Search Results

You are looking at 1 - 5 of 5 items for

  • Author or Editor: John P. Picanso x
  • Refine by Access: All Content x
Clear All Modify Search

Summary

A prospective observational study was performed to determine whether palpation per rectum of cows in the first 6 weeks of gestation to diagnose pregnancy contributed to fetal attrition. Pregnancy diagnoses were made by private practitioners as part of their routine herd-health service on 9 dairies in the San Joaquin Valley of California. To determine whether there was an association between abortion and fetal age at time of palpation, the probability of abortion was tested as a function of fetal age at palpation, controlling for possible modifying and confounding effects of herd, age at conception, gravidity, parity, and number of days-in-lactation at conception. Results of logistic regression analyses for 19,411 pregnancies followed for up to 90 days after palpation indicated that, during the 28- to 42-day period, palpation of fetuses earlier in the period was associated with a significantly (P < 0.0001) low probability of abortion, compared with that for palpation later in the period. An association between abortion and palpation of fetuses > 42 days of age was not found. Results were suggestive that, given conditions and techniques typical of private practice, fetal death may not be a usual manifestation of early palpation of cows to diagnose pregnancy, rather, that there may be a slight increase in risk of fetal death as the fetal age at palpation increases from 28 to 42 days.

Free access
in Journal of the American Veterinary Medical Association

Summary

A prospective clinical trial was conducted on 2 large dairies in the San Joaquin Valley of California to determine whether a single intrauterine infusion with procaine penicillin G or oxytetracycline reduced the calving-to-conception interval in cows with endometritis. Cows with endometritis were randomly assigned to a treatment or a control group. The uterus of treated cows on 1 dairy was infused with 0.8 to 1.0 million U of procaine penicillin G in 40 ml of sterile water, and the uterus of treated cows on the other dairy was infused with 500 mg of Oxytetracycline in 20 ml of sterile water, both of which were typical doses used on dairies in the area. A difference was not observed in the cumulative proportion of cows remaining nonpregnant between 87 penicillin-treated and 77 control cows on the 1 dairy (P = 0.356), or between 74 oxytetracycline-treated and 62 control cows on the other dairy (P = 0.174). Results suggest that routine infusion of antibiotics to treat endometritis, as commonly practiced, may not be efficacious.

Free access
in Journal of the American Veterinary Medical Association

SUMMARY

A study was conducted to develop valid estimates of lymphocyte count (lc; cells per microliter) of individual, clinically normal dairy cattle. Estimated weighted regression was used on repeated measures of individual lc to examine 6 models predicting lc as a function of age in cattle not infected with bovine leukemia virus. The generalized growth curve model of analysis of variance was used to estimate intercepts, slopes, and prediction limits for the models and to compare the lc-to-age relationship between Holstein and Guernsey breeds. The bestfitting model (P = 0.0001) with the narrowest prediction interval was lc = 4,414.4 − 84.6X, where X = (age -48) if age ≤ 48 months, and X = 0 if age > 48 months, and 163.6 and 8.1 are the se of the estimates, respectively. Upper one-sided 95%-predicted normal lc tended to be higher than estimates derived from traditional hematologic keys that use confidence limits of mean lc. Difference was not found in the lc-to-age relationship between the Holstein and Guernsey cattle (P = 0.67). Results of this study provided estimates of normal lc that are more specific in diagnosing lymphocytosis in individual cattle.

Free access
in American Journal of Veterinary Research

Summary

Milk samples were collected from all lactating cows on 60 dairies (mean number of cows/dairy, 584; range, 66 to 2,834) randomly selected from 701 California dairies enrolled in the Dairy Herd Improvement Association program. Samples were tested, by means of an elisa, for antibodies against Salmonella serogroup B, C1, and D1 antigens (somatic antigens 01, 4, 6, 7, 9, 12). Blood samples were collected from all cows with positive results and tested for serologic evidence of exposure to salmonellae. Samples for bacteriologic culture (pooled feces from 20 randomly selected calves, swabs of wet areas and feces from calf pens and dairy hospital pens, drag swab sample from wastewater lagoon, and samples of feed components) were also collected from all 60 dairies. Seven (11.7%) of the 60 dairies each had 1 sample that yielded Salmonella organisms (3 S typhimurium, 1 S dublin, 1 nonmotile Group D salmonella, 1 S derby, and 1 S oranienberg). Five of the Salmonella isolates came from the hospital pens and 2 came from calf pens. Thirty-three dairies did not vaccinate cattle against salmonellosis, and of these, 24 (72.7%) had ≥ 1 seropositive cow (titer ≥ 200), and 20 (61 %) had ≥1 persistently seropositive cow (titer for each of 2 blood samples collected ≥ 60 days apart was ≥ 200). Of the 27 dairies that did vaccinate cows against salmonellosis, 24 (89%) had ≥ 1 seropositive cow, and 21 (78%) had ≥ 1 persistently seropositive cow.

We concluded that studies that use of bacteriologic culture of fecal and environmental samples to determine the percentage of dairies with Salmonella-infected cows may underestimate the true percentage.

Free access
in Journal of the American Veterinary Medical Association

Objective—

To estimate the minimum rate of abortion attributable to infection with Neospora sp in selected California dairy herds.

Design—

Prospective study.

Animals—

Twenty-six dairy herds containing 19,708 cows were studied. Fourteen herds had a history of abortions attributable to neosporosis, and 12 were herds in which neosporosis had not been identified as a cause of abortions.

Procedure—

During a 1-year period, all available aborted fetuses were submitted to veterinary diagnostic laboratories to determine the cause of abortion. Reproductive records of cows that aborted were reviewed.

Results—

Neospora sp infection was the major cause of abortion identified (113/266 abortions, 42.5%). The majority (232/266, 87.2%) of the aborted fetuses were submitted from herds with a history of abortions attributable to neosporosis, and Neospora sp infection was identified as the causative agent in 101 of 232 (43.5%) of the abortions from these herds. Fewer aborted fetuses were submitted from the 12 herds that did not have a history of abortion attributable to Neospora sp; however, neosporosis was confirmed as a cause of abortion in 6 of these 12 herds and was identified as the causative agent in 12 of 34 (35.3%) abortions from these herds. The disease was widespread throughout the state (19/26 herds in our study). Available reproductive histories of cows that had abortions attributed to neosporosis were evaluated, and 4 cows were identified that twice aborted Neospora-in-fected fetuses.

Free access
in Journal of the American Veterinary Medical Association