Effect of acute heat stress on heat shock protein 70 messenger RNA and on heat shock protein expression in the liver of broilers

1. The synthesis of heat shock protein 70 (Hsp70) mRNA and the expression of Hsp70 in the liver of broiler chickens submitted to acute heat stress (35 degrees C for 5 h) was investigated.2. Hsp70 expression was detected by SDS-PAGE and Western blot analysis using a polyclonal antiserum against Hsp70 of Blastocladiella emersonii. The specific signal of Hsp70 mRNA was analysed by Northern blot using as probe a Hsp70 cDNA of B. emersonii.3. An increase in the amount of Hsp70 was detected from the first up to the fifth hour of acute heat exposure. This increase in the amount of Hsp70 was accompanied by an increase in Hsp70 mRNA which peaked at 3 h.4. This study shows that the heat induced increase in Hsp70 mRNA and protein in broiler liver, in vivo, are time dependent, similar to that in mammals.

Microbiological analyses of poultry litter used for ruminant feeding

The aims of this study were to estimate the changes in total bacterial counts (TBC) in poultry litter samples, consisting of rice hulls, after storage, and to identify pathogenic bacteria. For the countings Plate Count agar (Difco) was used. Enrichment and selective media such as blood agar, MacConkey, Baird Parker, brain and heart agar, and egg yolk solid media, and cooked meat and brain and heart infusion, incubated under aerobic or anaerobic conditions were used to isolate Staphylococcus aureus, Salmonella sp, Clostridium perfringens, C. botulinum, C. chauvoei, Campylobacter sp, Escherichia coli, and Corynebacterium sp. Litter samples were collected from the houses of the Veterinary School experimental aviary. A fully randomized experimental design was used with four treatments and four replications, for a total of 16 samples. A decrease in TBC was detected when treatment T1 (zero days of storage) was compared with treatments T2 (14 days of storage). on the other hand the treatments T3 (28 days of storage) and T4 (42 days of storage) presented significantly superior counting in relation to treatment T1. Some pathogenic bacteria of Enterobacteriaceae such as Escherichia coil, Proteus, Arizona, Providencia, Edwardsiella, as well as Staphylococcus aureus, S. epidermidis, different species of genus Clostridium as C. perfringens, C. sordelli, C. chauvoei, C. tetani and C. novyi as well as some strains of Corynebacterium pyogenes were isolated.

Inhibition between Salmonella-strains - A new aspect of Salmonellosis control in poultry

Freshly hatched chickens show a very high susceptibility to Salmonella infections and control measures are therefore frequently focused on the period shortly after hatching. Experimental investigations using one strain against itself, differentiated by different antibiotic resistance markers, have shown that colonisation with Salmonella prevents the establishment of subsequently inoculated challenge organisms in the chicken gut. The inhibition effect lasts for several days and is detectable even when a challenge dose of 10(8) organisms is used. It is independent of the breed of bird. Chickens colonised with Salmonella shed a subsequently inoculated challenge strain with significant lower numbers for several weeks than do non colonised control birds. The phenomenon is strain specific but not serovarspecific as has been shown in investigations using different strains of the same and other serovars for colonisation and challenge. The phenomenon shows a large variability between strains. Using other Enterobacteriaceae strains comparable inhibition against Salmonella was not observed.One important topic for further investigation is the capability of Salmonella live Vaccines given orally to establish a protection effect, based on the inhibition phenomenon in the first few days of live, developing into a long-lasting immunity when the birds reach immunological maturity.

Mapping QTLs on chicken chromosome 1 for performance and carcass traits in a broiler x layer cross

With the objective of mapping quantitative trait loci (QTLs) for performance and carcass traits, an F-2 chicken population was developed by crossing broiler and layer lines. A total of 2063 F-2 chicks in 21 full-sib families were reared as broilers and slaughtered at 42 days of age. Seventeen performance and carcass traits were measured. Parental (F-0) and F-1 individuals were genotyped with 80 microsatellites from chicken chromosome 1 to select informative markers. Thirty-three informative markers were used for selective genotyping of F-2 individuals with extreme phenotypes for body weight at 42 days of age (BW42). Based on the regions identified by selective genotyping, seven full-sib families (649 F-2 chicks) were genotyped with 26 markers. Quantitative trait loci affecting body weight, feed intake, carcass weight, drums and thighs weight and abdominal fat weight were mapped to regions already identified in other populations. Quantitative trait loci for weights of gizzard, liver, lungs, heart and feet, as well as length of intestine, not previously described in the literature were mapped on chromosome 1. This F-2 population can be used to identify novel QTLs and constitutes a new resource for studies of genes related to growth and carcass traits in poultry.

Effect of 17 beta-estradiol and alendronate on the removal torque of osseointegrated titanium implants in ovariectomized rats

Background: This study investigated the influence of estrogen deficiency and its treatment with estrogen and alendronate on the removal torque of osseointegrated titanium implants.Methods: Fifty-eight female Wistar rats received a titanium implant in the tibia metaphysis. After 60 days, which was needed for implant osseointegration, the animals were randomly divided into five groups: control (CTLE; N = 10), sham surgery (SHAM; N = 12), ovariectomy (OVX; N = 12), ovariectomy followed by hormone replacement (EST; N = 12), and ovariectomy followed by treatment with alendronate (ALE; N = 12). The CTLE group was sacrificed to confirm osseointegration, whereas the remaining groups were submitted to sham surgery or ovariectomy according to their designations. After 90 days, these animals were also sacrificed. Densitometry of femur and lumbar vertebrae was performed by dual-energy x-ray absorptiometry (DXA) to confirm systemic impairment of the animals. All implants were subjected to removal torque.Results: Densitometric analysis of the femur and lumbar vertebrae confirmed a systemic impairment of the animals, disclosing lower values of bone mineral density for OVX. Analysis of the removal torque of the implants showed statistically lower values (P <0.05) for the OVX group in relation to the other groups. However, the group treated with alendronate (ALE group) presented significantly higher torque values compared to the others.Conclusion: According to this study, estrogen deficiency was observed to have a negative influence on the removal torque of osseointegrated implants, whereas treatment with alendronate

Ability of bacteriophages isolated from different sources to reduce Salmonella enterica serovar enteritidis in vitro and in vivo

Salmonella enterica serovar Enteritidis-lysing bacteriophages isolated from poultry or human sewage sources were used to reduce Salmonella Enteritidis in vitro and in experimentally infected chicks. Cocktails of 4 different bacteriophages obtained from commercial broiler houses (CB4O) and 45 bacteriophages from a municipal wastewater treatment plant (WT45O) were evaluated. In experiment 1, an in vitro crop assay was conducted with selected bacteriophage concentrations (105 to 101 pfu/mL) to determine ability to reduce Salmonella Enteritidis in the simulated crop environment. Following 2 h at 37 degrees C, CB40 or WT45O reduced Salmonella Enteritidis recovery by 1.5 or 5 log, respectively, as compared with control. However, CB40 did not affect total SE recovery after 6 h, whereas WT45O resulted in up to a 6-log reduction of Salmonella Enteritidis. In experiment 2, day-of-hatch chicks were challenged orally with 3 x 103 cfu /chick Salmonella Enteritidis and treated cloacally with 1 X 109 WT45O pfu/chick I h postchallenge. One hour later, chicks were treated or not with a commercially available probiotic (Floramax-B11). Both treatments significantly reduced Salmonella Enteritidis recovery from cecal tonsils at 24 h following vent lip application as compared with controls, but no additive effect was observed with the combination of bacteriophages and probiotic. In experiment 3, day-of-hatch chicks were challenged orally with 9 x 103 cfu/chick Salmonella Enteritidis and treated via oral gavage with I X 108 CB40 pfu/chick, 1.2 x 108 WT45O pfu/chick, or a combination of both, I h postchallenge. All treatments significantly reduced Salmonella Enteritidis recovered from cecal tonsils at 24 h as compared with untreated controls, but no significant differences were observed at 48 h following treatment. These data suggest that some bacteriophages can be efficacious in reducing SE colonization in poultry during a short period, but with the bacteriophages and methods presently tested, persistent reductions were not observed.

Influence of diet on assimilation and turnover of C-13 in the tissues of broiler chickens

1. The C-13 turnover rates of the liver and thoracic pectoral muscle of growing broilers were determined by feeding diets with varying C-13 content.2. Male chicks ( 1- d- old) were subjected to treatments based on free choice of 5 different mixes of energy and protein sources from plants with C-3 and C-4 photosynthetic pathways that had differing C-13 content. Rice bran ( R) and soybean meal ( S) were the C-3 sources, while maize ( C) and maize gluten meal ( G) were the C-4 sources. Choices were R + S, C + G, R + G, C + S or R + C +G + S. The 6th treatment was a complete feed ( CF) that was similar to a commercial broiler feed.3. The isotopic composition of the birds' tissues was representative of the isotopic composition of the diets. The assimilation was faster for C-3, in both liver and muscle, than for C-4 diets, and give the delta per mil difference between the diet and tissues.4. The liver is the most active metabolic tissue and gave more rapid isotope turnover than in muscle.

Effect of early feed restriction and enzyme supplementation on digestive enzyme activities in broilers

The effect of feed restriction and enzymatic supplementation on intestinal and pancreatic enzyme activities and weight gain was studied in broiler chickens. Quantitative feed restriction was applied to chickens from 7 to 14 d of age. An enzyme complex mainly consisting of protease and amylase was added to the chicken ration from hatching to the end of the experiment. Birds subjected to feed restriction whose diet was not supplemented showed an increase in sucrase, amylase, and lipase activities immediately after the restriction period. Amylase, lipase, and chymotrypsin activities were higher in chickens subjected to feed restriction and fed a supplemented diet than in those only subjected to feed restriction. Trypsin activity increased after feed restriction and after supplementation, but there was no interaction between these effects. Early feed restriction had no effect on enzyme activity in 42-d-old chickens. Chickens subjected to early restriction and fed the supplemented diet presented higher sucrase, maltase, and lipase activities than nonsupplemented ones (P < 0.05). There was no effect of early feed restriction or diet supplementation on weight gain to 42 d. Percentage weight gain from 14 to 42 d of age was equivalent in feed-restricted and ad libitum fed birds. Feed-restricted broilers fed a supplemented diet showed a higher percentage weight gain than nonsupplemented birds. We conclude that enzymatic supplementation potentiates the effect of feed restriction on digestive enzyme activity and on weight gain.

Use of Yucca schidigera extract in broiler diets and its effects on performance results obtained with different coccidiosis control methods

A trial was conducted to assess the effects of the dietary supplement Yucca schidigera extract on the performance of broilers subjected to different coccidiosis control methods. Six hundred male broiler chicks were randomly allocated to 1 of 5 treatments with 4 replicates each. The treatments were as follows: T1, vaccinated against coccidiosis; T2, nonvaccinated, a dietary coccidiostat; T3, vaccinated against coccidiosis, diet supplemented with Y. schidigera extract (0.01%); T4, coccidiostat plus Y. schidigera extract added to feed (0.01%); and T5, nonvaccinated, nonsupplemented control. The parameters analyzed were bird performance and morphology of the intestinal mucosal surface. The intestinal villi were higher at 6 d of age in broilers treated with coccidiostats or vaccinated against coccidiosis and supplemented with Y. schidigera extract compared with groups receiving the vaccine only or no treatment. Addition of the Y. schidigera extract to the diet of vaccinated birds improved average daily gain and feed conversion rate at 42 d of age compared with the other treatments, suggesting there might be a beneficial, synergistic effect between the coccidiosis vaccine and the Y. schidigera extract.

Posthatching water and feed deprivation affect the gastrointestinal tract and intestinal mucosa development of broiler chicks

We studied the effect of feed and water deprivation on gastrointestinal tract and intestinal mucosa development of chicks at 24, 48, and 72 h posthatching. The treatments were water and feed ad libitum, water ad libitum and no feed, no water but feed ad libitum, and no water and no feed. The relative weight of the yolk sac was not influenced by the treatments. However, at 48 and 72 h posthatching, the relative weight of the liver increased, and the gizzard + proventriculus weight decreased in birds receiving feed ad libitum. An increase in jejunum and ileum relative weights and lengths was observed when the birds were supplied with feed and water. The lack of water produced the same effect as the lack of feed, both causing a higher number of villi per area with reduction in villus size, when compared with feed and water ad libitum treatments. The results of this study revealed that feed and water are able to affect intestinal villus development after hatching, indicating that both feed and water must be supplied to the chicks immediately after hatching.