Effects of the anabolic steroid, boldenone undecylenate, on certain reproductive parameters in bulls.

A total of 17 bulls was used to study the effects of boldenone undecylenate on growth and semen characteristics in beef bulls. In trial 1 nine mature mixed-breed beef bulls with satisfactory semen quality were divided into two groups. Group I (n = 5) received boldenone undecylenate (1.1 mg/kg) at 21 d intervals for a total of seven treatments (147 d). Group II (n = 4) served as untreated controls. Semen was collected from each group by electroejaculation on each treatment day and evaluated according to the standards of the Society for Theriogenology. Although neither the percentage of spermatozoa with primary or secondary morphological abnormalities was different, the ejaculates of Group I bulls contained a higher percentage of abnormal spermatozoa than those in Group II. In trial 2, eight mixed-breed bull calves, average weight 140.4 kg, were maintained under drylot conditions in a single paddock. The bulls were divided into two equal groups. Group I (n = 4) received boldenone undecylenate as in Trial 1. Group II (n = 4) served as untreated controls. The bulls were weighed and the scrotal circumference (SC) was measured every 21 d until it reached 30 cm, at which time semen was collected and evaluated as in Trial 1. Group I bulls had a higher percentage of spermatozoa with primary morphological abnormalities than bulls in Group II. Group I bulls had a higher average daily gain (ADG) than Group II bulls and required 21 d longer for the SC to reach 30 cm. Semen quality for all bulls was satisfactory at each sampling day.

A caudal flank approach for the collection of oviductal-stage bovine embryos.

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.

Embryo transfer from goats seropositive for caprine arthritis-encephalitis virus.

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.

Effects of xylazine and ketamine hydrochloride on the electroencephalogram and the electrocardiogram in the horse.

A continuous series of electroencephalograms (EEG) was obtained from each of 6 mature horses which had been given xylazine and ketamine hydrochloride IV. Electrocardiograms and respiratory rates were also obtained. The EEG of the unsedated standing adult horse displayed a dominant fast activity in the range of 25-35 Hz, 5-30 microV superimposed over slower 1-4 Hz, 10-50 microV activity with occasional 10-14 Hz, 10-40 microV spindle-type activity. The xylazine-sedated horse displayed hypersynchronous EEG patterns, with the dominant activity being 1-3 Hz, 10-70 microV with overlying mixed frequencies of 5-10 Hz, 10-40 microV and 10-14 Hz, 10-40 microV spindle-type activity. Some 25-35 Hz, 5-10 microV activity was present in 5 of the 6 horses. Ketamine administration 3 minutes after xylazine injection caused an increase in high-voltage slow activity. The dominant frequency was 1-3 Hz, 20-100 microV, with superimposed mixed irregular frequencies of 6-10 Hz, 10-50 microV and 10-14 Hz, 10-40 microV spindle-type activity. All horses developed some degree of second-degree atrioventricular (AV) heart block approximately 23 s after xylazine was injected. The second-degree AV heart block disappeared approximately 1 minute and 30 s after ketamine was injected in 4 of the 6 horses. The remaining 2 had second-degree AV heart block throughout the recording period (15 to 18 minutes). Respiration rates were depressed after xylazine was given and became irregular and apneustic after ketamine injection. The cyclic rate of respiration varied from 19 to 30 breaths/minute. Xylazine depressed heart rates from 13% to 41% (mean 29.3%). Heart rates became faster or remained unchanged after ketamine was administered.

Electroencephalographic patterns of clinically normal, sedated, and tranquilized newborn foals and adult horses.

To establish a clinically practical procedure for recording the equine EEG, 25 healthy adult horses and 6 newborn foals were used. Recordings were taken with the animals alert and tranquilized, confined in metal stocks, or physically restrained. The dominant alert waveforms of adult horses were fast activity (25 to 40 Hz) with medium-to-low voltages (5 to 40 microV-dominant 10 to 15 microV). Underlying this fast activity was slower (0.5 to 4.0 Hz) activity with medium-to-low voltages (10 to 40 microV). Twelve of the 25 adult horses had EEG frequencies in the alpha frequency range (10 to 15 Hz, 10 to 50 microV). Eight horses were given xylazine and 17 were given acetylpromazine. Those given xylazine had generalized slowing with several distinct frequency patterns (25 to 40 Hz, 5 to 30 microV; 10 to 15 Hz, 10 to 80 microV; and 0.5 to 4.0 Hz, 10 to 90 microV). Horses given acetylpromazine had fast activity (25 to 40 Hz) with medium-to-low voltages (5 to 40 microV). Underlying this activity were slower waveforms (1 to 4 Hz) with medium-to-low voltages (5 to 10 microV). Occasional well-formed spindle activity was observed (10 to 14 Hz, 10 to 50 microV). Acetylpromazine had little effect on the EEG recording, whereas xylazine exerted a substantial effect. All leads were synchronous with lower voltages in the left frontal, right frontal, and transfrontal leads. The alert pattern of a newborn foal was characterized by low frequency (2 to 6 Hz) with medium-to-high voltages (20 to 90 microV).(ABSTRACT TRUNCATED AT 250 WORDS)

Sensory nerve conduction velocity of the dorsal penile nerves of bulls.

Mean conduction velocity of sensory axons of the dorsal penile nerves of clinically normal bulls was determined by recording action potentials evoked by cutaneous stimulation. Locations of stimulating and recording electrodes were standardized. Overall mean +/- SD conduction velocity was 55.1 +/- 5.1 m/s. Mean +/- SD velocity recorded from the distal electrode was 53.3 +/- 4.9 m/s; velocity recorded from the middle electrode was 55.3 +/- 5.0 m/s; and velocity recorded from the proximal electrode was 56.7 +/- 5.1 m/s. Differences among means were not significant. Four bulls had mean conduction velocities of 54.0 m/s and 48.4 m/s before and 3 weeks after castration, respectively.

Ventral rupture of the penile tunica albuginea and urethra distal to the sigmoid flexure in a bull.

A 4-year-old Limousin bull sustained a rupture of the ventral aspect of the tunica albuginea of the penis, 20 cm distal to the distal bend of the sigmoid flexure. The corpus spongiosum penis and urethra apparently ruptured at the same time.

Incarceration of a section of small intestine by remnants of the ductus deferens in steers.

A 13-month-old Charolais steer was examined because of anorexia and weight loss of 1 week's duration. Initially, the steer passed tarry feces for 2 days, but no feces were passed for 4 days before examination. Palpation per rectum disclosed moderate distention of the small intestine and dark tenacious mucus in the rectum. Standing celiotomy was performed through the right paralumbar fossa, and a 60-cm segment of small intestine was found to be entrapped by a fibrous band between the caudal abdominal wall and the pelvic inlet. The band was transected and the intestine was freed. The intestine was judged to be viable and the abdomen was closed. Histologically, the fibrous band consisted of ductus deferens and adnexa; the intestine had become incarcerated through a rent in the mesoductus. Small intestine entrapment through a rent in the right mesoductus was diagnosed in 20 additional steers over a 10-year period. In all cases, the steers had been castrated when weighing more than 100 kg, by manual traction on the testicle and spermatic cord through a scrotal incision. Alternate means of castration that prevent disruption of the abdominal mesoductus may prevent development of this condition.

Mesothelioma in cattle: eight cases (1970-1988)

Over an 8-year period, 8 beef cattle with mesothelioma were admitted to the Auburn University College of Veterinary Medicine and the Louisiana State School of Veterinary Medicine. Diagnosis was confirmed by histologic examination of affected tissues. Five bulls, 1 steer, and 2 cows were affected. Four of the bulls had scrotal swelling; 2 cows and 1 bull had ventral abdominal swelling. The peritoneal cavity was involved in 5 cases, the pleural cavity was affected in 2 cases, and in 2 cases, disease was apparently confined to the vaginal cavity. Of the 8 cattle, 6 died or were euthanatized; only cattle with tumor apparently confined to the vaginal cavity survived.