Fertility of stallion spermatozoa isolated on albumin gradients

Fertility of stallion semen extended with bovine serum albumin (BSA) sucrose extender or cream-gelatin extender was compared. Pregnancy rates were 95% of 47 mares and 86% of 46 mares inseminated with BSA-sucrose and creamgelatin extended semen, respectively. Foaling rates and cycles per conception were not significantly different between treatment groups.Semen from 5 mature stallions was used in an attempt to isolate a population of highly motile spermatozoa. Immediately following collection, samples were evaluated for motility and forward movement. Seven to 10 ml of semen, extended 1:1 with BSA-sucrose extender, were pipetted onto BSA medium separation columns. After 1 hour incubation at 37°C, the top, middle and bottom layers were separately withdrawn from each separation column and pooled, respectively. A marked decrease (P<.001) was noted in the mean motility of spermatozoa in the top layer (35%) as compared to the mean pre-incubation motility (59%). Spermatozoa from middle and bottom layers were significantly (P<.001) more motile (70.6 and 87%) than those from the top layer and pre-incubation samples. Rate of forward movement (RFM) of spermatozoa in lower fractions was higher (P<.001) than RFM of spermatozoa in the top layer. Concentration of spermatozoa decreased (P<.001) as the concentration of BSA in the medium increased.     

Influence of concentration, duration and route of administration of melatonin on reproductive performance of spring-mated polypay and polypay-cross ewes

The effects of exogenous melatonin on reproductive performance of 737 Polypay and Polypay-cross ewes were evaluated during a late March and April breeding period. Different concentrations (2 or 10 mg) routes of administration (fed vs implanted) and durations of administration (20 or 40 d before breeding) were studied. Estrus was synchronized in all ewes using 60 mg medroxyprogesterone acetate (MAP) in a vaginal pessary. Number of mature ewes lambing/ewe present at lambing was increased (P less than .05) nearly 20% by implanting for 40 d with melatonin (75%) or by feeding either 2 (72%) or 10 mg (73%) melatonin for 40 d before spring breeding compared with untreated control ewes (54%) or ewes implanted for only 20 d before breeding (58%). Date of lambing, number of lambs born/ewes lambing and number of lambs born alive/ewe lambing were not altered significantly by treatments. Number of yearling ewes (n = 166 for ewes 1.5 yr old at lambing time) lambing/ewe present at lambing was lower (P less than .01; 26%) than that of mature ewes (n = 381, greater than or equal to 2.0 yr; 68%). We concluded that feeding 2 or 10 mg melatonin or implanting melatonin for 40 d enhanced reproductive performance and effectively overcame the restrictions of seasonality of breeding in mature ewes. In yearling ewes, 10 mg melatonin increased the number of ewes lambing.     

Dorsal Approach to the Caudal Pelvic Canal and Rectum Effect on Normal Dogs

A dorsal surgical approach to the perineal area and rectum was made on 10 healthy, adult dogs. The rectococcygeal muscle was incised and the levator ani and external sphincter muscles were separated to the level of the caudal rectal nerve. All dogs were clinically normal throughout a 3 week postoperative observation period.     

HEMOPOIETIC RESPONSES OF THE CAT TO TOTAL BODY IRRADIATION FOLLOWED BY CHEMOTHERAPY

Cats with lymphosarcoma are affected with rapidly progressive, fatal neoplasia of hemopoietic tissues. The very aggressive nature of this type of neoplasia requires intense therapy, which in most instances is only palliative. A combination of total body irradiation and cytotoxic chemotherapy in four normal cats was followed by similar patterns of leukopenia and throm-bocytopenia in all cats. The radiation protocol and the complications of the transient throm-bocytopenia and leukopenia are discussed and compared with reports of similar efforts in human medicine. The responses from these normal cats were quite similar to those seen in humans undergoing similar therapy. The cat may be considered as a possible model for further radiotherapy research.     

Reproductive toxicity in pseudopregnant and pregnant rats following postimplantational exposure: Effects of the herbicide dinoseb

In Day 10 decidualized pseudopregnant rats fed dinoseb in the diet from Days 6 through 9 of pseudopregnancy, uterine wet weight was reduced in the groups fed 100 to 750 ppm (the highest dose tested). Uterine protein and glycogen concentrations in these animals were reduced in a dose-related manner. In Day 16 pregnant rats, orally fed dinoseb from Days 6 through 15 of pregnancy, placental protein and glycogen concentrations were diminished at 200 ppm and greater. Pregnant rats fed dinoseb (Days 6–16) showed reductions in their embryonic survival rates at 200 ppm and greater. The fetal survival rates at birth, from pregnant rats which were similarly administered dinoseb, were reduced at 150 ppm and greater. Fetal weight of fetuses from dams given dinoseb (200 ppm) was diminished. These results from decidualized pseudopregnant and pregnant rats indicate a toxic role for dinoseb in the intrauterine environment. This toxicity is apparently responsible for a decline in fertility in pregnant rats. Moreover, 200 ppm dinoseb seems to be reproductively critical.     

Efficacy of tulathromycin in the treatment and prevention of natural outbreaks of bovine respiratory disease in European cattle

The efficacy of tulathromycin in the treatment (phase 1) and prevention (phase 2) of bovine respiratory disease (BRD) was evaluated on commercial farms in France, Germany, Italy, and Spain. In phase 1, commingled cattle with clinical BRD were treated with tulathromycin (n = 128) or florfenicol (n = 125) on day 0. Similar percentages of animals showed sustained clinical improvement at day 14 (tulathromycin 83.3% versus florfenicol 81.0%) and had not relapsed by day 60 (tulathromycin 63.3% versus florfenicol 58.4%). In phase 2, healthy in-contact cattle were treated with tulathromycin (n = 492), tilmicosin (n = 494), or saline (n = 265) on day 0. Significantly more (P = .0001) tulathromycin-treated cattle remained healthy to day 14 (92.4%) than tilmicosin-treated (83.7%) or saline-treated (63.7%) cattle, and this was maintained through day 60 (tulathromycin 85.4% versus tilmicosin 75.1% and saline 56.2%). Tulathromycin was highly effective in the treatment and prevention of BRD.     

Prevalence and risk factors associated with outcome of surgical removal of pedunculated lipomas in horses: 102 cases (1987-2002)

OBJECTIVE: To determine the prevalence of pedunculated lipomas and identify risk factors affecting postoperative complications and survival in horses at a veterinary teaching hospital undergoing surgery for colic caused by pedunculated lipomas. DESIGN: Retrospective study. ANIMALS: 102 horses with a diagnosis of pedunculated lipoma. PROCEDURE: Age, breed, weight, and sex of horses with pedunculated lipomas were compared with the total equine hospital population and the population of horses admitted for abdominal surgery during the same period. Follow-up information was obtained by reevaluation or contact with owners via telephone or written request. RESULTS: Prevalence of pedunculated lipomas as a reason for abdominal surgery in horses, compared with the population of horses with and without lipomas admitted for abdominal surgery, was 10%. Castrated male Saddlebred and Arabian horses > 14 years old were identified as being at risk for developing pedunculated lipomas. Postoperative complications were detected in 72% of horses with pedunculated lipomas. Variables associated with low survival rates included surgery before 1992, heart rate > 80 beats/min, abnormal color of abdominal fluid, pale mucous membranes, surgery requiring intestinal resection, and inability to attain a mean arterial pressure > or = 100 mm Hg. Horses undergoing surgery from 1992 to 1996, weighing < 409 kg (900 lb), or requiring jejunojejunal anastomosis had a high survival rate. CONCLUSIONS AND CLINICAL RELEVANCE: Although many of the variables reflected the health of the horse at the time of surgery, results may help veterinarians recognize risk factors associated with development of pedunculated lipomas and better predict the outcome of horses undergoing surgery for colic caused by pedunculated lipomas.     

Use of gyroscopic sensors for objective evaluation of trimming and shoeing to alter time between heel and toe lift-off at end of the stance phase in horses walking and trotting on a treadmill

OBJECTIVE: To determine whether a shoe with an axialcontoured lateral branch would induce greater lateral roll of the forelimb hoof during the time between heel and toe lift-off at end of the stance phase (breakover). Animals-10 adult horses. PROCEDURE: A gyroscopic transducer was placed on the hoof of the right forelimb and connected to a transmitter. Data on hoof angular velocity were collected as each horse walked and trotted on a treadmill before (treatment 1, no trim-no shoe) and after 2 treatments by a farrier (treatment 2, trim-standard shoe; and treatment 3, trim-contoured shoe). Data were converted to hoof angles by mathematical integration. Breakover duration was divided into 4 segments, and hoof angles in 3 planes (pitch, roll, and yaw) were calculated at the end of each segment. Multivariable ANOVA was performed to detect differences among treatments and gaits. RESULTS: Trimming and shoeing with a shoe with contoured lateral branches induced greater mean lateral roll to the hoof of 3.2 degrees and 2.5 degrees during the first half of breakover when trotting, compared with values for no trim-no shoe and trim-standard shoe, respectively. This effect dissipated during the second half of breakover. When horses walked, lateral roll during breakover was not significantly enhanced by use of this shoe. CONCLUSIONS AND CLINICAL RELEVANCE: A shoe with an axial-contoured lateral branch induced greater lateral roll during breakover in trotting horses, but change in orientation of the hoof was small and limited to the first half of breakover.