Two techniques performed on skin biopsy samples (ear notches), immunohistochemistry (IHC) and antigen-capture ELISA (AgELISA), were compared for detection of bovine viral diarrhea virus (BVDV) persistent infection (PI) in 559 Angus calves between the ages of 1 and 5 months. The calves also were tested for BVDV infection using virus isolation (VI) and reverse transcription (RT)-PCR on buffy coat samples and for antibodies to BVDV types la and 2 by serum neutralization (SN). Sixty-seven of 559 (12.0%) calves tested positive at initial screening by IHC, AgELISA, or VI, and all 67 were kept for a minimum of 3 months and retested monthly by IHC, AgELISA, VI, RT-PCR, and SN. Of the calves positive at initial screening, 59/67 (88.1%) were determined PI and 8/67 (11.9%) were determined acutely infected. Both IHC and AgELISA detected 100% of PI calves; however, IHC and AgELISA also detected 6 and 8 acutely infected calves, respectively, at initial screening. Furthermore, IHC and AgELISA continued to detect 3 and 4 acutely infected calves, respectively, 3 months after initial screening. Three acutely infected calves had IHC staining indistinguishable from PI calves at initial screening. Both IHC and AgELISA are accurate at detecting BVDV-infected calves, but veterinarians and producers should be advised that both tests detect some calves acutely infected with BVDV in addition to PI animals. Repeat testing using VI or RT-PCR on buffy coat samples should be performed at 30 days after initial screening to conclusively discriminate between acute and PI.

Primiparous Angus x Gelbvieh (n = 36) rotationally crossed beef cows (initial BW = 487.9 +/- 10.5 kg, body condition score = 5.5 +/- 0.02) were utilized to determine effects of supplemental safflower seeds high in linoleic (76% 18:2) or oleic (72% 18:1) acid on cow BW change, body condition score, milk production and composition, calf weight gain, cow serum metabolites, and metabolic hormones. On d 3 postpartum, cows were randomly assigned to one of three isonitrogenous dietary supplements with equal total quantity of TDN: corn-soybean control supplement (n = 12); high-linoleate safflower seeds (n = 12); or high-oleate safflower seeds (n = 12). Safflower-seed supplements were formulated to provide 5% DMI as fat. Supplements were individually fed from d 3 postpartum through 90 d postpartum. Cows had ad libitum access to native grass hay (7.8% CP), trace-mineralized salt, and water. Date of parturition was evenly distributed across treatments with all cows calving within 14 +/- 0.8 d. There were no differences (P = 0.65) in total OM intake among treatments. Although cow BW change did not differ (P = 0.33) by treatment, supplementation influenced cow body condition score (P = 0.02) with linoleate-supple-mented cows in higher (P = 0.005) condition overall than oleate-supplemented cows (5.1 +/- 0.06 vs 4.9 +/- 0.06). Twenty-four-hour milk production did not differ (P = 0.68) among treatments. Percentage milk fat was not different at d 30; however, at d 60 and d 90 percentage milk fat was greater (P ( 0.05) in control and oleate-supplemented cows than in linoleate-supplemented cows. Calf BW gains (P = 0.27) and adjusted 205-d weights (P = 0.48) were not affected by supplement treatment. Supplementation did not influence serum concentrations of glucose (P = 0.38), NEFA (P = 0.61), GH (P = 0.29), IGF-I (P = 0.81), insulin (P = 0.26), or IGF-I binding proteins (P > or = 0.11). Days to conception did not differ (P = 0.40) among treatments. Although overall productivity of the primiparous cows and their calves was not altered by safflower-seed supplementation, differential effects were noted between supplements. Oleate supplementation increased percentage milk fat at d 60, and cow body condition score was lower than in linoleate-supplemented cows. Linoleate-supplemented cows had greater body condition scores by 90 d postpartum than either corn-soybean- or oleatesupplemented cows.

Abstract. The etiology of abomasal ulcers/tympany was investigated in 48 animals from 36 ranches in Wyoming and Nebraska. Results indicate that subclinical trace mineral deficiencies of copper and/or selenium exist in the range cattle in west central Nebraska and Wyoming. Etiological agents most frequently incriminated by bacteriologic cultures and/or histopathic examination were Clostridium perfringens and Campylobacter species. Histopathologic evaluation of abomasums revealed 31 of 38 cases contained abundant gram-positive bacteria associated with the damaged abomasal mucosa. Campylobacter-like organisms were demonstrated in 9 of 38 cases using the modified Dieterle stain. Clostridium perfringens was isolated in 14 of 38 cases, and Campylobacter jejuni was recovered from 5 of 38 cases.

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