Binding of endogenous and exogenous homologous IgG, and IgM to bovine neutrophils before and after in vitro migration through micropore filters, and in vivo migration through mammary tissues after intramammary injection of endotoxin was evaluated by use of flow cytometry. Immunoglobulin binding to neutrophils at 4 and 37 C was also evaluated. Before and after in vitro migration, neutrophils with endogenously bound IgG, and IgM averaged 1 and 2% and 23 and 7%, respectively. Before and after in vivo migration, IgG2 and IgM binding averaged 1 and 7% and 26 and 15%, respectively. Before and after in vitro migration, binding of purified IgG2 and IgM averaged 75 and 67% and 8 and 24%, respectively. Before and after in vivo migration, percentage of neutrophils binding purified IgG2 and IgM averaged 92 and 98% and 54 and 70%, respectively. When serum was used as a source of exogenous immunoglobulins, binding of total Igg after in vitro migration increased from 5% to 28% and of IgM from 4% to 20%. After in vivo migration, binding increased from 21% to 47% and from 24% to 56%, respectively. Exogenous binding of IgG2 at 4 and 37 C averaged 75 and 84%, and binding of IgM averaged 8% at either temperature. Endogenous IgG2 was unaffected by temperature; however, binding of IgM decreased from 23% at 4 C to 2% at 37 C. These data indicate that endogenous binding was higher for IgM before migration than after migration, in vitro and in vivo. Furthermore, migration in vivo through cellular matrices induced receptor upregulation for IgG and IgM. Source and concentration of ligand and serum components, other than immunoglobulins, appeared to contribute to receptor expression and availability. Neutrophils that were exposed to endotoxin and migrated into milk expressed more receptors than did unstimulated and nonmigrating neutrophils. The association of IgM with its receptor was temperature-dependent.

Six Jersey cows were implanted with 8 pairs of bipolar electrodes: 1 in the jejunum, 1 in the ileum, 3 in the cecum, and 3 in the proximal loop of the ascending colon (PLAC). Myoelectric activity was recorded at 2- to 3-day intervals, 3 times for 8 hours or 4 times for 6 hours, using a computer-based oscillograph and data-acquisition program. Mean (+/- SD) duration of the migrating myoelectric complex (MMC) in the ileum was 84.52 +/- 4.87 minutes. Phases I and II of the MMC lasted significantly (P < 0.05) longer than phase III. Two types (A and B) of cyclic activity were found in the cecum and PLAC. Cyclic activity type A was observed predominantly in the cecum, and type B was observed exclusively in the PLAC. Phase III of the MMC in the ileum was accompanied by hyperactivity type A at the level of the ileocecocolic junction in 60.90 +/- 12.65% of the MMC. Twenty-seven types of orally and aborally propagated spike sequences, involving the cecum and PLAC, were found. They were most frequent when an MMC phase III was observed in the ileum, and least frequent when an MMC phase I was observed in the ileum (P < 0.05). All electrode sites of the cecum and PLAC served as pacemaker areas. Propagated and nonpropagated spikes were found at all electrode sites of the cecum and PLAC. Although propagated spikes lasted significantly (P < 0.05) longer than nonpropagated spikes, a clear distinction on the basis of duration could not be defined between the 2 spike types because broad overlapping of duration existed. Duration of cecocolic spiking activity per electrode (expressed as percentage of time) was significantly (P < 0.05) greater during MMC phase III in the ileum than during MMC phase I. It can be concluded that myoelectric activity of the cecum is well coordinated with the ileum and the PLAC. Phases of reduced and increased myoelectric activity in the cecum and PLAC are simultaneous with phases I and III of the MMC in the ileum.

Endoscopy of the nasopharynx, pharynx, and larynx was performed in each of 25 adult Jersey cows, age and body weight of which ranged from 2 to 6 years and 300 to 365 kg respectively. The endoscopic appearance of normal anatomic structures of the proximal portion of the airway were described. Observations specific to female dairy cattle were: the nasal septum, which tapered caudodorsally in the distal third of the nasal passage; the ability to observe both ethmoturbinates from the same viewing side; presence of a pharyngeal septum; the nasopharyngeal opening of the auditory tubes dorsolateral to the pharyngeal septum; and the appearance of the larynx--a triangular epiglottis with round borders and prominent corniculate process of the arytenoid cartilages. Tracheoscopy was performed in 13 cows. Of 11 cows for which the soft palate could be observed immediately after withdrawing the endoscope, 7 had dorsal displacement of the soft palate.

Association between individual cumulative milk yield and various reproductive disorders in 56,772 Finnish Ayrshire cows belonging to 5,912 herds in 80 communities was studied. All cows delivered calves between September 1985 and September 1986. Five logistic regression models were fitted, 1 for each outcome disorder of interest: early metritis, late metritis, silent heat, ovarian cyst, and other infertility. Cumulative individual 37-day milk yield was used in the early metritis model, and cumulative individual 60-day milk yield was used in the other models, on the basis of median days in milk when these disorders developed. Cumulative 305-day herd milk yield, parity, calving season, presence or absence of other disorders, and community were also included in the models. Point estimates from the models represented odds ratios for the likelihood of having the outcome disorder.Lactational incidence risks for the 5 reproductive disorders studied were: early metritis (2.4%), late metritis (1.1%), silent heat (5.4%), ovarian cyst (6.6%), and other infertility (2.1%). The risk of early metritis decreased with increasing 37-day milk yield. The risk of silent heat, ovarian cyst, and other infertility increased with increasing 60-day milk yield; 60-day milk yield had no effect on late metritis. The 305-day herd milk yield increased the risk of early metritis, ovarian cyst, and other infertility; it had no effect on late metritis or silent heat. Parity had an effect on all disorders, except late metritis. Cows that delivered calves during the colder, darker seasons of the year had a higher risk of reproductive disorders than did those that delivered calves at other times of the year. A number of other disorders, reproductive and otherwise, were significant predictors of development of the outcome disorders.

The main objective of the study reported here was to generate a panel of monoclonal antibodies (MAB) to bovine neutrophil surface antigens, and to identify MAB that modulate neutrophil chemotaxis, respiratory burst, and phagocytosis. A further objective was to study MAB reactivity with resting and activated neutrophils, to identify activation antigens and adhesion molecules. A panel of 14 MAB was generated by producing murine hybridomas. Neutrophils incubated with MAB at 4 C for 2 hours were used in chemotaxis, respiratory burst, and phagocytosis assays. Chemotaxis was evaluated in Boyden chambers, using Escherichia coli endotoxin-activated fetal bovine serum as the chemoattractant. Respiratory burst was determined by measuring chemoluminescence of neutrophils incubated with 5-amino-2,3-dihydro-1,4-phthalazinedione, and serum opsonized zymosan. Phagocytosis was determined by flow cytometry, using fluorescein-labeled Staphylococcus aureus. The MAB S7G8, S5F8G10, S7E10, and S5F8B8 enhanced chemotaxis (to > 125% of control). The MAB S7E10 and S8D9 enhanced respiratory burst activity (to > 125% of control), whereas MAB S2G8, S4G10, S8G10, and S5F8B8 caused inhibition (to < 75% of control). The MAB S2G8, S4G10, S8G10, and S5F8G10 enhanced phagocytosis (to > 125% of control). Chemotaxis, respiratory burst, and phagocytosis values of neutrophils not bound with MAB served as controls for comparison. The MAB binding for nonactivated neutrophils (at 4 C) ranged from 9 to 100%, and for activated neutrophils (at 37 C; at 37 C with phorbol myristate acetate) from 90 to 100%. Binding of MAB S4F5, S5F8B8, S6C6, S7E10, S8D9, and S5F8G10 increased when neutrophils had been incubated at 37 C. Binding of these MAB was further increased after incubation with phorbol myristate acetate (100 ng/ml) at 37 C, indicating recognition of activation antigens by MAB. The MAB generated in this study appeared to be potential candidates for studying mechanisms of neutrophil function and for enhancing neutrophil function in vitro and in vivo.

The efficacy of dihydrostreptomycin in stopping the shedding of Leptospira hardjo subtype hardjobovis was studied in naturally infected cows. Blood and urine samples were collected from dairy cows kept on a farm where the farmer had contracted L hardjobovis infection. A microscopic agglutination test and an ELISA were used to determine specific antibody responses in serum. Polymerase chain reaction was used to detect bacterial shedding in urine. On the first sample collection date, 6 cows were seropositive, and 3 of those shed leptospires in the urine. These 3 cows were treated once with 25 mg of dihydrostreptomycin/kg of body weight. Within 1 week, the 3 cows stopped shedding leptospires. Six weeks later, 8 more lactating cows were found to be shedding leptospires. These cows were also treated once with dihydrostreptomycin, and they too stopped shedding leptospires within 1 week. From then on, the whole herd was examined weekly for a period of 2 months, and all cows Leptospira-positive by polymerase chain reaction were treated once with dihydrostreptomycin. Again, all cows stopped shedding leptospires in the urine within 1 week after treatment with dihydrostreptomycin. After a single treatment of the whole herd at the same time, new infections were not seen.

An ELISA containing lipoarabinomannan (LAM) antigen was used to detect antibodies in milk and serum for diagnosis of Mycobacterium paratuberculosis infection in dairy cattle. In experiment 1, milk and serum samples were obtained from 25 cows, and subjected to LAM ELISA testing immediately, and after 1 year of storage at -70 C. Milk samples, with and without a commonly used chemical preservative, were tested. There was no significant difference in LAM ELISA results between fresh and frozen samples or between preserved and unpreserved milk samples. In experiment 2, milk samples were collected daily from 30 cows over a 14-day period. The day-to-day coefficient of variation was 0.19 for milk LAM ELISA and was 0.15 for serum LAM ELISA, with no statistically significant time effect detected. In experiment 3, single milk, serum, and fecal samples were obtained from 764 cows. The fecal samples were cultured for M paratuberculosis to identify infected cows, and the serum and milk samples were subjected to LAM ELISA testing. Results were compared, using the area under the receiver operating characteristic curves. The milk LAM ELISA had specificity (+/- 95% confidence limits) of 87 +/- 8.1% when the cutoff was set at 50% sensitivity, and specificity of 83 +/- 9.1% when sensitivity was set at 60%. The area under the receiver operating characteristic curve was 0.85 +/- 0.03 for the milk ELISA and 0.75 +/- 0.02 for the serum ELISA. In this population of cattle, the milk LAM ELISA had comparable accuracy to serum LAM ELISA, although the milk LAM ELISA was slightly less reproducible (higher coefficient of variation).

We characterized the clinicopathologic manifestations of experimentally induced endotoxin-induced mastitis. Responses to hypertonic fluid therapy also were assessed. Eight cows received 1 mg of endotoxin by in infusion in the left forequarter. Four hours after endotoxin administration, cows received 0.9% NaCl, 5 ml/kg of body weight (n = 4) or 7.5% NaCl, 5 ml/kg (n = 4) IV. Endotoxin-infused cows had expanded plasma volume, hyponatremia, transient hyperchloremia and hypophosphatemia, increased serum glucose concentration, and decreased serum activities of liver- and muscle-specific enzymes. Calculated plasma volume increased at 6 hours in cows receiving hypertonic NaCl, and at 12, 24, and 48 hours after endotoxin infusion in both groups. Concurrent observations of decreased serum protein concentration, erythrocyte count, and hematocrit supported observations of increased plasma volume. Relative plasma volume was greater in cows receiving hypertonic NaCl (124.3%) than in cows receiving isotonic NaCl (106.6%) at 6 hours after endotoxin infusion. Cattle receiving hypertonic NaCl had increased voluntary water intake after IV fluid administration. Increased water consumption was not accompanied by increased body weight, indicating probable occurrence of offsetting body water loss. Serum sodium concentration in cows receiving hypertonic NaCl was increased 2 hours after fluid administration, but the magnitude of the change was minimal (< 4 mmol/L) and transient, indicating rapid equilibration with either interstitial or intracellular spaces. Serum sodium concentration was decreased in cows receiving isotonic NaCl at 12, 24, and 48 hours after endotoxin administration, compared with concentration prior to endotoxin administration, indicating selective loss of sodium.

Twenty-five quarters of 12 dairy cows, 3 to 8 years old, with a bacteriologic history of freedom from infection with Streptococcus uberis were inoculated via the teat canal with S uberis (23 quarters) or sterile medium (2 quarters). The cows were sent to slaughter 1, 3, or 6 days later. Acute inflammatory response involving accumulation of large numbers of polymorphonuclear, neutrophilic leukocytes (neutrophils) in the secretory acini was recognized after 24 hours in infected cows. After 6 days, the neutrophil response was still evident, but infiltration of septa by lymphocytes, septal edema, extensive vacuolation of secretory cells, focal necrosis of alveoli, small outgrowths of the secretory and ductular epithelium, and widespread hypertrophy of the ductular epithelium also were recognized. Early stages of involution and fibrosis also were evident at that stage. Streptococci were identified by immunoperoxidase labeling, free or phagocytosed, in macrophages; in the alveolar lumina, adherent to damaged secretory or ductular epithelium; in the subepithelium and septal tissue; and in lymphatic vessels and lymph nodes. The importance of the macrophage as the primary phagocytic cell is highlighted, and doubt is cast on the value of the exuberant neutrophil response by the host in defense of the gland.

The effect of right paralumbar fossa exploratory celiotomy and omentopexy on peritoneal fluid constituents was studied in 22 adult dairy cows. Six cows were eliminated on the basis of physical examination findings (n = 2), surgical findings (n = 2), or inability to obtain a sufficient volume of peritoneal fluid (n = 2). Sixteen cattle had normal results of Csc and serum biochemical analysis, and a minimum of 1 ml of peritoneal fluid was obtained by abdominocentesis. Abdominocentesis was repeated on days 1, 2, and 6 after surgery. Statistical analysis for repeated measures was performed, using a significance level of P < 0.05. Stage of gestation was evaluated for interaction with time. Mean total nucleated cell count was 3,200 cells/1 before surgery, was significantly increased 2 days after surgery (16,336 cells/microliter), and continued to increase through day 6 (20,542 cells/microliter). Mean polymorphonuclear cell count was 1,312 cells/microliter before surgery and was significantly higher at 2 (11,043 cells/microliter) and 6 (10,619 cells/microliter) days after surgery. Mean lymphocyte count was 254 cells/microliter before surgery and was significantly increased 2 days (1,911 cells/microliter) after surgery. By day 6, lymphocyte numbers were similar to preoperative values. Mean mononuclear cell count was 770 cells/microliter before surgery and was significantly increased on days 1 (3,084 cells/microliter), 2 (3,285 cells/microliter and 6 (2,349 cells/microliter) after surgery. Mean eosinophil numbers were 1,388 cells/microliter before surgery and were significantly increased on day 6 (6,347 cells/microliter) only. Interaction between time and stage of gestation was found only for specific gravity and total protein concentration. In general, specific gravity and total protein concentration increased after surgery (mean before surgery, 1.016 and 3.6 g/dl; mean after surgery, 1.021 and 5.6 g/dl). Left paralumbar fossa celiotomy performed 7 days after surgery did not reveal complications of repeated abdominocentesis, and pregnancy status was unchanged. Peritoneal fluid constituents are highly variable after exploratory celiotomy and omentopexy in cattle. However, results of this study may provide a reference for interpretation of postoperative peritoneal fluid sample findings in cattle.