L. Ball

Effect of Actinomyces pyogenes and gram-negative anaerobic bacteria on the development of bovine pyometra.

Fifteen lactating Holstein cows were used in a trial designed to evaluate the effectiveness of intrauterine inoculation (challenge) of Actinomyces pyogenes (A) alone or in combination with Fusobacterium necrophorum (F) and Bacteroides melaninogenicus (B) to induce pyometra. Cows were assigned to one of five groups: A (n = 3), AB (n = 3), AF (n = 3), ABF (n = 3) or C (control, broth medium alone; n = 3). All cows exhibited estrus 12 or 13 d prior to challenge (Day 0=first day of challenge). During the prechallenge period, the reproductive tract of each cow was palpated per rectum and uterine fluid aspirates for culture and uterine biopsies were also obtained. All cows received an intravenous injection of 5,000 IU of human chorionic gonadotropin (hCG; Day 5) and an intrauterine infusion of 40 ml of 0.7% iodine solution (Day 1). Cows were then inoculated on Days 0, 1 and 2 of the experiment. Sequential palpations of the reproductive tracts, samples of uterine fluid for culture and uterine biopsies were performed for a total of 30 d after the first inoculation. A cow was diagnosed as having pyometra when purulent uterine fluid and a corpus luteum were detected by palpation per rectum. The number of cows that developed pyometra in Group A was 2 of 3, in Group AB 3 of 3, in Group AF 3 of 3, in Group ABF 3 of 3 and in Group C 0 of 3. Cows with pyometra did not exhibit estrus. In 7 of 11 cows, pyometra persisted for more than 21 d. In cows that developed pyometra, the same species of bacteria infused into the uterus were usually recovered one or more times during the postchallenge period. When clinical pyometra was diagnosed, histologic endometritis was invariably present. Histologic endometritis and concurrent isolation of A . pyogenes alone or A . pyogenes with gram-negative anaerobic bacteria occurred in 91.7% of samples during the postchallenge period. Regardless of bacterial treatment, gram-negative anaerobic bacteria were frequently isolated with A . pyogenes during this period.

Breeding soundness, libido and performance of beef bulls mated to estrus synchronized females

Ninety-three beef bulls and 2316 females were used to determine the relationships between breeding assessments of bulls and subsequent mating performance. Each bull was given a breeding soundness examination (BSE) and two 10-min libido/serving capacity (L/SC) tests. Breeding potential of each bull was classified as satisfactory (BSE score = 60 to 100) or questionable (BSE score = 30 to 59); libido was classified as either high (mean score = 9.0 to 10) or medium (mean score = 6.0 to 8.5). Bulls were then joined, single-sire, with groups of females which had received one of two treatments to synchronize estrus. Bull-to-female ratios ranged from 1:7 to 1:51. Continuous observations were conducted on the mating activity of each group. One bull was removed from the experiment due to a severe breeding problem. Bulls of satisfactory breeding potential (n = 80) did not differ (P > 0.10) from bulls of questionable breeding potential (n = 12) in measurements of mating activity. However, by the end of the synchronized breeding period, bulls classified as satisfactory breeders achieved approximately a 9% higher (P < 0.10) pregnancy rate than did bulls of questionable breeding status (45.6 +/- 2.1% vx 36.5 +/- 5.3%). Bulls with a high libido (n = 69) serviced more (P < 0.01) estrous females (81.3 +/- 3.1% vs 63.5 +/- 4.2%) than bulls with a medium libido (n = 23). However, pregnancy rates achieved by bulls of either libido classification did not differ significantly. Individual components of the BSE as well as mean libido score were poorly correlated with pregnancy rates (r = -0.22 to 0.18). It was concluded that classification of bulls by mean libido score can aid in identifying groups of bulls that service more estrus synchronized females, whereas classification by BSE score aids in identifying groups of bulls that impregnate more females.

Control of venereal disease in infected herds

Losses from trichomoniasis can be controlled by management and treatment strategies. The best strategy for control of campylobacteriosis is vaccination of cows and bulls with a competent vaccine.

Vesicular adenitis of bulls: A review

The prevalence of inflammatory disease of the vesicular glands can be as high as 49% in some groups of bulls under common management conditions. Since these bulls are classified as questionable or unsatisfactory potential breeders, this disease can cause significant economic loss to the producer. The current knowledge of the etiology, pathogenesis, diagnosis, treatment, and prevention are discussed.

Serum progesterone concentration in pyometritic and normal postpartum dairy cows

Two studies were conducted to evaluate the concentration of serum progesterone in pyometritic cows and relate it to palpation of ovarian structures per rectum . 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.

Risk factors for prebreeding pyometra on four Colorado dairy farms

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.

Elective termination of pregnancy in cattle by manual abortion

Abstract Abortion was induced in 91 cows and heifers by three manual methods applied per rectum . The three methods were: (1) rupture of the amnion and crushing of the fetus in cows pregnant 35 to 66 days, (2) decapitation of the fetus in cows 66 to 120 days into gestation, and (3) rupture of the amnion without crushing the fetus in cows pregnant less than 70 days. All the cows aborted between 10 and 54 days after treatment except three out of the 29 in the group in which the amnion was ruptured but the fetus not crushed. The mean interval (21.5 days) from treatment to abortion was shorter (P ∼-.07) when fetal decapitation was done between 70 and 120 days of gestation compared to the interval (26.5 days) when the amnion was ruptured and the fetus crushed between 35 and 66 days of gestation. The average interval from treatment to estrus with amnion rupture was 38 days; with fetal decapitation it was 32 days (P>.10). After abortion, estrus occurred in an average of 15 days in the amnion rupture group and in 12 days in the fetal decapitation group (P>.10).

Testing of trichomoniasis vaccine in heifers mated to infected bulls

This study was conducted to evaluate the effectiveness of a Trichomonas fetus vaccine to protect heifers from infection when bred to infected bulls. The vaccine consisted of a whole cell vaccine of T. fetus organisms stabilized in formaldehyde and adjuvanted in a mineral oil base. In the trial, fewer vaccinated heifers became infected than unvaccinated controls (69.4 vs 93.0%, respectively; P<0.08). The vaccinated heifers tended to clear the infections sooner than the controls (48.9 vs 68.5 days, respectively; P<0.10). The average number of days open was shorter in the vaccinated heifers than in the controls (33.2 vs 56.9 days, respectively; P<0.07). The first service conception rate was higher in the vaccinated heifers than in the controls (66.7 vs 33.3%, respectively; P<0.05). The number of services per conception in conceiving heifers was lower in vaccinated than in control heifers (1.44 vs 1.73, respectively; P<0.16). Cervicovaginal mucus (CVM) samples were collected every 14 days following first challenge (first service). On average, more CVM samples were positive for T. fetus for a longer period of time in the control than in the vaccinated heifers (3.9 vs 1.85 sampling periods, respectively; P<0.08). We concluded that, under the conditions of this trial, some protection to T. fetus was afforded by double vaccination with a whole cell vaccine. However, vaccination does not completely prevent heifers from developing infection.

Comparison of treatment of pyometra with estradiol cypionate or cloprostenol followed by infusion or non-infusion with nitrofurazone

One hundred-fifty-two dairy cows affected with pyometra were treated either with cloprostenol (CLP) or with estradiol cypionate (ECP). The cows which failed to respond within 7-10 days were re-treated with the same drug used in the first treatment. Half of the cows which responded to these treatments received intrauterine infusions with 50 cc nitrofurazone solution. After two treatments, 72 (94.9%) of 79 cows in the CLP group had evacuated the purulent exudate from their uteri whereas only 57 (78.1%) of 73 cows in the ECP group had responded (P<0.005). Treatment-to-breeding and treatment-to-conception intervals were not different between the ECP and CLP groups. The number of services/conception was not different up to the 4th service (3.16 vs 3.57, respectively, P>0.1). Eight (9.3%) of 86 CLP treated and 3 (5.1%) of 59 ECP treated cows had recurrence of pyometra (P>0.1). Incidence of follicular cysts within 30 days after treatment was 16.4% (13 79 ) and 7.0% (4 57 ) among CLP and ECP groups, respectively (P>0.1). Two of 106 CLP (1.9%) and 5 of 107 ECP treatments (4.7%) were associated with subsequent perimetritis and adhesions. Intrauterine infusion of nitrofurazone increased the number of services/ conception (3.57 vs 2.21, P<0.01). Cloprostenol was superior to ECP as an initial treatment of bovine pyometra. Intrauterine infusion of nitrofurazone following evacuation of the uterus appeared not to be effective in prevention of relapses and had a negative effect on conception rates.

The effect of PGF-2 alpha on reproductive performance of naturally bred dairy cows with or without pyometra

Abstract Five hundred thirty-four naturally bred Holstein dairy cows from two Colorado dairies were examined per rectum 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). Days open in 23 cows with pyometra were 98.7 ± 9.4, and 77.0 ± 2.2 in 493 herdmates without pyometra. The large inequalities in numbers precluded valid statistical comparisons between these groups. No overall difference (P>0.25) in reproductive performance was found in cows with pyometra treated at the initial examination compared to those not treated until two to four weeks after the initial examination. Contributing to the lack of significance were a number of cows with pyometra that had spontaneous cures before treatment was considered. Untreated cows that recovered spontaneously had better (P