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In ovo injection of camel lactoferrin (cLF36) as an antimicrobial peptide was applied in Ross 308 fertile eggs and tested in 320 post-hatched chickens challenged with Clostridium perfringens (Cp). In 8 treatments and five replicates of 8 birds each, performance, jejunum morphometry and ileal microbial counts of chickens were assayed. Feed intake and feed conversion ratio of the chickens affected by treatments. Together with the positive control group under the Cp (108 cfu/g) challenge and the negative control group under the antibiotic (AB) challenge, the highest villi length was observed. The highest crypt depth was related to the treatment with the Cp challenge and the lowest value was related to the in ovo injection of cLF36 group and combined Cp and AB challenges. The number of Clostridium spp. in the ileal contents increased in the chickens challenged with Cp (P < 0.05). The greatest change was observed in the treatment with injection of cLF36 during the embryonic period and challenge with Cp and the lowest value was related to negative control treatment. In addition, the difference between treatments with cLF36 in ovo injection during the embryonic period and challenge with or without Cp challenge was significantly increased. In the groups under the Cp challenge, the population of E. coli was numerically increased. Based on the obtained results, cLF36, derived from camel milk, could change some of the indices in performance. It caused morphological changes in the villi of ilium and caused a decrease the microbial counts of Clostridium spp., similar to the AB group in the chickens challenged with Cp. Our research attempts to create a new window for in ovo administration of cLF36, according to its beneficial effects in the present study, can be introduced as a candidate for growth-promoting antibiotics. [ABSTRACT FROM AUTHOR]

Background: The goal of this study was to evaluate marker-assisted selection (MAS) in broiler chickens using previously mapped gene regions associated with ascites syndrome incidence. The second-generation MAS products were assessed for impact on ascites phenotype and whether there were associated changes in important production traits. Previously, we used whole genome resequencing (WGR) to fine-map 28 chromosomal regions as associated with ascites phenotype in our experimental ascites broiler line (Relaxed, REL) based on a hypobaric chamber challenge. Genotypes for single nucleotide polymorphisms (SNPs) in mapped regions on chromosomes 2 and 22, were used for MAS in our REL line. After two generations, birds homozygous for the genotypes associated with resistance for both chromosomal regions were established. The MAS F2 generation was then compared to the REL line for ascites susceptibility and 25 production traits. Results: Selection based on SNPs in the carboxypeptidase Q (CPQ, Gga2) and leucine rich repeat transmembrane neuronal 4 (LRRTM4, Gga22) gene regions resulted in a sex- and simulated altitude- dependent reduction of ascites incidence in two F2 cohorts of the MAS line. Comparisons of the F2 MAS and REL lines for production traits when reared at ambient pressure found no significant negative impacts for feed intake (FI), feed conversion ratio (FCR), or deboned part yields for either sex for two F2 cohorts. There were, however, improvements in the MAS for full-trial body weight gain (BWG), FCR, absolute and relative tender weights, and relative drumstick weight. Conclusions: These results validate the mapping of the 28 chromosomal regions and demonstrate that fine mapping by WGR is an effective strategy for addressing a complex trait; it also stands as the first successful SNP-based selection program against a complex disease trait, such as ascites. The MAS line is comparable and, in some instances, superior, in growth performance to the REL control while being more resistant to ascites. This study indicates that MAS based on WGR can provide significant breeding potential in agricultural systems. [ABSTRACT FROM AUTHOR]

NaCl is the main component of freshwater salinization. High NaCl concentration in drinking water can cause pulmonary hypertension syndrome (PHS) and kidney damage in broilers. To explore the effect of NaCl in drinking water on broilers' kidneys, this study divided 80 chickens into four groups. With the control group fed with pure water, broiler chickens were fed with fresh water (FW, NaCl 1 g/L), low salt–contaminated water (L-SCW, NaCl 2.5 g/L), and high salt–contaminated water (H-SCW, NaCl 5 g/L). The results show that ascites heart index (AHI) and hematocrit (HCT) of broilers increase in L-SCW and H-SCW, the serum blood urea nitrogen and creatinine of broilers increase significantly, the kidney index increases, the kidney sections show vacuolar degeneration and fibrotic degeneration, and the TUNEL results show that the kidneys possess obvious apoptosis. In addition, the detection of RAAS-related genes (AGT gene in the liver, REN in the kidney, ACE in the lung) demonstrates that after using salt-contaminated water, the transcription levels of AGT, REN, and ACE rise significantly, and the concentration of angiotensin II (Ang II) also increases significantly. In order to verify the effect of Ang II on broiler kidneys, this research used exogenous Ang II to treat chicken embryonic kidney (CEK) cells. The results show that the cell activity of CEK decreased with the increase of the concentration of exogenous Ang II. Meanwhile, the flow cytometry assay shows that Ang II could promote the apoptosis of CEK cells. These results indicate that the salt-contaminated water can aggravate PHS and cause kidney damage. The mechanism may be related to the increase of Ang II. [ABSTRACT FROM AUTHOR]

Increased blood lactic acid is likely to be involved in the incidence of sudden death syndrome (SDS) in broiler chicken. Guanidinoacetic acid (GAA) with direct or indirect influence on the cardiovascular system may provide, to some degree, protection against lactic acidemia in birds. A total number of 144 male broiler chicks (Ross 308) were used in a complete randomised block design to investigate the effects of dietary supplementation of GAA at 0.6, 1.2, 1.8, 2.4 and 3 g/kg on the physiological response of broiler chicks to an acute lactic acidosis in an 8-days experiment. Birds receiving 1.8 and 3 g/kg GAA exhibited lesser mortality percentage compared with the control birds and those received dietary GAA at 0.6 and 1.2 g/kg (p <.03). Dietary inclusion of 1.2 g/kg GAA to broiler chicks increased serum concentration of uric acid compared to the control birds and those received 2.4 g/kg (p <.02). The mean serum concentration of creatinine was greater in the birds receiving different GAA levels compared with the control birds (p <.0001). The serum concentration of nitric oxide decreased in the birds receiving 1.2 g/kg GAA by 21.05 and 15.57% compared with the control birds and those received 1.8 g/kg of GAA, respectively (p <.04). A lesser frequency for liver colour score 5 was observed in the birds fed on the diet with 0.6 g/k GAA (p <.0001). It was concluded that dietary administration of GAA deteriorates the adaptive physiological responses to an acute lactic acidosis in broiler chicken possibly through liver and kidney dysfunction. Dietary guanidinoacetic acid decreased mortality but showed an adverse effect on growth performance in chickens exposed to acute lactic acidosis. The adverse effects of guanidinoacetic acid may happen through liver and kidney dysfunction. No firm evidence was found to suggest a significant effect of extra nutritional guanidinoacetic acid on the incidence of sudden death syndrome in chicken. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the effects of dietary total sulphur amino acids (TSAA) levels and guanidinoacetic acid (GAA) supplementation on performance, carcase yield and energetic molecular metabolites in heart and breast muscle of broiler chickens fed wheat-soy diet. A total of 450, male one-day-old Ross-308 broiler chicks were assigned in a 3 × 3 factorial arrangement of nine treatments, five replicates and 10 birds each. Dietary treatments included three graded levels of supplementary TSAA (+0.4 g/kg per level) resulting in a deficient, adequate and plus level of recommended by strain, with three levels of GAA (0, 0.6 and 1.2 g/kg) and were fed for 35 days. Dietary TSAA levels only enhanced performance during the starter period (p <.05). At adequate TSAA level, weight gain (WG) and feed conversion ratio (FCR) in the grower phase were positively affected by supplementing GAA at 1.2 g/kg (p <.05). The FCR during the overall experimental period was significantly lower when feeding GAA at 0.6 and 1.2 g/kg compared to non-supplemented (p <.05). Heart and breast muscle ATP/AMP ratio and breast muscle ADP and PCr concentration and PCr/CrN ratio in the birds fed 1.2 g/kg GAA diet were significantly higher than non-supplemented (p <.05). It is concluded, effects of dietary GAA supplementation were influenced by dietary TSAA level, this indicates to need for proper dietary sulphur amino acid formulation by GAA supplementation. Dietary GAA supplementation could improve broiler chicken's growth performance via regulating some aspects of energy metabolism. Guanidinoacetic acid plays a critical role in energy homeostasis. The effect of dietary Guanidinoacetic acid supplementation may influenced by the dietary sulphur amino acids. [ABSTRACT FROM AUTHOR]

Matrix metalloproteinases (MMPs) play an important role in intestinal extracellular matrix homeostasis. An overexpression of MMPs results in tissue destruction and local inflammation and has been associated with multiple inflammatory diseases. These host proteases might also be important in tissue damage caused by infectious agents, such as in intestinal damage in Clostridium perfringens-induced avian necrotic enteritis (NE). The aim of the present study was to elucidate the effect of a C. perfringens infection on the MMP activity in the small intestine of birds with a pre-disposing coccidial infection to obtain a more thorough understanding of the pathogenesis of NE. For this purpose, the gelatinolytic activity present in jejunal tissue of Eimeria infected birds which were challenged with either a pathogenic C. perfringens type G strain or a commensal C. perfringens type A strain was analyzed using substrate zymography. The results show that infection of broilers with Eimeria and different C. perfringens strains, independent of their pathogenicity, decreases the expression of a 40–45 kDa host collagenase in the jejunum, as compared to the expression in Eimeria-infected control birds. It was also shown that the expression of 2 MMPs with molecular weights of approximately 50–60 and 60–70 kDa was significantly lower in necrotic tissue as compared to the activity in macroscopically healthy tissue adjacent to the lesion. These results indicate that host collagenases are not elicited by the C. perfringens infection for permeabilizing the host mucosa to allow penetration of the NetB toxin in Eimeria infected broilers. [ABSTRACT FROM AUTHOR]

Background: Intensive selection for growth rate (GR) in broiler chickens carries negative after-effects, such as aberrations in skeletal development and the immune system, heart failure, and deterioration of meat quality. In Poland, fast-growing chicken populations are highly non-uniform in term of growth rate, which is highly unprofitable for poultry producers. Therefore, the identification of genetic markers for boiler GR that could support the selection process is needed. The hypothalamus is strongly associated with growth regulation by inducing important pituitary hormones. Therefore, the present study used this tissue to pinpoint genes involved in chicken growth control. Results: The experiment included male broilers of Ross 308 strain in two developmental stages, after 3rd and 6th week of age, which were maintained in the same housing and feeding conditions. The obtained results show for the overexpression of genes related to orexigenic molecules, such as neuropeptide Y (NPY), aldehyde dehydrogenase 1 family, member A1 (ALDH1A1), galanin (GAL), and pro-melanin concentrating hormone (PMCH) in low GR cockerels. Conclusion: The results reveal strong associations between satiety centre and the growth process. The present study delivers new insights into hypothalamic regulation in broiler chickens and narrows the area for the searching of genetic markers for GR. [ABSTRACT FROM AUTHOR]

Effects of pawpaw leaf and seed meals composite mix (PCM) supplementation on broiler chickens were assessed. A total of 396-day-old Arbor Acres broiler chicks were distributed to six diets: 1 = 0 g/kg PCM; 2 = 2 g/kg PCM; 3 = 4 g/kg PCM; 4 = 6 g/kg PCM; 5 = 8 g/kg PCM; and 6 = 10 g/kg PCM. Body weight gain and feed conversion ratio of the birds fed diet 5 was similar to those fed diets 4 and 6 but better than (P < 0.05) those fed diets 1, 2 and 3 at grower phase and overall period of the feeding trial. Alanine aminotransferase (ALT) concentration decreased in the birds with an increase in the dietary PCM supplementation level such that ALT concentration reduction (P < 0.05) was recorded in the birds fed diets 5 and 6 when compared to those fed diet 1. The serum cholesterol in birds fed diets 3, 4, 5 and 6 was similar to the level recorded for birds fed diet 2 but lower (P < 0.05) than the level in birds fed the control diet. The superoxide dismutase and glutathione peroxidase serum concentration improved (P < 0.05) in the birds fed PCM-supplemented diets (2 to 6) compared to those fed diet 1. Catalase serum concentration in birds fed diet 5 was similar to those fed diets 3, 4 and 6 but higher (P < 0.05) than the concentration in birds fed diets 1 and 2. The PCM dietary supplementations (6 g/kg to 10 g/kg) did not affect on the performance and health status of the broiler chickens negatively. [ABSTRACT FROM AUTHOR]

Background: Among the most prominent health problems marring the global poultry industry for several decades are skeletal abnormalities. The aim of this study was to investigate a recent emergence of a novel form of skeletal deformity affecting cervical spine in broiler chickens. This work presents the natural history of this newly emerging skeletal anomaly along with long term observations of epidemiological trends in commercial broiler flocks, and clinical and pathological features. Results: In distinction from other forms of skeletal deformities commonly reported in broiler chickens, this new form of cervical spine anomaly have been observed in newly hatched chicks and in fully developed embryos that died in the shell. On clinical and post mortem examination this condition presents characteristic features consistent with congenital cervical scoliosis and torticollis (CCST). The pathogenesis of CCST appears to be linked to pathological remodeling of the cervical vertebrae bone associated with excessive activity of osteoclasts. Long term observations indicate that the incidence of CCST showed increasing epidemiological trends over time. More recently CCST has been observed in newly hatched chicks with incidence ranging from 0.1 to > 1%, and in fully developed embryos that failed to hatch about 4 to 5%. Conclusions: The increasing trends in incidence of CCST in commercial broiler flocks are of concern from an economic perspective, and also represent a very specific and important aspect of animal welfare. [ABSTRACT FROM AUTHOR]

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Ascites syndrome (AS) is a harmful disease in fast-growing broilers characterized by heart failure and serious fluid accumulation in the abdominal cavity. One of the known functions of zinc transporter ZIP12 is an important regulator in pulmonary hypertension (PH) in rat. Whether chicken ZIP12 is involved in the process of AS need to be explored. Here, chicken ZIP12 was sequenced and expression pattern and histological distribution were detected in broilers of AS induced by intravenous cellulose microparticle injection. Phylogenetic analysis showed that ZIP12 was significantly different between chicken and mammalian. The relative mRNA expression level of ZIP12 in the liver and lung in AS and pre-ascites (PAS) groups were significantly higher (P < 0.01) than that in control. The immunohistological staining using rabbit anti-chicken ZIP12 IgG and integrated optical density analysis showed the positive cells of ZIP12 distributed in detected tissues and the expression level of ZIP12 protein increased in AS and PAS groups compared to control. The results will provide the basic data of ZIP12 in the pathological process of AS in broiler chickens and offer an important reference for prevention and control of the disease. [ABSTRACT FROM AUTHOR]

Modern fast-growing broilers are susceptible to cardiac dysfunctions because their relatively small hearts cannot adequately meet the increased need of pumping blood through a large body mass. To improve cardiac health in broilers through breeding, we need to identify the genes and pathways that contribute to imbalanced cardiac development and occurrence of heart dysfunction. Two broiler lines–Ross 708 and Illinois–were included in this study as models of modern fast-growing and heritage slow-growing broilers, respectively. The left ventricular transcriptome were compared between the two broiler lines at day 6 and 21 post hatch through RNA-seq analysis to identify genes and pathways regulating compromised cardiac development in modern broilers. Number of differentially expressed genes (DEGs, p<0.05) between the two broiler lines increased from 321 at day 6 to 819 at day 21. As the birds grew, Ross broilers showed more DEGs (n = 1879) than Illinois broilers (n = 1117). Both broilers showed significant change of muscle related genes and immune genes, but Ross broilers showed remarkable change of expression of several lipid transporter genes including APOA4, APOB, APOH, FABP4 and RBP7. Ingenuity pathway analysis (IPA) suggested that increased cell apoptosis and inhibited cell cycle due to increased lipid accumulation, oxidative stress and endoplasmic reticulum stress may be related to the increased cardiac dysfunctions in fast-growing broilers. Cell cycle regulatory pathways like “Mitotic Roles of Polo-like Kinases” are ranked as the top changed pathways related to the cell apoptosis. These findings provide further insight into the cardiac dysfunction in modern broilers and also potential targets for improvement of their cardiac health through breeding. [ABSTRACT FROM AUTHOR]

The effect of different feed withdrawal durations and re-feeding on broiler performance was investigated. A total of 225 broiler chicks (Ross 308) were assigned to 5 groups; control (full feeding) and feed withdrawal for 6, 8, 10 and 12 h daily. Feed intake and weight gain were reduced (P < .05) in the feed withdrawal groups during the starter phase, but were not affected during later growth. Feed conversion ratio was not affected by the treatment. The relative weight of carcass was reduced (P < .05) in 6 and 12 h feed withdrawal groups. Breast weight was lowest on the control group and highest on the 8 h withdrawal (P < .05) group. The weight of the thigh was reduced (P < .05) on the control group. Plasma protein was higher on the control group and 6 h group compared to 10 h feed withdrawal group (P < .05). Plasma albumin was reduced on 12 and uric acid on the control and 6 withdrawal groups. There were no treatment effects on plasma cholesterol, HDL and LDL values. E. coli count was not affected by treatment, but Lactobacilli count was higher (P < .05) on the 12 h feed withdrawal group. Young broilers subjected to feed withdrawal for 8-10 h daily can compensate for performance losses in the early stage of growth and maximize the relative weights of carcass, breast muscle and thigh, but withdrawal lengths of 6 and 12 h might be too short and too long, respectively, to improve performance losses after resumption of full feeding. [ABSTRACT FROM AUTHOR]

Ascites syndrome (AS) is a metabolic disorder in fast-growing broilers that is characterized by non-tumult fluid collection in the abdomen. The objective of this study was to evaluate the effects of variable feeding and rearing temperature on AS occurrence in broilers. A total of 360 one-day-old male Ross-308 chicks were assigned to three equal groups (n = 120) fed pellet, crumble or mash diets and within each group, half of birds (n = 60, starting from the 22nd day of age) were reared under two different temperatures: at 23°C (comfort) or at 14°C (cold), respectively. There were six treatments and four replicates including 15 broilers per replicate per treatment. Birds' growth performances and blood parameters as well the incidence of ascites were assessed. The haematocrit percentage, T3 and T4 hormones activity in pellet-fed group under cold temperature conditions were significantly higher (P < .05) than the other groups. Based on the results, the occurrence of AS under mash-fed regime was less than pellet and crumble dietary groups (P > .05). Further, feeding of mash diet reduced broilers' feed consumption per unit of time, especially by level of achieving energy that is reducing the growth and AS. [ABSTRACT FROM AUTHOR]

The present study was aimed to investigate the clinical, haematological, and serum biochemical alterations in commercial broiler chickens affected with pulmonary hypertension syndrome. Clinical signs were recorded. Haematological indices were investigated using a MS-4 automatic haem-analyser (MELET Schloesing Laboratories, France). Serum biochemical indices were studied using diagnostic kits (Aspen Laboratories Pvt. Ltd., Rapid Diagnostic Group of Companies, Karnal Road Industrial Area, Delhi, India) and semi-automatic blood chemistry analyser (model SFRI-BSA 3000, Lieu dit Berbanton, France) as per manufacturer’s literature. The specific clinical signs for pulmonary hypertension syndrome included potbelly with frog sitting posture, gasping, tortuous and distended blood vessels, prolonged bleeding, occasional diarrhoea, and cyanotic comb. Haematological profiling revealed significant increase in haemoglobin, haematocrit, TEC, MCH, and MCHC; and lymphocytic leukocytosis in clinically ascitic chicken as well as non-ascitic birds from ascitic flocks. Serum biochemical profiling showed significant increase in blood glucose, A:G ratio, serum bilirubin, AST, ALT, LDH, ALP, BUN, and creatinine levels; significant decrease in total protein, albumin, globulin, and HDL cholesterol levels; and non-significant changes in total cholesterol. [ABSTRACT FROM AUTHOR]

The present study was carried out to investigate the effect of different levels of guanidine acetic acid (GAA) on the performance, carcase yield and energetic molecular metabolites of breast muscle in broiler chickens fed with wheat-soy diet containing different levels of nutrient densities. 450- day-old male broiler chicks (Ross 308), assigned in a completely randomised design experiment with factorial arrangement 3×3, 9 treatments and 5 replicates of 10 birds each. The diets included three levels of GAA supplementation (0, 0.6, 1.2 g/kg of diet) and three dietary nutrient density (ND) levels (low; 2800 kcal ME/kg, medium; 2950 kcal ME/kg and high; 3100 kcal ME/kg with constant rates of ME to other nutrients). The experimental diets were fed ad libitum from 1-42 days of age. One bird per pen was euthanized on day 10 and 42 to determine the energetic molecular metabolites concentrations of adenosine phosphate (ATP, ADP and AMP), phosphocreatine (PCr) and creatinine (CRN) in breast muscles. The inclusion of 0.6 g/kg GAA in wheat-soy diet, improved production performance, the relative weight of breast yield and increased the concentration of high phosphate energy metabolites (PCr, ATP/ADT and PCr/ATP) in breast muscle. The supplementation of high-density diet with GAA compared with the lowdensity diet improved broiler chicken's performance. It is concluded that the use of GAA in diet may facilitate the conversion of high-energy phosphates to form ATP in muscles and thus improve broiler chicken's performance. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to evaluate the effect of bee glue (BG) on the performance, relative visceral weights, some blood parameters, and immune status of broilers. A total of 200 male Ross 308 broiler chicks were randomly assigned to 5 dietary treatments: basal diet (BD), and basal diet supplemented with 600, 700, 800, and 900 mg kg−1of BG. Each of the 5 diets was fed to 4 replicates of 10 chicks each from 0 to 42 days of age. The results indicated that the highest body weight, average daily gain, average daily feed intake, carcass weight, and carcass yield were observed in broilers offered 800 mg kg−1of BG (P < .05). Inclusion of BG improved the feed conversion ratio compared with the control group (P < .01). The calculated European broiler index and crop percentage were greater for the birds received 800 and 900 mg kg−1of BG compared with that of the control birds (P < .05). Inclusion of 900 mg kg−1of BG significantly increased the relative weight of spleen and bursa, but reduced total triglycerides, cholesterol, LDL, and LDL: HDL ratio than the control group (P < .05). The serum IgG and IgM levels were increased for the birds received 700 to 900 mg kg−1BG (P < .01), and addition of BG to the basal diet significantly increased antibody response against sheep red blood cell at 35 days of age (P < .05). It was concluded that an addition of 800 mg kg−1BG to diet improves economic efficiency possibly by creating miniscule improvement in FCR and promoting immune response of broilers. [ABSTRACT FROM PUBLISHER]

BACKGROUND Broiler diets mainly consist of cereals and protein-rich feed sources; in the EU-27, poultry farming consumes 24% of the total amount of protein-rich feedstuffs. Since the EU produces only 30% of the total quantity of protein crops used for feed, it is necessary to promote the use of traditional European protein crops (beans, peas) for feed in livestock farming. The research aim is to identify economic gains from the production of broiler chicken meat, replacing soybean meal with domestic faba beans and field peas in broiler chicken diets. RESULTS Adding field peas and faba beans to the broiler feed ration resulted in a significant live weight increase (5.74-11.95%) at the selling age, a decrease in the feed conversion ratio by 0.61-6.06%, and decrease in the product unit cost (15.34-37.06%) as well as an increase in the production efficiency factor (8.70-48.54), compared with the control group. CONCLUSION The optimum kind of legume species used in the broiler diet was peas, which were added in the amount of 200 g kg−1, resulting in live weight gain, a decrease in the feed conversion ratio and an increase in the production efficiency factor. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The present study was carried out to evaluate the effects of supplementing reduced-protein diets with L-carnitine on growth performance and occurrence of pulmonary arterial hypertension (PAH) syndrome in broiler chickens reared at high altitude. A total of 156 day-old male broilers (Ross 308) were assigned to three dietary treatments and reared up to 42 days of age. A normal-protein diet (NPD) was formulated according to the National Research Council (1994) and served as control. A reduced-protein diet (RPD) was also prepared to contain 3% less protein than that of the NPD. An additional RPD diet was prepared by supplementing L-carnitine (LC) at 100 mg/kg to the RPD. Results showed significant improvements in feed:gain and carcass yield in birds fed on RPD when supplemented with LC. The proportions of liver, heart, and abdominal fat pad relative to body weight and the right ventricular weight ratio (RV:TV) were significantly higher in birds fed on the RDP than those of the control fed the NPD. Electrocardiogram (ECG) measurements recorded from lead II supported the development of PAH in birds fed RPD as evidenced by deep S waves. Supplementing LC to the RPD significantly reduced the liver weight, abdominal fat deposition, and RV:TV, which reflected in reduced S waves. Feeding broilers with the RPD significantly reduced serum concentrations of nitricoxide (NO) and uric acid (UA). However, supplementation of the RPD with LC significantly increased the serum concentrations of NO. In conclusion, feeding reduced-protein diets to broilers reared at hypobaric hypoxia increases their susceptibility to pulmonary hypertension. Dietary LC supplementation of reduced-protein diets had beneficial effects in preventing PAH mortality mainly through enhancing blood NO concentration. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the effect of providing environmental enrichment in the form of perches and string on the behaviour and welfare of commercial broiler chickens. Houses containing ~23 000 broiler chickens were assigned to one of four treatments in a 2×2 factorial design. Treatments involved two levels of access to perches (P) (present (24/house) ‘+P’ or absent ‘−P’) and two levels of access to string (S) (present (24/house) ‘+S’ or absent ‘−S’). All houses contained windows, and 30 straw bales were provided from day 10 of the rearing cycle. Treatments were applied in one of four houses on a single farm, and were replicated over four production cycles. Behaviour and leg health were observed in weeks 3 to 5 of the rearing cycle. Production performance and environmental parameters were also measured. There was an interaction between perches and age in the percentage of birds observed lying, with higher percentages of birds observed lying in the +P treatment than in the −P treatment during weeks 4 and 5. There was also a significant interaction between string and age in the percentage of birds observed in locomotion, with higher percentages observed in locomotion in the −S treatment than in the +S treatment during weeks 4 and 5. There was also an interaction between string and age in average gait scores, with lower gait scores in the +S treatment than in the −S treatment during weeks 3 and 5 but not within week 4. Daytime observations showed that perches and strings were used frequently, with one bout of perching occurring approximately every 80 s/perch, and one bout of pecking at string occurring every 78 s/string on average. There was a significant effect of age on use of perches (P<0.001) and string (P<0.001), with perching peaking during week 5 and string pecking peaking during week 3. We conclude that commercial broilers in windowed houses with access to straw bales display an interest in additional enrichment stimuli in the form of perches and string, and therefore that these stimuli have the potential to improve welfare. In addition, provision of string as a pecking device appeared to positively influence walking ability. However, this effect was numerically small, was only shown in certain weeks and was not reflected in the other leg health measure (latency to lie). The results also showed an apparent negative effect of string and perches on the activity levels of birds (recorded away from the immediate vicinity of these enrichments) towards the end of the production cycle. These results emphasise the need for further research into optimum design and layout of enrichment stimuli for modern broilers in windowed houses to ensure that their provision leads to clear welfare benefits. [ABSTRACT FROM PUBLISHER]

The present research work was designed to know the effect of carbohydrate rich diet on the experimental pathology of necrotic enteritis in broilers. For experimental purpose, 15 birds of 14 days of age were grouped into 3 (A, B and C). Birds of group A were fed with 400gm maize/kg (40% increase) and group B were fed with 200gm maize/kg (20% increase) of normal feed from day 14 to day 27 and challenged from day 21 to 25 days with 1x108 CFU/3ml of inoculums of Cl. perfringens consecutive 5 days. Group C was kept in control without additional maize. Birds of all groups were observed up to 27 days of age. The clinical signs diarrhea, ruffled feather were common in both group A and B, and less feed intake in group A than group B. There was no mortality in any groups. Birds of all groups were sacrificed at the day 28. Necrosis and hemorrhage in intestine, enlarged liver, and hemorrhage in the base of heart were found in group A (+++). In impression smear of intestines, the average 10-12 bacteria were found in group A and 8-10 bacteria were found in group B in higher magnification (100X). In histopathology, severe infiltration of inflammatory cells including heterophils and lymphocytes and sloughing off mucosal epithelium that changed by pink color cytoplasm with pyknotic nuclei were observed in group A (+++) while group B showed infiltration of inflammatory cells and sloughing off mucosal epithelium (++). The birds of group C were normal in all respects. Anaerobic bacteria counted from intestinal content of group A was 2.8x107 CFU/ml, group B was 2.2x107 CFU/ml and group C was 1.0x107CFU/ml. From the findings, it may be said that carbohydrate rich diet is a predisposing factor for necrotic enteritis in broilers. [ABSTRACT FROM AUTHOR]

Two-factor experiment was designed to examine from lipid metabolism, proinflammatory eicosanoids, and lipid peroxidation for investigating the effects of dietary oils and zinc levels of cardiovascular system of broilers. One hundred sixty 1-d-old male broilers were divided into 4 groups with 8 replicates of 5 birds fed one of the diets containing either corn oil or fish oil with one of 2 levels (75 mg/kg, 150 mg/kg) of zinc. Fish oil significantly decreased the levels of serum total cholesterol, triglyceride, high density lipoprotein-cholesterol, low density lipoproteincholesterol of broilers, decreased the contents of plasma prostaglandin E2, thromboxane B2, and phospholipase A2 in broilers when compared with corn oil. Zn level did not alter lipid metabolism, but significantly affected eicosanoid synthesis and lipid peroxidation of broilers. Zinc at 150 mg/kg significantly decreased the contents of plasma prostaglandin E2, malondialdehyde, and phospholipase A2 in broilers when compared to zinc at 75mg/Kg. There were significant interactions between oil sources and zinc levels on production of serum triglyceride, high density lipoprotein-cholesterol, plasma 6-keto- prostaglandin F1a, phospholipase A2 and malondialdehyde. In conclusion, fish oil improved lipid profiles, reduced proinflammatory eicosanoid contents by inhibiting phospholipase A2 production in broilers; while zinc reduced the contents of plasma malondialdehyde, phospholipase A2, and then decreased the concentration of prostaglandin E2 of broilers. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the appropriate concentration of dietary supplementation of curcumin, and its effect on growth performance, intestinal morphology, fat metabolism and nutrients utilization of broiler chicks. Four hundred eighty, 1-day-old Arbor Acre broiler chicks were allocated into four groups with 6 replicates of 20 birds per cage. Birds were fed a corn-soybean basal diet supplemented with curcumin at 0 (control, CRM0), 100 (CRM100), 150 (CRM150) and 200 mg/kg (CRM200) levels for 42 days. All birds were kept in wire floor triple deck battery cages under semi-intensive housing management. The results revealed that dietary supplementation of curcumin at 200 mg/kg significantly improved live body weight and feed efficiency at marketing age (42 d); while, there was no significant difference on feed intake as compared to control. Curcumin significantly improved utilization of apparent metabolizable energy and decreased abdominal fat at 42 d in CRM 150 and CRM200 broilers, respectively. Plasma T4 hormone level and fat utilization were significantly increased; while plasma cholesterol level was significantly reduced in dose dependent manner for CRM200 broilers. The results showed that dietary supplementation of curcumin influenced the histomorphological measurements of small intestinal villi. The villus height was significantly increased in duodenum, jejunum and ileum in curcumin supplemented broilers. Villus width was also significantly increased in duodenum and jejunum (42 d). While, there was no significant difference in ileum villus width. Furthermore, villus height to crypt depth ratio was significantly increased in all segments (except jejunum 42 d) of small intestine in CRM200 group; however, the intestinal crypt depth was lowered in curcumin supplemented broilers. In conclusion, supplementation of curcumin at 200 mg/kg feed enhanced the growth performance and fat metabolism, and increased villus absorptive area of small intestine, resulting in improved nutrients absorption in CRM200 group. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyse the microscopic and ultrastructural lesions of the livers of broiler chickens during fattening. Three genetic lines of broiler chickens (Ross 308, Cobb 500, Hubbard F15) were investigated. The liver samples were taken on the 3rd, 10th, 17th, 24th, 31st, and 38th day of life from six healthy broiler chickens from each commercial broiler flock. The dominant microscopic lesions were associated with prolonged hypoxia and bile ductules, including: fatty, vacuolar and parenchymatous degeneration, necrosis of epithelial cells of bile ductules, necrosis of hepatocytes around the proliferating bile ductules, lymphoid cell infiltration around the bile ductules and blood vessels, proliferation of the bile ductules, proliferation of the connective tissue around bile ductules and stimulation of the lymph nodules. Ultrastructural evaluation revealed abnormalities involving mitochondria and rough endoplasmic reticulum. The mitochondria underwent swelling, polymorphism, proliferation and damage. The rough endoplasmic reticulum underwent defragmentation and acinar transformation. The cytoplasm of most hepatocytes showed vacuoles of varying size or lipid droplets and the presence of cytoplasmic myelin-like structures. This study shows that the livers of broiler chickens are the most predisposed to the occurrence of lesions on the 17th, 31st and 38th days of life. [ABSTRACT FROM AUTHOR]

Dried leaves of oleander were orally given at a single dose of 500 mg/kg body weight to 20 clinically healthy male chickens. Clinical signs of toxicosis began to appear about 1 h after receiving the oleander and included hypersalivation, vomiting, diarrhea, deep depression, and sudden death. Also, hyperemia in the combs and wattles was obviously seen. Electrocardiograms (ECG) were repeatedly recorded at 30 min intervals. ECGs findings included increasing the QRS duration in some birds and various kinds of arrhythmias. Bradycardia was the most frequently detected finding (30.43%). During necropsy, there were congestion and hemorrhages in the visceral organs particularly in heart, liver, kidney, and lung. Histopathology revealed myocardial cell necrosis with hyperemia and hemorrhage, severe diffuse pulmonary congestion and edema, severe renal congestion and hemorrhage with tubular necrosis, and coagulative necrosis of hepatocytes with hyperemia and hemorrhage. There were also congestion, mild epithelial necrosis and desquamation with infiltration of mononuclear inflammatory cells in the proventriculus of all birds. There was also mild to moderate congestion in the intestines with scattered necrosis of surface enterocytes. The lack of information about the toxicity of oleanders in poultry was the main cause for this study. The results suggest that chickens appear to respond to oleander poisoning in a manner similar to other species. [ABSTRACT FROM AUTHOR]

Two experiments were conducted to evaluate the nutritional value of three cultivars (Promore, Kiev mutant and Ultra) of white lupins (Lupinus albus L.) for broilers. In experiment 1, the apparent metabolisable energy (AME) and ileal amino acid digestibility coefficients of the three cultivars were determined. The cultivar effects were significant (P < 0.05) for AME, but the ileal amino acid digestibility coefficients were similar (P > 0.05) between cultivars. The AME value of Ultra cultivar was lower (P < 0.05) than those of Promore and Kiev mutant cultivars. In Experiment 2, using the AME and ileal digestible amino acid values determined in Experiment 1, diets containing 200 g/kg of lupin were formulated and the effects of feeding these diets on performance, digestive tract development and excreta quality of broiler starters were investigated. Weight gain, feed intake and feed per gain of broilers fed diets containing white lupins were similar (P > 0.05) to those fed the maize–soybean meal diet. The performance of birds fed diets containing different cultivars of white lupins was similar (P > 0.05). Several digestive tract parameters were influenced by the dietary inclusion of white lupins. In particular, the relative liver weight and the relative empty weights of small intestine and caeca in birds fed diets containing white lupins were higher (P < 0.05) than those fed the maize–soybean meal diet. No differences (P > 0.05) were observed in the excreta quality scores between the birds fed the maize–soybean meal diet and those fed diets containing white lupins. [ABSTRACT FROM PUBLISHER]

1. Two experiments were conducted to evaluate the nutritional value of three cultivars (Wallan, Tanjil and Borre) of narrow-leafed lupin (Lupinus angustifolius) for broilers. 2. In Experiment 1, the apparent metabolisable energy (AME) and the apparent ileal amino acid digestibility of the three cultivars were determined. The cultivar effects were not significant for AME and apparent ileal amino acid digestibility coefficients. In general, amino acids in narrow-leafed lupin were well digested, with the notable exception of methionine. Among the indispensable amino acids, arginine had the highest digestibility coefficient (0·92–0·95), while the lowest was for methionine (0·74–0·83). 3. In Experiment 2, using the energy and digestible amino acid values determined in Experiment 1, diets containing 200 g/kg of the three lupin cultivars were formulated and the effects of feeding these diets on the performance and the digestive tract development of broiler starters were investigated. 4. Weight gain, feed intake and feed per gain of broilers fed narrow-leafed lupins diets were similar to those fed on the maize-soy basal diet. The performance of birds fed on diets containing different cultivars of lupins was also similar. Birds fed on lupin diets had similar excreta scores to those fed on the basal diet. 5. Inclusion of 200 g/kg lupins in broiler diets had no effects on the relative weight and length of the intestinal tract. Broilers fed on lupin diets, however, had higher relative weights of liver. 6. These results suggest that narrow-leafed lupins are good sources of protein, but poor sources of AME and sulphur-containing amino acids. It is concluded that, when diets are properly balanced in terms of AME and digestible amino acids, lupins can be included at 200 g/kg inclusion level in broiler starter diets with no adverse effects on performance. [ABSTRACT FROM PUBLISHER]

This work examined the effects of three enzyme preparations (A,B,C) directed towards degradation of Non Starch Polysaccharides (NSP) and one targeting phytates (D) on performance traits in broilers fed maize meal basal diets containing 400 g/kg of yellow lupine seeds (LM). A soybean meal (SBM) based diet served as a reference control. Growth rate, coefficients of total tract apparent digestibility (CTTAD) of organic matter, protein and energy, as well as morphometric measurements of selected sections of gastrointestinal tract (GIT) were determined. In comparison to chickens fed the SBM diet, chickens fed the LM diet consumed less feed, had considerably lower body weight gain, as well as lower CTTAD of measured nutrients and energy. Also the GIT relative weight and length were increased within the group fed the LM diet. Addition of each NSP degrading enzymes (A,B,C) to the LM diet increased feed intake and decreased size of GIT organs (all p < 0.05). Addition of enzymes A or B increased ( p < 0.05) growth rate of chicks, whereas only enzyme B increased fed efficiency ( p < 0.05) and tended to slightly improve CTTAD of nutrients. The addition of enzyme D did not have any effect on feed intake, growth rate or CTTAD. This study indicates that a diet containing high levels of LM is detrimental to feed intake and condition of the digestive tract of young broilers, and thus affects their performance. However, when the LM diet is supplemented with suitable enzyme preparations, performance parameters are not different from those obtained with SBM. [ABSTRACT FROM AUTHOR]

Coliform cellulitis in broilers is caused by certain avian pathogenic Escherichia coli strains. Sixty-four E. coli samples were isolated in a slaughterhouse from broiler carcasses with cellulitis. The isolates were examined for the presence of selected virulence genes and phylogenetic determination by PCR assays. E. coli isolates belonged to A (51.56%), B1 (18.75%) and D (29.68%) phylogenetic groups. All of the isolates were positive for at least two virulence genes. The three most prevalent genes were csgA (92.18%), fimH (85.93%) and iucD (76.56%). F17 fimbrial family (f17A), P (papC) and S (sfa) fimbriae encoding genes were detected in one, nine and two isolates, respectively. The highest and the lowest number of virulence genes were found in D and A phylogenetic groups, respectively. Several combination of the virulence genes were detected; csgA, fimH, iucD was the most prevalent pattern. None of the isolates harboured the afa E-VIII, afaI B-C, eaeA, hly, stx1 and stx virulence genes. [ABSTRACT FROM AUTHOR]

1. Objectives. To validate the whole blood chemiluminescence (WBCL) assay in chickens, a simple and rapid method of measuring production of reactive oxygen species by circulating polymorphonuclear (PMN) leukocytes. To determine the physiological response and innate immune response associated with oral challenge with Clostridium perfringens in broiler chickens under different nutritional conditions. 2. In Experiment 1, birds were orally challenged with C. perfringens 1. type A or sham-challenged saline on days 14-21 post-hatch and fed protein-balanced diets containing 160 or 180 g crude protein/kg and 0·98 or 1·75% glycine in a 2 × 2 × 2 factorial arrangement of treatments. 2. Challenged birds had higher WBCL responses and more severe intestinal lesions than unchallenged birds. Birds fed diets containing 1·75% glycine had more intestinal lesions than those fed 0·98% glycine. 3. In Experiment 2 birds were fed protein-balanced diets containing 0·76, 2·10, 3·43 or 4·77% glycine. The birds fed 0·76% glycine diet had lower WBCL responses compared to birds fed the other three diets. Intestinal lesions were worse in the birds fed the highest, 4·77% glycine diet than in those fed the 0·76 or 2·10% glycine diets. 4. We conclude that the WBCL assay is a practical and sensitive means of assessing innate immune function in birds. The results suggest that both bacterial challenge and glycine content of chickens' diet influence their lesion scores and innate immune function. [ABSTRACT FROM AUTHOR]

1. Standardised data on husbandry were recorded for a flock of birds in one house on each of 150 broiler farms in the UK during the 4 d prior to slaughter. 2. For each flock, the incidence of birds found dead on arrival (DoAs) and the Meat Hygiene Service carcase rejection records were recorded at the slaughterhouse. 3. The mean percentage of birds in each flock found DoA was 0·12% (range 0-0·64%) and the mean percentage of Total Carcase Rejects (TCRs) for each flock was 1·23% (range 0·07-5·51%). 4. A general linear model was developed to examine factors associated with flock percentage DoAs. Assuming a linear relationship, all other factors remaining the same, a one percentage point (PP) increase in small/emaciated birds will result in a 0·155 PP increase in DoAs and a 1 PP increase in wheat in diet 4 will result in a 0·003 PP decrease. An increase by one in the total number of vaccines administered will cause a 0·029 PP decrease in DoAs, a 1 g increase in live weight at slaughter will be associated with a 0·000043 PP increase and a 1 PP increase in mortality on farm would be associated with a 0·000044 PP increase. A 1 PP increase in Ross birds decreases DoAs by 0·0004 PPS: there is also a seasonal effect. 5. The model developed for flock percentage TCRs found that a 1 PP increase in wheat in diet 3 will result in a 0·052 PP decrease in TCRs and a 1 PP increase in Ross birds will cause a 0·009 PP decrease. A 1 PP increase in birds culled on farm will be associated with a 0·03 PP increase in TCRs and the diagnosis of disease during the flock cycle increases TCRs by 0·397 PPs. A one day increase in age at slaughter will result in a 0·046 PP increase in TCRs. [ABSTRACT FROM AUTHOR]

1. This study compared the effect of dietary supplementation with organic or inorganic selenium (Se) sources plus control amounts or large amounts of vitamin E (α-tocopherol acetate) in broilers raised at control (20 to 24°C) or low (14·5 to 16·8°C) temperatures after 2 weeks of age. 2. The following dietary treatments were used from one day old. Diet 1, the control diet, comprised a commercial diet containing 0·15 mg/kg inorganic Se and 50 mg vitamin E/kg feed. Diet 2 was the same as diet 1, supplemented with 0·15 mg/kg inorganic Se. Diet 3 was the same as diet 2 but was supplemented with 200 mg/kg vitamin E. Diet 4 was the same as diet 1, but inorganic Se was replaced with 0·30 mg/kg organic Se. Diet 5 was the same as diet 4, supplemented with 200 mg/kg vitamin E. 3. Low temperature reduced the growth rate of broilers; however, at 6 weeks, there were no differences in the body weights of birds fed on organic Se supplemented diets housed at low or control temperature. The feed conversion ratio was significantly affected by low temperature but not by diet. The heterophil/lymphocyte ratio was higher in chicks after one week in the cold, indicating mild stress. Blood triiodothyronine levels were significantly higher in birds after 1 and 4 weeks in the cold but thyroxin was not affected. 4. Organic Se supplementation increased relative lung weight at the control temperature, which might lead to greater respiratory capacity. Relative spleen weight significantly decreased in broilers fed diets supplemented with inorganic Se under cold conditions, a possible indication of chronic oxidative stress. 5. At the low temperature, supplementation with organic Se alone, or with inorganic Se and vitamin E increased glutathione peroxidase (GSHPx) activity and glutathione (GSH) concentration in the liver of broilers, which may indicate increased activity of birds' antioxidant defence against suboptimal environments. [ABSTRACT FROM AUTHOR]

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 with 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 both the end of systole and of diastole was greater in ascitic chickens at all ages. Left 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 (ΔT), 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 ΔT were all negatively correlated with ascites heart index at all ages. 5. Taken together the results suggest heart failure of both ventricles, 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. [ABSTRACT FROM AUTHOR]

1. The effects of acute heat stress (2&ThickSpace;h at 32°C and 75% RH) on body temperature and indices of respiratory thermoregulation and skeletal muscle function were examined in two divergently selected male grandparent lines of broiler and layer-type chickens at two ages (35 and 63&ThickSpace;d), or at a similar body weight (&nvsim;2·2&ThickSpace;kg). 2. The two chicken lines exhibited markedly different baseline blood acid–base and skeletal muscle characteristics. At the same age or live weight, birds from the broiler line had significantly higher venous blood carbon dioxide tensions associated with lower blood pH. Plasma creatine kinase (CK) activities reflecting muscle membrane damage were also greatly elevated in the broiler line. 3. Exposure to acute heat stress caused an increase in deep body temperature, panting-induced acid–base disturbances and elevated plasma CK activity in both lines of chicken, an effect that increased with age. The extent of disturbances in acid–base regulation and heat-stress-induced myopathy were more pronounced in the broiler than the layer line at the same age or similar live weights. 4. It is suggested that genetic selection for high muscle growth in broiler lines has compromised their capacity to respond to an acute thermal challenge, leading to detrimental consequences for muscle function. This reduction in heat tolerance may have important implications for bird welfare and subsequent meat quality. [ABSTRACT FROM AUTHOR]

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 (h 2 ) of SDS on the liability scale was 0&CenterDot;30?&PlusMinus;?0&CenterDot;002 and 0&CenterDot;25?&PlusMinus;?0&CenterDot;002 in the Cornish and White Rock breeds, respectively.3. A positive genetic correlation (rg) with ascites (AS) was determined (~0&CenterDot;3?&PlusMinus;?0&CenterDot;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&CenterDot;8% in the Cornish and 1&CenterDot;5% in the White Rock).4. Heritability of SDS calculated using male records only was 0&CenterDot;45?&PlusMinus;?0&CenterDot;009 and 0&CenterDot;35?&PlusMinus;?0&CenterDot;009, and rg with body weight was 0&CenterDot;30?&PlusMinus;?0&CenterDot;010 and 0&CenterDot;27?&PlusMinus;?0&CenterDot;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. [ABSTRACT FROM AUTHOR]

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&CenterDot;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&CenterDot;49) showed considerable genotype by environment interaction. 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. [ABSTRACT FROM AUTHOR]

Revealing the multifocal mechanisms affecting cross-talk between Clostridium perfringens pathogenesis and the host response is an urgent need in the poultry industry. Herein, the activity of Cannabis sativa-derived cannabidiol (CBD) and selenium nanoparticles (Nano-Se) in modulating the host response to Clostridium perfringens challenge was investigated in broiler chickens subjected to a mild infection model. The infected chickens exhibited no clinical manifestations, confirming the potential hazard of pathogen transmission to the food chain in the commercial sector. However, both CBD and Nano-Se affected the responses of chickens to C. perfringens challenge. The beneficial actions of both agents were manifested in the upregulated expression of genes determining gut barrier function. Both CBD and Nano-Se promoted shifts in gut bacterial enzyme activity to increased energy uptake in challenged chickens and upregulated potential collagenase activity. There was no opposite effect of CBD and Nano-Se in mediating the host response to challenge, whereas an additive effect was evidenced on the upregulation of gene determining gut integrity. Collectively, these findings indicate that understanding the action mechanisms of CBD and Nano-Se is of great interest for developing a preventive strategy for C. perfringens infection in broilers. [ABSTRACT FROM AUTHOR]