Use of Pyrosequencing and Denaturing Gradient Gel Electrophoresis to Examine the Effects of Probiotics and Essential Oil Blends on Digestive Microflora in Broilers Under Mixed Eimeria Infection

A protective digestive microflora helps prevent and reduce broiler infection and colonization by enteropathogens. In the current experiment, broilers fed diets supplemented with probiotics and essential oil (EO) blends were infected with a standard mixed Eimeria spp. to determine effects of performance enhancers on ileal and cecal microbial communities (MCs). Eight treatment groups included four controls (uninfected-unmedicated [UU], unmedicated-infected, the antibiotic BMD plus the ionophore Coban as positive control, and the ionophore as negative control), and four treatments (probiotics BC-30 and Calsporin; and EO, Crina Poultry Plus, and Crina PoultryAF). Day-old broilers were raised to 14 days in floor pens on used litter and then were moved to Petersime batteries and inoculated at 15 days with mixed Eimeria spp. Ileal and cecal samples were collected at 14 days and 7 days postinfection. Digesta DNA was subjected to pyrosequencing for sequencing of individual cecal bacteria and denaturing gradient gel electrophoresis (DGGE) for determination of changes in ileal and cecal MC according to percentage similarity coefficient (%SC). Pyrosequencing is very sensitive detecting shifts in individual bacterial sequences, whereas DGGE is able to detect gross shifts in entire MC. These combined techniques offer versatility toward identifying feed additive and mild Eimeria infection modulation of broiler MC. Pyrosequencing detected 147 bacterial species sequences. Additionally, pyrosequencing revealed the presence of relatively low levels of the potential human enteropathogens Campylobacter sp. and four Shigella spp. as well as the potential poultry pathogen Clostridiun perfringens. Pre- and postinfection changes in ileal (56%SC) and cecal (78.5%SC) DGGE profiles resulted from the coccidia infection and with increased broiler age. Probiotics and EO changed MC from those seen in UU ilea and ceca. Results potentially reflect the performance enhancement above expectations in comparison to broilers not given the probiotics or the specific EO blends as feed supplements.

Breeding of Ornidia obesa (Diptera: Syrphidae: Eristalinae) on Pig Carcasses in Brazil

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

Use of lytic bacteriophage for control of experimental Escherichia coli septicemia and meningitis in chickens and calves

A lytic bacteriophage, which was previously isolated from sewage and which attaches to the K1 capsular antigen, has been used to prevent septicemia and a meningitis-like infection in chickens caused by a K1+ bacteremic strain of Escherichia coli. Protection was obtained even when administration of the phage was delayed until signs of disease appeared. The phage was able to multiply in the blood. In newly borne colostrum-deprived calves given the E. coli orally, intramuscular inoculation of phage delayed appearance of the bacterium in the blood and lengthened life span. With some provisos there is considerable potential for this approach to bacterial-disease therapy.

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.

Detection of infectious bronchitis virus in experimentally infected chickens by an antigen-competitive ELISA

An antigen-competitive enzyme-linked immunosorbent assay (Ag-C-ELISA) was developed for the detection of infectious bronchitis virus (IBV) antigens, M41 strain, in tissues from experimentally infected chickens, or in allantoic fluid harvested from inoculated embryonated eggs. The detection limit of IBV in the Ag-C-ELISA was 104.1 median embryo infective doses (EID50)/well. Tracheal and lung samples from chickens vaccinated with 102.5 EID50 of live attenuated infectious bronchitis (H120) vaccine were negative in the direct detection Ag-C-ELISA. The results indicate that the Ag-C-ELISA has the potential to detect IBV, either directly in tissue samples or when combined with the passage of material in embryonated eggs, thereby constituting an alternative method for the diagnosis of IBV.

Organophosphate induced delayed neuropathy in genetically dissimilar chickens: Studies with tri-ortho-cresyl phosphate (TOCP) and trichlorfon

Measurements of plasma cholinesterase (pl.ChE), brain cholinesterase (Br.ChE) and brain Neuropathy Target Esterase (Br.NTE) were made in three different lineages of chickens. All birds received toxicants through gavage in a single oral dose between 08:00 and 09:00 h, after overnight fast. Babcock chickens were treated with 800 mg/kg tri-ortho-cresyl phosphate (TOCP) or 80 mg/kg trichlorfon. The TOCP group had 82% Br.NTE inhibition, when compared to the control group, and no birds displayed symptoms of clinical organophosphate-induced delayed neuropathy (OPIDN). Hy-line w36 lineage chickens were given 1600 mg/kg TOCP and despite this higher dose, Br.NTE inhibition was similar that presented by Babcock chickens. Isabrown chickens were given 1600 mg/kg TOCP or 80 mg/kg trichlorfon. At 36 h all trichlorfon treated birds had from 80 to 90% inhibition of Pl.ChE and Br.ChE, when compared to controls. However, Br.NTE was inhibited less than 20%, and there were no clinical signs of OPIDN. All TOCP treated isabrown chickens had more than 80% Br.NTE inhibition while one of them exhibited just light signs of OPIDN, two chickens became totally paralyzed. This finding suggested that chicken strain was important in the appearance of OPIDN. In addition, 70-80% of NTE inhibition was necessary but was not sufficient to produce OPIDN in chickens, since babcock and hy-line w36 chickens exhibited NTE inhibition in the range of 70-80% without clinical signs of OPIDN. © 2002 Elsevier Science Ireland Ltd. 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%).

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.

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.

Efeito da temperatura ambiente e da restrição alimentar protéica ou energética sobre o ganho de peso e crescimento ósseo de frangos de corte

The effect of protein or energy restriction during the second week post-hatching on body weight gain and femur development of broiler chickens reared at different environmental temperatures (18°C, 25°C and 33°C) was studied. From 1 to 7 days of age and after a restriction period broilers were fed on a control diet with 2850 kcal ME/kg and 20% crude protein. From 8 to 14 days of age, two groups of broilers were fed on restricted energy and protein diets with 2565kcal ME/kg and 20% of crude protein or 2850kcal ME/kg and 15% of crude protein, respectively. At 14, 21, 28, 35 and 42 days, the bones were weighed and the length and width of bones measured. The protein restriction reduced the body weight gain and the diameter of bone at second week of life. After 21 days of age no differences between treatments for these traits were observed. The body weight gain and femur growth were not affected by energy restriction. The high temperature (33°C) reduced weight gain and femur diameter from 21 to 42 days of age, and femur length at 42 days of age. The protein restriction at second week or the high environmental temperature after 21 st day of life decreased body weight gain and femur growth of broiler chickens.

Different criteria for feed formulation based on digestible amino acids for broilers

An experiment was carried out to evaluate different criteria in feed formulation based on digestible amino acids for broilers during the grower phase. Diets were formulated according to the recommendations for digestible methionine, methionine + cysteine, lysine, and threonine. A total number of six hundred Cobb 500 male day-old chicks were distributed in a completely randomized experimental design, with three formulation criteria supplying the recommendations established by Baker & Chung (1992), Degussa (1997), and Rostagno et al. (2000), with 4 replicates of 50 birds each. No significant differences were observed for weight gain and feed intake. However, feed conversion ratio improved when birds were fed the diets containing the profiles recommended by Baker & Chung (1992) and Degussa (1997). No difference was observed in terms of leg, wings, back, and head yields. Broilers fed with the profile of Baker & Chung (1992) presented worst breast yield, whereas those fed the Degussa (1997) standard had better carcass yield.

Surface area of the tip of the enterocytes in small intestine mucosa of broilers submitted to early feed restriction and supplemented with glutamine

A total of 640 one-day-old male Cobb chicks were used to evaluate the effects of early feed restriction and glutamine on villi density and tip surface of enterocytes in the small intestine of broilers. A two-factor factorial experimental design with glutamine and feed restriction as main factors was used. Treatments consisted of quantitative feed restriction at 30% of ad libitum intake from 7 to 14 days of age, and glutamine addition at 1% in the diet from 1 to 28 days of age. Sections of the small intestine (duodenum, jejunum, ileum) were collected at 14 and 21 days of age for analyses by scanning and transmission electron microscopy. Villi density decreased with age and increased in cranial-caudal direction. Glutamine increased villi density in the small intestine. Microvilli density and height decreased with age. Glutamine increased microvilli width. The jejunum was the segment with the largest surface area of the tip of the enterocytes, followed by the duodenum and the ileum. Feed restriction decreased the surface area of the tip of the enterocytes in the small intestine at 14 and at 21 days of age. Glutamine supplemented in the feed increased the surface area of the tip of the enterocytes of the jejunum and ileum at 21 days of age. © Asian Network for Scientific Information, 2007.

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.