Heifers were inoculated IV with 1 of 4 modified-live bovine herpesvirus-1 vaccinal strains against infectious bovine rhinotracheitis (2 heifers/strain) on postbreeding day (PBD) 14. The effect of infection on fertility was monitored by plasma progesterone assay at 1- to 3-day intervals from the time of virus exposure until PBD 60. Infertility was detected in 4 of 8 inoculated heifers. In 2 heifers, progestrone concentrations decreased to values indicative of estrus within 10 days after inoculation (PBD 24). The 2 other heifers had evidence of embryonic death on PBD 40 and 42. Two control heifers inoculated with culture medium from noninfected cells maintained their pregnancies.

Uterine response to inoculation with Streptococcus zooepidemicus organisms, 51Cr-labeled 15-micromoles microspheres, and charcoal was evaluated in 9 mares (4 resistant and 5 susceptible to endometritis) to determine mechanical and cellular clearance rates during the early postovulatory period. Mares were inoculated at estrus prior to ovulation during estrous cycles 1, 3, and 5. Uterine swab specimens for aerobic and anaerobic bacteriologic culture and serum for progesterone determination were obtained on postovulation day 3 during estrous cycle 1, on the day of ovulation during estrous cycle 3, and on postovulation day 5 during estrous cycle 5. Immediately thereafter, the uterus was irrigated with 50 ml of sterile physiologic saline solution containing tracer amounts of 125I-labeled human serum albumin. Streptococcus zooepidemicus was isolated from 10 of 15 (67%) uterine specimens collected from susceptible mares and incubated aerobically. Escherichia coli also was isolated from 2 of the 10 specimens incubated aerobically. Anaerobic bacteriologic culture of specimens from all mares yielded no growth. Chromium-labeled microspheres were recovered twice from 2 susceptible mares, on day 0 and day 5. Charcoal was retained in 5 specimens collected from 3 susceptible mares. Bacteriologic culture of specimens from resistant mares did not yield growth. On day 0, chromium-labeled microspheres and charcoal were recovered once from 1 resistant mare. Mares susceptible to end ometritis accumulated more fluid within the uterine lumen after ovulation than did resistant mares (mean +/- SEM, 52.73 +/- 15.22 ml and 7.41 +/- 1.96 ml, respectively; P less than 0.01). From this study, it appeared that uterine cellular and bactericidal mechanisms are dysfunctional during the early postovulatory period. However, there appeared to be no disruption of the mechanisms responsible for mechanical clearance of materials inoculated in the uterus.

Efficacy of a repositol formulation of melengestrol acetate (MGA) for inhibition of pregnancy was determined in one hundred 14- to 16-month-old beef heifers. Nonpregnant heifers were allocated on the basis of weight into 5 groups of 20 heifers each and were given 0, 30, 60, 90, or 120 mg of repositol MGA, SC, on day 0. Four bulls, determined to be satisfactory potential breeders, were pastured with the heifers from postinjection days (PID) 7 to 177. The day of gesation was estimated for each heifer by rectal palpation at PID 59, 91, 134, 177, and 225. Heifers not pregnant by PID 177 were assigned a day of conception of greater than 177. For heifers given 0, 30, 60, 90, and 120 mg of MGA, respectively, the percentage pregnant at PID 177 was 95, 95, 50, 15, and 15%, and the median day of estimated conception was PID 21, 87, 175, greater than 177, and greater than 177. Repositol MGA significantly (P less than 0.001) affected the distribution of conception times over all doses. Average daily gain (+/- SEM) for 178 days was 0.28 +/- 0.04 kg, 0.24 +/- 0.03 kg, 0.33 +/- 0.04 kg, 0.40 +/- 0.03 kg, and 0.35 +/- 0.03 kg for heifers given 0, 30, 60, 90, and 120 mg of MGA, respectively. Increased dose of repositol MGA was associated with increased average daily gain, but this effect was not apparent when days pregnant were taken into account. Repositol MGA was an effective contraceptive for pastured heifers and the duration of its effect was dose-dependent.

Serum protein electrophoresis was performed on 71 clinically healthy juvenile and adult llamas (6 juvenile males, 7 juvenile females 25 adult males, 13 adult females, and 20 pregnant females) to determine normal serum protein concentrations. Values were reported for each of the 5 groups because the groups were not homogeneous in all 8 peaks. Although the values reported here may serve as reference values for adults, they represent only a guideline for the juveniles because of the limited number of animals in each of these groups.

Fetal and neonatal lamb hemostasis were studied from the 60th day of pregnancy to birth. Platelet counts and blood coagulation, as assessed by tests such as recalcification time and thromboelastography, were similar in fetuses, neonates, and adult sheep. The values of coagulation factors were low, ie, vitamin K-dependent Factors II, VII, IX, and X remained unchanged (30 and 40% of adult reference values) until the last 10 days of gestation, and then increased until birth (40 to 60%). Values of fibrinogen and Factor V followed a similar pattern, although their activities became identical to adult values at birth. Also, we measured values of protein C and antithrombin III, which are synthesized by the liver. The importance of hepatic failure and fetal vitamin K deficiency were discussed. Factors VIII and XII activities increased gradually during pregnancy to reach adult values at birth. Fetal fibrinolytic activity increased. This could not be explained by the values or tissue-type plasminogen activator (it was not detectable) or by the presence of its fast-acting inhibitor, whose concentration did not decrease.

Serum concentrations of relaxin and progesterone were measured by specific radioimmunoassays in pregnant, pseudopregnant, or ovariectomized (between gestation weeks 4 and 5) pregnant Labrador Retriever bitches. Daily administration of 17 alpha-ethyl-19-nortestosterone was performed to maintain gestation in the ovariectomized pregnant bitches. This synthetic gestagen was selected because it did not interfere with the assay for endogenously secreted progesterone concentration in serum. Serum progesterone concentration was high in ovarian-intact pregnant or pseudopregnant bitches, but the mean progesterone concentration in pseudopregnant bitches (evaluated at 4 weeks after mating) was only 56% of the concentration in pregnant bitches. After ovariectomy, serum progesterone concentration decreased to undetectable values. Unlike progesterone, serum relaxin concentration increased during the latter half of pregnancy in the ovarian-intact and in the ovariectomized pregnant bitches, but relaxin was not detectable at any time in the pseudopregnant bitches. The amount of relaxin measured in the ovariectomized pregnant bitches was less (P less than 0.05) than that in ovarian-intact bitches, suggesting that the ovaries may have contributed to the total circulating relaxin concentration in the latter. Placental production of relaxin might have accounted for the serum relaxin concentration after ovariectomy; thus, the ovary and placenta each may secrete relaxin during gestation in bitches. Regardless of its source, measurement of serum relaxin concentration may offer a useful way of distinction between pregnancy and pseudopregnancy in dogs.

Colostral volume and IgG and IgM concentrations were determined in 6 multiparous mares at foaling and then every 2 hours from 16 to 20 hours after parturition. Serum IgG and IgM concentrations at foaling also were determined in each mare. The rate of mammary secretion was 292 +/- 26 ml/h (range, 202 to 389 ml/h), and the colostral volume was 5.1 +/- 0.5 L (range, 3.2 to 7.0 L). The colostral IgG and IgM contents were 440 +/- 106 g (range, 199 to 855 g) and 3.1 +/- 0.9 g (range, 0.7 g to 7.1 g), respectively. There was no significant correlation between serum and initial colostral IgG and IgM concentration or between serum and total colostral IgG or IgM values. The colostral IgG and IgM concentrations at foaling correlated well with the total colostral IgG and IgM contents, respectively. The initial 250 ml of colostrum contained 10 +/- 1.4% (range, 6.0 to 13.9%) and 6 +/- 1.0% (range, 2.4 to 8.5%) of the total IgG and IgM contents, respectively, and the initial 500 ml of colostrum contained 20 +/- 2.7% (range 12.0 to 27.1%) and 14 +/- 1.2% (8.2 to 17%) of the total colostral IgG and IgM contents, respectively.

We studied the antibody responses to transmissible gastroenteritis (TGE) in serum, colostrum, and milk from sows vaccinated with 2 attenuated (1 IM and 1 oral-IM) and 1 nonattenuated live vaccines and the relationship of these responses with the survivability of the sow's suckling pigs after challenge exposure with virulent TGE virus. Contrary to previous studies, the anti-TGE virus-neutralizing geometric mean titers (GMT) in the milk of sows vaccinated with attenuated vaccines at 3 and 5 days of lactation were similar to that found in the colostrum. Colostral and serum antibody titers were highest in sows given 2 injections of the IM attenuated vaccine. Half of the sows given the oral-IM attenuated vaccine did not seroconvert after 2 oral doses. Only sows vaccinated with the nonattenuated live vaccine had milk GMT that remained high for 21 days after farrowing. The linear relationship between colostral GMT and percentage of survivability of suckling pigs challenge exposed at 3 days of age was significant (P less than 0.05), although the relationship between serum GMT and percentage of survivability and the relationship between milk GMT and percentage of survivability were not significant (P greater than 0.10). The linear relationship between colostral (P less than 0.10) or pre-challenge exposure milk (P less than 0.05) GMT and percentage of survivability of suckling pigs challenge exposed at 5 days of age was significant. We have no adequate explanation for the relatively low colostral GMT, the relatively high milk GMT at 3 and 5 days of lactation in vaccinated sows, or the lack of significant linear relationship between milk GMT and survivability of pigs challenge exposed at 3 days of age.

Basal serum triiodothyronine (T3) and tetraiodothyronine (T4) concentrations have not been established for the llama (Lama glama). In addition, changes in T3 and T4 concentrations in response to thyroid-stimulating hormone (TSH) administration have not been determined, making clinical evaluation of problems referable to thyroid dysfunction difficult. In study 1, basal T3 and T4 concentrations were determined in serum samples collected from 132 clinically healthy llamas. The llamas were allotted to 3 groups: mature intact or neutered males (group I, n = 25), nonpregnant sexually mature females (group II, n = 21), and pregnant females (group III, n = 86). A mean concentration and a 95% confidence interval were computed for each group. An analysis of variance (ANOVA) indicated that a single confidence interval range (0.45 to 4.18, mean = 1.37 ng T3/ml) adequately defined the normal T3 concentrations for all groups. An ANOVA indicated that the T4 concentrations for the female populations (groups II and III) could be combined with a normal confidence interval range of 39 to 204 ng/ml (mean = 88 ng/ml), whereas a separate range (70 to 220 ng/ml, mean = 124 ng/ml) was determined for the male population. An ANOVA indicated that a single confidence interval range (0.0066 to 0.0321, mean = 0.0146) adequately defined the normal T3/T4 ratio for all groups. In study 2, T3 and T4 concentrations were evaluated in 10 healthy llamas immediately preceding and at 2, 4, 6, 8, and 24 hours after the IV administration of 3 IU of TSH/44 kg of body weight. The T3 and T4 concentrations were significantly higher by 2 hours after TSH administration in both groups. Peak T3 and T4 concentrations were observed at 4 and 8 hours, respectively, after TSH administration. When normalized with respect to serum T3 concentrations in samples collected immediately prior to TSH administration, the maximal increase in predicted T3 concentration was 4.06-fold (80% confidence interval range = 2.99- to 5.50-fold) at 4 hours after TSH administration. The maximal increase in predicted normalized T4 concentration was 2.32-fold (80% confidence interval range = 1.76- to 3.05-fold) at 8 hours after TSH administration. The TSH-stimulated increases in T3 and T4 concentrations at 4 hours were clearly distinguishable from values in samples obtained before TSH administration.

Swine herds suspected to be infected with Leptospira interrogans serovar bratislava were vaccinated with bacterins containing 5 or 6 leptospiral serovars in which serovar bratislava was the unique component. The principal diagnostic feature indicating an infection by this organism was demonstration of antibody against serovar bratislava in sera from stillborn pigs. For 1 breeding cycle after vaccination of herds on 3 farms, 255 of 266 (95.9%) sows and gilts given the 6-serovar bacterin farrowed. In contrast, 233 of 311 (74.9%) sows and gilts given the 5-serovar bacterin farrowed. These results, as evaluated by analysis of variance techniques, showed a significant improvement (P less than 0.01) in reproductive performance for groups vaccinated against serovar bratislava.