Teratogenic activity of Arasan fed to broiler breeder hens.

Tetramethylthiuramdisulfide (TMTD), the active ingredient in Arasan, fed to broiler breeder hens at 10, 20, or 40 ppm depressed egg production, reduced hatchability, and resulted in soft-shelled eggs. The progeny of these hens had anomalies manifested by bilaternal medial deviation of the toes, exophthalmia, and shortened femurs. Broiler breeder hens that consumed a ration containing 80 ppm of TMTD produced only soft-shelled eggs.

An outbreak of type-C botulism in three-weeek-old broilers.

Botulism was diagnosed in 3-week-old broilers from clinical signs, absence of postmortem and histopathological lesions, and demonstration of toxin in the serum of comatose birds. Passive immunization of mice with Clostridium botulinum type-C antitoxin protected against a challenge with serum from comatose birds containing the Cl. botulinum toxin. Total mortality for the grow-out period exceeded 27% and was not altered by water medication with penicillin. Bacitracin at 100 g per ton reduced mortality to 5-7 birds per day.

Myopathy of the deep pectoral muscle in broiler breeder hens.

Myopathy of the pectoralis profundus and ambiens muscles was found in chickens from 5 flocks of broiler breeder hens. Histological lesions in the muscles varied from steatosis to loss of striations, fragmentation of fibers, and mineral deposition. A clinical response followed oral medication with vitamin E and selenium although analysis showed that selenium and vitamin E levels in the feed were normal. The possible relation between myopathy and Cassia seed in the feed is discussed.

Field experiments with viral arthritis/tenosynovitis vaccination of breeder chickens.

Vaccination of three commercial broiler-breeder flocks at 15 weeks old with viral arthritis/tenosynovitis via the drinking water resulted in serologic conversion of two flocks to agar-gel-precipitin (AGP)-positive, while the third flock was still AGP-negative at 24 weeks, but was AGP-positive at 30 weeks old, presumably as a result of natural exposure. Progeny from the two successfully vaccinated breeder flocks remained free of clinical viral arthritis/tenosynovitis and had average condemnation rates of 0.99%. In contrast, six hatches of progeny from the third breeder flock experienced clinical viral arthritis/tenosynovitis and average condemnation rates of 3.64%.

Acute hemorrhagic enterocolitis in ratites: isolation of eastern equine encephalomyelitis virus and reproduction of the disease in ostriches and turkey poults.

Two emus died with acute hemorrhagic enterocolitis. Eastern equine encephalomyelitis (EEE) virus was isolated in Vero cells from non-pooled samples of brain and intestine. Enterocolitis with splenic and hepatic necrosis was reproduced by intramuscular or oral inoculation of this isolate in two ostriches and three turkey poults.

Newcastle disease vaccination of broilers with high- and low-titered commercial vaccines.

The virus titers of seven commercial B1 strain Newcastle disease vaccines were evaluated. A 2 log difference in virus content was found between the vaccine with the highest titer (10(8.8) EID 50/ml) and the one with the lowest titer (10(6.8) EID 50/ml). Broiler chickens were vaccinated with the high- and low-titered vaccines to compare hemagglutination-inhibition (HI) antibody and challenge responses. The effect of vaccination at different ages on the HI titers was also examined. There were no significant differences between vaccine groups in HI antibody response or resistance to challenge. However, the high-titered vaccine may provide a margin of safety with the currently used methods of mass vaccination.

Infectious tenosynovitis in young turkeys.

Two viruses serologically related to the tenosynovitis virus of chickens were isolated from two flocks of turkeys experiencing outbreaks of tenosynovitis. Both viruses produced a tenosynovitis when injected into the foot pad of young turkeys. Staphylococcus aureus was not isolated from either flock, nor was there any evidence of Mycoplasma synoviae antibody in either flock.

Field studies with convalescent serum and infectious bursal disease vaccine to control turkey coryza.

Convalescent serum given to 1-day-old poults delayed clinical signs of turkey coryza by several days and reduced mortality on infected farms. Turkey breeders immunized with cell-culture-adapted infectious bursal disease virus (IBDV) or turkey infectious bursal disease virus (TIBDV) had a marked increase in virus-neutralization (VN) antibody titers. The VN antibody titer was significantly higher in progeny poults than in poults from unimmunized breeders. Clinical turkey coryza and mortality was considerably less in poults from IBD- or TIBD-vaccinated breeders than in control poults. They also responded more favorably to hemorrhagic enteritis and fowl cholera vaccination.

Viral arthritis in fryers related to reovirus infection in breeders.

In 1983, twenty-two outbreaks of viral arthritis/tenosynovitis were diagnosed in a 6-month period on 18 fryer farms of one commercial operation located in western Washington. The main source of the reovirus infection was traced to a breeder flock that supplied progeny chicks to all of the affected farms.

Suspected mycotoxicosis in laying hens.

A flock of 15,000 leghorn-type hens experienced a 10% drop in egg production. Enlarged, blue combs and diarrhea were also present. Clinical signs, postmortem and histopathological lesions, and response to therapy were compatible with a diagnosis of mycotoxin intoxication. However, all feed samples submitted were negative for mycotoxins, so the diagnosis could not be confirmed.

Incidence of Pasteurella multocida in poultry house cats used for rodent control programs.

Cats used as mousers in commercial poultry breeder farms were tested for the presence of Pasteurella multocida. Of the cats tested, 72.7% were positive for P. multocida serotypes common to both farm cats and commercial broiler breeders. Thirty-one percent were type 1, 19% were type 4, and 6% were type 3.4.

Effects on feed consumption and egg production of coffee bean seed (Cassia obtusifolia) fed to White Leghorn hens.

Coffee bean seed (Cassia obtusifolia) was ground and mixed in the feed at levels of 2,5, and 10% and fed to White Leghorn hens. Feed consumption and egg production were reduced by all three although more so at 5 and 10%. Feed consumption and egg production had not returned to control levels four weeks after the adulterated feed was suspended, though the response was more pronounced in the younger birds. The semitendinosus and pectoralis superficialis muscles were pale and edematous at postmortem examination of the birds, being most pronounced at the 5 and 10% levels.

A comparison of the efficacy against Marek's disease of cell-free and cell-associated turkey herpesvirus vaccine.

One-day-old White Leghorn and broiler chicks with maternal antibody to turkey herpesvirus (HVT) were vaccinated with 300 or 1,000 plaque-forming units (PFU) of cell-free or cell-associated HVT vaccine and challenged with virulent Marek's disease virus (MDV) by contact exposure. Broiler chicks receiving 300 PFU of cell-associated HVT had a 3.3% incidence of MD lesions, whereas only 2.0% of those receiving 1,000 PFU had macroscopic lesions. Broiler chicks vaccinated with 300 PFU of cell-free vaccine had 6.8% gross lesions, and 0.67% of the birds receiving 1,000 PFU had MD lesions. Unvaccinated broiler chickens had a 28.3% incidence of MD lesions. Unvaccinated White Leghorn chickens had a 48.9% incidence of macroscopic lesions, whereas 5.4% of the birds receiving 300 PFU of cell-associated HVT had gross lesions, and 8.3% of the birds vaccinated with 1,000 PFU had lesions. In contrast, 6.7% of the chicks vaccinated with 300 PFU of cell-free HVT had MD lesions, and only 4.0% of those receiving 1,000 PFU of cell-free HVT had macroscopic lesions.

Cryptosporidiosis of the bursa of Fabricius of chickens.

Light-microscope and electron-microscope studies of a coccidial organism found in the bursa of Fabricius from 3 chickens clearly established the parasite as belonging to the family Cryptosporiidae. Hyperplasia and heterophil infiltration were associated with the presence of organisms attached to the microvillus border of epithelial cells lining the plicae of the bursa of Fabricius. Although there were no clinical signs or gross lesions common to the 3 cases described, all had similar histologic lesions in the epithelium lining the bursa of Fabricius.

Interaction of aflatoxin with Eimeria tenella infection and monensin in young broiler chickens.

Young broiler chicks inoculated with Eimeria tenella and given a diet containing 2.5 mug aflatoxin/g had significantly higher mortality than birds with aflatoxicosis or coccidiosis alone or uninoculated controls. This effect was seen even when a light coccidial infection alone did not increase mortality or cause weight depression. In addition this higher mortality with the combination began earleir and occurred at a higher rate than did mortality from aflatoxin or cecal coccidiosis alone. Dietary monensin sodium (99 umg/g) did not completely prevent mortality and weight depression when aflatoxin and E. tenella were in combination. Aflatoxin and E. tenella singly significantly depressed three-week body weights; however, the depression was most severe when the two were in combination. Both dietary aflatoxin and E. tenella significantly reduced hemoglobin, packed cell volume, and plasma pigmentation, and in combination resulted in more severely reduced hemoglobin, packed cell volume, and plasma pigmentation. Coccidial lesion scores were significantly less for the combination of E. tenella and aflatoxicosis than for coccidiosis alone. This atypical response of the ceca to E. tenella in the presence of dietary aflatoxin was characterized by less distended ceca, very little coagulated blood in the ceca, and apparently more profuse cecal hemorrhage.

Rhinotracheitis in turkey poults.

A severe upper respiratory disease of young turkeys is described that resulted in high morbidity and mortality. Death was due to asphyxiation produced by occlusion of the trachea or nostrils. The postmortem lesions were tracheitis, pulmonary edema, swollen livers and spleens, and a drastic reduction in bursa size. Bursal necrosis and loss of tracheal epithelium were found in tissue sections from clinically affected birds. Antibody to infectious bursal disease was found by agar-gel precipitin and virus-neutralization tests of serum samples from affected flocks. A geometric mean titer of 31.5 for Newcastle disease was found in unvaccinated flocks of five-week-old turkeys.

Aspergillosis in turkeys associated with use of contaminated litter.

Severe mortality occurred in a flock of 16,000 turkey poults after fresh litter consisting of poplar, oak, sweetgum, and pine shavings was added to the brooder house. Signs and lesions seen were consistent with aspergillosis. Mortality for the first 21 days of brooding was 305 poults. New litter was added on day 21; 6,041 poults died during the next 24 days. Mold counts were done on the original litter and added litter. The mold counts for the original litter was 1.0 X 10(5) organisms per gram of litter. The mold count for the added litter was 2.5 X 10(6) organisms per gram of litter. After the added litter had been treated with nystatin and copper sulfate, the mold count dropped to less than 1 X 10(4) organisms per gram of litter. Mortality was also reduced but not to pre-infection levels. Rales, mucus rhinitis, and airsacculitis due to Escherichia coli developed. Despite treatment, performance of the flock remained poor.

Infectious coryza: preventing complicated coryza with Haemophilus gallinarum and Mycoplasma gallisepticum bacterins.

Three types of infectious coryza were produced in unvaccinated chickens by challenge inoculums containing different combinations of Haemophilus gallinarum (HG) and Mycoplasma gallisepticum (MG). Monovalent and combination bacterins of HG and MG were tested to determine their efficacy against chronic complicated infectious coryza. Challenge exposure of vaccinates with MG and HG showed protection against the HG component to be immunotype-specific. Some protection against complicated coryza resulted from HG bacterins only, whereas MG bacterin was ineffective. Protection against transient and chronic coryza was provided by a combination MG-HG bacterin. Two doses of this bacterin gave better protection against upper respiratory clinical signs and lowered the incidence of airsacculitis.

Acute toxicity of boric acid and boron tissue residues after chronic exposure in broiler chickens.

The acute oral mean lethal dose of boric acid in 1-day-old chickens was found to be 2.95 +/- 0.35 g/kg of body weight, which classifies this product as only slightly toxic to chickens. One-day-old broiler chicks were housed in floor pens in which litter had been treated with 0, 0.9, 3.6, or 7.2 kg of boric acid per 9.9 m2 of floor space. Boron residue levels in brain, kidney, liver, and white muscle were not statistically elevated following a 15-day exposure period. Boron residue levels in the same types of tissue were not significantly elevated in chicks fed 500 ppm or 1250 ppm boric acid in feed ad libitum for 3 weeks; however, residues were significantly higher in chicks fed 2500 ppm or 5000 ppm boric acid. These data indicate that broilers grown on boric acid-treated litter do not consume enough boric acid to cause elevated boron levels in tissues.