The association between ocular squamous cell tumors and various measures of solar radiation was evaluated for 2,775 contemporaneous Hereford cattle. The animals were from 34 herds located in 21 states in the United States and in one Canadian province. Examinations and photographs were made of the eyes of all cows and heifers in a herd; 33 herds were examined between June and August 1957 and 1 herd was examined in 1958. Solar radiation was measured by altitude and mean annual hours of sunshine applying to an individual herd, and global radiation, a cloudiness index, and elevation of nearby National Weather Service stations. All measures of solar radiation provided evidence of a significant association between increasing risks of developing cancer eye and increasing levels of radiation; adjustments were made for possible confounding effects of age and corneoscleral pigmentation. Associations were evident whether affliction was defined as the occurrence of any type of tumor (ie, plaque, papilloma, or carcinoma), or as the occurrence of only papilloma or carcinoma. Average ages of affected cattle also tended to be lower at high radiation levels than at low levels, further supporting the hypothesis that solar radiation has an important role in the development of this disease. In view of the heritability of eye pigmentation and its inhibitory effect on lesions, cancer eye may be controlled by selective breeding for increased pigmentation in and around the eye to afford protection against the harmful effects of incident UV radiation.

Larkspur poisoning is a major cause of acute death of cattle on mountain and high plains rangelands of western United States. A nonlethal method to quantify dose response in cattle is needed to better estimate the toxicity of larkspur plants and the response of cattle to larkspur poisoning and to provide a basis for reference during studies. A numerical system of rating the clinical signs of larkspur poisoning was developed and used to describe the response of 10 Hereford cows given a repeated single daily dose of larkspur (Delphinium occidentale X barbeyi) by gavage. Larkspur poisoning resulted from a short-term cumulative effect, and a statistically significant increase in score was essentially maximal by 4 days. At the dose given, this effect did not persist for more than 4 days after cessation of dosing. Poisoning was most severe between 5 and 9 hours after dosing. Early signs of poisoning can be subtle and sometimes brief. The effect of larkspur poisoning can be exacerbated temporarily by exertion. Therefore, cattle could probably repeatedly consume an otherwise toxic daily dose, without manifesting marked signs of poisoning, if consumption decreased to a sufficient degree intermittently at 2- to 4-day intervals.

Biological responses to recombinant DNA-derived bovine interferon alpha (rBoIFN-alpha I1) by bovine alveolar macrophages were examined by measuring viral yield reduction and 2',5'-oligoadenylate synthetase (2',5'-OAS) production by IFN-treated cells. In vitro IFN pretreatment of alveolar macrophages reduced viral yield in cultures challenged exposed with parainfluenza-3 virus, compared with control cultures. In vitro treatment of alveolar macrophages with IFN also resulted in increased 2',5'-OAS activity. The 2',5'-OAS activity was measured in alveolar macrophages and blood mononuclear leukocytes of calves injected im with 3.6 X 10(6) U of rBoIFN-alpha I1/kg of body weight. The IFN action was monitored by measuring 2',5'-OAS activity of blood mononuclear leukocytes beginning 6 days before and ending 24 hours after IFN treatment. The 2',5'-OAS activity in the blood mononuclear leukocytes sharply increased 24 hours after IFN treatment, indicating response to IFN. The alveolar macrophages collected from the same calves 24 hours after IFN administration also had increased 2',5'-OAS activity, compared with alveolar macrophages from the same calves collected 6 days before treatment. Increased 2',5'-OAS activity indicates: a possible mechanism of IFN action in cattle that may be responsible for viral yield reduction; potential use of high enzyme activity as a marker for IFN induction; and potential use of 2',5'-OAS activity as a marker for determining effects of IFN on bovine macrophages and other cells of the bovine immune system.

Sixty-three drugs, belonging to 10 chemical classes, were tested in vitro to determine effects on phagocytosis of 32P-labeled Staphylococcus aureus by neutrophils isolated from milk. Within each class, the number of antibiotics tested were: nonsteroidal anti-inflammatory drugs (NSAID; 8), peptolids (2), aminoglycosides (8), tetracyclines and fusidic acid (4), beta-lactam antibiotics (25), secretolytic agents (2), macrolides (5), polypeptides (2), and antibacterial quinolones (8). Percentage of phagocytosis was determined after incubating (2 hours at 37 C) 12.5 X 10(6) viable neutrophils, 200 X 10(6) 32P-labeled S aureus with antibiotics and 5% skimmed milk. Concentrations of antibiotics tested were 1,000, 500, and 10 microgram/ml of incubation media. When compared with nonantibiotic controls at the highest drug concentration, the NSAID acetylsalicylic acid and centrophenoxine increased phagocytosis 23.2 and 8.8%, respectively, and benzydamine, indomethacin, phenylbutazone, ibuprofen, and acetominophen decreased phagocytosis 22.8, 14.2, 9.8, 27.0, and 18.2%, respectively. The peptolids novobiocin and pristinamycin decreased phagocytosis 24.5 and 22.0%, respectively. The aminoglycosides tobramycin, amikacin, and gentamicin decreased phagocytosis 21.1, 15.4, and 19.2%, respectively. For the tetracyclines and fusidic acid, minocycline and doxycycline decreased phagocytosis 39.8 and 54.2%, respectively. The beta-lactam antibiotics carfecillin, cephapirin sodium, and cephacetrile sodium decreased phagocytosis 11.2, 12.8, and 23.8%, respectively. The secretolytic agent, bromhexin, increased phagocytosis 10.8%. These data indicate that the potential for enhanced phagocytosis exists through use of some NSAID, and for depressed phagocytosis through use of aminoglycosides, peptolids, tetracyclines, and beta-lactams, as well as certain other NSAID.

Sixteen Holstein cows were used to test the effect of postmilking teat treatment on colonization and intramammary infection by Staphylococcus aureus on chapped teats. Treatments were (1) chapping the teat and using 1% I2/10% glycerin postdip solution, (2) 1% I2/10% glycerin postdip solution on nonchapped teats, (3) chapping the teat and using 10% glycerin postdip solution, (4) chapping the teat and not using a postdip solution. All mammary glands were free of S aureus teat skin colonization and intramammary infection at the start of the study. Teats selected for chapping were dipped in 1N NaOH prior to 3 applications of S aureus broth culture; cultures were applied at 12-hour intervals on all teats. Treatments were applied after each milking for 30 days and were initiated after the second broth dip. Teat skin swab specimens and milk samples were collected before treatment application. Teat skin condition was scored daily. Nonchapped teats (treatment 2) did not support skin or orifice colonization by S aureus. Treatment-1 teats healed most rapidly and supported less colonization in skin and orifice than did treatment-3 and -4 teats. Teat skin scores and skin colonization were lower for treatment-3 than treatment-4 teats. A correlation between teat skin colonization and teat skin conditions was found. Two intramammary infections were found in treatment-4 quarters and 1 in a treatment-3 quarter. On the basis of our findings, we concluded that poor teat skin condition will more readily support S aureus colonization, that a dip of 1% I2 with glycerin helped reduce S aureus colonization and was associated with faster healing, and that glycerin in teat dips may be of value in preventing colonization by S aureus and in promoting healing.

Twenty mature Holstein cows were randomized into 5 treatment groups. Cows of groups 2 to 5 were given 2 mg of elemental Pb/kg of body weight for 28 days. Clinical signs of plumbism were scored, and blood for Pb, progesterone, and hematologic analyses was collected weekly. Cows also were examined weekly for anomalous ovarian cycles. Starting on study day 28, cows in group 3 were treated once daily with 2 mg of thiamine HCl/kg (IM) for 13 days, cows in group 4 were treated twice daily with 62 mg of Na2,Ca-EDTA/kg (IV) for 4 days, and cows in group 5 were given thiamine (dosage regimen the same as for group 3) plus Na2,Ca-EDTA (dosage regimen the same as for group 4). On study days 96 through 139, cows were slaughtered in a commercial abattoir and samples of blood, skeletal muscles, bones, liver, and kidneys were collected and assayed for Pb concentration. Thiamine was not effective in reducing blood Pb concentration, and treatment with Na2,Ca-EDTA and thiamine plus Na2,Ca-EDTA was effective in reducing the concentration of Pb in blood. However, treatment with thiamine was more effective than treatment with Na2,Ca-EDTA or thiamine plus Na2,Ca-EDTA in inducing remission of clinical signs of plumbism. The concentration of Pb in blood was significantly (P < 0.05) correlated to the concentration of Pb in liver, kidneys, skeletal muscles, and bones. Significant (P < 0.05) relationship existed between number of days from Pb exposure to slaughter and concentration of Pb in blood, liver, and skeletal muscles. Exposure to Pb did not significantly alter CBC values. On the basis of progesterone analysis and ovarian examination, exposure to Pb and treatment for plumbism did not induce changes in the ovarian cycle.

Several investigators have suggested that the conventional multicompartmental exponential analysis of in vivo glucose metabolism is arbitrary and possibly not the most accurate description of glucose kinetics, especially in the large animal. In support of that hypothesis, we found that in a systematic comparison of 3 methods, blood-specific radioactivity data in single-injection studies of glucose metabolism in lactating cows was better described graphically, or by a hybrid polynomial-biexponential curve fit, than by an exclusively exponential curve fit. We hypothesized that this finding was attributable to partial failure of linearity and steady-state assumptions that underlie the exponential model. Second, using both an irreversible tracer (3H-labeled glucose) and reversible tracer (14C-labeled glucose), we found that glucose carbon recycling had no effect during the first 2 hours, but became significant in lactating cows 7 hours after injection. Finally, we determined that approximately 52 to 55% of the glucose replacement rate was being used to generate lactose.

Six calves with suppurative arthritis were given a single IM injection of sodium cephapirin at a dosage of 10 mg/kg of body weight. Cephapirin concentrations were serially measured in serum and in normal and suppurative synovial fluid over a 24-hour period. Mean peak serum concentration was 6.33 microliter/ml at 20 minutes after injection. The highest cephapirin concentrations in normal and suppurative synovial fluid were 1.68 and 1.96 microgram/ml, respectively, 30 minutes after injection. Overall mean cephapirin concentration in normal synovial fluid for the first 4 hours (1.04 +/- 0.612 microgram/ml) was not significantly different from that in suppurative synovial fluid (0.88 +/- 0.495 microgram/ml; P > 0.05). Elimination half-life was 0.60 hours and clearance was 1,593 ml/h/kg.

Four consecutive 6-hour urine sample collections were performed on 7 healthy adult Holstein cows fed a diet of coastal Bermuda hay with ad libitum water consumption. Urine (via indwelling urinary catheter) and venous blood samples were collected at 6, 12, 18, and 24 hours. Total 24-hour urine production for the 7 cows ranged from 4,515 to 7,130 ml/d (mean +/- SD, 5,633 +/- 946 ml/d) or 0.02 to 0.04 ml/kg of body weight/d (mean +/- SD, 0.03 +/- 0.007 ml/kg/d). Renal clearance (C) of creatinine (Cr), sodium (Na), calcium (Ca), and magnesium (Mg) varied significantly (P less than 0.05) among individuals, but did not vary significantly among the four 6-hour collection periods. Clearance of chloride (Cl) and phosphorous (P) did not vary significantly either among individuals or among the four 6-hour periods. Clearance of potassium (K) varied significantly (P less than 0.05) among individuals and among the four 6-hour periods. Creatinine clearance was significantly (P less than 0.01) correlated with CCl, CCa, CP, and CMg when all data were considered. Significant (P less than 0.05) correlations were also found between CCl, and CK, CCa, CP, and CMg; between CCa and CP and CMg; and between CP and CMg. Fractional excretion (FE) of Na, K, Cl, Ca, P, and Mg did not vary significantly among the four 6-hour periods. Fractional excretion of Na, Ca, and Mg (P less than 0.01) and K and P (P less than 0.05) varied significantly within individuals among the 6-hour periods. Mean FE values, calculated by averaging values for each of the 4 collection periods for all 7 cows, ranged from 0.05 to 0.78% for FENa; 129.33 to 670.40% for FEK; 1.23 to 6.23% for FECl; 0.17 to 4.44% for FECa; 0.36 to 1.14 for FEP; and 4.96 to 11.73% for FEMg. Linear relationships between the clearance and fractional excretion of electrolytes were observed on base-10 logarithmically transformed data for Na, Ca, P, and Mg. Linear relationship was not found between CK and FEK or between CCl and FECl.