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The purpose of this study was to evaluate the pharmacokinetics of ketamine in mature Holstein cows following administration of a single intravenous (i.v.) dose. Plasma and milk concentrations were determined using a high-performance liquid chromatography assay. Pharmacokinetic parameters were estimated using a noncompartmental method. Following i.v. administration, plasma T(max) was 0.083 h and plasma C(max) was 18,135 ± 22,720 ng/mL. Plasma AUC was 4484 ± 1,398 ng·h/mL. Plasma t(½β) was 1.80 ± 0.50 h and mean residence time was 0.794 ± 0.318 h with total body clearance of 1.29 ± 0.70 L/h/kg. The mean plasma steady-state volume of distribution was calculated as 0.990 ± 0.530 L/kg and volume of distribution based on area was calculated as 3.23 ± 1.51 L/kg. The last measurable time for ketamine detection in plasma was 8.0 h with a mean concentration of 24.9 ± 11.8 ng/mL. Milk T(max) was detected at 0.67 ± 0.26 h with C(max) of 2495 ± 904 ng/mL. Milk AUC till the last time was 6593 ± 2617 ng·h/mL with mean AUC milk to AUC plasma ratio of 1.99 ± 2.15. The last measurable time that ketamine was detected in milk was 44 ± 10.0 h with a mean concentration of 16.0 ± 9.0 ng/mL., (© 2010 Blackwell Publishing Ltd.)

The purpose of this study was to evaluate the pharmacokinetics of lidocaine in mature Holstein cows following an inverted L and caudal epidural nerve block. Plasma and milk concentrations were determined using high-performance liquid chromatography assay. Pharmacokinetic parameters were estimated using a noncompartmental method. Following administration via inverted L nerve block, serum T(max) was 0.521 +/- 0.226 h and serum C(max) was 572 +/- 207 ng/mL. Serum AUC was 1348 +/- 335 ng.h/mL. Apparent serum t((1/2)beta) was 4.19 +/- 1.69 h and MRT was 5.13 +/- 2.33 h with clearance uncorrected for the extent of absorption of 2.75 +/- 0.68 L/kg/h. The last measurable time of lidocaine detection in serum was 8.5 +/- 1.4 h with a mean concentration of 51 +/- 30 ng/mL. Milk T(max) was detected at 1.75 +/- 0.46 h with C(max) of 300 +/- 139 ng/mL. Milk AUC till the last time was 1869 +/- 450 ng.h/mL with the mean AUC milk to AUC serum ratio of 1.439 +/- 0.374. The last measurable time of lidocaine detection in milk was 32.5 +/- 16.2 h with a mean concentration of 46 +/- 30 ng/mL. There was no detectable lidocaine concentration in any samples following caudal epidural administration.

Two recent studies demonstrated that a high-affinity isolate of BVDV (SD-1), remained associated with a small percentage of in vivo-derived bovine embryos following artificial exposure to the virus and either washing or trypsin treatment. Further, the embryo-associated virus was infective in an in vitro environment. Therefore, the objective of this study was to determine if the quantity of a high-affinity isolate of BVDV associated with single-washed or trypsin-treated embryos could cause infection in vivo. Twenty zona-pellucida-intact morulae and blastocysts (MB) were collected on day 7 from superovulated cows. After collection, all MB were washed according to International Embryo Transfer Society (IETS) standards, and all but 4 MB (negative controls) were exposed for 2 h to 10(5)-10(6) cell culture infective doses (50% endpoint) per milliliter (CCID(50)/mL) of viral strain SD-1. Following exposure, according to IETS standards, one half of the MB were washed and one half were trypsin treated. All MB were then individually sonicated, and sonicate fluids were injected intravenously into calves on day 0. Blood was drawn to monitor for viremia and(or) seroconversion. Seroconversion of calves injected with sonicate fluids from washed and trypsin-treated embryos occurred 38% and 13% of the time, respectively. Therefore, the quantity of a high-affinity isolate of BVDV associated with single-washed or trypsin-treated embryos was infective in vivo.

Bovine viral diarrhea virus (BVDV) replicates in embryo co-culture systems and remains associated with developing IVF bovine embryos, despite washing and trypsin treatment. Previous research demonstrated that 2-(4-[2-imidazolinyl]phenyl)-5-(4-methoxyphenyl)furan (DB606) inhibits replication of BVDV in cultured cells. The objective of this study was to evaluate the capability of IVF embryos to develop into normal, weaned calves after exposure to antiviral concentrations of DB606 during IVC. Oocytes were obtained from cows via transvaginal, ultrasound-guided follicular aspiration. Presumptive zygotes (n = 849) that resulted from fertilization of these oocytes were cultured for 7 d in medium supplemented with 0.4 microM DB606 or medium lacking antiviral agent. All blastocysts (n = 110) were transferred individually into the uterus of a synchronized recipient. The pregnancy status of recipients was determined using transrectal ultrasonography at 21-23 d after embryo transfer. Additional pregnancies as controls (n = 21) were initiated by natural breeding. Developing fetuses and resulting calves were evaluated every 27-34 d. Blastocyst development, pregnancies per transferred embryo, pregnancies maintained per pregnancies established, gestation length, gender ratio, birth weights, viability of neonates, complete blood counts, and serum chemistry profiles at 3 mo of age and adjusted 205 d weaning weights were compared for research treatments. Development to weaning after exposure to DB606 did not differ significantly from controls. In conclusion, bovine embryo cultures can be safely supplemented with antiviral concentrations of DB606; addition of DB606 agent might prevent viral transmission if BVDV were inadvertently introduced into the embryo culture system.

Early research indicated that bovine viral diarrhea virus (BVDV) would not adhere to zona pellucida-intact (ZP-I), in vivo-derived bovine embryos. However, in a recent study, viral association of BVDV and in vivo-derived embryos was demonstrated. These findings raised questions regarding the infectivity of the embryo-associated virus. The objectives of this study were to evaluate the infectivity of BVDV associated with in vivo-derived bovine embryos through utilization of primary cultures of uterine tubal cells (UTC) as an in vitro model of the uterine environment and to determine if washing procedures, including trypsin treatment, were adequate to remove virus from in vivo-derived embryos. One hundred and nine ZP-I morulae and blastocysts (MB) and 77 non-fertile and degenerated (NFD) ova were collected on day 7 from 34, BVDV-negative, superovulated cows. After collection, all MB and NFD ova were washed according to International Embryo Transfer Society (IETS) standards and exposed for 2h to approximately 10(6) cell culture infective doses (50% endpoint) per milliliter of viral strain SD-1. Following exposure, some groups of <10 MB or NFD ova were washed in accordance with IETS standards. In addition, an equivalent number of MB and NFD ova were subjected to IETS standards for trypsin treatment. Subsequently, NFD ova were immediately sonicated and sonicate fluids were assayed for presence of virus, while individual and groups of MB were placed in microdrops containing primary cultures of UTCs and incubated. After 3 days, embryos, media, and UTCs were harvested from each microdrop and assayed for BVDV. Virus was detected in the sonicate fluids of 56 and 43% of the groups of NFD ova that were washed and trypsin-treated, respectively. After 3 days of microdrop culture, virus was not detected in media or sonicate fluids from any individual or groups of MB, regardless of treatment. However, virus was detected in a proportion of UTC that were co-cultured with washed groups of MB (30%), washed individual MB (9%) and trypsin treated individual MB (9%), but no virus was detected in the UTC associated with groups of trypsin-treated embryos. In conclusion, virus associated with developing embryos was infective for permissive cells. Further, the quantity of virus associated with a proportion of individual embryos (both washed and trypsin treated) was sufficient to infect the UTC. In light of these results, an attempt should be made to determine if the quantity of a high-affinity isolate of BVDV associated with an individual embryo would infect recipients via the intrauterine route.

Washing procedures (without trypsin treatment) recommended by the International Embryo Transfer Society (IETS) for use on in vivo-derived embryos effectively removed a cytopathic strain (NADL) of bovine viral diarrhea virus (BVDV) after artificial exposure. However, these washing procedures have not been evaluated using other isolates of BVDV, including representative non-cytopathic strains. Thus, the objective of this study was to evaluate the efficacy of the IETS procedures following artificial exposure of in vivo-derived bovine embryos to two different strains and biotypes of BVDV. One hundred and twenty-nine zona pellucida-intact (ZP-I) morulae and blastocysts (MB) and 56 non-fertile and degenerated (NFD) ova were collected 7 days following exposure to bulls from 32, BVDV-negative, superovulated cows. After collection, all MB and NFD ova were washed according to IETS standards. Subsequently, half of the MB and NFD ova were exposed for 1h to approximately 10(6)-cell culture infective doses (50% endpoint) per milliliter of viral strain SD-1, and the other half were exposed to the same concentration of CD-87. After exposure, groups of > or =3 and < or = 10 MB or NFD ova were washed using methods that met or exceeded IETS standards. Then, the washed groups were sonicated, and sonicate fluids were assayed for presence of virus using virus isolation and a reverse transcription nested polymerase chain reaction. No virus was detected in any group of MB or NFD ova that had been exposed to the CD-87 isolate. However, virus was detected in association with 50% of the groups of MB and 33% of the groups of NFD ova that had been exposed to the SD-1 isolate. Therefore, standard embryo-washing procedures recommended by the IETS are more effective for removal of some isolates of BVDV than for others. It remains to be determined if the quantity of a high-affinity isolate of BVDV associated with individual washed embryos would infect recipients via the intrauterine route. Further, it should be determined if an alternative embryo processing procedure, washing and trypsin treatment, would be more effective for removal of high-affinity isolates.

The sedative effect induced by administering xylazine hydrochloride or detomidine hydrochloride with or without butorphanol tartrate to standing dairy cattle was compared in two groups of six adult, healthy Holstein cows. One group received xylazine (0.02 mg/kg i.v.) followed by xylazine (0.02 mg/kg) and butorphanol (0.05 mg/kg i.v.) 1 week later. Cows in Group B received detomidine (0.01 mg/kg i.v.) followed by detomidine (0.01 mg/kg i.v.) and butorphanol (0.05 mg/kg i.v.) 1 week later. Heart rate, respiratory rate, and arterial blood pressure were monitored and recorded before drugs were administered and every 10 minutes for 1 hour after drug administration. The degree of sedation was evaluated and graded. Cows in each treatment group had significant decreases in heart rate and respiratory rate after test drugs were given. Durations of sedation were 49.0 +/- 12.7 minutes (xylazine), 36.0 +/- 14.1 (xylazine with butorphanol), 47.0 +/- 8.1 minutes (detomidine), and 43.0 +/- 14.0 minutes (detomidine with butorphanol). Ptosis and salivation were observed in cows of all groups following drug administration. Slow horizontal nystagmus was observed from three cows following administration of detomidine and butorphanol. All cows remained standing while sedated. The degree of sedation seemed to be most profound in cows receiving detomidine and least profound in cows receiving xylazine.

This study quantified the relationship between calibrated caliper and ultrasonographic derived measurements of bovine testicles in vivo with actual testicular length, width, volume and weight. The prolate spheroid formula was tested to accurately predict testicular volume and a modification to predict weight. Ten bulls were employed to derive caliper and ultrasound testicle (n = 20) length and width measurements in vivo. Caliper length measurements were more reliable than ultrasound derived lengths, with correlations of r2 = 0.8023; P < 0.05 and r2 = 0.5111; P < 0.05, respectively. Width for both the calipers and ultrasound measurements when compared to actual width measurements were r2 = 0.7313; P < 0.05 and r2 = 0.8310; P < 0.05, respectively. The prolate spheroid formula is reliable in determining testicle (n = 116) volume (r2 = 0.8928; P < 0.05). Testicular volume and weight are highly correlated (r2 = 0.9776; P < 0.05); therefore, a modification of the prolate spheroid formula was used to predict weight (r2 = 0.9084; P < 0.05) against the actual weight. Caliper-derived length and width measurements used in the prediction of volume and weight had correlation coefficients against actual volume and weight of r2 = 0.5497; P < 0.05 and r2 = 0.6340; P < 0.05, respectively. Ultrasound in vivo measurements for prediction of testicular volume and testicular weight had a correlation of r2 = 0.3276; P < 0.05 and r2 = 0.6249; P < 0.05, respectively. A testicular (n = 116) length to width ratio of 1.8:1 (SEM = 0.01) was determined for both slaughterhouse and castrated animals. Caliper measurements are reliable, inexpensive and much simpler to obtain than ultrasound determinations for in vivo testicle length, width, volume and weight. The two-dimensional measurement of length and width would be a more accurate predictor of testicle volume and weight than the one-dimensional measurement of scrotal circumference (SC), especially in bulls with variation in testicular shape.

In vitro embryo production has been used extensively in research and is now offered as a commercial service, yet the hazards of introducing specific infectious agents into in vitro embryo production systems have not been completely defined. The introduction of noncytopathic bovine viral diarrhea virus (BVDV) is a special concern. One objective of this study was to determine if noncytopathic BVDV-infected uterine tubal cells in IVF and IVC systems affected the rate of cleavage and development. An additional objective was to determine if either degenerated ova or embryos produced in the presence of the infected cells had virus associated with them after washing. Follicular oocytes (n = 645) collected from slaughterhouse ovaries were matured and fertilized in vitro, and presumptive zygotes were cultured for 7 d. Primary cultures of uterine tubal cells for use during IVF and IVC were divided into 2 groups. One-half of the cultures was infected with noncytopathic BVDV while the other half was not exposed to the virus. Approximately equal groups of mature oocytes were inseminated, and the presumptive zygotes were cultured with infected or noninfected uterine tubal cells. After 7 d in IVC, zona pellucida-intact (ZP-I) morulae and blastocysts and degenerated ova were washed and assayed for the presence of infectious virus. Infections of uterine tubal cells were not apparent and did not reduce rates of cleavage and development (P > 0.05; Chi-square test for heterogeneity). After washing, BVDV was isolated at a significantly higher rate from groups of virus-exposed degenerated ova (79%) than from individual virus-exposed morulae and blastocysts (37%; P = 0.0002; Mantel-Haenszel summary, Chi-square).

This study was conducted to determine the relationship between testicular shape, scrotal circumference (SC) and sperm production. Twenty-seven mature Holstein bulls were evaluated subjectively and objectively for testicular shape as indicated by testicular length and width, then placed in 1 of 3 groups. Group 1 contained 17 bulls with a normal ovoid testicular shape and a length to width ratio of 1.61:1 +/- 0.01 (SEM). Group 2 was composed of 4 bulls with a long, slender testicular shape and a length to width ratio of 1.95:1 +/- 0.06 (SEM). Group 3 was comprised of 6 bulls with spheroid-shaped testicles and a length to width ratio of 1.3:1 +/- 0.03 (SEM). All the groups were statistically different for length to width ratios (P < 0.05). Length measurements from cranial to caudal pole of the testis proper were also different between groups (P < 0.05). Width or testicular diameter was different between Group 2 and Group 3 at P < 0.05; however, there was no difference between Group 1 and Group 2 or between Group 1 and Group 3. Predicted volumes and weights of testicles were not significantly different between groups. Scrotal circumference measurements were significantly different between groups (P < 0.05). Group 1 had an average SC of 43.07 +/- 0.36 cm (SEM), Group 2 of 39.33 +/- 1.18 cm (SEM) and Group 3 of 46.22 +/- 0.69 cm (SEM). Sperm production for a twice daily, 2-day-per-week collection schedule revealed a statistically significant difference for sperm output. A total of 2742 ejaculates was evaluated. A total of 1818 ejaculates was evaluated in Group 1, 440 ejaculates in Group 2 and 484 ejaculates in Group 3. The mean spermatozoal harvest per day for Group 1 bulls was 13.62 +/- 0.09 x 10(9) (SEM). Group 2 bulls with the longer-shaped testicles produced 14.82 +/- 0.18 x 10(9) (SEM) spermatozoa per day, and Group 3 bulls, with the more rounded testicle shape and the significantly larger SC produced 11.72 +/- 0.64 x 10(9)(SEM) sperm cells per day. All 3 groups were statistically different at the P = 0.05 level. The results suggest that prediction of sperm production may be dependent on factors other than SC, testicular volume, or weight. Testicular shape may influence sperm output in mature Holstein bulls.

Objective: To determine plasma and milk concentration-time profiles and pharmacokinetic variables after i.v. administration of ketoprofen to lactating dairy cows., Design: Cows received a single i.v. bolus of ketoprofen (3.31 mg/kg of body weight). Blood and milk were collected at 0, 5, 10, 15, 25, 40, 60, 90, 120, 180, 240, 360, and 480 minutes. Ketoprofen concentrations in plasma and milk were determined., Animals: 6-clinically normal lactating Holstein cows., Procedure: Plasma and milk samples were processed by solvent extraction, and ketoprofen concentrations were determined, using high-performance liquid chromatography with octadecyl silane reverse-phase guard and analytic columns. A computer polyexponential curve-stripping program was used to fit ketoprofen concentration-time data and to calculate pharmacokinetic variables., Results: The lower limit of detection for ketoprofen in plasma was 18 ng/ml; the lower limit of quantification was 60 ng/ml. The lower limit of detection for ketoprofen in milk was 27 ng/ml; the lower limit of quantification was 90 ng/ml. Plasma ketoprofen concentration-time curves best fit an open two-compartment pharmacokinetic model. Harmonic mean apparent volume of distribution at steady state was 0.11 (range, 0.095 to 0.13) L/kg, elimination half-life was 0.49 (range, 0.40 to 0.67) hour, and total clearance was 0.17 (range, 0.14 to 0.19) L/kg/h. Ketoprofen was detected in some milk samples, 10 to 120 minutes after administration, but all concentrations were below the limit of quantification. Adverse effects were not observed in cows given ketoprofen., Conclusions: The elimination of half-life for ketoprofen is short, and low concentrations of ketoprofen can be detected in normal milk, after i.v. treatment of cattle with ketoprofen. Milk and meat from cattle treated i.v. with ketoprofen should not be an important drug residue risk if appropriate withholding periods are used.

Because caffeine is metabolized by the hepatic P-450 cytochrome oxidase system, clearance of caffeine is an excellent quantitative test of hepatic function in human beings. It is currently used in much the same way that creatinine clearance is used to assess renal function. Caffeine clearance was measured in lactating dairy cows initially to determine the suitability of caffeine clearance as an indicator of hepatic function in cattle. Pharmacokinetic variables of caffeine were studied in 6 adult lactating dairy cows after i.v. administration of a single dose of caffeine sodium benzoate (2 mg of caffeine/kg of body weight). Caffeine concentration was analyzed by use of an automated enzyme immunoassay. The lower limit of detection of the assay for caffeine in serum was 0.079 micrograms/ml. Serum caffeine concentration-time curves best fit an open two-compartment pharmacokinetic model. Harmonic mean elimination half-life was 3.8 (range, 2.6 to 6.9) hours, and total clearance was 0.118 (range, 0.090 to 0.197) L/kg/h. Milk caffeine concentration was similar to serum concentration 1.5 to 24 hours after caffeine administration. Adverse effects were not observed in cows given caffeine.

Neurofibromatosis in cattle is typically a noncutaneous disease. A small group of cows in a Holstein dairy herd developed cutaneous neurofibromatosis. This unique condition was investigated and compared with neurofibromatosis type 1 (NF1) in humans. All cutaneous lesions but one were consistent with neurofibromas in noncutaneous sites in cattle and neurofibromas in patients with NF1. One bovine lesion was classified as a neurofibrosarcoma. Immunohistochemistry and electron microscopy supported Schwannian differentiation in benign and malignant lesions. Linkage analysis with a polymorphism in the bovine NF1 gene confirmed that two affected animals from the same sire inherited the same paternal NF1 allele. Bovine cutaneous neurofibromatosis is a naturally occurring disease in this group of animals, characterized by skin tumors morphologically identical to those of NF1. An informative polymorphism at the NF1 locus of two animals and their sire suggests this disorder may be caused by hereditary mutations at the bovine NF1 locus.

Milk production was monitored in 16 cows for 6 milkings after intramammary infusion of 1 mg of endotoxin in a single forequarter. The cows were randomly assigned to 1 of 2 treatment groups; 8 cows were treated with isotonic saline solution and 8 cows were treated with hypertonic saline solution. Saline solutions were administered IV (5 ml/kg of body weight) 4 hours after infusion of endotoxin. Mean cumulative change in milk yield and interval change in milk yield were greater in cows treated with isotonic saline solution than in cows treated with hypertonic saline solution. Significant differences between treatment groups were not detected.

Techniques for in vitro production of bovine embryos have evolved to the extent that applications for the commercial production of calves have been proposed. However, little is known about the epidemiological implications of the procedures. One concern is the introduction of noncytopathic bovine viral diarrhea virus (BVDV). In this study, follicular oocytes (n=247) collected from 10 cows were matured and fertilized in vitro and presumptive zygotes were cultured for 7 d. Primary cultures of bovine oviductal epithelial cells for use during in vitro fertilization and culture were divided into 2 groups. Treated oviductal cells were infected with BVDV while control cells were not exposed to the virus. Two approximately equal groups of mature oocytes from each cow were inseminated, and the presumptive zygotes were cultured with infected or noninfected oviductal cells. After 7 d in culture, zona pellucida-intact morulae/blastocysts and degenerated ova were washed, sonicated and assayed for the presence of virus. The rates of cleavage and development were also compared by Chi-square analysis. After washing, virus was not isolated from morulae and blastocysts but was isolated from some groups of degenerated ova. Infections of oviductal cells were inapparent and did not significantly (P>0.05) affect rates of cleavage or development.

Semen was collected from 5 mature beef bulls by electroejaculation before, during, and after 20 days of scrotal insulation. Thermally-induced testicular degeneration was irreversible in 3 of the bulls. Analysis of sperm and seminal plasma polypeptides revealed that 15 to 30 sperm polypeptides and 25 to 30 seminal plasma polypeptides were indistinguishable between bulls prior to the insulation treatment. Changes in the sperm polypeptides pattern appeared as early as 2 days after the insulation treatment and persisted for at least 11 months in 2 of the bulls. In the spermatozoa, there was a detectable loss of 31, 34, 49 and 58 kDa polypeptides and an appearance of 6 to 8 new major polypeptides, ranging from 32 to 83 kDa. The 83 kDa polypeptide was most prominent in the 2 bulls that regained normal sperm motility and morphology following the insulation period. The post-insulation appearance of a seminal plasma polypeptide (circa 60 kDa) was also identified in these 2 bulls. Seminal plasma polypeptides remained qualitatively unaltered by the insulation treatment in the 3 bulls with irreversible testicular degeneration.

Purpose: The main purpose of the study was to assess the feasibility of a combined system for in vitro maturation of oocytes, in vitro fertilization, and in vitro culture of embryos for production of calves from cows that have to be removed prematurely from production units., Results: Eighteen cows that were to be culled from experimental dairy production units were ovariectomized. An average of 45.7 oocytes per cow was collected from the ovaries. After in vitro maturation and fertilization of the oocytes, an average of 40.8 presumptive zygotes was placed into in vitro culture, with an average of 16.1 cleaving by day 2 and an average of 5.7 developing to morulae/blastocysts by day 6 or 7. A greater mean quantity of oocytes was collected from cows that were ovariectomized between day 5 and day 13 of the estrous cycle than from those that were ovariectomized between day 0 and day 3 of the estrous cycle. Correspondingly larger mean numbers of cleaved zygotes and morulae/blastocysts were produced from the cows that were ovariectomized between day 5 and day 13 of the cycle. Transferable embryos were produced from 17 of the 18 cows. Eighteen embryos from six oocyte donor cows were transferred to recipients. Six of the eighteen recipients were confirmed to be pregnant after 40 days. Three of the pregnant recipients delivered live calves at term. Two others remain pregnant but have not reached term. The sixth recipient aborted at approximately 120 days of gestation., Conclusions: Results from the preliminary study indicate that this system can be used for production of calves from cull cows. Although transferable embryos were produced from all except one cow, there was a high degree of variability among cows in total number of oocytes recovered and embryos produced. More donors need to be evaluated to determine the effects of age, breed, reason for culling, and source of semen.

Thirty superovulatory treatments were administered to 19 mixed-breed, nonlactating cows. In 10 superovulatory treatments, the cows were primed with follicle stimulating hormone (FSH) on the second and third day of the estrous cycle, and in another 10 superovulatory treatments, the cows received no priming dosage of FSH. Initiation of the superovulatory treatments in both groups was determined by ultrasonically monitoring for regression of the dominant anovulatory follicle. Still another 10 superovulatory treatments were begun on Day 10 without regard for regression of the dominant anovulatory follicle and without a priming dosage of FSH. The mean days for starting the superovulatory treatment in the FSH-primed cows, in the nonprimed cows and in the controls were 10.5, 11.9 and 10 days, respectively. All cows were treated with eight injections of FSH at 12-hour intervals in a declining dosage (36 mg total). Cows were bred naturally and embryos collected nonsurgically seven days later. There was no significant difference (P>0.05) between the total number of embryos or transferable embryos in the three treatment groups. In this study neither priming on Days 2 or 3 nor initiating the superovulatory treatment, based on the morphologic regression of the dominant anovulatory follicle, was an effective means for improving the superovulatory response in cattle.

In 8 Holstein cows, 50 colony-forming units (CFU) of Escherichia coli was administered into 1 mammary gland. Infections were established in all inoculated glands. In 4 of the 8 cows, 500 mg of gentamicin sulfate was administered by intramammary infusion 14 hours after inoculation; the other 4 cows were untreated controls. Infusions of gentamicin also were given after each of the 3 successive milkings after the initial infusion, so that a total dose of 2 g of gentamicin was given to each of the treated cows. During the 33-hour treatment period and for the first milking after the last infusion of gentamicin, the treated cows had a mean gentamicin concentration of greater than or equal to 31.0 micrograms/ml in milk samples that were collected from inoculated quarters immediately before each milking. Concentrations of 0.34 and 0.69 micrograms of gentamicin/ml were detected in milk from 2 cows at 8 days after inoculation with E coli. Mean serum concentrations of gentamicin were greater than or equal to 0.37 micrograms/ml throughout the treatment period and the first 12 hours after the last infusion, with a mean peak concentration of 0.96 micrograms/ml at 24.4 hours. The range of peak concentration of gentamicin detected in urine from all treated cows was 42 to 74.4 micrograms/ml. Peak concentration of E coli in milk in the treated cows (6.08 +/- 1.02 log10 CFU/ml) did not significantly (P greater than 0.05) differ from that of the control cows (5.26 +/- 1.00 log10 CFU/ml). Similarly, mean duration of infection in the treated cows (54 hours) did not differ significantly from that of the control cows (48 hours).(ABSTRACT TRUNCATED AT 250 WORDS)

Zona pellucida-intact ova collected from ewes seronegative to Brucella ovis were exposed in vitro to B ovis and washed 10 times in medium that contained no antibiotics. After exposure and washing, nontransferable ova were cultured for isolation of Brucella , and the viable ova were transferred into seven B ovis seronegative ewes. No pregnancies resulted, thus recipient ewes were bred during the next breeding season, and blood samples were collected for bacteriological and serological examination until one month after lambing. Brucella ovis was isolated from all of the nontransferable ova, indicating that the transferred ova had viable organisms adhered to them. Although no recipient was found to be pregnant at Day 45, all seven ewes responded to the transferred ova by producing anti-Brucella antibodies. With the exception of a ewe that was euthanized early in the project due to a traumatic injury, all recipients lambed normally during the following breeding season. Brucella was not found in any sample collected from ewes or lambs. However, ELISA titers for B ovis remained in the suspicious range and a ewe was positive on the CF test within 2 wk of lambing.

Beef cattle were treated to synchronize estrus using one of three procedures, and effects on subsequent endocrine responses and fertility were studied. Procedures were 1) feeding .5 mg.head-1.d-1 of melengestrol acetate (MGA) for 21 d (M), 2) feeding .5 mg.head-1.d-1 of melengestrol acetate for 21 d followed 14 d later by a single injection of prostaglandin F2 alpha (M + P) and 3) two injections of prostaglandin (PGF) 14 d apart (P). In Exp. 1, 94 beef cows were assigned to be artificially inseminated 12 h after detection of estrus. Procedures for synchronizing estrus did not affect the proportion of cows observed in estrus within 7 d (mean = 70.2%). However, conception rate of cows treated with MGA alone was lower (P less than .01) than that of cows treated with PGF alone (31.8 vs 78.3%). The conception rate of cows in the M + P group was intermediate (57.1%) but greater than that of cows treated with MGA alone (P less than .10). In Exp. 2, 18 heifers were observed for estrus four times daily and bled daily from 1 wk before predicted estrus until second estrus or 35 d post-treatment. Heifers treated with MGA alone maintained lower concentrations of progesterone and higher concentrations of estradiol-17 beta before first estrus than heifers treated with MGA and PGF or PGF alone (P less than .01). Conception rate following insemination was lower after long-term feeding of MGA than after two injections of PGF. Delaying insemination until after a PGF-shortened cycle 14 d after MGA resulted in an intermediate conception rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Oviductal-stage embryos were surgically collected from 27 superovulated adult cows of various breeds, ages, and parity. A total of 88 surgeries was performed via a caudal flank grid approach, with the animals in lateral recumbency and the reproductive tract irrigated with sterile glycerol solution prior to surgical closure. Eight cows were operated on twice and five cows were operated on three or more times. The maximum number of surgeries for a single cow was five. Successful ova collection was accomplished in each surgical attempt, and all cows submitted to this procedure subsequently became pregnant following return to the breeding herd. This technique provided greater exposure of the ovary, uterine tube, and uterine horn, with less adhesion formation than traditional ventral midline techniques.

Fluids produced by the uterus of pregnant sheep (OUF-ovine uterine fluids) were assayed for mitogenic activity in a thymidine incorporation assay. A dose-dependent mitogenic activity was observed in OUF which exceeded that of adult ovine plasma or fetal bovine serum. Uterine fluids were capable of stimulating thymidine incorporation in mouse 3T3 fibroblasts, rat L6 myoblasts, ovine trophoblast-derived cells, HeLa S3 cells, and bovine aortic endothelial cells. The greatest stimulation was observed in L6 myoblasts. The name ovine uterine-derived growth factor (ovine UDGF) has been suggested for this activity.

Seventy-three zona pellucida-intact ova were collected surgically from 15 superovulated, Brucella -free mixed-breed ewes. Twenty-one groups containing one to five ova were incubated in medium containing Brucella ovis . Subsequently, seven and five groups were incubated for 24 and 4 h, respectively, at 37 degrees C in medium containing penicillin and streptomycin, while nine groups were not treated with antibiotics. All groups of ova were washed 10 times, and ova and sequential washes were cultured for the presence of B. ovis . Brucella were isolated from seven of the nine groups of nontreated ova and from the 10th wash for six of these groups. While Brucella were detected in fewer washes after antibiotic treatment, the organism was still isolated from 11 of the 12 treated groups. Results indicate that standard washing techniques are not reliable for removing B. ovis from exposed, zona pellucida-intact, ovine ova.

Thermographic patterns of the bovine scrotum were established in 15 clinically normal bulls and were compared with patterns in 10 bulls with scrotal and testicular diseases. Thermography of a normal scrotum was characterized by a symmetrical and constant thermal pattern with a temperature gradient of 4 degrees to 6 degrees (C) from the base to the apex of the scrotum. There was a significant difference (P less than 0.05) in the temperature from the base to the apex of the scrotum (34.94 +/- 0.60 C to 30.11 +/- 0.91 C). Lack of thermal symmetry was seen in bulls with unilateral lesions. Inflammation of one testicle increased ipsilateral scrotal infrared emission temperature 2.5 degrees to 3 degrees (C) above that in the contralateral side. If both testes were inflamed and hyperemic, there was an overall increase in scrotal temperature of at least 3 degrees (C), and a reduction in temperature gradient of 2 to 3 degrees (C) from the base to the apex of the scrotum. Area temperatures in bulls with chronic testicular degeneration with fibrosis were reduced.

Fifty-three zona pellucida-intact ova were collected surgically from superovulated, Brucella -free mixed-breed ewes. Groups containing two to seven ova were incubated in medium containing Brucella abortus . All groups of ova were then washed 10 times, and ova and sequential washes were cultured for the isolation of B. abortus . Brucella were not found beyond the fifth wash for any group of ova, but were isolated from one of 12 groups of ova. Results indicate that mechanical washing in the absence of antibiotics is advantageous, but alone, is not totally reliable for removing B. abortus from exposed, zona pelucida-intact ovine ova.

Twelve attempts were made to isolate caprine arthritis-encephalitis virus (CAEV) from the uterine flushings of serologically positive superovulated does mated to serologically positive bucks. Embryos were transferred to eight serologically negative estrus-synchronized recipient does and the recipients were monitored serologically following embryo transfer. Virus isolation was attempted from colostrum and placental tissues from does that kidded following embryo transfers and the surviving kid was monitored serologically until four months of age. The CAEV was not isolated from any of the uterine flushings, colostrum or placental tissues. All recipients and the kid remained seronegative throughout the trial.

Semen collection was attempted from 18 stallions with an artificial vagina (AV) and without use of a mare or dummy mount. After the stallions were sexually excited by the presence of another horse (mares, and in some instances, geldings) an AV was placed over the erect penis. Thirteen of the 18 stallions manifested thrusting and ejaculation in at least one attempt at semen collection. Semen was collected from 12 of the stallions on the first attempt with all subsequent attempts at semen collection from 11 of these 12 stallions being successful. The ejaculate from one of the stallions was judged incomplete based upon spermatozoal concentration compared with the concentration of a subsequent ejaculate obtained with a mount.

To determine effects of age and administration and withdrawal of a synthetic progestin (P) on endometrial development and DNA synthesis, ewe lambs were ovariectomized on d 0 (birth) and assigned to one of four groups (n = three/group) that provided (by means of hemihysterectomy) the following uterine tissue types: 1) d 0 control, 2) d 13 control, 3) d 26 control, 4) d 13 after 13 d exposure to P (13P) and 5) d 26 after P exposure from d 0 to 13 (26P). Uterine tissues were processed for histology or explanted with [methyl-3 H] thymidine for autoradiography. Labeling index (LI) was determined for stroma and epithelium in caruncular and intercaruncular endometrial areas and for lumenal and glandular epithelium in uteri with glands. Endometrial glands were absent on d 0, evident at d 13 and well developed by d 26. Day 0 LI was greater (P less than .05) in caruncular than in intercaruncular areas, and greater in stromal than in epithelial tissues. Relationships were reversed in d 13 endometrium (day X endometrial area, P less than .07). Caruncular stromal LI was greater on d 0 than later (P less than .02), whereas intercaruncular epithelial LI was greater after d 0 (P less than .05), but decreased from d 13 to 26 (P less than .05). Glandular epithelial LI was higher on d 13 than on d 26 (P less than .03). Administration of P inhibited endometrial gland development and suppressed d 13P intercaruncular LI (P less than .05). Withdrawal of P was followed by endometrial gland development and increased (P less than .01) intercaruncular epithelial LI in d 26P uteri. Ovary-independent initiation of endometrial gland development involves age- and region-specific alterations in DNA synthesis and could involve negative control.