Detection of T lymphocytes in intestine of broiler chicks treated with Lactobacillus spp. and challenged with Salmonella enterica serovar enteritidis

The expression of immune response in the form of leukocytic infiltrate by CD3+, CD4+, and CD8+ cells in the epithelium and in the intestinal lamina propria of chicks was studied in the present work by means of immunohistochemical reaction. The chicks were treated with Lactobacillus spp. or cecal microflora (CM) and experimentally challenged or not with Salmonella enterica serovar Enteritidis. The 320 birds utilized were divided into 4 groups containing 80 chicks each and submitted to treatments with Lactobacillus reuteri, Lactobacillus salivarius, Lactobacillus acidophilus, and CM. Each group was subdivided into 4 subgroups of 20 birds each and classified into a subgroup that did not receive treatment (negative control), subgroup treated, subgroup treated and challenged with Salmonella Enteritidis, and subgroup only challenged with Salmonella Enteritidis (positive control). The results obtained show that the treatment with L. reuteri, L. salivarius, L. acidophilus, or CM and challenged or not with Salmonella Enteritidis determine immune response in the form of leukocytic infiltrate by CD3+ and CD8+ lymphocytes followed by CD4+ in the epithelium and in the lamina propria of the duodenum, jejunum, and cecum of chicks up to 12 d of age. The quantity of CD3+ lymphocytes was significantly higher (P < 0.05) in the intestine of chicks treated with L. acidophilus or CM and challenged or not with Salmonella Enteritidis; however, the higher quantity of CD8+ lymphocytes was in the intestine of chicks treated with CM and challenged with Salmonella Enteritidis. The duodenum was the segment in which the immune response by T cells (CD3+, CD4+, and CD8+) was stimulated with the greatest intensity, followed by, respectively, the jejunum and cecum. The quantity of CD3+ lymphocytes present in the duodenum, jejunum, and cecum increases with the age of chicks, independent of the stimulus determined by treatments or challenge.

Estimating the thermoneutral zone for broiler breeders using behavioral analysis

Knowledge about bird's heat stress is extensively discussed in the literature. From behavior data collected during the summer of 2000/2001 in an open-sided reduced scale model of a poultry barn, this study estimated the thermoneutral zone for female broiler breeders. The birds were electronically identified and the frequency of use of passage, indicating movement, and drinker, indicating thirst, where the antennas were placed, was recorded. Environmental data such as dry and wet bulb temperature were collected in the geometric center of the model and continuously registered by a datalogger. From the statistical analysis, it was possible to predict a real-time-based zone where the birds showed coherent behavior towards the use of the drinker and movement in the passage. (c) 2007 Elsevier B.V. All rights reserved.

Evaluation of Salmonella-Lytic Properties of Bacteriophages Isolated from Commercial Broiler Houses

Because of recent interest in bacteriophage therapy in poultry, information regarding the interaction of bacteriophages and potential host bacteria in the environment should be collected. The present studies were initiated with a rather typical commercial broiler integrator within the south-central United States to examine environmental Salmonella levels in two broiler complexes, attempt to isolate Salmonella-lytic bacteriophages, and elucidate a possible reason for differing apparent Salmonella prevalence. Significantly ( P<0.05) less Salmonella was isolated from houses in complex 1 ( 15/44 [ 34%] Salmonella-positive drag swabs) as compared to houses in complex 2 ( 22/24 [ 92%]). A total of seven Salmonella-lytic bacteriophages were isolated from Salmonella-positive environments, and two bacteriophages were isolated from a single Salmonella-negative house. During the initial bacteriophage isolation, individual bacteriophages did not replicate in the Salmonella host isolated from the same environment, and lysis of additional Salmonella hosts relied on high numbers of bacteriophage to be present. This suggests that the presence of these bacteriophages in the environment of a commercial broiler house had little to no effect on the presence of Salmonella. This study highlights the need to find additional bacteriophage sources, more effective isolation methods, and more innovative approaches to using bacteriophages to treat enteric disease.

Effect of Phytase Supplementation in Diets on Nutrient Digestibility and Performance in Broiler Chicks

A performance trial was conducted with broiler chicks to Study the effect of phytase (PHY) supplementation in diets formulated With reduced AME, Ca, and P. The nutrient digestibility was determined during the 14- to 21-d and 28- to 35-d periods. The treatments consisted of 3 diets (NC1, NC2. NC3) differing ill nutrient content and each diet with Or without supplemental PHY (NC1, 0 oi 500; NC2, 0 or 750; NC3, 0 or 1,000 U of PHY/kg feed) and I positive control diet (PC). Compared with the PC diet. negative control diets (NC) resulted in lower AME and apparent ileal amino acid digestibility for some amino acids. Phytase Supplementation of the NC diets increased AME. apparent ileal amino acid digestibility, and apparent ileal crude protein digestibility. Phytase addition also increased mineral absorption in 2 1 - and 35-d-old broilers fed NC diets. Reduced nutrient digestibility appears to be I factor in the weight gain and feed intake results. Reducing Ca and P content reduced feed intake in a stepwise fashion in the NC diets. Phytase increased feed intake and generally improved nutrient digestibility, which resulted in an increase in digestible nutrient intake. Averaged across NC diets. PHY improved body weight. Bone-breaking strength was the most consistent predictor of Ca and P reduction. All NC diets had significantly lower bone-breaking strength than the PC. Phytase supplementation of the NC diets gave bone-breaking strengths that were comparable to the PC. Diets with PHY had the highest bioeconomic index.

Broiler breeder trace mineral nutrition and feeding practices on embryo progeny development

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of dietary protein level on the broiler chicken's response to methionine and betaine supplements

Two experiments were conducted to compare broiler chicken responses to methionine and betaine supplements when fed diets with low protein and relatively high metabolizable energy levels (17%, 3.3 kcal/g) or moderate protein and lower metabolizable energy levels (24%, 3.0 kcal/g), resulting in different levels of carcass fat. In Experiment 1, the basal diets were formulated with corn, soybean meal, poultry by-product meal, and poultry oil. In Experiment 2, glucose monohydrate was also added, so that identical amino acid profiles could be maintained in the 17 and 24% protein diets. On average, feeding the 17 vs. 24% protein diet decreased 21-d body weight gain by 20%, increased feed conversion ratio (FCR) by 13%, and increased abdominal fat pad weight by 104%. Methionine and betaine supplements improved the performance of chicks fed the 24% protein diet in both experiments, as indicated by body weight gain and FCR. Only supplementary methionine increased performance of chicks fed 17% protein diets, and then only in Experiment 2. Neither methionine nor betaine decreased abdominal fat pad size in either experiment. Methionine supplementation decreased relative liver size and increased breast muscle protein. Both methionine and betaine increased sample feather weight, but when expressed as a percentage of body weight, no significant differences were detected. It is concluded that increasing carcass fat by manipulating percentage dietary protein level or amino acid balance does not influence betaine's activity as a lipotropic agent.

Broiler Response to Different Wind Speeds

Broiler production in Brazil has turned into a very competitive activity in the late years. Constant innovation leads to higher productivity maintaining the same cost of production, which is a desirable situation. Lately one characteristic for broiler housing in Brazil has been the increase in birds density requiring the use of controlled environment through the use of fan and fogging systems in order to achieve better birds productive performance. Most Brazilian producer already uses cooling equipment however it is still unknown the right way to control the wind speed and direction towards the birds. This present research has the objective to evaluate the effect of the wind speed on the heat transfer from the birds to the environment for broilers at 27 days old. There was used 200 birds, placed in a wind tunnel measuring 1.10 m high by 1.10m wide x 10.0 m of length, and the birds density varied from 9, 16 and 20 birds/m 2. Two wind speed were simulated 340 rpm (1.0 m/s) and 250 rpm (0.3 m/s). The increase in the wind velocity related to the smaller bird densityled to a higher heat loss and to a more uniform temperature distribution in its exposed areas.

Sodium and chloride requirements of young broiler chickens fed corn-soybean diets (one to twenty-one days of age)

Sodium (Na+) and chloride (Cl-) nutritional requirements, dietary electrolyte balance (DEB), and their effects on acid-base balance, litter moisture, and tibial dyschondroplasia (TD) incidence for young broiler chickens were evaluated in two trials. One-day-old Cobb broilers were distributed in a completely randomized design with six treatments, five replicates, and 50 birds per experimental unit. Treatments used in both experiments were a basal diet with 0.10% Na+ (Experiment 1) or Cl- (Experiment 2) supplemented to result in diets with Na+ or Cl- levels of 0.10, 0.15, 0.20, 0.25 ,0.30, or 0.35%, respectively. In Experiment 1, results indicated an optimum Na+ requirement of 0.26%. Sodium levels caused a linear increase in arterial blood gas parameters, indicating an alkalogenic effect of Na+. The hypertrophic area of growth plate in the proximal tibiotarsi decreased with Na+ levels. The TD incidence decreased with increases in dietary Na+. Litter moisture increased linearly with sodium levels. In Experiment 2, the Cl- requirement was estimated as 0.25%. Chloride levels caused a quadratic effect (P ≤ 0.01) on blood gas parameters, with an estimated equilibrium [blood base excess (BE) = 0] at 0.30% of dietary CT-. No Cl- treatment effects (P ≥ 0.05) were observed on litter moisture or TD incidence. The best DEB for maximum performance was 298 to 315 mEq/kg in Experiment 1 and 246 to 264 mEq/kg in Experiment 2. We concluded that the Na+ and Cl- requirements for optimum performance of young broiler chickens were 0.28 and 0.25%, respectively.

Evaluation of plasma membrane integrity of frozen-thawed goat spermatozoa with or without seminal plasma

The aim of the present work was to evaluate plasma membrane integrity, motility, vigor and morphology of fresh and frozen goat spermatozoa with or without seminal plasma. Semen samples were diluted in Tris solution, before and after thawing, with a combination of carboxifluorescein diacetate and propidium iodide. The results showed differences (P < 0.01) for motility and minor defects in the presence or absence of seminal plasma, for both fresh and frozen samples. Periods of collection had a significant effect on motility, probably due to changes in the photoperiod. Plasma membrane integrity was significantly reduced by the freezing process, whether seminal plasma was present or absent. In conclusion, removal of seminal plasma decreased motility and vigor rates in frozen samples. The photoperiod probably decreased the testosterone level, contributing negatively to the high percentage of sperm abnormalities, mainly damaged membranes. The use of fluorescent probes allowed a better estimation of the percentage of functional cells, instead of only estimating the percentage of motile cells or morphology defects. © 2001 Elsevier Science B.V. All rights reserved.

Dietary electrolyte balance for broiler chickens under moderately high ambient temperatures and relative humidities

Cobb male broiler chicks (1,000) on new litter were used to evaluate effects of dietary electrolyte balance [DEB; Na+K-Cl, milliequivalents (mEq) per kilogram] under tropical summer conditions. Corn-soybean meal-based mash diets had salt (NaCl) alone or in combination with one or more supplements: sodium bicarbonate (NaHCO3), ammonium chloride (NH4Cl), or potassium bicarbonate (KHCO3). A completely randomized design, with five starter and grower feed treatments (control: 145, then 130 mEq/kg; or 0, 120, 240, or 360 mEq/kg throughout) and four replicate pens (1.5 x 3.2 m) per treatment (50 chicks per pen), was used. Diets were analyzed for Na, K, and Cl for confirmation. There were no significant (P < 0.05) effects of treatments on mortality or processing parameters. Water intake increased linearly with increasing DEB, giving higher litter moistures and lower rectal temperatures. Blood HCO3 and pH increased with the highest DEB (360 mEq/kg) causing respiratory alkalosis. The DEB of 240 mEg/kg gave best weight gain and feed conversion ratio, and ideal DEB predicted by regression analyses were 186 and 197 mEq/kg from 0 to 21 d of age and 236 and 207 mEq/kg of feed from 0 to 42 d, respectively. These DEB corresponded to estimated (interpolated) values in predicted optimal 186 to 197 mEq/kg starter of Na 0.38 to 0.40% and Cl 0.405 to 0.39% (K = 0.52%), in 207 to 236 mEq/kg starter, Na 0.409 to 0.445% and Cl 0.326 to 0.372% Cl (K = 0.52%), and in grower Na 0.41 to 0.445%, Cl 0.315 to 0.267% (K = 0.47%).

Modeling metabolizable energy utilization in broiler breeder pullets

The objective of this study was to determine models for ME requirements for broiler breeder pullets using the factorial method. The influence of the temperature on maintenance ME requirements was determined by experiments conducted in three environmental rooms with temperature kept constant at 15, 22, and 30°C, using the comparative slaughter technique. The energy requirements for weight gain were determined based on the body energy content and efficiency of energy utilization for weight gain. Two ME requirement models for each age were developed using the coefficients for maintenance and weight gain. The models for 3 to 8 wk were ME = W 0.75 (186.52 - 1.94T) + 2.47WG, and ME = W 0.75 (174 - 1.88T) + 2.83WG; for 9 to 14 wk, ME = W 0.75 (186.52 - 1.94T) + 2.69WG, and ME = W 0.75 (174 - 1.88T) + 2.50WG; and 15 to 20 wk, ME = W 0.75 (186.52 - 1.94T) + 2.76WG, and ME = W 0.75 (174 - 1.88T) + 3.24WG. In these equations, W is BW (kg), T is temperature (°C), and WG is daily weight gain (g). These models were compared to the breeder's recommendations in a feeding trial from 5 to 20 wk of age. Models 1 and 2 provided energy intakes that promoted BW smaller than the breeder's recommendation. However, all breeder pullets had weights above the standard recommendation. Model 2 gave the smallest ME intake and BW close to the standard recommendation and provided the best prediction of ME requirements.

Dietary electrolyte balance for broiler chickens exposed to thermoneutral or heat-stress environments

Ross male broiler chicks (n = 480) on new litter were used in a randomized block design with two blocks (environmental rooms) and four treatments having four replicate pens (1.0 × 2.5 m; 15 chicks) each to evaluate dietary electrolyte balance (DEB; P < 0.05). Two rooms were 1) thermoneutral (Weeks 1 through 6, with decreasing maximum from 32 to 25°C and minimum from 28 to 19°C; relative humidity 49 to 58%) and 2) cyclic daily heat stress (Weeks 1 and 2, thermoneutral; Weeks 2 through 6, maximum temperatures 35, 35, 33, and 33°C, respectively; and minimum temperatures 23, 20, 19, and 19°C, respectively; relative humidity 51 to 54%). The DEB treatments (0, 140, 240, or 340 mEq Na + K - Cl/kg) had NaHCO3 plus NH4Cl, or KHCO3, or both added to corn-soybean meal mash basal diets with 0.30% salt (NaCl). In the thermoneutral room, DEB 240 increased 42-d weight gain and 44-d lymphocyte percentage and decreased heterophil percentage and heterophil to lymphocyte ratio compared to the DEB 40 treatment. The DEB 240 diets had 0.35 and 0.35% Na and 0.37% and 0.29% Cl in starter (0.75% K) and grower (0.67% K) diets, respectively. No DEB treatment differences were found in the heat stress room. For combined rooms, 42-d feed intake was higher for DEB 240 than for DEB 40. The 21-d weight gain was higher for DEB 240 than for DEB 40 or 140; and 21-d feed/gain was lower for DEB 40 than for DEB 340. The predicted maximum point of inflection for 21- and 42-d weight gains were DEB 250 and 201, with highest 42-d feed intake at 220.