Turkey Breeder Flocks Research Articles

Egg Production Drops in Breeder Turkeys Associated with Western Equine Encephalitis Virus Infection

Egg production drops associated with western equine encephalitis (WEE) virus infection occurred in three turkey breeder flocks in California during summer 1993 and again in one flock the following year. Egg production losses totaled 8.76%, 9.57%, 9.71%, and 10.12% and were accompanied by an increase in small white-shelled and shell-less eggs. The outbreaks coincided with peak WEE virus activity in the state on the basis of statistics compiled by the California Department of Health Services on seroconversion rates in sentinel chicken flocks. Paired serum samples taken 2-3 wk apart showed increased titers to WEE between acute and convalescent sera in turkeys from three affected flocks. Convalescent sera were not available for testing from the fourth flock. WEE virus was isolated from one breeder hen submitted to the diagnostic laboratory during the early stages of the outbreak.

Femoral Fractures in a Young Male Turkey Breeder Flock

Twenty-two 32-to-35-wk-old male turkeys from a commercial breeding flock were presented to the California Veterinary Diagnostic Laboratory System, Fresno Branch, with a clinical complaint of lameness and increased mortality. Necropsy findings included a unilateral, closed oblique fracture involving the femur in 12 birds. Ten complete femoral fractures had periosteal new bone adjacent to and bridging the fracture. Periosteal callus formation, in this case, suggested that preexisting lesions preceded complete fracture of the femur. Factors such as selection for heavy body weight, lack of exercise, and handling might have contributed to the development and promotion of complete fractures.

Natural and Experimental Infection of Turkeys with Avian Paramyxovirus-7

Avian paramyxovirus-7 was isolated from a natural outbreak of respiratory tract disease in male and female commercial turkey breeder flocks. The disease spread readily between different housing complexes. The virus was isolated from affected flocks and used for experimental studies in specific-pathogen-free poults. Inoculated and contact-exposed poults developed a respiratory disease characterized by rhinitis and airsacculitis. The virus was isolated from the inoculated and contact-exposed poults, and hemagglutination inhibition antibodies were detected in exposed birds.

Mycoplasma iowae: A review

Mycoplasma iowae is an avian mycoplasma which has rather different properties from other avian mycoplasmas such as resistance to bile salts, predilection for the gastrointestinal tract and a relative resistance to many antimicrobials. There is also an unusually large degree of antigenic variation among strains belonging to this species. The Mycoplasma has been isolated from a number of avian hosts, but in natural infections the main manifestation is mortality of turkey embryos in the later stages of incubation. In experimental infections some strains cause chick and turkey embryo mortality and, depending on the route of infection and the age of bird, can give rise to joint and bone abnormalities and occasional air sacculitis. In turkeys it is well known that the organism is egg-transmitted and can also spread laterally. In the mature bird the oviduct, semen and cloaca are sources of infection. Less is known about the natural infection in chickens. The humoral response in turkeys and chickens is poor and diagnosis is currently by culture although several polymerase chain reaction (PCR) detection methods have been developed. Eradication from some turkey breeder flocks has been achieved by treating eggs with fluoroquinolones, monitoring the progeny for infection, and imposing stringent hygiene measures, especially at artificial insemination.

The Relation of Egg Specific Gravity to the Incidence of Spontaneous Cardiomyopathy in Tom Turkeys

The specific gravity and weight of eggs were determined for two groups of 600 eggs each, originating from Nicholas and British United Turkey of America (BUTA) turkey breeder flocks. A total of 137 Nicholas and 190 BUTA toms hatched from these eggs were used for the experiment. At days 21, 33, 40, 47, 56, and 61, toms that showed retarded growth were euthanatized, along with a corresponding number of normal birds. Both groups were measured for body weight, heart weight, separate weights of left and right ventricles, and combined atrial weight. At market age, the remaining toms were weighed, and the hearts were checked at processing for lesions characteristic of spontaneous turkey cardiomyopathy (STC). STC was found in 10.2% of Nicholas and 8.4% of BUTA toms. No correlation could be found between specific gravity of eggs and incidence of STC. Body weights of affected toms were reduced during the growing period. At processing, 2.8% of toms had lesions of STC, and mean body weight was 1298 g lower than average. The ratios of combined atrial weight:body weight, right ventricular weight:body weight, left ventricular weight:body weight, and total heart:body weight were significantly higher at all times in affected toms than in controls, and the differences were the greatest at 3 weeks of age.

Clinical Mycoplasma gallisepticum Infection in Multiplier Breeder and Meat Turkeys Caused by F Strain: Identification by Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis, Restriction Endonuclease Analysis, and the Polymerase Chain Reaction

In February 1991, a flock of North Carolina multiplier breeder turkeys experienced respiratory signs, sinusitis, airsacculitis, and increased mortality. Mycoplasma gallisepticum (MG) was isolated, and appropriate control measures were initiated. Ultimately, this outbreak involved several breeder flocks of an integrated turkey production company before the last infected flock was identified in May 1991. During this time, MG was also isolated from a flock of commercial layer-type chickens raised as pullets in close proximity to the index turkey flock. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and restriction endonuclease analysis indicated that these isolates were identical to each other and to examples of the vaccinal F strain. Additionally, MG isolates from the affected turkey breeder and layer flocks were identified as MG F strain by use of an F strain-specific DNA probe and polymerase chain reaction. A separate outbreak of MG disease in several meat-turkey flocks of a Midwest producer/processor yielded isolates identified as F strain by the polymerase chain reaction. These studies demonstrated: 1) the utility of newer technologies for disease outbreak investigations; and 2) the potential of MG F strain to cause disease in breeder and meat turkeys under field conditions.

Use of an Enzyme-Linked Immunosorbent Assay to Measure Antibody Levels in Turkey Breeder Hens, Eggs, and Progeny Following Natural Infection or Immunization with a Commercial Bordetella avium Bacterin

Twelve large white turkey hens were immunized with a commercially available Bordetella avium bacterin. Hens and eggs were tested using an enzyme-linked immunosorbent assay (ELISA) to determine the response to the bacterin. Three hundred poults were then obtained from two commercial flocks, the hens of one flock having been immunized with the same bacterin used on the group of 12 turkeys. Titers of the poults were monitored for 7 weeks, and poults were challenged by exposure to infected poults at 1, 7, 14, and 21 days post-hatch. Hens produced an antibody response following immunization, with a parallel antibody response being detected in eggs. Maternal antibodies were present in poults from immunized hens. Poult titers declined to near the level of poults from unimmunized hens by 14 days of age. Poults from immunized hens challenged at 1 and 7 days were resistant to development of clinical disease and gross lesions, whereas all poults from unimmunized hens exhibited clinical signs and gross lesions. After 14 days, the resistance of both groups to development of clinical disease, became near equal, neither group being affected as severely as the unimmunized hens challenged at days 1 and 7. Six commercial turkey breeding flocks and their progeny that had not been vaccinated for B. avium and had no history of B. avium infection were evaluated with the B. avium ELISA. There were variations between the flocks, with poult titers reflecting those found in the hens.

Effects of Egg Weight, Glucose Administration at Hatch, and Delayed Access to Feed and Water on the Poult at 2 Weeks of Age

Eggs from a 42-wk-old small-type turkey breeder flock were weighed and divided into heavy, medium, and light categories relative to the population average. Poults from each category were sexed, then given .5 mL of 50% glucose in saline by either crop intubation (CI) or subcutaneous injection at the neck (SC). Controls did not receive glucose. One-half of the birds from each treatment were immediately given access to feed and water in pens of brooder batteries; the remainder were held 3 days in transportation boxes before placement in other pens of the same batteries.Poult weight at hatching and 3 days later paralleled egg weight. Improvement in 3 day BW occurred after glucose administration and was greater by SC than CI, but these advantages were only apparent when feed and water had been accessible during the interim. Egg weight effects on BW and gain persisted to 2 wk of age, as did the depression from delayed nutrient access; however, the advantage from glucose with poults having early access to nutrition disappeared. Alterations in the proximate compositions of livers and carcasses among treatments were small. Total mortality increased with egg weight when poults received feed and water early after hatching, while the converse occurred when delayed. Deaths were not altered by either glucose or fasting (P>.05).

Sudden Death Syndrome in Turkey Hens

A turkey breeder flock of 5600 31-week-old hens experienced an abrupt increase in daily mortality for a 2-day period. This higher mortality rate corresponded with the handling and moving of the hens 1 to 2 days before. No clinical illness was seen in the hens before carcasses were discovered. The four hens that were necropsied had small spleens, congested lungs, and enlarged livers. The most consistent histologic lesions were pulmonary hemorrhage and edema, and congestion of veins and capillaries in several visceral organs. One hen had subserosal hemorrhage of the oviduct and perirenal hemorrhage. The increased mortality pattern, the lack of clinical signs, and the histopathologic changes are consistent with a diagnosis of sudden death syndrome. The presence of concurrent inflammatory lesions in the lungs predisposed the hens to sudden death following the stress of handling and moving.

The use of a specific dna probe for detection ofMycoplasma gallisepticumin field outbreaks

A specific DNA probe (pMG4) was used to diagnose M. gallisepticum (MG) infection in field outbreaks in chicken and turkey breeder flocks in Israel. Dot-blot hybridisation of tracheal swab suspensions with the probe enabled positive identification of MG as early as 4 days after sampling, even in flocks at an early stage of infection when no other specific indications of infection were available.

Vertical Transmission of Reticuloendotheliosis Virus in Breeder Turkeys

Epizootiological studies were conducted on a commercial turkey breeder flock naturally infected with nondefective reticuloendotheliosis (RE) virus. Although RE virus was isolated from 27 (46%) of the 59 hens studied, only 4 of the 45 hens tested transmitted RE virus to progeny during a 6-week observation period and the overall transmission rate was 1.8%. The transmitter hens were of two types: three hens were consistently viremic and antigenemic and lacked antibody; one hen was viremic but lacked detectable viral antigen and possessed antibody. Toms appeared to play no role in vertical transmission of the infection. Of several tests evaluated for detection of transmitter hens, the direct enzyme-linked immunosorbent assay on albumen was probably best, since it detected three of four transmitter hens, detected relatively few nontransmitter hens, and had the best consistency of any test. No significant differences in hatchability were found between eggs from viremic and non-viremic hens. These findings can be utilized in the development of programs for eradication of RE virus from turkey breeding flocks.

An Outbreak of Influenza (H1N1) in Turkey Breeder Hens

Outbreaks of influenza were diagnosed in two turkey breeder flocks on the same premises in eastern North Carolina during the "dark-out" period of recycling for a second lay. Clinical history included increased mortality from acute death with no apparent predisposing illness. Mortality attributed to the disease was 4.5% in one flock and 3.3% in the other. Necropsy findings included severe diffuse congestion and edema of both lungs, with little or no pleural exudate. Spleens were moderately to markedly enlarged and mottled, and kidneys were swollen and congested. Microscopic lesions included moderate to severe serofibrinous pneumonia with severe pulmonary congestion. Splenic changes included fibrin deposition and severe congestion, and severe congestion was noted in kidneys. Influenza virus (H1N1) was isolated from pools of tissues including lung, spleen, liver, and kidney, and both flocks seroconverted to influenza (H1N1) virus.

Clinical Outbreak of Bordetella avium Infection in Two Turkey Breeder Flocks

An acute upper respiratory disease was observed in two broad-breasted white (BBW) turkey primary breeder flocks. Associated clinical signs included sneezing, depression, and a deep dry cough originating from large conducting airways. Morbidity reached approximately 15-20% of the hens in an affected house. None of the turkeys died, and total feed consumption was not affected. A minimal effect upon egg production was noticed. Sera from an acutely affected flock exhibited a marked rise in titer to Bordetella avium compared with preinfection sera samples. In Case 1, B. avium was isolated in pure culture from affected birds. In Case 2, B. avium was diagnosed by serological results and clinical signs; bacteriological examination was not attempted. The findings presented here are consistent with an acute clinical outbreak of B. avium-induced turkey rhinotracheitis (turkey coryza) in BBW turkey breeder hens.

Serologic Evidence in Commercial Chicken and Turkey Flocks of Infection with Reticuloendotheliosis Virus

A serologic survey has documented probable infection with reticuloendotheliosis (RE) virus in 21.0% of 101 layer flocks, 23.5% of 85 broiler and broiler-breeder flocks, 2.3% of 43 backyard chicken flocks, and 4.8% of 125 turkey production and breeder flocks. However, no infection was detected in 72 grandparent lines of chicken breeding stocks representing meat-type and layer strains. The existence of natural infection was further supported by isolation of RE virus from one experimental chicken flock and two commercial turkey flocks. This study supports earlier but subsequently discounted data by Aulisio and Shelokov that exposure to RE virus occurs commonly among commercial chickens in the United States, as has also been reported in other countries.

Characteristics and Serologic Studies of Two Serotypes of Infectious Bursal Disease Virus in Turkeys

Two serotypes of infectious bursal disease virus (IBDV) were distinguished using the virus-neutralization test. An IBDV isolate from chickens, two commercial IBDV vaccine viruses, and an IBDV isolate from turkeys were designated serotype I. Two IBDV isolates from turkeys were designated serotype II. A common antigen shared by serotype I and serotype II viruses was detected using an indirect immunofluorescent assay. The virions of both IBDV serotypes were determined to be nonenveloped icosahedrons with diameters ranging from 58 to 60 nm. The virion densities of one serotype I isolate and two serotype II isolates were similar (1.32 g/ml). Twenty-three turkey breeder flocks and 22 commercial turkey flocks from Ohio, North Carolina, and Indiana were tested for antibodies to the two IBDV serotypes. Seventy percent of the 23 breeder flocks had antibody titers to serotype I, and 75% had antibody titers to serotype II. None of the 22 commercial flocks had antibodies to serotype I, and 77% had antibody titers to serotype II. Antibodies to serotype I were detected only in breeder flocks that were vaccinated using a commercial serotype I IBDV vaccine. Only antibodies to serotype II viruses were naturally widespread in the flocks tested.

Severe Egg-Production Drops in Turkey Breeders in Southcentral Missouri

Avian influenza virus can cause any number of different clinical symptoms in turkeys, depending on the subtype of virus involved. These clinical conditions included decreased activity, decreased feed consumption, emaciation, increased broodiness of hens, decreased egg production, mild to severe respiratory signs, coughing, sneezing, rales, excessive lacrimation, huddling, ruffled feathers, sinusitis, edema of the head and face, cyanosis, nervous disorders, and diarrhea. These clinical signs can occur singly or in any combination (1). This report describes a localized outbreak of subtype Hswl N1 influenza in six turkey breeder flocks. Although all of the information desired was not available, the report is presented because there was no history of Type A influenza being a problem in the area.

Serologic and Epidemiologic Evidence of Infection in Turkeys with an Agent Related to the Swine Influenza Virus

Two outbreaks of influenza were diagnosed in two turkey breeder flocks raised in consecutive years on an Ohio farm that also had a swine operation. The antibody detected indicated that the virus causing the disease had the Hswl hemagglutinin (swine influenza). Signs of disease onset were a decline in egg production and an increase in the number of abnormal eggs. Antibodies against the Hswl hemagglutinin were detected in swine raised on the farm.

Decreased Egg Production in a Turkey Breeder Flock Associated with Newcastle Disease Virus

SUMMARY Newcastle disease virus recovery and rising hemagglutinationinhibition (HI) titers were associated with a drop in egg production in a turkey breeder flock previously vaccinated for Newcastle disease.

Yield, Quality, and Subsequent Performance of Poults Removed from the Hatcher Using Early-Late and Complete Collection Procedures

Eggs from a Small White Turkey breeder flock were weighed and separated into equal numbers of heavy, medium, and small categories. A total of 6912 eggs was set and after 25 days incubation, half of each category was transferred to two hatchers. With one unit, “dry” poults were removed “early,” when hatching approximated 50% of eggs transferred (27 days, 0 hr) to be followed by a second, “late” removal 27 hr later. All “dry” poults were removed from the second unit when hatching was judged to be “complete” (27 days, 18 hr).Total yield of salable poults was better if removal from the hatcher was twice than if once. Yield differences could be wholely attributed to an alteration in pips without change in dead and cull birds. Average total body weight with the “early-late” regimen was greater than “complete” group. Early poults were heavier than late ones, irrespective of egg weight category. Small eggs viable at the time of transfer hatched earlier than heavy ones. No sex distribution differences appeared. All aspects of the dressed carcass and its efficiency of production with sample poults from each treatment were equivalent at 14 weeks of age.

Serological survey for the prevalence of antibodies to egg drop syndrome 1976 virus in domesticated and wild birds in Israel

A serological survey of chicken, turkey, goose and duck flocks for the presence of antibodies to egg drop syndrome virus 1976 (EDS 76) has been carried out in Israel. In most of the chicken flocks sampled egg production was not normal, but no antibodies against this virus were detected. Likewise, turkey breeding flocks were similarly negative. All Pekin duck flocks tested showed some serological activity. Muscovy ducks that were reared in direct or indirect contact with Pekin ducks had haemagglutination-inhibition antibodies to EDS 76 virus. Seven cattle egrets trapped on a duck farm were serologically positive. No antibodies were detected in a collection of water fowl raised in a zoological garden.