Effects of pregnant mare's serum gonadotropin treatment on follicular populations and ovulation rates in prepuberal gilts with two morphologically different ovarian types.

Two experiments were conducted to determine the effects of pregnant mare's serum gonadotropin (PMSG) on follicular populations and ovulation rates in prepuberal gilts with grape-type (GT) and honeycomb-type (HT) ovaries. The follicular populations were determined at 170 d of age (d 0) and 19 d after PMSG (d 19). In Exp. 1, the mean number of macroscopic follicles of Classes 2 and 3 was greater (P less than .05) in GT (n = 11) than in HT (n = 32) ovaries at d 0, whereas the mean number of those of Class 1 was greater (P less than .05) in HT ovaries. At d 19, no difference was observed between the two ovarian types for any class of follicles. The PMSG-induced ovulation rates were comparable between the two ovarian types (8.3 vs 7.9, GT vs HT, respectively; P greater than .10). In Exp. 2, the microscopic follicular populations were determined on right and left ovaries removed, respectively, on d 0 and 19. At d 0, GT ovaries (n = 5) contained a greater number of Class 5 nonatretic (P less than .01) and atretic (P less than .02) follicles than did HT ovaries (n = 5), whereas at d 19 the mean number was not statistically different between the two ovarian types (P greater than .10). In contrast, gilts with HT ovaries contained a greater (P less than .01) number of Class 4 atretic follicles than gilts with GT ovaries at d 0, whereas at d 19 the mean number was not statistically different between the two ovarian types (P greater than .10).(ABSTRACT TRUNCATED AT 250 WORDS)     

Timing of induction of ovulation in mares treated with Ovuplant or Chorulon

Reliable induction of timed ovulation is an important managerial tool in any horse-breeding operation. Not only does breeding close to ovulation increase pregnancy rates when using cooled, frozen, or poor-quality semen, but it also reduces the number of inseminations needed per cycle, resulting in a more efficient breeding program. To better predict ovulation time in the long estrus period of the mare, one could increase the frequency of transrectal palpations and ultrasounds and/or implement hormonal therapies to induce ovulations. However, previous studies have been unclear on the exact timing of ovulation of mares treated with human chorionic gonadotropin (Chorulon, Intervet Inc, Millsboro, DE) or deslorelin acetate (Ovuplant, Pharmacia and UpJohn Co, Kalamazoo, MI). This study was designed to determine the timing of ovulation after Ovuplant or Chorulon treatment in normal cycling mares presented to the veterinary clinic. In addition, the pregnancy rates were determined for mares bred when a single insemination, using frozen or chilled semen, was performed at a fixed time (36 hours) after Ovuplant or Chorulon treatment. Thirty-two mares were given a subcutaneous injection of 7.5 mg of prostaglandin F2α (Lutlyse, Ft Dodge Animal Health, Ft Dodge, IA) 5 days after the last ovulation and were examined every 48 hours until estrus was detected based on a dominant follicle and the presence of endometrial edema as determined by ultrasonographic examination. Group 1 (N = 12) was treated intravenously with 2,500 units of Chorulon, and group 2 (N = 20) was treated subcutaneously with Ovuplant as soon as mares were determined to be in estrus. Once treated all mares were examined by rectal palpation and ultrasound at 0, 12, 24, 28, 30, 32, 34, 36, 38, 40, 42, 44, 48, 60, 72, 84, 96, hours or until ovulation was detected. Ovulation rate in response to Chorulon was 83.3% at 48 hours, 91.6% at 72 hours, and 100% at 96 hours. All of the mares in the Ovuplant-treated group had ovulated by 48 hours. Chi-square analysis of the data showed a significant (P < .01) variation in the distribution of ovulation times between mares treated with Chorulon and mares treated with Ovuplant. This study provides enough evidence to support the hypothesis that timing of ovulation is a more reliable event in mares treated with Ovuplant compared with those treated with Chorulon.     

Ovarian morphological conditions and the effect of injection of human chorionic gonadotropin on ovulation rates in prepuberal gilts with two morphologically different ovarian types

The purpose of this experiment was to determine the ovulation rate after treatment with human chorionic gonadotropin (hCG) in two groups of gilts characterized by different ovarian morphology: grape-type (GT; n = 11) and honeycomb-type (HT; n = 7). At 170 d of age (d 0), gilts were examined by laparoscopy and ovarian type was determined by the distribution of macroscopic follicles present on the ovarian surface. Five to ten minutes after surgery, each gilt received a single injection (i.m.) of 750 IU of hCG. At d 0, GT ovaries had a greater number of large follicles (greater than or equal to 6 mm) than HT ovaries (10.0 +/- .5 vs 2.6 +/- .3; P less than .05), whereas HT ovaries had more small follicles (1 to 3 mm; HT: 42.3 +/- .8 vs GT: 26.7 +/- .9; P less than .05) and total follicles (HT: 59.4 +/- 2.3 vs GT: 52.2 +/- 1.5; P less than .05), although numbers of medium follicles (4 to 5 mm) were similar (GT: 15.6 +/- .8 vs HT: 14.6 +/- 1.7; P greater than .10). Number of induced corpora lutea (CL) per ovary was greater (P less than .05) in gilts with GT ovaries (10.59 +/- 2.9 CL) than in gilts with HT ovaries (5.21 +/- .66 CL). Total weight of luteal tissue (LT) per ovary and serum progesterone concentrations 8 d after induction of ovulation were greater in GT gilts than in HT gilts (GT: 6.37 +/- 1.09 g vs HT: 3.31 +/- .49 g for LT, P less than .05; GT: 21.08 +/- 4.76 ng/ml vs HT: 13.40 +/- 2.05 ng/ml for progesterone, P less than .07).(ABSTRACT TRUNCATED AT 250 WORDS)     

A comparison of predictions made by three simulation models of foot-and-mouth disease

AIMS: To describe results of a relative validation exercise using the three simulation models of foot-and-mouth disease (FMD) in use by the quadrilateral countries (QUADS; Australia, Canada, New Zealand, and United States of America; USA). METHODS: A hypothetical population of farms was constructed and, following the introduction of an FMD-like disease into a single farm, spread of disease was simulated using each of the three FMD simulation models used by the QUADS countries. A series of 11 scenarios was developed to systematically evaluate the key processes of disease transmission and control used by each of the three models. The predicted number of infected units and the size of predicted outbreak areas for each scenario and each model were compared using the Kruskal-Wallis test. Agreement among the three models in terms of geographical areas predicted to become infected were quantified using Fleiss' Kappa statistic. RESULTS: Although there were statistically significant differences in model outputs in terms of the numbers of units predicted to become infected, the temporal onset of infection throughout the simulation period, and the spatial distribution of infected units, these differences were generally small and would have resulted in the same (or similar) management decisions being adopted in each case. CONCLUSIONS: Agreement among the three models in terms of the numbers of premises predicted to become infected, the temporal onset of infection throughout the simulation period, and the spatial distribution of infected premises provides evidence that each of the model developers are consistent in their approach to simulating the spread of disease throughout a population of susceptible individuals. This consistency implies that the assumptions taken by each development team are appropriate, which in turn serves to increase end-user confidence in model predictions. CLINICAL RELEVANCE: Relative validation is one of a number of steps that can be undertaken to increase end-user confidence in predictions made by infectious disease models.     

Preliminary study of the factors that determine nutrient composition of bean-cooking broth

Bean cooking broth or liquor is a food preparation that results from cooking beans under a number of circumstances. This preparation is the first bean-derived food provided by mothers to their children as young as two months of age. Because of this, bean cooking plays an important nutritional role that must be evaluated. The present study attempted to evaluate, through a number of experiments, the significance of cultivars, method of cooking — either under atmospheric or vapor pressure — cooking time, salt addition, soaking and grain size on bean broth content. This was established mainly by solid content, and also by protein, ash and tannin content in different experiments.The results indicated that cultivars, but mainly cooking and soaking time, cooking method, and seed size were all important factors in determining brean-broth composition, mainly of total solids. Protein and ash contents were less affected. Prolonged cooking of the bean-broth resulted in a decrease in polyphenolic content. The relative nutritional importance of the above factors should be studied further.INCAP Publication I-1511.     

Analyzing genotype by environment interaction in potato using yield-stability index

The plant breeding program of the National University of Colombia carried out 10 potato regional trials during 1998 and 1999 to evaluate 15 promising potato clones (Solanum tuberosum ssp.andigena). Genotype by environment interaction was analyzed using Kang’s methodology, which links yield performance and phenotypic stability. A MACRO was implemented using the SAS system to obtain yield-stability indices. Shukla’s variance was estimated by restricted maximum likelihood (REML), which allowed handling unbalanced data for both genotypes and replicates. In addition, a multivariate analysis methodology was developed, based on the yield-stability index. This methodology is useful when tuber yield is categorized by size and quality, which is usual in Colombian potato harvests.     

When, how and why to perform a double ballooning technique for dogs with valvular pulmonic stenosis

Pulmonic valvuloplasty is a well-established method for the treatment of valvular pulmonic stenosis in people and dogs. In dogs, pulmonic valvuloplasty has been restricted to a single balloon; however, the simultaneous use of two balloons is common in pediatric cardiology. The use of two balloons provides an alternative to the use of a single large balloon in small dogs with a pulmonic anulus size that requires a large dilation catheter and large diameter introducer. Moreover, double balloon valvuloplasty permits dilation in large dogs with large pulmonic anulus sizes for which standard dilation catheters are not available. This report outlines the materials required, describes the technique, gives the advantages and disadvantages encountered when performing percutaneous double balloon valvuloplasty and provides some ‘tips’ for a successful outcome.     

Echocardiographic evaluation of dogs receiving 1:1 thiopental/propofol in a clinical setting

The purpose of this study was to compare the echocardiographic Doppler blood pressure and heart rate effects of 1:1 thiopental/propofol with thiopental and propofol, when used as anesthesia‐induction agents. Seven healthy dogs (six Beagles and one Pembroke Welsh Corgi), ranging in age from 1 to 9 years and weighing 14.2 ± 2.4 kg (mean ± SD), were used during the study. In a cross‐over study design with a minimum drug interval of 3 days, each dog received propofol, thiopental, or a mixture of propofol–thiopental IV until each dog received all the three anesthetic agents. An initial dose (propofol 4.9 ± 0.8 mg kg^?1; thiopental 12.9 ± 2.4 mg kg^?1; propofol–thiopental 2.3 ± 0.3 mg kg^?1 (P)?5.7 ± 0.8 mg kg^?1 (T)) of each anesthetic agent was titrated IV until intubation was accomplished. Echocardiographic Doppler blood pressure and heart rate variables were recorded prior to anesthesia and at 1, 5, and 10 minutes after induction of anesthesia. anova and the Bonferroni's t‐test were used to evaluate the groups for differences. Alpha was <0.05. There was no significant effect of treatment on systolic or diastolic ventricular wall thickness, septal thickness, left atrial diameter, or systolic left ventricular diameter. There was a tendency for diastolic left ventricular diameter to decrease over time. There was a tendency for heart rate to increase with a significant difference at the 10‐minute time period between propofol (109 ± 26 beats minute^?1) and thiopental (129 ± 23 beats minute^?1). At the 10‐minute recording period, heart rate following the propofol/thiopental mixture (110 ± 34 beats minute^?1) was closer to that following propofol than to that following thiopental. With all induction agents, indirect blood pressure tended to decrease over time (p = 0.005); however, there was no difference between the groups. The changes observed were not considered to be of clinical significance. The propofol/thiopental mixture produces similar changes in echocardiographic variables when compared to propofol or thiopental, and could be substituted for propofol for induction of anesthesia in dogs.