Development of computational models for the purpose of conducting individual livestock and premises traceback investigations utilizing National Animal Identification System-compliant data.

Many of the efforts surrounding the development of the National Animal Identification System have encompassed the identification of livestock production and handling premises as well as individuals or herds of animals, whereas little effort has been directed toward the ultimate goal of animal traceback within 48 h. A mock data set representative of the Colorado cattle population was created for modeling of cattle traceability. Using this data set, algorithms were developed to complete rapid and accurate traceback and traceforward of animals or premises or both.

Evaluation of abortions in cattle attributable to neosporosis in selected dairy herds in California.

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.

Serum zinc and copper concentrations in relation to spontaneous abortion in cows: implications for human fetal loss.

The purpose of this study was to investigate the effect of the status of dietary zinc and serum zinc and copper concentrations on the risk of fetal loss in 570 cows. three herds received no supplements (herds 1, 3, 4), while cows in herd 2 received supplements of either 7 g zinc week-1 (n = 118), as zinc methionine, or a control diet containing methionine (n = 128). Serum zinc, copper and metallothionein concentrations were determined once a month throughout gestation.

Prevalence of salmonellae in cattle and in the environment on California dairies.

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 O1, 4, 6, 7, 9, 12). Blood samples were collected from all cows with positive results and tested for serologic evidence of exposure to salmonellae.

Effect of intrauterine antimicrobial treatment in reducing calving-to-conception interval in cows with endometritis.

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.