Three doses of sodium propionate (.75, 1.5, and 3.0 mmol/kg) were administered intravenously to 6, 8, and 14 dairy cows. Using first order kinetic analysis, the apparent plasma half-life increased significantly with increasing propionate dose. The apparent increase of propionate half-life with increasing propionate dose was attributed to saturation of uptake and disposal mechanisms. Using the nonlinear mathematical model of Henri-Michaelis-Menten for propionate concentrations at 3.0 mmol/kg, propionate half-life was significantly shorter than that obtained with the first order kinetic model. The Michaelis constant was 4.0 mM, the maximal rate of concentration decrease was .55 mM/min, half-life was 4.8 min, and distribution volume was .37 L/kg. Plasma glucose concentrations increased following all doses of propionate. The maximal increase in glucose concentration occurred earliest for the lowest dose and latest for the highest dose and increased in magnitude with increasing propionate dose. The plasma glucose response to intravenous propionate has been suggested as a measure of liver function in ruminants. Of the three propionate doses tested, the 3.0 mmol/kg dose appeared to saturate the uptake and disposal mechanisms of healthy liver and should be the most satisfactory dose for observing the plasma glucose response to injected propionate.

Three factors were associated with lamb neonatal mortality: birthweight (P<0.003), number of lambs born per ewe (P<0.001) and lamb sex (P<0.32). Lamb birthweight had the greatest predictive power for survival during the neonatal period. The neonatal mortality rate was 14.3%. The age specific mortality for lambs one day old was 7.9% (P<0.05). Seventy-nine percent of the lambs that died, did so by the end of the fourth post-natal day. Starvation was associated with 58.3% (P < 0.05) of the lamb deaths.

In an effort to clarify the pathogenesis of pyometra, 20 cows with retained fetal membranes and 20 without, but with contemporary calving dates were studied. They were palpated and their uteri were subjected to sample collections for bacteriologic cultural examinations twice weekly for 4 weeks. Blood samples were obtained each day and evaluated for serum progesterone concentration. Three cows without and 3 with retained fetal membranes developed pyometra during the study, resulting in 3 groups designated control (CON), cows with retained fetal membranes (RFM), and cows with pyometra (PYO). Bacterial isolations occurred less frequently in the CON group than in the PYO and RFM groups. Growth patterns of bacteria also varied between groups. Coliform and incidental bacteria disappeared from the uterus of the PYO group by the end of the 3rd week. In contrast, heavy growth of Corynebacterium pyogenes and gram-negative anaerobic bacteria developed during this same period in the PYO group. In cows with pyometra, the significant persistent pathogenic bacteria recovered were C pyogenes and gram-negative anaerobic bacteria, especially Fusobacterium necrophorum and Bacteroides melaninogenicus. Anaerobic bacteria were isolated simultaneously with C pyogenes in most cows of the PYO group, but less often in CON and RFM groups, and highest growth levels were present near the time of ovulation. Clinically, pyometra usually developed about 10 days after observation of concurrent ovulation and high growth levels of C pyogenes and gram-negative anaerobic bacteria. A hypothesis is presented for development of pyometra in the cow.

To determine risk factors for development of diarrhea in litters of preweaned piglets, data were analyzed from records of 4,397 litters of swine farrowed on a central California ranch 1978-1982. Sixty-four percent of litters were treated for diarrhea. Statistical analysis by multiple logistic regression showed that litters born to young sows (parity less than or equal to 2) were 1.7 times more likely to develop diarrhea before weaning than were litters born to older sows (parity greater than or equal to 3) and that litters born on one end of farrowing barns were 1.3 times more likely to develop diarrhea than were litters born in the other end. The association of diarrhea with other variables--dam breed, sire, gestation group, gestation length, size of litter, number of mummies, runts or stillbirths per litter, farrowing barn of birth or day of the week farrowed--was weak or nonexistent (P greater than 0.01).

Five hundred thirty-four naturally bred Holstein dairy cows from two Colorado dairies were examined perrectum between 21 and 36 days after calving. Alternate cows in each herd received either 25 mg PGF-2 alpha or no treatment at the time of initial examination. No differences were found in days open or pregnancy rates between groups (P>0.25).

The effect of Dermatophiluscongolensis on reproductive performance and milk production of dairy cattle was investigated using a prospective cohort study design. The following results were obtained: the calving to conception interval was 122 vs 104 days (P<0.05) for cows with lesions (cases) and those without lesions (non-cases), respectively; the 180-day pregnancy rate was 70.3% vs 84.3% (P<0.02) for cases and non-cases, respectively; the interval to first service was 69 days for cases and 64 days for non-cases (P<0.05) and the interval from first to second service was 32.7 days for cases and 49.4 days (P<0.01) for non-cases. The prevalence of cows with lesions was 33% (66200). Lesions were most commonly found on the skin covering the coccygeal and sacral vertebrae and the gluteal muscles. White skin had a greater prevalence of lesions than did black skin (P<0.05).

Risk factors associated with pyometra were studied in 4 confinement managed dry-lot dairies in Colorado. The incidence of pyometra for the 3-year study was 7.0%. The first risk factor to enter the step-wise logistic regression model was “lactation number”. Cows in their first lactation were at lesser risk of developing pyometra (P<0.001) than cows in all other lactations. The second and final variable to enter the logistic regression model was “dairy farm”. Cows on 1 of the dairy farms were at lesser risk of pyometra than the other herds, (P<0.005), after adjusting for the lactation number of the cows. There was no statistical association for year or season with the incidence of pyometra; however, the probability of three consecutive spring seasons having the greatest frequency of pyometra was 0.0045.

Two studies were conducted to evaluate the concentration of serum progesterone in pyometritic cows and relate it to palpation of ovarian structures perrectum. In Trial 1, serum samples from 34 pyometritic cows were assayed for progesterone. Mean serum progesterone concentrations were 6.8 ± 0.7 ng/ml. In Trial 2, each of 54 pyometritic cows was paired with a control cow on the basis of days post partum (18–50 days). Mean concentration of progesterone was 9.7 ± 1.0 ng/ml for the pyometritic cows and 5.7 ± 0.8 ng/ml in control cows (P<0.005). Progesterone concentration was greater (P<0.005) in both groups of cows with palpable corpora lutea (CLs). Ninety-six percent of the pyometritic cows had palpable CLs compared to 57% of the control group. Comparing serum progesterone only in cows with a palpable CL, the mean concentration was still greater (P<0.005) in the pyometritic group (10.6 ± 1.0 ng/ml) than the control group (6.6 ± 1.0 ng/ml). Compatability of rectal palpation findings and concentrations of serum progesterone were 92.6% for the pyometritic group and 72.2% for the control group. Progesterone concentration increased (P<0.05) by increased days post partum in Trial 2 (n=54) but not in Trial 1 (n=23). In both Trials 1 and 2, uterine size due to pyometra increased (P<0.05) with increased days post partum. No other associations were found.

Cystic ovarian disease (COD) was studied in a closed 300-cow dairy herd, using Dairy Herd Improvement Association and individual health records for a 7-year period (1974-1980). There were 2,112 calvings by 649 cows during the period. Cysts were found in 130 cows. Of the 649 cows that calved, 110 (16.9%) produced at least 1 daughter in which COD developed. Two bulls sired 17.6% of the daughters with COD, which was more than anticipated inasmuch as they sired only 11.6% of all daughters (P less than 0.05). These bulls were removed from the breeding program in an attempt to reduce code in the herd.

Clinical and clinicopathologic features of transport tetany in 9 feedlot lambs were investigated. The lambs became recumbent within 10 days after arrival in the feedlot. The mean serum calcium concentration, mean magnesium concentration, and calcium:phosphorus ratio were significantly (P less than 0.01) less in affected lambs than in 6 unaffected lambs from the same feedlot. The mean serum phosphorus concentration was significantly (P less than 0.05) greater in the group of affected lambs. High activities of serum glutamic oxalacetic transaminase, creatine kinase, and lactate dehydrogenase in the serum of affected lambs indicated muscle necrosis, which was confirmed by histologic examination. Blood pH, HCO-3, and total carbon dioxide were significantly greater in affected lambs (P less than 0.01) than in unaffected lambs.

Of 254 sheep examined for antibodies to the virus of ovine progressive pneumonia, 162 (63.8%) were seropositive. The mean age of the seropositive ewes was 4.9 +/- 1.8 years, which was significantly greater than that for the seronegative ewes (4.1 +/- 2.3 years). The age-specific prevalence increased with ewe age, from 25% among yearling ewes to 85% among 7-year-old ewes. Seropositive ewes produced more pounds of live lamb at birth than did seronegative ewes.

Serum concentrations of chloramphenicol were determined after oral doses (55 mg/kg body weight) were administered to 7-9 day old Holstein-Friesian calves. Chloramphenicol in an oral solution produced greater serum concentrations than did an equivalent dose of chloramphenicol in capsules (P less than 0.005). A second dose of each formulation administered 12 h after the first dose elevated serum chloramphenicol concentrations significantly (P less than 0.001). The average serum chloramphenicol concentration exceeded 5 micrograms/ml of serum 1 h after administration of the solution compared with 4 h for the capsules. Average serum chloramphenicol concentration was greater than 5 micrograms/ml for at least 12 h after the dose was administered for both formulations. Of the eight calves receiving repeat doses of chloramphenicol, seven (87.5%) developed diarrhea in 76 +/- 8.6 h. Six of the eight calves (75%) died during or shortly after the period of chloramphenicol administration.

The indirect hemagglutination method was used to determine the seroprevalence of Toxoplasma gondii in a random sample (250) of lambing ewes from a large (4,226 ewes) western range flock. Agglutination (greater than or equal to 2+) at the 1:64 serum dilution was considered a positive reaction; the seroprevalence was 20.8%. The neonatal mortality for lambs born to seropositive ewes was 30.7%, which was significantly greater than that for seronegative ewes (13.6%). The average age at death for lambs born to seropositive ewes was 24.8 hours, which was significantly less than that for lambs born to seronegative ewes (31.2 hours).