Tracing metabolic routes of feed ingredients in tissues of broiler chickens using stable isotopes

The present study aimed to quantify the proportion of 13C from energy and protein feed ingredients that follow the metabolic routing of the liver and muscle in broiler chickens. A stable isotope of carbon technique was used that is based on the isotopic discrimination that occurs in the plants during the photosynthesis process. One-day-old male chicks were subjected to treatments based on free choice of energy and protein sources. Rice bran (R) and soybean meal (S), C3 plants, have higher isotopic ratios than corn (C), a C4 plant, and corn gluten meal (G). Choices were R+S, C+G, R+G, C+S, or R+C+G+S. A complete feed (CF) was a sixth treatment. Feed intake and BW were measured at 30 d of age, when liver and breast muscle were collected for isotopic analysis. Treatments affected the amount of feed intake and the choices of energy or protein sources. Complete feed had the largest intake, differing from the other treatments that had free-choice feeding. Final BW was a direct reflection of consumption by these birds in all treatments. The isotopic results indicated that the 13C/12C ratio was generally higher in breast muscle than in liver, probably because of higher protein content. Moreover, in the liver, the proportion of 13C retained from the energy ingredient was greater than the proportion from the protein ingredient. That is in contrast to muscle, where the proportion of 13C retained from the protein ingredient was greater than from the energy ingredient that was self-selected.

Physiological responses of broiler chickens to heat stress and dietary electrolyte balance (sodium plus potassium minus chloride, milliequivalents per kilogram)

Individually caged male Cobb broilers (24), 44 d of age, were used to evaluate effects of heat stress (1 d of data collection) and dietary electrolyte balance (DEB; Na + K - Cl, mEq/kg from 1 d of age). During summer rearing, mortality was variable, but DEB 240 improved growth, feed conversion ratio, water intake, and waterrfeed ratio vs. DEB 0. The temperature sequence for heat stress was 24 to 32°C in 30 min, 32 to 36°C in 30 min, 36 to 37°C in 15 min, and 37 to 41°C in 45 min. Maximum temperature was held for 15, 60, 90, or 360 min for data collection (relative humidity averaged 42 ± 7%). Results from the same room before and after heat stress were analyzed by DEB (1-factor ANOVA) and before vs. after heat stress compared across DEB (2-sample t-test). Heat stress decreased blood Na, K, and pCO2, and lymphocytes but increased heterophils. Blood HCO3 rose, Cl declined, and hematocrit gave a concave pattern (lowest at DEB 120) as DEB increased. After heat stress, DEB O decreased blood Na and K, and DEB O and 120 levels decreased blood HCO3. After heat stress blood pCO2 and hemoglobin decreased with DEB 240, but it had highest pCO2, a key factor. The DEB 120 gave longest times to panting and prostration with DEB O and 240 results lower but similar statistically. In heat stress, DEB 360 was excessive, DEB 120 and 240 were favorable, and DEB 0 was intermediate based on hematology, panting, and prostration responses.

Modeling energy utilization and growth parameter description for broiler chickens

Two experiments were conducted to develop and evaluate a model to estimate ME requirements and determine Gompertz growth parameters for broilers. The first experiment was conducted to determine maintenance energy requirements and the efficiencies of energy utilization for fat and protein deposition. Maintenance ME (ME m) requirements were estimated to be 157.8, 112.1, and 127.2 kcal of ME/kg 0.75 per day for broilers at 13, 23, and 32°C, respectively. Environmental temperature (T) had a quadratic effect on maintenance requirements (ME m = 307.87 - 15.63T + 0.3105T 2; r 2= 0.93). Energy requirements for fat and protein deposition were estimated to be 13.52 and 12.59 kcal of ME/g, respectively. Based on these coefficients, a model was developed to calculate daily ME requirements: ME = BW 0.75 (307.87 - 15.63T + 0.3105 T 2) + 13.52 G f + 12.59 G p. This model considers live BW, the effects of environmental temperature, and fractional fat (G f) and protein (G p) deposition. The second experiment was carried out to estimate the growth parameters of Ross broilers and to collect data to evaluate the ME requirement model proposed. Live BW, empty feather-free carcass, weight of the feathers, and carcass chemical compositions were analyzed until 16 wk of age. Parameters of Gompertz curves for each component were estimated. Males had higher growth potential and higher capacity to deposit nutrients than females, except for fat deposition. Data of BW and body composition collected in this experiment were fitted into the energy model proposed herein and the equations described by Emmans (1989) and Chwalibog (1991). The daily ME requirements estimated by the model determined in this study were closer to the ME intake observed in this trial compared with other models. ©2005 Poultry Science Association, Inc.

Effect of organic acids and probiotics on Salmonella enteritidis infection in broiler chickens

The effect of an organic acid mixture (OA) and a Lactobacillus-based probiotic culture on Salmonella enteritidis (SE) infection in broiler chicks was evaluated. In exp. 1, chicks were challenged by oral gavage with SE, held in chick boxes for 2 h and randomly assigned to either untreated control or continuous OA treatment in the drinking water. Crop and cecal tonsils were cultured at 48 h and 5 d post-challenge for recovery of SE. Recovery of SE in the crop and cecal tonsils at 48 h was significantly (p<0.05) lower in the OA treated group as compared to control chickens but not different at 5d. In exps.2 and 3, chicks were SE challenged, held in chick boxes for 2 h and randomly assigned to either untreated control, probiotic, OA, or probiotic+OA. After 24 or 48 h, crop and cecal tonsils were cultured for the presence or absence of SE. After 24 h, probiotic or probiotic+OA significantly reduced SE recovery from the crop as compared to controls. All treatments reduced SE recovery from the cecal tonsils at 24 h. While no significant differences were observed in SE recovery from crop at 48 h, SE recovery from probiotic and or probiotic+OA groups was significantly lower than the controls in the cecal tonsils. These data suggest that combination treatment with the selected OA and Lactobacillus-based probiotic culture is more effective than individual treatment for Salmonella reduction in chicks. © Asian Network for Scientific Information, 2007.

Evaluation of tibial dyschondroplasia development in broiler chickens fed diets containing 25 hydroxicolecalciferol

This research was carried out to evaluate the development of tibial dyschondroplasia (TD) in broilers from 1 to 21 days. Four hundred forty day-old male chickens, from broiler breeders aged 60-62 weeks, were randomly distributed in a 3×3+2 factorial arrangement, resulting in 11 treatments with four replicates of 10 birds each. The factors evaluated were: bird strains (Ross 308, Cobb 500, and Hybro), levels and sources of vitamin D (1250UI D3/kg without 25-(OH)D3; 1250UI D3/kg with 69mg 25-(OH)D3/ton, and 3000UI D3/kg with 69mg 25-(OH)D3/ton), and two control treatments containing calcium and phosphorus levels with 3000UI D3/kg without 25-(OH)D3 and 3000UI D3/kg with 69mg 25- (OH)D3/ton of feed. Bone characteristics were evaluated. From 1 to 21 days, the results showed that bone calcium and phosphorus concentrations were not influenced by the treatments, however, feed intake was higher for factorial than control treatments. Bone breaking resistance was not influenced by the treatments and there were no typical lesions of TD. In conclusion, it was not observed TD development in broilers from 1 to 21 days according to experimental procedures of this research.

Mean surface temperature prediction models for broiler chickens-a study of sensible heat flow

Body surface temperature can be used to evaluate thermal equilibrium in animals. The bodies of broiler chickens, like those of all birds, are partially covered by feathers. Thus, the heat flow at the boundary layer between broilers' bodies and the environment differs between feathered and featherless areas. The aim of this investigation was to use linear regression models incorporating environmental parameters and age to predict the surface temperatures of the feathered and featherless areas of broiler chickens. The trial was conducted in a climate chamber, and 576 broilers were distributed in two groups. In the first trial, 288 broilers were monitored after exposure to comfortable or stressful conditions during a 6-week rearing period. Another 288 broilers were measured under the same conditions to test the predictive power of the models. Sensible heat flow was calculated, and for the regions covered by feathers, sensible heat flow was predicted based on the estimated surface temperatures. The surface temperatures of the feathered and featherless areas can be predicted based on air, black globe or operative temperatures. According to the sensible heat flow model, the broilers' ability to maintain thermal equilibrium by convection and radiation decreased during the rearing period. Sensible heat flow estimated based on estimated surface temperatures can be used to predict animal responses to comfortable and stressful conditions. © 2013 ISB.

Effect of lipid sources and inclusion levels in diets for broiler chickens

This research aimed to evaluate the interactions and effects of 2 and 4% addition levels of poultry slaughterhouse fat (chicken tallow) and soybean oil in diets for broiler chickens. Two experiments were carried out using one-day-old male Cobb chicks in an entirely random design with a 2x2 factorial scheme. In the first experiment, 560 chicks were used to evaluate performance and carcass characteristics. In the second experiment, 100 chicks were used to determine the nutrient digestibility, dietary energy utilization and the lipase and amylase pancreatic activity. There was no interaction between the fat sources and the addition levels for any of the analyzed variables, except for the digestibility coefficient of dry matter (DCDM), which was higher in diets added with 2% soybean oil when compared to chicken tallow. The addition of 4% fat in the diet, regardless of fat source, improved the digestibility coefficient of ethereal extract (DCEE) and increased weight gain and feed intake. Moreover, in the initial phase, the addition of 4% fat to the diet increased lipase activity when compared to diets with 2% addition, and a positive correlation between DCEE and pancreatic lipase activity was observed. In conclusion, there is no interaction between fat sources and addition levels, except for DCDM. Carcass characteristics are not influenced by any of the studied factors. The addition of 4% fat increases pancreatic lipase activity and improves DCEE, resulting in greater weight gain, regardless of the tested fat source, making chicken tallow a great alternative to soybean oil.

Induction of immune response in broiler chickens immunized with recombinant FliC and challenged by Salmonella Typhimurium

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bacteriophage- induced reduction in Salmonella Enteritidis counts in the crop of broiler chickens undergoing preslaughter feed withdrawal

Salmonella food poisoning is a public health problem. Feed withdrawal from broiler chickens before slaughter can favor the multiplication of Salmonella in the cecum and crop of contaminated animals and subsequently lead to contamination of carcasses in the processing plant. In the present study, a cocktail of lytic bacteriophages isolated from sewage water was orally administered to 45-d-old broiler chickens 1 h after they received an oral dose of 107 cfu/mL Salmonella enterica subspecies enterica serotype Enteritidis. Immediately after phage administration and 30 min, 1, 3, 6, and 12 h thereafter, groups of chicken were killed. Ceca and crops were analyzed for the presence of Salmonella. At 3 h posttreatment, there were 103 cfu/g and 101 cfu/g of cecal and crop suspension, respectively. At 6 h after treatment, the number of Salmonella was 103 cfu/g in the cecal suspension, but below the detection limit in the crops. our results suggest that bacteriophage therapy may be able to reduce the contamination of chicken carcasses by reducing the preslaughter load of Salmonella in the birds.

Immune response of broiler chickens immunized orally with the recombinant proteins flagellin and the subunit B of cholera toxin associated with Lactobacillus spp.

Processo FAPESP: 09/53570-3

A meta-analysis of the feed intake and growth performance of broiler chickens challenged by bacteria

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of a commercially available organic acid product on body weight loss, carcass yield, and meat quality during preslaughter feed withdrawal in broiler chickens: A poultry welfare and economic perspective

The effect of a commercial organic acid (OA) product on BW loss (BWL) during feed withdrawal and transportation, carcass yield, and meat quality was evaluated in broiler chickens. Two experiments were conducted in Brazil. Commercial houses were paired as control groups receiving regular water and treated groups receiving OA in the water. Treated birds had a reduction in BWL of 37 g in experiment 1 and 32.2 g in experiment 2. In experiment 2, no differences were observed in carcass yield between groups. Estimation of the cost benefit suggested a 1: 16 ratio by using the OA. In experiment 3, conducted in Mexico, significant differences on water consumption, BWL, and meat quality characteristics were observed in chickens that were treated with the OA (P < 0.05). These data suggest this OA product may improve animal welfare and economic concerns in the poultry industry by reducing BWL and improving meat quality attributes.

Effects of Lactobacillus Probiotic, P22 Bacteriophage and Salmonella Typhimurium on the Heterophilic Burst Activity of Broiler Chickens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of hydrolyzed copra meal separately or in combination with Bacillus cereus var. toyoi on growth performance of broiler chickens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Analysis of the intestinal bacterial microbiota in maize- or sorghum-fed broiler chickens using real-time PCR

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)