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Biomedical subjects

J H Kirk

Publications and source records attributed to J H Kirk.

At least 37 records · Page 2Linked to original sources
PubMed1989

Failure to detect antibody to bovine respiratory syncytial virus in bovine fetal serum.

Sera obtained from 147 bovine fetuses estimated to be between 120 and 270 days of gestation at an abattoir were tested for antibody to bovine respiratory syncytial virus. Antibody to bovine respiratory syncytial virus was not detected in any of the sera examined. Based on the results of this study and a review of the literature, it appears that transplacental infection by bovine respiratory syncytial virus does not occur, or is uncommon.

Animals↗
PubMed1988

The effect of age at calving on reproduction, milk production and disease incidence in the first lactation of dairy heifers.

Herd health and production records of 1161 Holstein-Friesian heifers from 22 Michigan dairy herds were utilized to study the effect of age at first calving upon reproductive efficiency, milk production and the incidence of disease in the first lactation. Age at first calving was not significantly related to either milk production or reproductive efficiency. Heifers displaying dystocia were significantly older at calving than those that calved without problems. Additionally, the incidence of ketosis was associated with a significantly greater age at first calving. Heifers with diarrhea and those that aborted were significantly younger at calving than their herdmates. Incidence of 12 other common dairy diseases was not related to age at first calving. It would, therefore, appear that the dairy producers we studied could inseminate their heifers at an earlier age, and thereby increase production per day of life, without suffering serious detrimental effects in lactational milk production, reproductive efficiency or overall disease incidence.

Journal Article↗
PubMed1986

Repeated insemination in Michigan Holstein-Friesian cattle: Incidence, descriptive epidemiology and estimated economic impact.

Twenty-two Michigan dairy herds participating in a computerized herd-health program were studied to determine the incidence and epidemiologic characteristics of repeat-breeder syndrome. A cow with repeat-breeder syndrome was defined as having been inseminated three or more times within the same lactation. Repeat-breeder syndrome was observed in 24% of 3,309 lactations. Cost components associated with unsuccessful inseminations included costs of delayed conception, extra inseminations, extra veterinary service and losses due to culling. Lactations with repeat-breeder syndrome were associated with a loss of approximately $385. An estimated extra cost of $140 was associated with a second insemination, $279 with three inseminations, $429 with four inseminations and $612 with five inseminations.

Journal Article↗
PubMed1985

Factors associated with neonatal lamb mortality.

Three factors were associated with lamb neonatal mortality: birthweight (P<0.003), number of lambs born per ewe (P<0.001) and lamb sex (P<0.32). Lamb birthweight had the greatest predictive power for survival during the neonatal period. The neonatal mortality rate was 14.3%. The age specific mortality for lambs one day old was 7.9% (P<0.05). Seventy-nine percent of the lambs that died, did so by the end of the fourth post-natal day. Starvation was associated with 58.3% (P < 0.05) of the lamb deaths.

Journal Article↗
PubMed1984

Stray voltage on Michigan dairy farms.

Stray voltage investigations were performed on 59 Michigan dairy farms at the request of dairymen, veterinarians, and county extension agents. On 32 farms, sources of stray voltage were detected. When the voltage exceeded 1 volt alternating current, there were increased numbers of dairy cows that had abnormal behavior in the milking facility and increased prevalence of clinical mastitis. Recovery from the stray voltage-induced abnormalities was related to the type of abnormality and the magnitude of the exposure voltage.

Animals↗
PubMed1984

Nonclinical Pseudomonas aeruginosa mastitis in a dairy herd.

Atypical Pseudomonas aeruginosa mastitis in a dairy herd was characterized by nonclinical mastitis that responded to antibiotic treatment, but only for the cows to become reinfected because of a persisting source of contamination in the milking parlor wash water. At least 36% of the cows were infected during a 37-month period. The source of infection was contaminated water, wash hoses, and spray nozzles in the parlor. After the source of infection was removed and long-term control measures were instituted, the nonclinical infections became less severe and shorter in duration and they occurred for a lesser percentage of the lactation period.

Animals↗
PubMed1984

Programmable calculator program for linear somatic cell scores to estimate mastitis yield losses.

A programmable calculator program calculates loss of milk yield in dairy cows based on linear somatic cell count scores. The program displays the distribution of the herd by lactation number and linear score for present and optimal goal situations. Loss of yield is in pounds and dollars by cow and herd. The program estimates optimal milk production and numbers of fewer cows at the goal for mastitis infection.

Animals↗
PubMed1982

Bovine cystic ovarian disease: hereditary relationships and case study.

Cystic ovarian disease (COD) was studied in a closed 300-cow dairy herd, using Dairy Herd Improvement Association and individual health records for a 7-year period (1974-1980). There were 2,112 calvings by 649 cows during the period. Cysts were found in 130 cows. Of the 649 cows that calved, 110 (16.9%) produced at least 1 daughter in which COD developed. Two bulls sired 17.6% of the daughters with COD, which was more than anticipated inasmuch as they sired only 11.6% of all daughters (P less than 0.05). These bulls were removed from the breeding program in an attempt to reduce code in the herd.

Animals↗
PubMed1982

Border disease virus isolation from postpartum ewes.

The prevalence of border disease virus in a flock of Targhee sheep in southern Idaho was determined by serologic and virologic techniques. Of 249 ewes, 73 (29%) were seropositive to the antigenically related togavirus, bovine seropositive to the antigenically related togavirus, bovine viral diarrhea virus (BVDV). Concurrent testing of sera from 337 neonatal lambs indicated that 172 (51%) were seropositive for BVDV. It was observed that a high percentage (35%) of the BVDV-seropositive lambs were derived from seronegative ewes. Immunotolerance of the ewe was considered as the explanation for the lack of serologic relationship between seropositive lambs and their seronegative dams. Eleven cytopathogenic viruses were isolated from nasal and vaginal specimens obtained from 80 clinically healthy ewes within 24 hours of parturition. The viral isolates were demonstrated to be antigenically related to BVDV by direct immunofluorescence. Six of the 11 isolates were obtained from BVDV-seronegative ewes.

Animals↗
PubMed1981

Relationship of neonatal mortality in lambs to serologic status of the ewe for Toxoplasma gondii.

The indirect hemagglutination method was used to determine the seroprevalence of Toxoplasma gondii in a random sample (250) of lambing ewes from a large (4,226 ewes) western range flock. Agglutination (greater than or equal to 2+) at the 1:64 serum dilution was considered a positive reaction; the seroprevalence was 20.8%. The neonatal mortality for lambs born to seropositive ewes was 30.7%, which was significantly greater than that for seronegative ewes (13.6%). The average age at death for lambs born to seropositive ewes was 24.8 hours, which was significantly less than that for lambs born to seronegative ewes (31.2 hours).

Animals↗
PubMed1981

Serologic prevalence of ovine progressive pneumonia in a western range flock of sheep.

Of 254 sheep examined for antibodies to the virus of ovine progressive pneumonia, 162 (63.8%) were seropositive. The mean age of the seropositive ewes was 4.9 +/- 1.8 years, which was significantly greater than that for the seronegative ewes (4.1 +/- 2.3 years). The age-specific prevalence increased with ewe age, from 25% among yearling ewes to 85% among 7-year-old ewes. Seropositive ewes produced more pounds of live lamb at birth than did seronegative ewes.

Animals↗
PubMed1981

Application of programmable calculators to Mastitis control programs.

Three programs pertaining to subclinical mastitis losses and control are described for use in handheld programmable calculators. Subclinical mastitis losses are calculated on the basis of lost milk estimates for California Mastitis Test evaluations. A cost profile for control programs using costs of single use towels, teat dips, and dry cow treatment is described. The cost-benefit value of a mass lactating cow antibiotic treatment regimen is presented. The programs quickly calculate the magnitude of the present subclinical mastitis loss, estimate the cost of control programs, and present information to aid in deciding whether to treat all the infected cows during lactation in an effort to reduce herd infection. User instructions and program listings are included.

Animals↗
PubMed1980

Mastitis and udder abnormalities as related to neonatal lamb mortality in shed-lambed range ewes.

Bacterial isolations were attempted from milk samples taken from 242 range ewes in a southwestern Idaho shed lambing enterprise. Eighty-five percent of the ewe milk samples had no pathogenic bacterial growth at lambing and 3 weeks later. The few organisms that were isolated did not appear to affect udder condition of the ewe or contribute to lamb mortality. Shed conditions did not affect the frequency of isolation of potentially pathogenic bacteria. The prevalence of udder abnormalities, however, did appear to have a positive association with ewes that lost theim lambs. The most frequent abnormality was a diffuse homogeneous induration of the udder. This hardening was apparently unrelated to bacterial isolation or the age of the ewes. Mastitis, either subclinical or clinical, did not appear to be a serious problem in this particular flock. Mastitis was not related to lamb mortality.

Animals↗
PubMed1979

Effects of feeding cull domestic onions (Allium cepa) to sheep.

Twenty crossbred Panama yearling ewes were used to determine the effects of feeding cull onions (Allium cepa) to sheep. Ten test ewes were fed onions free choice with supplemntal alfalfa hay and grain, whereas ten control ewes were fed only alfalfa hay and grain. Anemia developed within 3 weeks in the test ewes, but was not seen in the controls. All ewes remained clinically normal during the study. Onions were fed for about 130 days. Recovery of the erythrocyte system began before the end of the feeding period. Even though onions were fed during most of the gestation period, the numbers of lambs born in the test and control groups were essentially the same.

Animal Feed↗