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Influence of feed on the course of tenosynovitis caused by REO virus infection in broilers.

The first outbreak of tenosynovitis caused by infection with REO virus in the Netherlands, involving 15 broiler flocks, is described. The disease could be reproduced easily by subcutaneous, oral and contact infection of susceptible broilers with the isolated virus. The 15 affected flocks all came from one broiler parent flock and were fed with feed from one mill (A). Twenty other flocks, also coming from this parent flock and reared in the same period on feed from another feed mill (B) did not suffer from tenosynovitis. The parent flock showed no disease symptoms but seroconversion to REO virus occurred after the onset of the problems in the offspring. The influences of the different feeds on the course of the synovitis could be reproduced experimentally, but with less extreme differences than observed in the field. The possible ways in which feeds may influence tenosynovitis causing REO virus infection are discussed.

Animal Feed↗

A study of the effects of replacing monensin ionophore with lasalocid ionophore in the field control of coccidiosis in broilers.

The following conclusions are made from an introductory investigation on the use of the coccidiostat lasalocid on 11 production farms of an integrated broiler production organisation. In terms of the incidence of sub-clinical coccidiosis, no significant difference was found between the previous use of monensin and the use of lasalocid during the investigation. However, the incidence of coccidiosis decreased with the introduction of lasalocid. Despite the fact that on some farms sub-clinical coccidiosis was diagnosed, the production performance clearly improved with lasalocid. EBI figures significantly increased from 163.6 to 172.5. During the investigation, in which approximately 220,000 broilers were involved, litter quality did not differ from that of previous crops in which monensin had been used. Feathering of the broilers in the trial crops in which lasalocid was used was similar to that of previous crops.

Animals↗

Reduction of salmonella infection of broilers by spray application of intestinal microflora: a longitudinal study.

The Nurmi concept for diminishing salmonella infection of poultry by application of gastrointestinal microflora from adult birds into newly hatched chicks was tested in a field study in which 8 million broilers were involved. Half of the 284 flocks was treated in the hatchery by spray application of an undefined microflora propagated in SPF chicks. A significant reduction in salmonella-contaminated flocks, as well as in the number of infected broilers in these flocks was demonstrated. No undesirable side effects were detected. It was concluded that hygienic improvements in transportation and slaughtering of broilers are needed in order to maintain the reduced salmonella contamination rate.

Animals↗

Influence of coccidiosis on growth rate and feed conversion in broilers after experimental infections with Eimeria acervulina and Eimeria maxima.

Under experimental conditions, the effects of subclinical Eimeria (E.) acervulina and E. maxima infections on growth and feed conversion in broilers of different ages were analysed. It was concluded that infection with E. acervulina and E. maxima led to a process which was independent of the age at which the birds were infected. The infection adversely affected growth and feed conversion for 2 to 3 weeks, followed by a recovery period of 2 to 3 weeks when compensatory growth took place. From this study it may be concluded that subclinical coccidiosis in the first weeks of life and in the last week of life of broilers does not lead to appreciable damage on growth and feed conversion. Since coccidiosis cannot be avoided in practice, systems in which broilers contact subclinical coccidiosis either in the first weeks of life or in the last week of life should be aimed for. It is suggested that in a coccidiostat programme an efficient anticoccidiosis agent is particularly desirable in the 3rd and 2nd week before slaughter. Examinations performed one week or less before slaughter can hardly be justified, on the grounds that there is a risk of a negative effect on growth an feed conversion due to subclinical coccidiosis.

Animal Nutritional Physiological Phenomena↗

Cadmium and lead in muscle tissue and organs of broilers, turkeys and spent hens and in mechanically deboned poultry meat.

Cadmium and lead levels have been determined in meat, livers and kidneys of turkeys, in livers and kidneys of spent hens, in kidneys of broilers and in mechanically deboned poultry meat (MDPM), by dry ashing of the sample with Mg(NO3)2 followed by differential pulse anodic stripping voltammetric analysis. The possible age-dependent cadmium and lead accumulation in livers and kidneys of turkeys was also studied. The cadmium concentrations in meat and organs of poultry are in good agreement with data reported for other countries, but lead concentrations were low compared with most data reported in the literature. The cadmium levels in kidneys and livers of turkeys increased with age, whilst the lead concentrations were unrelated to age. The cadmium and lead concentrations in industrially prepared MDPM from broiler carcasses were very low (less than 0.001-0.004 mg/kg and less than 0.01-0.06 mg/kg, respectively). In MDPM prepared from backs (including the kidneys) and necks, elevated cadmium concentrations were found. The increase was related to the cadmium concentrations in the kidneys. In MDPM prepared from broilers, turkeys and spent hens the cadmium concentrations varied between 0.001 and 0.002 mg/kg, 0.005 and 0.006 mg/kg and 0.007 and 0.028 mg/kg, respectively. For lead the concentrations in meat and MDPM were similar. It can be concluded from the results that in MDPM prepared from spent hens and possibly turkeys, when incorporating the kidneys, cadmium concentrations greater than 0.05 mg/kg, (the legal limit for cadmium in poultry meat in The Netherlands) may occur.

Aging↗

Validation of HPLC method of analysis of tetracycline residues in eggs and broiler meat and its application to a feeding trial.

HPLC with ion-pairing chromatography and diodearray detection at 355 nm was used to determine tetracycline antibiotics in eggs and broiler meat. The analytical methods were optimized and validated. The mean recovery values for oxytetracycline for eggs and for tetracycline for breast meat were 76%. The within-day precision ranged from 8.0 to 11.8% for oxytetracycline in eggs and from 6.1 to 15.5% for tetracycline in breast meat. The between-day precision was 4.8% and 5.0% respectively for oxytetracycline in eggs and tetracycline in breast meat. The limit of detection and the limit of quantitation for oxytetracycline in eggs were 2.2 and 13.0 ng/g respectively. These limits for tetracycline in breast meat were 10.5 and 20.9 ng/g respectively. Residue values of tetracycline antibiotics in eggs and broiler meat were determined after oral administration of medicated feed. Medicated feed with 840 mg/kg oxytetracycline was provided to laying hens for seven successive days. Two days after the administration was stopped, the mean oxytetracycline residue value in the eggs was already lower than the Maximum Residue Limit (MRL)-level and reached 118 ng/g. Broilers were supplied with medicated feed containing 480 mg/kg tetracycline for seven successive days. Four days after the administration was stopped, the mean tetracycline residue value in breast meat decreased below the MRL and was 86 ng/g.

Administration, Oral↗

Effect of an in ovo infection with a Dutch avian leukosis virus subgroup J isolate on the growth and immunological performance of SPF broiler chickens.

The effect of an in ovo infection with a Dutch isolate of avian leukosis virus subgroup J (ALV-J) on the growth of specific pathogen free (SPF) broiler chickens was analysed. During this study, possible immune suppressive effects of ALV-J were assessed by measuring delayed-type hypersensitivity with keyhole limpet haemocyanin (KLH), natural killer (NK) cell activity, the production of radicals of nitric oxide (NO) by macrophages, humoral immune response against Newcastle and infectious bursal disease vaccine viruses, and automated total and differential leukocyte counts. In an attempt to elucidate the underlying causal mechanisms of the induced growth retardation, 3,3',5-triiodothyronine (T3) concentrations in serum were measured. Four experiments were conducted. In experiment 1, ALV-J-injected birds were compared with ALV subgroup A (ALV-A)-injected and negative control chickens. In experiment 2, ALV-J-injected birds were only compared with negative controls. Finally, in experiments 3a and 3b, ALV-J-injected chickens were compared with negative controls and a group of chickens in which only 10% of birds had been injected with ALV-J. Birds were injected in ovo at day 7 of incubation with 10(4) median tissue culture infectious dose (TCID(50)) ALV-J or ALV-A, except in experiment 3a where 10(2) TCID(50) ALV-J was injected. Significant growth suppression was found in all 100% of ALV-J-infected groups. The average growth retardation of ALV-J-infected birds compared with negative controls at 6 weeks of age was approximately 8, 11, 2.5 and 6% for the four successive experiments performed. The delayed-type hypersensitivity test against KLH of ALV-J-infected birds showed a tendency towards lower wattle thickness; however, the difference with controls was not significant (P > 0.05). The same was true for NK cell activity and NO production by macrophages, although the difference was not significant. The total and differential leukocyte counts performed on blood samples from birds at 3, 4 and 6 weeks of age as well as the humoral immune response against Newcastle and infectious bursal disease vaccine viruses did not show significant differences between treatment groups either. Only the number of basophils were significantly higher (P = 0.02) in ALV-J-infected birds at 3 weeks of age. No significant lower T(3) levels were found in ALV-J-infected birds in weeks 2 and 3 (experiment 2) and weeks 3 and 5 (experiment 3b); however, at 4 weeks (experiment 2) and 6 weeks (experiment 3b) of age, T(3) levels were significantly lower suggesting mild hypothyroidism in these broilers. In conclusion, the present experiments show the occurrence of significant growth retardation in SPF broilers after an ALV-J in ovo infection. The various studies performed to assess the immune competence of ALV-J-infected chickens did not show significant differences in immune responsiveness. The assays on cellular immunity showed a tendency to a lower response in ALV-J-infected birds, but these differences were not statistically significant.

Animals↗

Further evidence for the involvement of cardiac beta-adrenergic receptors in right ventricle hypertrophy and ascites in broiler chickens.

The present study was carried out to determine, first, the cardiac beta-adrenergic receptor characteristics of broiler chick embryos exposed to two different CO(2) levels during the last stage of embryonic development, and second, the prophylactic effect of beta(1)-adrenoceptor blocker on right ventricular hypertrophy in broiler chickens. High CO(2) embryos showed significantly higher haematocrit values, higher partial pressure of CO(2) levels and lower partial pressure of O(2) levels than those of normal CO(2) embryos. Exposure of chick embryos to high CO(2) levels reduced the binding capacity of myocardial beta-adrenergic receptors compared with those embryos incubated at the normal CO(2) level. Atenolol-supplemented diet numerically reduced ascites incidence in broiler chickens (7%) compared with birds fed the control diet (15%). In conclusion, these data support the important role of the beta-adrenergic receptor in the cardiovascular system for cardiac output, and secondary to pulmonary hypertension syndrome.

Animals↗

Ability of Massachusetts-type infectious bronchitis virus to increase colibacillosis susceptibility in commercial broilers: a comparison between vaccine and virulent field virus.

The abilities of Massachusetts-type vaccine virus and virulent infectious bronchitis (IB) field virus to increase colibacillosis susceptibility were compared. In four experiments, 29-day-old female commercial broilers housed in isolators, were infected intratracheally and oculonasally with IB vaccine strains (H120 and H52) or virulent IB field strains (D387 and M41) (4.8 or 6.8 log(10) median embryo infective dose, per broiler). Five days later, Escherichia coli 506 strain was given intratracheally (5.6 to 8.8 log(10) colony forming units/broiler). The incidence of nasal discharge at 3 and 5 days after IB virus infection was used to assess the clinical effect of the IB infection, while mortality, body weight uniformity and E. coli lesions at 7 days following E. coli inoculation were used as parameters for colibacillosis. Nasal discharge was observed in 6/117 (5%), 26/119 (22%), 35/119 (29%) and 115/120 (96%) of broilers infected with H120, H52, D387 and M41 virus, respectively. Apart from H52 and D387, differences between IBV strains were significant. IB vaccine and virulent IB viruses did not generally differ significantly in their ability to induce colibacillosis susceptibility. Mean colibacillosis lesion scores of H52-infected birds even significantly exceeded those of birds infected with the other IB viruses. The ability of H120 virus to induce colibacillosis susceptibility tended to be the weakest. The practical consequences of these findings are discussed.

Animals↗

Association between in vitro heterophil function and the feathering gene in commercial broiler chickens.

We recently showed that in vitro heterophil functional efficiency in commercial broiler chickens is genetically controlled and may be a sex-associated trait. To further characterize the genetic mechanism(s) of heterophil functional efficiency, we wanted to determine whether the feathering gene, present on the Z sex chromosome, contributes to heterophil functional efficiency. Heterophils from two pairs of broiler lines were evaluated; each pair contained a fast feather (FF) (lines A and X) and a slow feather (SF) line (lines B and Y). On days 1 and 4 post-hatch, heterophils isolated from two sets of pure line broilers (A and B, and X and Y) were evaluated for their ability to (1) phagocytize Salmonella enteritidis, and (2) exhibit bactericidal activity against S. enteritidis. On days 1 and 4 post-hatch, heterophils isolated from the FF lines were statistically (P < or = 0.02) more proficient at phagocytizing S. enteritidis than heterophils from SF lines. Bactericidal activity was also statistically (p < or = 0.02) greater on day 1 post-hatch in the heterophils isolated from FF lines compared to heterophils isolated from SF lines. These data indicate that the presence of the FF gene locus on the Z sex chromosome contributes to heterophil function and may contribute to the early innate immune competence of a flock.

Animals↗

Prophylactic action of lipoic acid on oxidative stress and growth performance in broilers at risk of developing ascites syndrome.

The objective of this study was to assess the effects of dietary supplementation with lipoic acid (LA) on broilers maintained at 2235 m above sea level with high risk to develop ascites syndrome (AS). A total of 2040 chicks were fed under commercial conditions with water and specific diets ad libitum during 7 weeks in two consecutive experiments. Mortality and indicators of performance and oxidative stress were compared weekly in broilers fed a basal diet plus 0, 10, 20, or 40 parts/10(6) LA. The effects of LA at 40 parts/10(6) were also studied during the initial 3 weeks or the last 4 weeks of the production cycle. Diets supplemented with 40 parts/10(6) of LA during 7 weeks significantly improved feed conversion, decreased general mortality and mortality attributable to AS, and lowered thiobarbituric acid reactive substances and hydroxyl radicals in liver, and increased total glutathione pool. Smaller doses or shorter periods of exposure to LA were partially effective. In conclusion, LA under our experimental conditions has a prophylactic action in broilers with high risk to develop AS due to oxygen availability limitation.

Animals↗

Growth enhancement in broiler chickens receiving CHEMEQRTM polymeric antimicrobial.

This study investigated the use of CHEMEQRTM polymeric antimicrobial as a means of enhancing health and growth rates in broiler chickens. One-day-old Cobb-500 broilers were reared to 42 days. In trial 1, 100 birds received CHEMEQRTM polymeric antimicrobial via water, and 100 birds were untreated. Treated birds had significantly greater (P<0.0001) average daily gain (ADG), significantly lower (P<0.0016) feed conversion ratios, significantly lower (P<0.05) mortality, and a significantly lower (P<0.0042) viscosity of their ileal contents. In trial 2, three groups of 40 birds received reducing dosages of CHEMEQRTM polymeric antimicrobial, and a fourth group remained untreated. Groups receiving CHEMEQRTM polymeric antimicrobial had significantly greater (P<0.05) ADG, and two groups had significantly lower (P<0.05) feed conversion ratios than the controls. In trial 3, groups of 40 birds received either CHEMEQRTM polymeric antimicrobial, Salinomycin or Lasalocid in-feed, or were untreated. Birds receiving CHEMEQRTM polymeric antimicrobial had significantly greater (P<0.05) ADG than those receiving Salinomycin. CHEMEQRTM polymeric antimicrobial helped to maintain the health and to improve the growth performance of broiler chickens.

Animals↗

Rupture of the right auricle in broiler chickens.

This report describes a case of cardiac right auricle rupture (RAR) in a flock of 11,500 broilers that were 14 days old. The birds were housed at an altitude of 300 m, with an external temperature of -10 degrees C and an internal temperature of 15 degrees C. There was 3.6% mortality, due to sudden deaths, from 10 to 14 days of age. All necropsied birds had haemopericardium due to RAR at the point of the junction with the vena cava, and 85% of them had blood in the oral cavity and external acoustic meatus. The vena cava and its caudal branches, the intestinal vessels, and the sinus durae matris and sinus saggitalis were distended. Histological examination showed haemorrhages into the myocardium, degeneration of the cardiac muscle fibres, as well as oedema of the lungs and hypertrophy of the smooth muscle bundles of the parabronchial walls. Blood in the mouth of the broilers may have been due to haemoptysis, which in humans is caused mainly by mitral stenosis. In broilers, mitral stenosis and/or insufficiency, and left ventricular failure with consequent pulmonary hypertension (PH) were considered as possible triggers for right ventricular failure. The alarm reaction in hypoxaemia, due to secondary factors such as cold, caused tachycardia and tachypnoea, may have induced further elevation of PH, and acute myocardial infarction causing cardiac rupture and haemopericardium in this case. Hypertension and PH, due to possible mitral stenosis/insufficiency in association with acute myocardial ischaemia, were probably the determinant factors causing this acute episode. This opens the possibility that the RAR may be cardiogenic.

Animals↗

The identification of matrix metalloproteinases and their tissue inhibitors in broiler chickens by immunohistochemistry.

The aim of this study was to investigate the distribution of matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitor of matrix metalloproteinase (TIMP)-1 and TIMP-2 using immunohistochemistry in the ascites syndrome of broiler chickens in a salt-induced experimental model. The presence of the enzymes in the lung, heart, liver, kidney and brain was evaluated semi-quantitatively with the streptavidin-biotin-peroxidase (Strep-ABC) method using commercially available primary monoclonal antibodies. Immunostaining of MMP-2 and MMP-9 was more intense and extensive in ascitic broilers than in the controls, although a decrease was seen with increasing age both in normal and ascitic chickens. The presence of MMP-9 enzyme was negatively correlated with the presence of TIMP-1 enzyme. It is suggested that MMP-2 and MMP-9 enzymes might play a role in the permeability increase of vessel walls by the destruction of the basement membranes in the salt-induced experimental ascites syndrome in broiler chickens.

Animals↗

Experimental ochratoxicosis in broiler chickens.

This study describes the toxicity signs that developed when the diet of male broiler chickens was artificially contaminated with different levels of the mycotoxin ochratoxin A (OTA). Chicks were assigned randomly to three groups of 80 chicks that were fed a diet containing 0 parts per billion (ppb) (control, group 1), 400 ppb (group 2) or 800 ppb (group 3) OTA from day 1 to 5 weeks of age. Signs of ochratoxicosis were assessed on the basis of changes in the following criteria: body weight, relative weights of two representative internal organs (gizzard and thymus), feed consumption, feed conversion ratio, mortality, thyroid activity, blood profile, humoral and cell mediated immunity. Feeding OTA at levels of 400 and 800 ppb (groups 2 and 3) significantly decreased the body weight, thymus weight, feed consumption, feed conversion ratio and thyroxine concentration (P < 0.05). The OTA groups developed anaemia manifested by a significant decrease in the red blood cell count, packed cell volume percentage and haemoglobin concentration (P < 0.05). By the end of the experiment both groups that received OTA showed a 37% reduction in red blood cell count compared with the control group. Furthermore, a significant decrease in the white blood cell count, humoral immune response and cell-mediated immunity was found in both groups fed ochratoxin compared with the control group (P < 0.05). The reduction in the above parameters was more noticeable with time and was proportional to the level of OTA exposure. A significant increase in relative gizzard weight, cumulative mortality and triiodothyronine concentration was found in OTA-fed chicks (P < 0.05). These data provide a description of ochratoxicosis in broilers that should be useful in diagnosis and in improved understanding of the practical implications on broiler performance and health, a problem that can threaten the poultry industry.

Animals↗

Composition of aqueous extracts of broiler litter treated with aluminum sulfate, ferrous sulfate, ferric chloride and gypsum.

More knowledge on the composition of aqueous extracts of broiler litter amended for Water Soluble P (WSP) reduction would help to understand how amendments work. We measured pH, concentrations of Ca, Mg, Fe, Al, Cu, Mn, Zn, Molybdate Reactive P (MRP), and Dissolved Unreactive P (DUP) in water extracts of broiler litter treated with aluminum sulfate (ALS), ferrous sulfate (FES), ferric chloride (FEC), and gypsum (GYP) at 0, 5, 15, and 25% w/w. In order to study the effects of acidification, the same properties were measured in aqueous extracts of broiler litter suspensions that were titrated to end-points 3, 4, or 6 with 0.5N HCl. Concentrations of MRP, DUP, Ca and Mg, were 61%, 53%, 3.8 times, and 2.6 times greater in extracts from suspensions acidified to pH 6 than at the original pH of 8.9. ALS, FES, and FEC reduced pH, and showed similar effects on WSP concentrations, which were greater than with GYP. The magnitude of the reductions in WSP by ALS, FES, and FEC is uncertain because the actual amount of WSP immobilized cannot be determined. This is because of two opposite effects: 1) Through adsorption, soluble aluminum and iron remove phosphates from solution, and 2) Through acidification, iron and aluminum compounds release phosphates to solution.

Adsorption↗

Effect of different dietary ideal protein concentrations on broiler performance.

1. The aim of the study was to examine the response of male broilers of different age categories to different dietary ideal protein (IP) concentrations and to compare the effects to IP recommendations based on single lysine (Lys) requirement studies from the literature. 2. Two experiments were carried out, in which diets containing different IP concentrations (9.0 to 14.4g apparent faecal digestible (AFD) Lys/kg) were fed to male broilers from 14 to 34 (Exp. 1) and 28 to 41 d of age (Exp. 2). The diets (12.88MJ AMEN/kg) were prepared by the dilution technique. The effect of dietary IP concentrations on weight gain, feed intake, feed conversion efficiency (FCE) and slaughter characteristics were studied in both experiments. 3. In Exp. 1, weight gain and FCE increased linearly and fat concentration in the carcase decreased with increasing IP concentration. In Exp. 2, weight gain and FCE improved exponentially, whereas breast meat yield improved linearly with increasing dietary IP concentration. On the basis of these results, it was concluded that the weight gain and FCE of male broilers respond to higher dietary IP levels than would be expected from single lysine requirement studies in the literature.

Age Factors↗

The measurement of muscle protein synthesis in broilers with a flooding dose technique: use of 15N-labelled phenylalanine, GC-MS and GC-C-IRMS.

An experiment was carried out to measure fractional muscle protein synthesis rates (k(s)) in broilers with injection of a flooding dose of phenylalanine (1 ml/100 g body weight of 150 mM phenylalanine; 38 atom percent excess (APE) [15N]phenylalanine). K(s) was calculated from the [15N] enrichment in phenylalanine of tissue-free and protein-bound phenylalanine using both gas chromatography mass spectrometry (GC-MS) and gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) for measurements after a 10 min isotope incorporation period. The tertiary-butyldimethylsilyl (t-BDMS) derivatives of phenylalanine were used for gas chromatographic separation in both systems. GC-MS and GC-C-IRMS were calibrated for a range of 7 to 37 [15N]APE and 0 to 0.62 [15N]APE, respectively, and for sample sizes of 0.45 to 4.5 nmol phenylalanine and 7 to 40 nmol phenylalanine, respectively. Reproducibility of standards as a measure of precision varied from 0.06 to 0.29 [15N]APE and from 0.0004 to 0.0018 [15N]APE in GC-MS and GC-C-IRMS, respectively. K(s) was measured in the m. pectoralis major of broilers fed rye based diets (56%) which were provided either unsupplemented (-) or supplemented (+) with an enzyme preparation containing xylanase. K(s) in breast muscles was significantly increased from 21.8%/d to 23.9%/d due to enzyme supplementation. It can be concluded from the study that the measurement of protein synthesis in broilers with the flooding dose technique can be carried out by using [15N]phenylalanine, GC-MS and GC-C-IRMS.

Animals↗