Bands of respiratory rate and cloacal temperature for different broiler chicken strains

The objective of this investigation was to estimate ideal bands of respiratory rate and cloacal temperature for broiler chicken strains during the rearing period and to evaluate the influence of time of exposure on bird physiological variables under different thermal stress conditions. The research was conducted in a climatic chamber during the six weeks of the rearing period, with Avian and Cobb strains exposed to two climatic conditions (comfort and stress), in three distinct times of exposure, in three conditions (before going to the chamber; at the end of exposure time; 30 minutes after the end of exposure), in four treatments: comfort with 60 minutes of exposure; stress with 30 minutes of exposure; stress with 60 minutes of exposure; stress with 90 minutes of exposure. Bands of respiratory rate and cloacal temperature were elaborated for both strains, for each one of the weeks of the rearing period. Strains differed, regardless of treatments and conditions adopted in the research on the third, fifth and sixth weeks of life in relation to the cloacal temperature. The Cobb strain is more tolerant to thermal stress in comparison with the Avian. There was difference for both variables between comfort and stress, but time of exposure to stress did not influence the physiological response of birds, except for cloacal temperature on the second week of life.

Acute heat stress impairs performance parameters and induces mild intestinal enteritis in broiler chickens: Role of acute hypothalamic-pituitary-adrenal axis activation

Studies on the environmental consequences of stress are relevant for economic and animal welfare reasons. We recently reported that long-term heat stressors (31 +/- 1 degrees C and 36 +/- 1 degrees C for 10 h/d) applied to broiler chickens (Gallus gallus domesticus) from d 35 to 42 of life increased serum corticosterone concentrations, decreased performance variables and the macrophage oxidative burst, and produced mild, multifocal acute enteritis. Being cognizant of the relevance of acute heat stress on tropical and subtropical poultry production, we designed the current experiment to analyze, from a neuroimmune perspective, the effects of an acute heat stress (31 +/- 1 degrees C for 10 h on d 35 of life) on serum corticosterone, performance variables, intestinal histology, and peritoneal macrophage activity in chickens. We demonstrated that the acute heat stress increased serum corticosterone concentrations and mortality and decreased food intake, BW gain, and feed conversion (P < 0.05). We did not find changes in the relative weights of the spleen, thymus, and bursa of Fabricius (P > 0.05). Increases in the basal and the Staphylococcus aureus-induced macrophage oxidative bursts and a decrease in the percentage of macrophages performing phagocytosis were also observed. Finally, mild, multifocal acute enteritis, characterized by the increased presence of lymphocytes and plasmocytes within the lamina propria of the jejunum, was also observed. We found that the stress-induced hypothalamic-pituitary-adrenal axis activation was responsible for the negative effects observed on chicken performance and immune function as well as for the changes in the intestinal mucosa. The data presented here corroborate with those presented in other studies in the field of neuroimmunomodulation and open new avenues for the improvement of broiler chicken welfare and production performance.

The Laboratory Efficacy of Cypermethrin Dust Against Lesser Mealworm Larvae and Adults, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae)

Cypermethrin dust was evaluated as a tool for the integrated management of lesser mealwonns (also called the darkling beetle), Alphitobius diaperinus (Panzer). This experiment examined the efficacy of the cypermethrin against adult and late instar lesser mealwonns under laboratory conditions. Two bioassay methods were evaluated, using either a petri plate or a covered plastic container simulating poultry house conditions. In the simulated conditions, two different samples were used and cypermethrin was either dusted onto the surface of the container or was directly dusted onto the bottom. The LC50 for adults was 636.6 ppm, however, 929.7 ppm of cypermethrin dust was needed to achieve a 50% mortality rate in late instar larvae 24 h after the administration of the insecticide. A similar trend was observed in the simulated poultry houses when the adult mortality was > 90% while effectiveness in late in. star larvae was decreased, i.e., between 50 and 85%. Significant differences in the toxicity profiles were observed in larvae mortality when cypermethrin it was dusted directly onto the litter surface, compared to the bottom of the container. We have verified that cypermethrin dust is available for use in poultry houses however, toxicity profiles of lesser mealworm may depend on the beetle's stage of development and method of application

Current perspectives in avian salmonellosis: Vaccines and immune mechanisms of protection

Salmonellosis is one of the most prevalent foodborne diseases worldwide. Food animals have been identified as reservoirs for nontyphoid Salmonella infections. in poultry, host-specific Salmonella infections cause fowl typhoid and pullorum diseases that produce economic losses in different parts of the world. Several measures have been used to prevent and control Salmonella infections in poultry, and vaccination is the most practical measure because it avoids contamination of poultry products and by-products and prevents disease in humans. Salmonella vaccines can decrease public health risk by reducing colonization and organ invasion, including invasion of reproductive tissues, and by diminishing fecal shedding and environmental contamination. We review available information on the host-specific and non-host-specific Salmonella serotypes found in poultry and the improved understanding of the pathogenesis of and immune responses to infection. We also include some approaches based on updated publications regarding killed and live attenuated vaccines and their immune mechanisms of protection.

Effect of natural antioxidant combinations on lipid oxidation in cooked chicken meat during refrigerated storage

The effect of combinations of sage, oregano and honey on lipid oxidation in cooked chicken meat during refrigeration at 4 degrees C for 96 h was determined. Chicken samples (thigh and breast) were then separated into five groups; control; butylated hydroxytoluene; oregano + sage; oregano + sage + 5%honey and oregano + sage + 10%honey. Quantitative measurements of thiobarbituric acid reactive substances, conjugated dienes, hexanal, fatty acids, cholesterol and cholesterol oxides were used as indicators of lipid oxidation. Acceptability and preference were also evaluated. The effectiveness of the natural antioxidants for reducing the velocity of lipid oxidation in cooked chicken thigh and breast was demonstrated after 48 and 96 h of refrigeration at 4 degrees C. The treatments that presented the lowest hexanal values after 96 h of refrigeration were oregano + sage + 5%honey and oregano + sage + 10%honey. Only traces of free cholesterol oxides were found (25-OH, 7-k, 7 alpha-OH and 7 beta-OH). The natural antioxidants protected cooked chicken meat from oxidation processes and resulted in great acceptability. (C) 2012 Elsevier Ltd. All rights reserved.

Evaluation of the Concentration of Nonessential and Essential Elements in Chicken, Pork, and Beef Samples Produced in Brazil

Food safety is a global concern. Meat represents the most important protein source for humans. Thus, contamination of meat products by nonessential elements is a ready source of human exposure. In addition, knowledge of the concentration of essential elements is also relevant with respect to human nutrition. The aim of the present study was to determine the concentration of 17 elements in pork, beef, and chicken produced in Brazil. Meat samples were analyzed by inductively coupled plasma mass spectrometry. The estimated daily intake for nonessential elements including arsenic (As), cadmium (Cd), lead (Pb), mercury (Hg), and antimony (Sb) through meat consumption is below the toxicological reference values. However, high levels were detected for the nonessential element cesium (Cs), mainly in beef samples, an observation that deserves future studies to identify the source of contamination and potential adverse consequences.

Comparison of Ozone and Chlorine in Low Concentrations as Sanitizing Agents of Chicken Carcasses in the Water Immersion Chiller

The aim of this study was to investigate the effects of the use of chlorine or ozone as sanitizing agents in the water of chicken immersion chilling, using the residual levels usually applied in Brazil (1.5 ppm), comparing the effects of these treatments on the microbiological, physicochemical, and sensory characteristics of carcasses. Chicken carcasses were chilled in water (4 degrees C) with similar residual levels of ozone and chlorine until reaching temperatures below 7 degrees C (around 45 min). The stability of carcasses was assessed during 15 days of storage at 2 +/- 1 degrees C. Microbiological, surface color (L*, a*, b* parameters), pH value, lipid oxidation (thiobarbituric acid reactive substances index), and sensory evaluation (on a 9-point hedonic scale for odor and appearance) analyses were carried out. The presence of Salmonella was not detected, coagulase-positive staphylococci counts were below 10(2) CFU/ml of rinse fluid, and Escherichia coil and total coliform counts were below 10(5) CFU/ml of rinse fluid until the end of the storage period for both treatments. Psychrotrophic microorganism counts did not differ (P > 0.05) between chlorine and ozone treatments, and both values were near 10(9) CFU/ml of rinse fluid after 15 days at 4 +/- 1 degrees C. pH values did not differ between treatments (P > 0.05) or during the storage period (P > 0.05). In addition, neither chlorine nor ozone treatment showed differences (P > 0.05) in the lipid oxidation of carcasses; however, the thiobarbituric acid reactive substances index of both treatments increased (P <= 0.05) during the storage period, reaching values of approximately 0.68 mg of malonaldehyde per kg. Samples from both treatments did not differ (P > 0.05) in their acceptance scores for odor and overall appearance, but in the evaluation of color, ozone showed an acceptance score significantly higher (P <= 0.05) than that for the chlorine treatment. In general, under the conditions tested, ozone showed results similar to the results for chlorine in the disinfection of chicken carcasses in the immersion chilling, which may indicate its use as a substitute for chlorine in poultry slaughterhouses.

RGMa and RGMb expression pattern during chicken development suggest unexpected roles for these repulsive guidance molecules in notochord formation, somitogenesis, and myogenesis

Background: Repulsive guidance molecules (RGM) are high-affinity ligands for the Netrin receptor Neogenin, and they are crucial for nervous system development including neural tube closure; neuronal and neural crest cell differentiation and axon guidance. Recent studies implicated RGM molecules in bone morphogenetic protein signaling, which regulates a variety of developmental processes. Moreover, a role for RGMc in iron metabolism has been established. This suggests that RGM molecules may play important roles in non-neural tissues. Results: To explore which tissues and processed may be regulated by RGM molecules, we systematically investigated the expression of RGMa and RGMb, the only RGM molecules currently known for avians, in the chicken embryo. Conclusions: Our study suggests so far unknown roles of RGM molecules in notochord, somite and skeletal muscle development. Developmental Dynamics, 2012. (C) 2012 Wiley Periodicals, Inc.

Heat stress impairs performance and induces intestinal inflammation in broiler chickens infected with Salmonella Enteritidis

Stressful situations reduce the welfare, production indices and immune status of chickens. Salmonella spp. are a major zoonotic pathogens that annually cause over 1 billion infections worldwide. We therefore designed the current experiment to analyse the effects of 31 +/- 1 degrees C heat stress (HS) (from 35 to 41 days) on performance parameters, Salmonella invasion and small intestine integrity in broiler chickens infected with Salmonella Enteritidis. We observed that HS decreased body weight gain and feed intake. However, feed conversion was only increased when HS was combined with Salmonella Enteritidis infection. In addition, we observed an increase in serum corticosterone levels in all of the birds that were subjected to HS, showing a hypothalamus-pituitary-adrenal axis activation. Furthermore, mild acute multifocal lymphoplasmacytic enteritis, characterized by foci of heterophil infiltration in the duodenum, jejunum and ileum, was observed in the HS group. In contrast, similar but more evident enteritis was noted in the heat-stressed and Salmonella-infected group. In this group, moderate enteritis was observed in all parts of the small intestine. Lastly, we observed an increase in Salmonella counts in the spleens of the stressed and Salmonella-infected chickens. The combination of HS and Salmonella Enteritidis infection may therefore disrupt the intestinal barrier, which would allow pathogenic bacteria to migrate through the intestinal mucosa to the spleen and generate an inflammatory infiltrate in the gut, decreasing performance parameters.

Glycerine derived from biodiesel production as a feedstuff for broiler diets

The performance, carcass traits, and litter humidity of broilers fed increasing levels of glycerine derived from biodiesel production were evaluated. In this experiment, 1,575 broilers were distributed according to a completely randomized experimental design into five treatments with seven replicates of 45 birds each. Treatments consisted of a control diet and four diets containing 2.5, 5.0, 7.5, or 10% glycerine. The experimental diets contained equal nutritional levels and were based on corn, soybean meal and soybean oil. The glycerine included in the diets contained 83.4% glycerol, 1.18% sodium, and 208 ppm methanol, and a calculated energy value of 3,422 kcal AMEn/kg. Performance parameters (weight gain, feed intake, feed conversion ratio, live weight, and livability) were monitored when broilers were 7, 21, and 42 days of age. On day 43, litter humidity was determined in each pen, and 14 birds/treatment were sacrificed for the evaluation of carcass traits. During the period of 1 to 7 days, there was a positive linear effect of the treatments on weight gain, feed intake, and live weight gain. Livability linearly decreased during the period of 1 to 21 days. During the entire experimental period, no significant effects were observed on performance parameters or carcass traits, but there was a linear increase in litter humidity. Therefore, the inclusion of up to 5% glycerine in the diet did not affect broiler performance during the total rearing period.

Occurrence and characterization of rotavirus A in broilers, layers, and broiler breeders from brazilian poultry farms

Rotaviruses are a major cause of diarrhea in humans and animals, including several mammalian and avian species. Using different PCR protocols, we report the occurrence of rotavirus A in 21 (53.84%; 21/39) from 39 fecal pool samples of broilers, layers, and broiler breeders from Brazilian avian farms. We typed the G5, G8, G11, G19, and P[31] genotypes