 0.01) in ascitic birds (mean: 21.7 +/- 2.0 SE) in comparison with normal broilers (mean: 39.1 +/- 3.6 SE), or leghorns (mean: 43.3 +/- 2.4 SE). The presented findings indicate that pathological and functional changes in the left ventricle and atrium play a significant role in the pathogenesis of ascites in broilers. Severe dilation of the left atrium and pulmonary veins seen on postmortem examination, as well as regurgitant blood flow in the left atrium, demonstrated by Doppler study in ascitic birds, provide evidence that chronically elevated pressure in the left atrium is involved in the aetiology of pulmonary hypertension and ascites in fast-growing broilers.

Selection strategies for body weight and reduced ascites susceptibility in broilers

Ascites syndrome is a metabolic disorder in broilers. Mortality due to ascites results in significant economic losses and has a negative impact on animal welfare. It has been shown that genetic factors play a considerable role in susceptibility of birds to ascites, which offers perspectives for selection against this syndrome. The aim of the present study was to evaluate the consequences of alternative selection strategies for BW and resistance to ascites syndrome using deterministic simulation. In addition to the consequences of current selection (i.e., selection for increased BW only) alternative selection strategies including information on different ascites-related traits measured under normal or cold conditions and the consequences of having information on the underlying genes (i.e., MAS) were quantified. Five different breeding schemes were compared based on the selection response for BW, ascites susceptibility, and the rate of inbreeding. Traits investigated in the index as indicators for ascites were hematocrit value (HCT) and ratio of right ventricle to the total ventricular weight of the heart (RV:TV). The results indicated that by ignoring ascites susceptibility in the breeding goal, the gain for BW is 130 g and the birds will become more susceptible to ascites. Testing 50% of the birds under cold temperature conditions and including information of ascites related traits (HCT and RV:TV) measured under normal and cold conditions makes it possible to achieve a relatively high gain for BW (111.4 g) while controlling the genetic level for ascites susceptibility (selection response was 0). The results of scenarios including QTL information of ascites susceptibility showed that QTL information could be used very effectively in controlling ascites susceptibility.

Characterization of equine intestinal fatty acid binding protein and its use in managing horses with colic

OBJECTIVE

To determine the nucleotide sequence of the equine intestinal fatty acid binding protein (I-FABP) gene, its expression in various regions of the gastrointestinal tract, and the use of measuring I-FABP in horses with colic. Animals-86 horses with colic.

PROCEDURE

The mRNA sequence for the I-FABP gene was obtained by use of a rapid amplification of complementary DNA ends technique. Comparative I-FABP gene expression was quantitated by use of a real-time reverse transcription-polymerase chain reaction assay. Amounts of I-FABP in abdominal fluid and plasma were measured by use of an ELISA kit. Association between I-FABP concentrations and clinical variables was performed by nonparametric analysis, and associations of these variables with intestinal ischemia were determined by the Spearman correlation test.

RESULTS

The nucleotide sequence had 87% identity with human I-FABP The I-FABP gene was highly expressed in the small intestinal mucosa but had low expression in the colon. High concentrations of I-FABP in abdominal fluid correlated with an increase in protein concentrations in peritoneal fluid and nonsurvival, whereas plasma I-FABP concentrations correlated with the necessity for abdominal surgery. Clinical variables associated with intestinal ischemia included the color and protein content of abdominal fluid and serum creatine kinase activity.

CONCLUSIONS AND CLINICAL RELEVANCE

Determination of I-FABP concentrations in abdominal fluid and plasma may be useful for predicting survival and the need for abdominal surgical intervention in horses with colic. Furthermore, serum creatine kinase activity and color and protein concentrations of abdominal fluid may be useful in the diagnosis of intestinal ischemia.

A new periparturient disease in Eastern Europe, Clostridium difficile causes postparturient sow losses

Postparturient sow losses caused by Clostridium difficile have not been reported in the veterinary literature. Recently in Croatia, in a large outdoor production unit with suboptimal environmental conditions, a sudden increase in postparturient sow mortality was diagnosed. After postpartal application of enrofloxacine to postparturient mastitis metritis agalactia (MMA) suffering sows, diarrhea, respiratory distress, and mortality of these sows were recorded. While 13% of MMA suffering and treated sows died, only 0.4% of the non-treated (no MMA suffering) sows died postpartum. Gross pathology revealed mesocolonic edema, hydrothorax, and ascites. Microscopic examination showed scattered foci of suppuration in the colonic lamina propria and accumulation of neutrophils and fibrin on colonic mucosa. Anaerobic cultures of the colon yielded heavy growth of C. difficile. Enzyme immunoassay revealed C. difficile toxins A and B. C. difficile infections of postparturient MMA suffering sows may be associated with environmental stress, the application of antibiotics, or both. C. difficile infections are an impending danger in Eastern Europe and does not only raise animal welfare issues, but seriously inflict the economical well being of outdoor production units.