Biomedical subjects

W E Huff

Publications and source records attributed to W E Huff.

At least 19 recordsLinked to original sources

PubMed2006

Effects of humic acid on broiler chickens.

In view of the alleged effect of humic acid (HA) on growth plate arthrosis in humans, we sought to find if poultry tibial dyschondroplasia (TD) is caused by HA that can occur as a ground water contaminant. In 2 separate trials, broiler chickens were fed different concentrations of HA added to their diet for 4 and 5 wk. The effects of these treatments were measured by general health indices such as growth, feed conversion ratio, relative organ weights, blood differential count, serum chemistry, TD index, and bone biomechanical strength. Humic acid treatment decreased BW but appeared to improve feed conversion ratio. There was no effect on TD index or bone biomechanical strength in HA-treated birds compared with controls. There was no toxic effect of HA that was evident by the absence of any dramatic change in relative organ weights or other telltale signs of serum clinical chemistry that would suggest liver, muscle, or kidney dysfunction. Red blood cell, white blood cell, monocyte, and hematocrit values were not affected, but there was a decrease in blood heterophil counts and heterophil to lymphocyte ratio, which was significant in 4-wk HA-treated birds. Overall these results show that HA slows down growth, but it does not have any adverse health effects on chickens.

Animals↗

PubMed2006

Limited treatment with beta-1,3/1,6-glucan improves production values of broiler chickens challenged with Escherichia coli.

The development of antibiotic-resistant bacteria has led to a need for alternatives to antibiotics for growth promotion and disease prevention in poultry production. The helical polysaccharide beta-1,3/1,6-glucan is derived from the cell wall of Saccharomyces cervisiae and has immunomodulating activities. The objective of this study was to determine the ability of 2 supplementation programs with a commercial beta-1,3/1,6-glucan product to protect broiler chicks from experimental respiratory challenge with Escherichia coli. Chicks were housed in battery-brooders from 1 d of age and fed a standard starter diet or the same diet containing 20 g/ton (22 ppm) of purified beta-1,3/1,6-glucan either continuously (BG25d) or for only the first 7 d prior to challenge (BG7d). At d 7 one-half of the birds were inoculated in the thoracic air sac with 800 cfu of a serotype O2, nonmotile strain of E. coli. All surviving birds were necropsied at d 25. Body weight of survivors and feed conversion efficiency were protected from the adverse effects of E. coli challenge by BG7d but not by BG25d. Mortality was nominally decreased from 63% (control) to 53% in BG25d and 47% in BG7d, but these decreases were not significant. The relative weights of the liver and heart were increased, and the bursa of Fabricius relative weights were decreased by E. coli challenge, and these effects were modulated by beta-glucan treatment. Despite positive effects of BG7d in E. coli-challenged birds, the BW of nonchallenged birds was decreased by BG7d and BG25d. These results suggest that supplementation of broiler diets with beta-1,3/1,6-glucan may be valuable for decreasing production losses due to E. coli respiratory disease, but that the immune stimulation provided may also result in decreased production values under experimental battery conditions or for birds raised in an environment with minimal disease challenges.

Animals↗

PubMed2006

Evaluation of the influence of bacteriophage titer on the treatment of colibacillosis in broiler chickens.

Two studies were conducted to determine the efficacy of bacteriophage SPR02 and DAF6 at varying titers to treat colibacillosis in chickens. In Study 1, the treatments consisted of a control, i.m. injection of bacteriophage SPR02 or DAF6, Escherichia coli airsac challenge, and E. coli challenge followed by treatment at different titers with bacteriophage SPR02 or DAF6. The E. coli- challenged birds were injected with 6 x 10(4) cfu into the left thoracic airsac at 7 d of age. Immediately after the birds were challenged with E. coli, they were treated by administration of bacteriophage SPR02 or DAF6 by i.m. injection into the left thigh with 4 x 10(8), 10(6), 10(4), or 10(2) pfu. Study 2 was identical to Study 1, with the exception that the E. coli challenge was increased to 9 x 10(4) cfu, and the titers of SPR02 and DAF6 were slightly less at 3 x 10(8), 10(6), 10(4), and 10(2) pfu. Both studies were concluded when the birds were 3 wk of age. Mortality in the birds challenged with E. coli in Studies 1 and 2 was 48 and 47%, respectively. The only consistently effective bacteriophage treatment was the highest titer (10(8) pfu) of bacteriophage SPR02, which significantly reduced mortality from 48 and 47% in the birds only challenged with E. coli (positive control) to 7% in both studies, which was not significantly different from the unchallenged negative control treatments. These studies indicate that an effective multiplicity of infection for i.m. treatment with SPR02 was 10(4) in this experimental model of colibacillosis. Bacteriophage administered at sufficient titers can be effective therapeutic agents and provide an alternative to antibiotics in the treatment of bacterial diseases.

Animals↗

PubMed2005

Changes in the tibial growth plates of chickens with thiram-induced dyschondroplasia.

Tibial dyschondroplasia (TD) is a metabolic cartilage disease of young poultry in which endochondral bone formation is disrupted leading to the retention of a non-calcified, avascular plug of cartilage in the tibial growth plate. Chicks aged 7 days were fed either a control diet or one containing thiram 100 ppm for 48 h to induce TD. Cell multiplication in the growth plate was determined thereafter with bromodeoxyuridine (BrdU) labelling, and metabolic changes by measuring alkaline phosphatase (ALP), tartrate-resistant acid phosphatase (TRAP), and glutathione (GSH) activities. The effect on chondrocyte maturation was examined by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of gene expression. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) and DNA fragmentation were used to determine the effects of thiram on cell survival. The results showed that thiram-induced TD was not due to the multiplication of cells in the post-proliferative zones. Thiram did not affect ALP activity, which would have indicated a loss of calcification potential, but it reduced both TRAP and the glutathione concentrations, suggesting that the growth plate metabolism and remodelling functions were adversely affected. Thiram appeared to have no effect on the expression of type X collagen, transglutaminase, RUNX2, or matrix metalloproteinase-2 (MMP) genes suggesting that it did not alter the maturation potential of chondrocytes. On the contrary, the expressions of MMP-13 and vascular endothelial growth factor (VEGF) genes were "up-regulated," suggesting that thiram has pro-angiogenic activity. However, TUNEL assay showed that thiram induced endothelial cell apoptosis in the capillary vessels of the growth plates, as early as 10 days of age, when TD was not visually evident. The vascular death increased on subsequent days accompanied by massive death of chondrocytes in the transition zone of the growth plate. The induction of apoptosis in the growth plate was also demonstrated by DNA fragmentation. It was concluded that thiram induced TD not through an increase in the multiplication of chondrocytes in the transition zone and not by altering the expression of genes causing the arrest of chondrocytes in a prehypertrophic state, but by creating a metabolic dysfunction which led to the destruction of blood capillaries in the transition zone chondrocytes.

Acid Phosphatase↗

PubMed2005

Alternatives to antibiotics: utilization of bacteriophage to treat colibacillosis and prevent foodborne pathogens.

Bacteriophages are viruses that infect and kill bacteria. Bacteriophage do not infect animal and plant cells, which makes them a potentially safe alternative to antibiotics. We have been conducting research on the efficacy of bacteriophage to prevent and treat colibacillosis in poultry. Bacteriophages that were lytic to a non-motile, serotype 02 isolate of Escherichia coli were isolated from municipal wastewater treatment plants and poultry processing plants. This E. coli isolate is pathogenic to poultry, causing severe respiratory and systemic infections. Two bacteriophage isolates were selected for use in studies designed to determine the efficacy of these bacteriophage to prevent and treat severe colibacillosis in poultry. Colibacillosis was induced by injecting 6 x 10(4) cfu of E. coli into the thoracic air sac when birds were 1 wk of age. Initial studies demonstrated that mortality was significantly reduced from 85 to 35% when the challenge culture was mixed with equal titers of bacteriophage, and the birds were completely protected when the challenge culture was mixed with 10 pfu of bacteriophage. In subsequent studies, we have shown that an aerosol spray of bacteriophage given to birds prior to this E. coli challenge could significantly reduce mortality even when given 3 d prior to the E. coli challenge. Our research on treating colibacillosis in poultry has demonstrated that an intramuscular injection of bacteriophage given 24 or 48 h after the birds were challenged rescued the birds from this severe E. coli infection. We have demonstrated that bacteriophage can be used to prevent and treat colibacillosis in poultry and may provide an effective alternative to antibiotic use in animal production.

Animal Feed↗

PubMed2005

Stress response differences and disease susceptibility reflected by heterophil to lymphocyte ratio in turkeys selected for increased body weight.

Three genetic lines of turkeys were compared for their responses to Escherichia coli challenge following dexamethasone injection (Dex) or E. coli challenge preceding transport stress (TS). The turkey lines were a slow growing line selected for increased egg production (Egg line), a fast growing line selected for increased 16-wk BW (F line), and a commercial line (Comm line). At 14 wk of age, the Dex group was treated with 3 injections of 2 mg of Dex/kg of BW followed by airsac challenge with 100 cfu of E. coli. The TS group was given the same E. coli challenge at 1 x 10(4) cfu/bird without Dex treatment, and was subjected to transport stress, including 12 h of holding time in a transport vehicle, 8 d after the challenge. All treated birds and untreated control birds were bled at the same time, which was 1 d after transport and 9 d after challenge with E. coli. The main effect mean (MEM) total leukocyte counts (WBC) and the percentages of eosinophils (Eos) and basophils (Baso) were the same for all 3 lines; however, the MEM percentages of heterophils (Het) and monocytes (Mono) and the heterophil/lymphocyte ratio (H/L) were lower and the percentage of lymphocytes (Lym) was higher in the Egg line compared with the 2 fast-growing lines. Both stress treatments increased WBC, Het, and H/L and decreased Lym in all 3 lines; however, these effects were significantly greater in both fast growing lines compared with the Egg line. Sixteen-week BW was unaffected by either treatment in the Egg line and was decreased by both treatments in the Comm line and by the Dex treatment in the F line. Main effect mean airsacculitis score (AS) was not affected by line and was significantly increased by TS and Dex treatments. Neither treatment affected AS of the Egg line birds, whereas Dex treatment increased AS of the F line, and both Dex and TS increased AS of the Comm line. Mortality was significantly higher in the Comm line compared with the Egg line and was intermediate in the F line. The differences between these lines in their disease resistance and physiological response to stress in 2 stress models suggests that increasing selection for BW of turkeys is accompanied by changes in the stress response resulting in increased susceptibility to opportunistic bacterial infection.

Animals↗

PubMed2005

Respiratory infection of turkeys with Listeria monocytogenes Scott A.

The pathogenesis of L. monocytogenes strain Scott A was studied by challenging day-old male turkey poults by air sac inoculation with tryptose phosphate broth containing 10(0) cfu (control), 10(4), 10(5), and 10(6) cfu (low challenge), or 10(7) and 10(8) cfu (high challenge) of the Scott A (serotype 4b) strain of L. monocytogenes. Mortality at 2 wk postinfection (PI) ranged from 25% for low challenge to 100% for high challenge (P= 0.0001). Gross and histopathological lesions were observed in heart, liver, spleen, lung, and bursa of Fabricius of mortalities at 4 days PI. Listeria monocytogenes challenge resulted in significantly decreased relative weight of the bursa of Fabricius and increased relative weight of the spleen, and L. monocytogenes was isolated by direct plating of liver, pericardium, brain, and both left and right stifle joint synovium (knee) cultures, as well as gall bladder, yolk sac, and cecal tonsil from transfer swabs onto Listeria-selective agar. Isolates were confirmed as positive using Gram stain, biochemical tests, and the Biolog system. High challenge resulted in confirmed L. monocytogenes isolation from 48% of left knee and 59% of right knee cultures. Low challenge resulted in isolation of L. monocytogenes from 11% of both left and right knee cultures. These results suggest that L. monocytogenes Scott A colonization of turkey knee synovial tissue can initiate in day-of-age poults and that L. monocytogenes Scott A can be invasive through air sac infection.

Animals↗

PubMed2004

Therapeutic efficacy of bacteriophage and Baytril (enrofloxacin) individually and in combination to treat colibacillosis in broilers.

A study was conducted to evaluate the therapeutic efficacy of bacteriophage and the antibiotic enrofloxacin individually and in combination to treat colibacillosis. The experimental design was a 2 x 2 x 2 factorial with 8 treatments and 4 replicate pens of 10 birds. The treatments were 1) control, 2) unchallenged birds treated with bacteriophage, 3) enrofloxacin, or 4) the combination; 5) birds challenged with Escherichia coli, and birds challenged with E. coli and treated with 6) bacteriophage, 7) enrofloxacin, or 8) the combination of bacteriophage and enrofloxacin. Birds in the E. coli challenged treatments were challenged at 7 d of age by injecting 10(4) cfu of E. coli into the thoracic air sac. The antibiotic treatment was initiated immediately after the birds were challenged and consisted of 50 ppm enrofloxacin in the drinking water for 7 consecutive days. The bacteriophage treatment consisted of a single intramuscular injection of 2 different bacteriophage (10(9) pfu) administered immediately after the E. coli challenge. Mortality in the birds challenged with E. coli and untreated was 68%, and the bacteriophage and enrofloxacin treatments significantly decreased mortality to 15 and 3%, respectively. There was total protection in birds that received both the bacteriophage and enrofloxacin representing a significant synergy. The decrease in mortality with enrofloxacin (3%) was significantly better than the decrease in mortality with bacteriophage (15%). Airsacculitis lesion scores and lesion incidence in surviving birds were significantly less in the enrofloxacin treatment compared with the bacteriophage treatment. Both bacteriophage and enrofloxacin provided effective treatments of colibacillosis, and the synergy between these 2 treatments suggests that bacteriophage combined with antibiotic treatment has significant value.

Animals↗

PubMed2004

Comparative efficacy of different dithiocarbamates to induce tibial dyschondroplasia in poultry.

Tibial dyschondroplasia (TD) is a metabolic cartilage disease in poultry the natural etiology of which is not known. In the absence of biomarkers to monitor the initiation and progression of the naturally occurring disease, experimentally induced TD can provide a suitable venue to study the mechanism of its pathogenesis. Therefore, the objective of this study was to establish a streamlined experimental protocol to induce TD using dithiocarbamates and to determine a time course of its progression. Three different dithiocarbamates, dimethyldithiocarbamate, pyrrolidine dithiocarbamate, and tetramethyl thiuram disulfide (thiram), were tested with respect to their abilities to induce TD and affect different physiological factors. Our results show that chickens fed thiram during the first 2 wk of age showed a maximum TD index. Thiram appeared to be the most potent of the 3 dithiocarbamates with dimethyldithiocarbamate having the least ability to induce TD and pyrrolidine dithiocarbamate showing an intermediate potency. A transient exposure to thiram for a day or 2 was sufficient to markedly increase the incidence of TD and produce lasting damage as determined by the presence of severe lesions in a high percentage of birds at 2 to 3 wk after the treatment. Thiram affected the chondrocyte morphology of maturing zone cartilage evident by nuclear shrinkage and emptied chondrocyte lacunae during later times and also involutions of capillary vessels. Such changes were not seen in prehypertrophic zone chondrocytes of the same growth plates. Thiram reduced the BW, increased blood heterophil-to-lymphocyte ratios, and elevated serum corticosterone concentrations indicating physiological stress. However, there was no change in relative liver weights or blood clinical chemistry including the serum concentrations of Ca, P, and Cu in thiocarbamate-fed chickens. Induction of TD in young chickens by means of a short feeding protocol with thiram may be useful to study the mechanisms of pathogenesis of TD and to identify micronutrients that can provide protection against this disease.

Animals↗

PubMed2003

The effects of behavior and environmental enrichment on disease resistance of turkeys.

Turkey poults were provided with environmental enrichment for the first 14 days after hatch. At 2 days of age each bird was tested for the speed in which it would cross a T-maze. At 5 weeks of age birds were treated with dexamethasone and challenged with Escherichia coli. Enriched birds had higher body weights and incidence of disease and mortality and lower numbers of leukocytes when challenged. Challenged and enriched birds that tested FAST had higher mortality and air sacculitis scores and lower body weights than SLOW birds. Non-enriched, SLOW birds were the only ones to respond to challenge with increases in leukocyte counts and heterophil/lymphocyte ratios. These data suggest that environmental enrichment during the first 2 weeks after hatch may be detrimental to those birds with a FAST T-maze response, and that poults with a FAST response in the T-maze may be more susceptible to experimental bacterial infection.

Analysis of Variance↗

PubMed2003

Evaluation of aerosol spray and intramuscular injection of bacteriophage to treat an Escherichia coli respiratory infection.

Two studies were conducted to determine the efficacy of either aerosol or i.m. injection of bacteriophage to treat an Escherichia coli respiratory infection in broiler chickens. An additional two studies were conducted to enumerate the bacteriophage in the blood of birds at 1, 2, 3, 4, 5, 6, 24, and 48 h after being sprayed or injected i.m. with bacteriophage. Five birds were bled at each period. In study 1, there were 10 treatments with three replicate pens of 10 birds. The treatments consisted of an untreated control, heat-killed bacteriophage spray, active bacteriophage spray, E. coli challenge at 7 d of age, and E. coli challenge followed by spraying the birds with heat-killed bacteriophage or active bacteriophage at 2, 24, or 48 h after challenge. In study 2 there were 11 treatments with three replicate pens of 10 birds per pen. The treatments were untreated controls, birds injected i.m. in the thigh with heat-killed or active bacteriophage, E. coli challenge at 7 d of age, PBS challenge, E. coli challenge followed by injection of heat-killed or active bacteriophage immediately after challenge or at 24 or 48 h after challenge. In both studies the E. coli challenge consisted of injecting 10(4) cfu into the thoracic air sac. Treatment of this severe E. coli infection with the bacteriophage aerosol spray significantly reduced mortality from 50 to 20% when given immediately after the challenge but had little treatment efficacy when administered 24 or 48 h after challenge. The i.m. injection of bacteriophage significantly reduced mortality from 53 to 17%, 46 to 10%, and 44 to 20% when given immediately, 24, or 48 h after challenge, respectively. Only a few birds sprayed with bacteriophage had detectable bacteriophage in their blood with an average of 96 pfu/mL 1 h after bacteriophage administration, and no bacteriophage was detected 24 and 48 h after bacteriophage administration. All birds injected i.m. with bacteriophage had detectable levels of bacteriophage in their blood at levels of 10(4) pfu/mL of blood up to 6 h after bacteriophage administration, and four of the five birds had detectable bacteriophage in their blood at an average level of 70 pfu/mL of blood 24 h after bacteriophage administration. The relative inefficiency of the spray treatment to the i.m. injection treatment may be due to the inability to get bacteriophage into the blood at high concentrations when the birds are sprayed versus the consistent high titers achieved with the i.m. injection of bacteriophage. These data provide support to the concept that bacteriophage may be an effective alternative to antibiotics in animal production when they are administered in a way that delivers high titers of the bacteriophage to the critical site of the bacterial infection.

Aerosols↗

PubMed2003

Effect of cold stress on broilers selected for resistance or susceptibility to ascites syndrome.

Genetic selection for an ascites-resistant line of broilers is seen as a permanent solution to the ascites problem. Ascites-resistant and ascites-susceptible lines have been developed using sire family selection based on mortality data taken from siblings reared in a hypobaric chamber (simulated 2,900 m above sea level). The relaxed line is representative of the original commercial pureline stock randomly mated with no artificial selection pressure. The objectives of this study were to evaluate the differences between the lines when reared in floor pens and subjected to an ascites-inducing cold stress. Seven hundred eighty three straight run broilers were reared in floor pens at local elevation (390 m above sea level). Feed and water were available ad libitum. Birds were brooded at 32 C during the first week. The second week birds were maintained at 30 degrees C. Cold stress was applied for the remaining 4 wk at 14 degrees C. Mortalities were necropsied daily to determine cause of death. Birds and feed were weighed weekly. At 6 wk, five birds per pen were bled, and half the survivors in each pen (8 to 15 birds) were killed, necropsied, and scored for ascites. Blood gases, clinical chemistries, and blood cell counts were taken. Liver, spleen, split heart, and lung weights were recorded. Body weights were not different among the resistant, susceptible, and relaxed lines (P < 0.05). Feed conversion was better in the resistant line when compared to the susceptible and relaxed lines (P < 0.05). Ascites incidence, as measured by mortality and lesion score at necropsy, was higher in the susceptible and relaxed lines when compared to the resistant line; 18.8, 12.7, and 1.6% respectively (P < 0.001). Susceptible and relaxed lines showed more right ventricular hypertrophy when compared with the resistant line (P < 0.05). The results show that under severe cold stress at local altitude (390 m above sea level), the ascites-resistant line was growing as rapidly as the other lines and was as resistant to ascites as it had been under hypobaric conditions.

Animal Feed↗

PubMed2002

Identification of ovotransferrin as an acute phase protein in chickens.

Inflammation is homeostatic process associated with a variety of cellular injuries resulting from infections, toxicosis, and physical trauma. The studies on inflammation in avian species are limited. To understand the inflammation-induced changes, 4-wk-old male broiler chickens were subjected to experimental inflammation by a subcutaneous injection of croton oil (inflammatory) with changes in serum measured over time and were compared with birds treated similarly with olive oil (injected control). Croton oil treatment significantly elevated serum interleukin (IL)-6 concentrations and heterophil counts by 6 and 16 h postinjection, respectively, which returned to the basal levels of controls at 16 and 24 h, respectively. Croton oil treatment affected the serum protein profiles of chickens as assessed by SDS-PAGE and densitometric analyses. Compared with olive oil-injected or noninjected chicken sera, there were increases in the density of protein bands corresponding to molecular weights (MW) of 42, 65, 200, and 219 kDa and decreases in bands corresponding to 49 kDa (serum albumin) and a 56-kDa protein in chickens treated with croton oil. Most of these changes were evident at 24 h and lasted through 48 h. The protein band corresponding to 65 kDa was further characterized using two-dimensional gel electrophoresis and N-terminal sequence analyses. A sequence similarity search in the Genbank database using the first 22 amino acids yielded a complete homology with chicken ovotransferrin. Western blot analysis using antichicken serum transferrin or antichicken ovotransferrin antibodies also confirmed the 65-kDa protein band to be ovotransferrin. Under nonreducing conditions, the ovotransferrin standard also showed an apparent MW corresponding to 65 kDa, like the serum transferrin. The serum ovotransferrin was found to be glycosylated using a glycoprotein stain. Although the significance of ovotransferrin in avian inflammation is not clear, these results show that it is a major acute phase protein (APP) in chickens.

Acute-Phase Proteins↗

PubMed2002

Prevention of Escherichia coli infection in broiler chickens with a bacteriophage aerosol spray.

Bacteriophage to an Escherichia coli isolate that is pathogenic in poultry were isolated from municipal sewer treatment facilities or poultry processing plants. Three studies were conducted to determine the efficacy of aerosol administration of bacteriophage to prevent an E. coli respiratory infection in broiler chickens. In all three studies the experimental design consisted of nine treatments with three replicate pens of 10 birds. Three treatments were not challenged with E. coli and consisted of unsprayed birds, birds sprayed with a diluent control, and birds sprayed with a combination of two bacteriophages. Six treatments were challenged with E. coli by injecting 10(4) cfu into the thoracic air sac when birds were 7, 8, or 10 d of age after being sprayed at 7 d of age with either a diluent control or a combination of two bacteriophages. In Studies 1 and 2, BW at 2 wk of age of all the birds challenged with E. coli, regardless of spray treatment, were decreased significantly from the unchallenged controls, except in Study 2 for the birds sprayed with bacteriophage and challenged at 10 d of age. There was a significant decrease in mortality in Studies 1 and 2 when the birds were challenged with E. coli immediately after bacteriophage administration and in Study 2 in birds challenged at 10 d of age. In Study 3 a suspected pre-existing E. coli infection resulted in mortality in the unchallenged, unsprayed controls, and in the diluent sprayed controls of 20 and 27%, respectively. The mortality in the unchallenged bacteriophage sprayed birds was 3%, representing a significant decrease. Mortality in Study 3 was significantly decreased in the bacteriophage-sprayed birds challenged with E. coli immediately or 1 d later but not 3 d after bacteriophage administration. The decrease in BW at 2 wk of age in challenged birds indicates that bacteriophage treatment did not provide complete protection; however, in all three studies mortality was significantly decreased, indicating that aerosol spray of bacteriophage may be practical for administration of bacteriophage and may provide an alternative to the use of antibiotics in poultry production.

Aerosols↗

PubMed2002

Prevention of Escherichia coli respiratory infection in broiler chickens with bacteriophage (SPR02).

Bacteriophages are viruses that can infect and kill bacteria. Three studies were conducted to determine the efficacy of bacteriophage to prevent an Escherichia coli respiratory infection in broiler chickens. In the first study 3-d-old-birds were challenged with an air sac inoculation of 10(3) cfu of E. coli per mL mixed with either 10(3) or 10(6) pfu of bacteriophage, or 10(4) cfu E. coli mixed with 10(4) or 10(8) pfu of bacteriophage. In the second study, drinking water of birds to 1 wk of age was treated with 10(3) or 10(4) pfu of bacteriophage per mL and birds were air sac challenged with 10(3) cfu of E. coli, or water was treated with 10(4) or 10(6) pfu of bacteriophage per milliliter and birds were challenged with 10(4) cfu of E. coli. In the third study, birds were air sac challenged at 1 wk of age with 10(4) cfu of E. coli and given 10(5) or 10(6) pfu of bacteriophage per mL of water from 1 d of age to 2 wk of age. In Studies 1 and 2, there were two replicate pens per treatment with 10 birds per pen, and in Study 3, there were four replicate pens per treatment with 10 birds per pen. The studies were all concluded when the birds were 3 wk of age. In Study 1, BW was decreased at 1 and 2 wk of age in the birds that were challenged with 10(3) or 10(4) cfu of E. coli and was decreased at 2 wk of age in the birds challenged with 10(4) cfu of E. coli mixed with 10(4) pfu of the bacteriophage. Mortality was decreased from 80% in the birds challenged with 10(3) cfu of E. coli to 25 and 5% when mixed with 10(3) or 10(6) pfu of the bacteriophage, respectively. Mortality was decreased from 85% in birds challenged with 10(4) cfu of E. coli to 35% when mixed with 10(4) pfu of the bacteriophage, and no mortality occurred when mixed with 10(8) pfu of bacteriophage. There was essentially no protection observed in Studies 2 and 3 when the birds were challenged with 10(3) or 10(4) cfu of E. coli with bacteriophage present in their drinking water at any level. These data suggest that bacteriophage can protect birds from a respiratory challenge with E. coli, but that adding the bacteriophage to the drinking water offered no protection to the birds. The complete protection of the birds observed in Study 1 suggests that bacteriophage may possibly be developed as an alternative to antibiotic use in poultry.

Animals↗

PubMed2002

Effect of dietary supplementation with vitamin D metabolites in an experimental model of turkey osteomyelitis complex.

Supplementation with vitamin D3 was previously shown to protect Escherichia coli challenged birds that underwent two dexamethasone (DEX) treatments at 5 and 12 wk of age in an experimental model of turkey osteomyelitis complex (TOC). The purpose of the present study was to determine the effects of dietary supplementation with 10 microg of 1,25 dihydroxyvitamin D3 (1,25D)/ kg feed or 99 microg of 25-hydroxyvitamin D3 (25D)/kg feed on disease resistance in the same model. Birds were fed the supplemented diets continuously and ad libitum. Seven hundred twenty turkey poults were placed into 24 floor pens in a 3 x 2 x 2 design (three vitamin D treatments, two DEX treatments, two E. coli treatments, with two replicate pens per treatment). At 5 wk of age, half of the birds were treated with DEX, and half of the DEX-treated birds and half of the nontreated birds were challenged with E. coli. All mortalities and lame birds were necropsied. At 9 wk, all of the DEX- or E. coli-treated birds were given another series of DEX injections; 2 wk later 10 birds per pen were necropsied. At 12 wk, survivors of the previous challenges were given a third DEX treatment, and all birds were necropsied 2 wk later. After the first series of DEX injections, mortality was increased in the 25D-supplemented birds that were given the DEX treatment and the E. coli challenge. After the second series of DEX injections, the main effect mean BW was significantly lower in birds given 1,25D as compared to controls and 25D-supplemented birds. Mortality was higher in 1,25D-supplemented birds that were challenged with E. coli at 5 wk and treated with DEX at 9 wk as compared to 25D-supplemented birds. The 1,25D-treated birds that were treated with DEX at 5 and 9 wk and challenged with E. coli at 5 wk had higher mortality and air sacculitis scores as compared to controls and 25D-treated birds. The main effect mean mortality was significantly higher in birds given 1,25D as compared to controls and 25D-treated birds. The percentage of birds with TOC lesions was decreased from 27% to 0 by 25D and 1,25D in the groups given two DEX treatments and E. coli challenge. After the third DEX treatment, BW of 1,25D-suppplemented birds was decreased, and mortality and air sacculitis scores were increased. Bone strength was generally increased by supplementation with 1,25D, whereas 25D supplementation increased bone strength only in birds challenged at 5 wk and treated with DEX at Weeks 9 and 12. In this study, supplementation with vitamin D metabolites decreased TOC incidence in E. coli-challenged birds given two DEX treatments. However, toxic effects were observed in most supplemented DEX-treated birds and may be attributed to an additive effect of DEX treatment, E. coli septicemia, and vitamin D supplementation.

Animal Nutritional Physiological Phenomena↗

PubMed2001

Inflammation-induced changes in serum modulate chicken macrophage function.

Inflammation-induced changes in serum protein profiles and the effects of such serum on a chicken macrophage cell line HD11 were studied to find whether the changes in serum affect cellular immunity. Four-week-old male broiler chickens were injected subcutaneously with either olive oil or 50% croton oil mixed in olive oil to induce inflammation. The birds were bled at 48h after injection, and serum protein profiles were compared using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and densitometric evaluation. At 48h post-injection the serum from croton oil-injected birds showed distinct changes in protein profiles characterized by a selective increase or decrease in levels of several serum proteins. The protein bands which showed increases had relative molecular weights (Mr) corresponding to 65kilo Daltons (kD), 42kD, and two or more proteins with Mr> or =200kD. The levels of serum albumin (49kD), and a 56kD protein were reduced in croton oil-injected birds. The modulating effects of such serum on HD11 cells were studied using bacterial lipopolysaccharide (LPS) or phorbol myristate acetate (PMA) induced functional activation of these cells. The LPS-induced interleukin-6 (IL-6) production by HD11 cells was not affected by the presence of either olive oil-treated control or croton oil-treated inflammatory serum but nitrite production was enhanced by the inflammatory serum. Similarly, inflammatory serum also enhanced PMA-induced respiratory burst measured using dichlorofluorescein diacetate (DCF-DA) oxidation mediated by reactive oxygen intermediates. These results suggest that inflammatory serum can modulate macrophage function by influencing the production of reactive oxygen and nitrogen species which could affect their phagocytic and bactericidal activities.

Animals↗

PubMed2001

Matrix metalloproteinase activities of turkey (Meleagris gallopavo) bile.

The bile from turkey (Meleagris gallopavo) gall bladders was found to contain substantial matrix metalloproteinase (MMP) activities using gelatin, collagen, and casein substrate zymography, [3H]labeled collagen degradation assays, and gelatin-agarose affinity purification. Five major bands corresponding to approximate M(w) of 64, 60, 46, 40 and 36 kDa showed gelatinolytic activities. On incubation with p-aminophenylmercuric acetate or thimerosal, the densities of both the 64- and 46-kDa bands decreased with increasing intensities of the 60- and 40-kDa bands. Both the 64- and 60-kDa bands showed collagenolytic activities whereas the caseinolytic activities appeared as diffuse bands corresponding to M(w) of approximately 60, 40 and 36 kDa. Using [3H]collagen as substrate, the bile enzymes showed both a time and concentration-dependent degradation, which could be inhibited by the MMP inhibitors such as EDTA, phenanthroline, and N-[(2R)-2-(hydroxyamido carbonylmethyl)-4-methylpentanonyl]-L-tryptophan methylamide, but not by serine and cysteine protease inhibitors like trans-epoxysuccinyl-L-leucylamido-(4-guanidino)butane, phenylmethylsulfonyl fluoride or leupeptin. Both 60- and the 40-kDa gelatinolytic bands showed affinity adsorption to a gelatin-agarose matrix. The physiological roles of bile MMPs are not clear, but their involvement in the digestive functions of birds are likely.

Animals↗