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PubMedDate not supplied

Economic effects of subclinical chicken anemia agent infection in broiler chickens.

To evaluate the economic effects of subclinical chicken anemia agent (CAA) infection on broiler performance, clinically normal broiler flocks were grouped into two categories: A) flocks in which none of 10 birds sampled at slaughter had antibody to CAA, and B) flocks in which six or more of 10 similarly sampled birds had CAA antibody. Production and performance parameters of 25 flocks in each category were compared. No statistically significant differences were found between category A and category B flocks in major production parameters such as sex, feed manufacturer, type of litter, stocking density, and age at slaughter. However, category A flocks achieved 13% (P less than 0.05) greater net income per 1000 birds, 2.0% better feed-conversion ratio (P less than 0.05), and 2.5% (P less than 0.05) greater average weight per bird than category B flocks. No significant differences in hockburn bonus per 1000 birds (a bonus payable to growers whose broilers have the lowest prevalence of contact dermatitis lesions on the hocks) and mortality were found between category A and category B flocks. These results show that subclinical CAA infection has a substantial, statistically significant effect on commercial broiler performance and profitability.

Age Factors↗

PubMedDate not supplied

Reduced erythrocyte deformability as a possible contributing factor to pulmonary hypertension and ascites in broiler chickens.

Deformability of erythrocytes and hematological parameters in white leghorn and broiler chickens were measured at age 7, 14, 21, 28, and 35 days. For deformability testing, a simple vertical apparatus containing a polycarbonate membrane with 5-microns pores was used. This technique assesses erythrocyte deformability by measuring the filtration time of an erythrocyte suspension through the pores. There was a significant difference in filtration time between the leghorns and broilers at all sampling times. These results indicate that reduced erythrocyte deformability in broilers may be one of the predisposing factors that increase resistance to blood flow and alter the rheology of blood in the microcirculation in the lung. Increased resistance to flow may result in pulmonary hypertension, heart failure, and ascites in broiler chickens.

Animals↗

PubMedDate not supplied

Comparison of phytohemagglutinin-induced cutaneous hypersensitivity reactions in the interdigital skin of broiler and layer chicks.

Cutaneous basophil hypersensitivity (CBH) responses elicited by intradermal injection of phytohemagglutinin-P (PHA-P) were evaluated in the interdigital skin of broiler and layer chicks. Five- and 10-day-old broiler and layer chicks were injected intradermally in the interdigital skin between the third and fourth digits of the right foot with 25, 50, or 100 micrograms of PHA-P. The PHA-P-elicited CBH responses were evaluated by determining interdigital skin thickness before injection and 12 and 24 hr after injection. The effect of treatment with the T-lymphocyte-suppressing drug cyclosporin on the CBH responses was determined in chicks treated daily for 4 days before skin-testing at 10 days of age. Injection of PHA-P caused significant increases (P less than 0.005) in skin thickness at all dose amounts, with the maximum CBH response elicited by 100 micrograms PHA-P. The CBH response was significantly higher (P less than 0.05) in broilers than in layers. Treatment with cyclosporin significantly suppressed (P less than 0.01) the CBH response in 10-day-old chicks of both types. Results indicate that the interdigital skin-test is a rapid, simple means of assessing normal and suppressed T-lymphocyte-mediated immune response in broiler and layer chicks.

Animals↗

PubMedDate not supplied

Marek's disease (MD). XX. Incidence and epizootology of MD in broiler flocks.

The frequency of Marek's disease in broiler chickens as measured by gross evidence of tumors at processing differs markedly among flocks and between poultry farm origin. Organs affected in broilers, in order of frequency of tumors, were proventriculus (57.6%), spleen (42.3%), kidney (30.6%), lung (19.1%), liver (15.3%), gonads (12.3%), heart (7.6%). Virus isolations were performed on samples from three broiler flocks to examine the possibility that such differences in MD incidence were causally related to differences in the frequency of naturally occurring, nononcogenic serotype 2MD virus infection. Serotype 2 virus was isolated from two flocks. MD condemnations were lower in two serotype-2 infected flocks (V1) than in the third one serotype 1 and serotype 2 positive flock (Mh). Thus, these data suggest a strong positive association between MD losses, housing and a weak probable negative association between serotype 2 virus and MD losses in broilers. However, low level of leukosis condemnations in certain flocks from the same farm are not related to high serotype 2 virus exposure.

Animals↗

PubMed1989

[Therapeutic use of enilconazole in broiler chicks with aspergillosis].

The course of a spontaneous outbreak of aspergillosis in a broiler flock was studied. Up to the 10th day of life the total mortality was 8%. Surviving broiler had an average body weight of 141 g on the 7th day of life, in contrast to the normal body weight of 150 g per bird. Aspergillosis was diagnosed in another three broiler flocks as well in an early stage of infection. Treatment with Enilconazole (Clinafarm Spray, Janssen, Neuss) in these flocks at a single time via spray in a dosage of 1.5 g enilconazole per 10 m2 housing ground obviously reduced mortality from the second day on after treatment. The average body weight of 7-day-old broiler was in a normal range. The success of the treatment depends on an early diagnosis and immediate start of the therapy. The source of infection (hatchery, transport, litter etc.) should be discovered and eliminated to prevent flocks from further infections.

Animals↗

PubMed1989

The broiler chicken as a model for immunotoxicity assessment. 1. Standardization of in vitro immunological assays.

The broiler chicken was developed as an alternative animal model to laboratory rodents for immunotoxicologic assessment. In vivo treatment with 100-200 mg/kg cyclophosphamide (CY) was used as a known immunosuppressive treatment to standardize the assay systems. Protocols for assessing specific immunological functions were developed in specific pathogen-free (SPF) broilers to measure lymphocyte blastogenesis to T-cell (concanavalin A and phytohemagglutinin) and B-cell (Staphylococcus aureus cells) mitogens, delayed-type hypersensitivity (DTH) to tuberculin, natural killer (NK) cell cytotoxicity, plaque-forming cell (PFC) response to sheep red blood cells (SRBC), and serum antibody titers to SRBC. CY was an effective immunosuppressant in the broiler system for assessment of lymphocyte responsiveness to mitogenic stimulation, DTH reactivity, and the antibody response to SRBC as assessed by PFC and serum antibody titers. NK cytotoxicity was not altered on a cellular level following treatment with CY at a dose that produced greater than 75% depletion of spleen cellularity. However, under these conditions, it must be assumed that the capacity of CY-treated birds to mediate NK effector functions would be reduced. These results demonstrate the applicability of the broiler chicken as an animal model for immunotoxicity testing.

Animals↗

PubMed1987

[Meat quality in broilers affected with inflammation of the feather follicles].

Broilers with feather follicle inflammation and birds free of this disorder were selected from the broiler chickens kept on plastic (bralen-)coated metallic slats. Both groups of broilers were killed on a sanitary slaughter line and the samples of breast and thigh muscles were analyzed for the basic composition and characteristics of the metabolism of nitrogenous and lipidic components. The content of individual amino acids in the muscles and the proportion of fatty acids in the intramuscular fat of broilers were determined for the evaluation of nutritive value. The samples of the affected spots of skin and samples of organs (liver) were subjected to microbiological examination. The resultant finding represented the common mesophilous microflora. No substantial statistically significant differences in chemical characteristics were found between the two groups. It follows from the results that the inflammation of feather follicles is a local skin disorder with no effect on the quality of the meat.

Animals↗

PubMed1977

[Cross-infection during scalding and plucking of broiler chickens (author's transl)].

In two poultry-processing plants, experiments were carried out to detect cross-infection during scalding and plucking of broiler chickens. These trials showed that cross-infection was only detectable when experimental infection with the indicator micro-organism Escherichia coli K12 was applied externally to the broiler chickens. When infection was applied internally, only a small degree of transmission was observed. Indicator micro-organisms applied externally to broiler chickens prior to scalding and plucking, were present on the cooled product in larger numbers than those applied internally in the intestines of broilers. The number of carcasses which were positive after cooling was found to have decreased in poultry-processing plant B compared with the situation after plucking, whereas this number was not affected to any appreciable extent in processing plant A.

Animals↗

PubMedDate not supplied

A survey of sensitivity to anticoccidial drugs in 60 isolates of coccidia from broiler chickens in Brazil and Argentina.

Coccidia were isolated from 90 broiler farms in 15 poultry-producing areas in Brazil and Argentina. Sixty isolates were tested for sensitivity to 7 anticoccidial drugs. The common species were: a) Eimeria tenella, 47 isolates; b) E. maxima, 49 isolates; c) E. acervulina, 44 isolates; d) E. mitis, 26 isolates; and e) E. brunetti, 12 isolates. Isolates were considered sensitive to drugs if intestinal lesion scores of medicated broilers were reduced by at least 50% compared with unmedicated infected broilers or if weight gain was at least 75% of that of uninfected birds in a 6-day laboratory test. According to lesion scores, there was evidence of resistance or seriously reduced sensitivity to monensin in 20 isolates, narasin in 29, salinomycin in 11, maduramicin in 1, clopidol in 36, amprolium in 40, and nicarbazin in 1. According to broiler weight gain, there was resistance to monensin in 36 isolates, narasin in 32, salinomycin in 28, maduramicin in 2, clopidol in 28, amprolium in 50, and nicarbazin in 4. These results suggested incomplete cross resistance of coccidia to polyether ionophorous drugs. The degree of resistance might be explained by previous patterns of use of these drugs.

Animals↗

PubMed1987

[Effect of the gas composition of the air on the growth of broilers].

Comparative investigations were carried out with the gas composition of air and the productivity of broilers raised in cells and on deep litter in the region of Northeast Bulgaria. The buildings were sized 75 X 15 X 3.8 m. The air exchange in them was effected through mechanical ventilation at lowered pressure, after the pattern 'from above--sideways'. As many as 17.3 birds/m2, when deep litter was used, and 28.6 birds/m2, when cells were used, were housed in the buildings for raising up to the age of 56 days. The content of harmful gases, such as ammonia, hydrogen sulfide, and carbon dioxide was determined at 14-day intervals at 3 sites in the buildings. The body mass of broilers, raised after the two methods, was followed up on the 14th, 28th, 42nd, and 56th day of age. The number of birds and the live mass produced per square meter of floor area in the various seasons of the year were calculated at the end of the fattening periods. It was found that by the end of fattening on deep litter the concentration of ammonia varied around the upper admissible threshold, while with fattening in cells it was within the standard range. With cell raising of broilers the live mass produced per 1 m2 of flooring was 50.5 to 83.6 per cent more as compared with the live mass produced on deep litter. The total broiler produce with cell raising over the 4 seasons was 63.3 per cent, on an average, more than that with the use of deep litter.

Aging↗

PubMedDate not supplied

Serological profiles of commercial broiler breeders and their progeny. 2. Newcastle disease virus.

Newcastle disease virus (NDV) hemagglutination-inhibition (HI) titers were determined for serum samples from eight commercial broiler breeder flocks and their progeny. The chickens sampled had been vaccinated and reared by different producers in different regions of the United States. Breeder flocks had the highest number of NDV-positive HI titers (greater than or equal to 1:10). Eighty percent or more of the samples from six of eight breeder flocks were positive; the geometric mean titers (GMTs) for those six breeder flocks ranged from 19 to 92. Only 3 of 8 broiler flocks had an increased frequency of positive titers and higher GMTs after vaccination. The frequency of positive titers was greater than 80% in only 2 of 8 of the oldest broiler flocks. The number of NDV-negative titers (less than 1:10) increased with age in most broiler flocks, even though all had been vaccinated once or more with live NDV vaccines.

Animals↗

PubMed1977

[Effect of the temperature-humidity regime during broiler raising on serum proteins and amino acids].

The study on the effect of the temperature and moisture regime on the serum proteins and amino acids in broiler chickens has revealed that under the conditions of relatively lower temperatures and higher relative moisture levels the total protein, the albumin, and the gamma-globulin fraction show higher contents. Noticeable are also some changes in the content of the bound amino acids (tyrosin, alfa- and beta-alanine, aspartic acid, and glycin) in the blood sera that are likewise depending on the temperature and moisture regime. The total amount of amino acids and the free forms of arginine and lysine are at higher levels in the broilers raised prior to the experiment at 32 degrees C and relative air humidity 70--75 per cent. With the remaining free and bound amino acids in the blood serum there are no differences in broilers raised at various temperature and moisture regimes. The body weight of broilers raised prior to the experiment at 32 degrees C and relative air humidity 70--75 per cent is higher, while the consumption of forage for kilogram weight gain is lower as compared to that with birds raised at higher temperature and lower relative humidity (35--45 and 50 per cent).

Amino Acids↗

PubMedDate not supplied

Isolation of avian reovirus as a possible etiologic agent of osteoporosis ("brittle bone disease"; "femoral head necrosis") in broiler chickens.

Avian reovirus was isolated from intestines of 3-to-7-day-old broiler chickens with enteritis from broiler houses where osteoporosis was a problem. The virus was purified in a cesium chloride gradient (buoyant density 1.37 gm/ml) and identified as a reovirus by electron microscopy. Specific-pathogen-free (SPF) chickens and commercial broiler chickens with anti-reovirus maternal antibodies inoculated at 1 day of age with the reovirus isolate developed lesions of femoral head fractures and/or osteoporosis; reovirus could be reisolated from the bone marrow and intestinal tracts of experimentally infected SPF birds. The reovirus isolate, although isolated from intestines, induced development fo tenosynovitis lesions in SPF and commercial broiler chickens.

Animals↗

PubMedDate not supplied

Prevalence of Alcaligenes faecalis in North Carolina broiler flocks and its relationship to respiratory disease.

In order to assess the role of Alcaligenes faecalis in respiratory disease of broilers, a study was conducted to determine the prevalence of this bacterium in North Carolina broilers and to determine the relationship of A. faecalis infection to clinical disease. Our studies showed that A. faecalis is prevalent in North Carolina commercial broilers during the winter months. Bacteriological examination of turbinates and tracheas revealed that almost 40% of individual birds between 35 and 45 days of age yielded positive cultures; 62% of tested flocks were infected. When present, A. faecalis was usually the predominant bacterium isolated. Furthermore, because of a higher frequency of A. faecalis isolation in broiler flocks with respiratory disease (75% vs. 29% in flocks without respiratory diseases), these studies suggest a causal relationship between this bacterium and clinical respiratory disease.

Alcaligenes↗

PubMed1980

[Effect of population density on the raising of broiler chickens].

Experiments were carried out to study the influence of density in industrial broiler-raising. They took place during different seasons of the year and with a different density of habitation (12, 14, 16, 18, 20 and 22 pieces on m2) and through an optimization of technological indices in broiler-raising. The dynamism of microclimatic indices was traced out (temperature, humidity, gas composition, dust and microbe contamination of air in the buildings having a different density of habitation. Hematological and biochemical studies were carried out concerning total protein, protein fractions, contents of hemoglobin and number of erythrocytes, as well as the contents of alkaline reserves of blood. The experiments were also devoted to the growth and development, the consumption of fodder for a single unit of production, the morbidity rate and the death rate with chickens raised in different density. It was proved that the density of habitation exerts an influence over microclimatic indices. If the density is greater the contents of ammonia in the buildings is by 1.5 times over the zoohygienic requirements. Under the influence of the density of habitation certain changes occurred concerning the hematological and biochemical indices of blood. A correlation was observed between the density of habitation and the development of some diseases. Certain changes occurred also in the growth and in the development of broilers. By virtue of the results obtained, suggestions are put forward to optimize the density of habitation in industrial broiler-raising.

Animal Husbandry↗

PubMed1978

[Toxicity studies of Pharmachem's tylosin tartrate for broilers and turkeys].

Studied were the acute, subchronic, and chronic toxicity of the Pharmachim tylosin tartrate as well as the tolerance of chicken broilers and turkeys. The mean lethal dose of the antibiotic at subcutaneous application to 28-32 day-old broilers was 620 mg/kg; the oral dose was 1500 mg/kg. In the case of 42-45-day-old broilers these values were 740 and 5400 mg/kg. The LD50 at i/v infusion for 75-77-day-old ones was 48 mg/kg. Beside the age and route of introduction toxicity was found to depend on the initial biologic activity of tylosin tartrate. The subcutaneous injection of tylosin tartrate at the rate of 30 mg/kg for 20 days did not lead to changes in the appetite, behaviour, growth, and structure of viscera. A 42-day treatment at the same rate, however, resulted in slightly manifested and fully reversible dystrophic changes in the liver and kidneys. Higher doses (90 and 150 mg/kg) led to transient depression, stunting of growth, and a rise of the urea level and the activity of blood transaminases as well as to moderate destructive changes in the liver and kidneys. The stimulation of growth and the improvement of feed conversion (without deviations in the clinical and biochemical indices of the blood and the structure and development of the viscera in broilers) were recorded after the application of a water-soluble formula of tylosin tartrate for a period of 98 days offered via the drinking water in amounts equal to or exceeding 2 to 4 times the ED50. Turkeys' tolerance for the preparation was evaluated as very good so far as single i/m injective applications were concerned in doses exceeding 3, 5, and 10 times the average effective rates, no differences in this respect being noted with the comparative use of tylosin tartrate produced by the Elanco firm.

Animals↗

PubMedDate not supplied

Prevalence of Salmonella in broiler flocks: effect of litter water activity, house construction, and watering devices.

Litter samples from 24 flocks of broilers and four flocks of broiler breeders were evaluated for Salmonella contamination, water activity (Aw), and total moisture content (MC). The drag swab (DS) monitoring system was used to collect samples to detect Salmonella contamination. Simultaneously, representative samples of the uppermost surfaces of dry (loose) litter and wet (caked) litter were collected for Aw and MC analyses. On dry litter surfaces, high Aw values (0.90-0.95) were associated with flocks Salmonella-positive using DS; low Aw values (0.79-0.84) were associated with flocks Salmonella-negative by DS; and transition Aw values (0.85-0.89) were associated with flocks having an increased risk for the presence of Salmonella. The association of high Aw values with Salmonella risk was not observed for wet (caked) litter surfaces. Observations suggest that limiting Aw in the litter base of broiler houses may create a less favorable environment for the multiplication of Salmonella and thus a more hygienic environment for broiler production.

Animals↗

PubMed1994

Occurrence of Listeria species in broilers pre- and post-chilling in chlorinated water at two slaughterhouses.

Altogether 323 pooled samples of neck skins from 1615 broilers from 2 processing plants (A and B) were examined for the presence of Listeria species. The broilers were sampled pre-chilling-after leaving the final rinser but before entering the chiller with chlorinated water-and post-chilling-immediately upon leaving the chiller. Free available chlorine in the chilling water varied from 2 to 15 ppm in plant A and was about 10 ppm in plant B. Listeria monocytogenes was only isolated from broilers in plant A sampled post-chilling (58% of 62 samples). L. innocua was isolated from 19% and 39% of broilers sampled pre-chilling in plants A and B, respectively. Post-chilling, L. innocua was isolated from 3% and 6% of samples from plants A and B, respectively.

Abattoirs↗