Synchronization of estrus and fertility in beef cattle with two injections of buserelin and prostaglandin

Postpartum beef cows and heifers in Group 1 received 8 mug of buserelin on Day 0 (the beginning of the experiment) and 500 microg of cloprostenol (PGF) on Day 6 (GnRH I, n=54). In Group 2 (GnRH II, n=54), the females were injected with buserelin on Day 0 (8 microg) and Day 3 (4 microg), and PGF on Day 6 and Day 9 for females not detected in estrus previously. Animals were bred by AI 12 hours after the onset of estrus. Blood samples were collected on Day -11 and Day 0 to assess cyclicity and on Day 3 and Days 6 to 12 to examine luteal activity. Progesterone levels did not differ between the 2 groups between Days 0 to 9. In both groups, the proportion of spontaneous estruses from Days 0 to 6 was reduced. Precision of estrus was higher (P<0.005) in the GnRH II group than in the GnRH I group of cows that were detected in estrus between Days 6 and 9. The synchronization rate, interval to estrus, pregnancy and conception rates were similar in GnRH I and GnRH II groups. The conception rate and interval to estrus were similar in cyclic and acyclic cows. Increasing the number of buserelin injections enhanced the precision of estrus, but not the conception rate, without any detrimental effect on luteal activity and induced more estruses in postpartum acyclic beef cattle.

Influence of an agonist of gonadotropin-releasing hormone (buserelin) on estrus synchronization and fertility in beef cows

The objective of this experiment was to determine the effect of sequential treatment with buserelin (a GnRH agonist) and cloprostenol (a prostaglandin F2 alpha analog) on estrous response and fertility in beef cattle with different ovarian conditions. On d 0 (1st d of treatment), the control group (n = 52, 10 heifers and 42 cows) and the GnRH group (n = 48, 10 heifers and 38 cows) received 2 mL of saline or 2 mL of Receptal (8 micrograms of buserelin), respectively. On d 6, all cows that had not exhibited spontaneous estrus were given i.m. 500 micrograms of cloprostenol (PGF). Ultrasonography on d 0 and assays of progesterone in blood on d -11, 0, and 6 were used to identify follicular and luteal status of animals. Cattle were observed for estrus from d 0 to 10. Cows showing estrus were bred artificially 12 h after onset of estrus. Over the 10-d period, the number of cows detected in estrus and pregnancy and conception rates were identical for the two groups. However, between d 0 and 6, the proportion of cows exhibiting estrus was lower (P less than .01) in the GnRH group than in the control group. Between d 6 and 10, the synchronization rate and precision of estrus were greater (P less than .01) in the buserelin-treated group than in the control group. Conception rate and interval from PGF injection to onset of estrus were not different between the two treatment groups. Presence of a large (greater than 10 mm) follicle on d 0 enhanced synchronization rate and precision of estrus.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of Synchro-Mate B and prostaglandin F2α on estrus synchronization and fertility in beef cattle

The efficiency and precision of estrus synchronization and fertility were evaluated after prostaglandin F2α (PGF) treatment with or without pretreatment with Synchro-Mate B (SMB) in beef cattle. In the treatment group (SMB-PGF, n = 109), postpartum suckled (n = 53), and nonsuckled (n = 32) cows and virgin heifers (n = 24) received SMB for 9 d and PGF 72 h before implant withdrawal. In the control group (Control, n = 111), postpartum suckled (n = 51), and nonsuckled (n = 36) cows and virgin heifers (n = 24) were observed for estrus and bred at spontaneous estrus over a 6-d period. Those not detected in estrus were then injected with PGF and bred at induced estrus over an additional 6-d period. Synchronization rate at induced estrus was higher (95.4 vs. 84.2%, P < 0.01) and time interval from induction to onset of estrus was shorter (37.0 ± 2.1 h vs. 56.7 ± 2.8 h, P < 0.01) in the SMB-PGF group than after PGF in the Control group. Whether the time around the mean interval to estrus (precision) was ± 6, ± 12, ± 18 or ± 24 h, the synchronization rate was always higher (P < 0.01) in the SMB-PGF than in the Control group. Heifers and cows in both groups had similar estrus synchronization rates and mean intervals to estrus. Suckled and nonsuckled cows behaved similarly in their estrus response within the SMB-PGF group but not in the Control group. Our results indicate that administration of PGF 72 h before SMB implant withdrawal could be a very efficient and precise synchronization method without a negative effect on fertility in beef cattle. Key words: Estrus synchronization, beef cattle, Synchro-Mate B, prostaglandin F2α

Effect of vitamin E and selenium supplementation on some immune parameters following vaccination against brucellosis in cattle

Twenty-four 7-mo-old beef heifers (Charolais Simmental cross), weighing 213 kg, were used to determine the effect of vitamin E (VitE) and(or) selenium (Se) supplementation on the humoral response to a standard dose of Brucella abortus strain 19 vaccine and on the levels of naturally occurring immunoglobulins (Ig) to several antigens. The treatments were as follows: Group 1, no supplement; Group 2, supplementation with 6 g of elemental Se; Group 3, supplementation with 1,400 IU/d of VitE; and Group 4, Se and VitE supplements combined. There were no significant differences in anti-B. abortus IgG1, IgG2, or IgM antibody levels due to Se, VitE or Se/VitE treatments; the concentrations of IgA antibody were too low to be measured with the ELISA test used. Statistical analysis revealed that the levels of total and IgM natural antibody to Salmonella typhimurium were higher in Group 3. Perhaps VitE supplementation given in conjunction with B. abortus vaccine enhanced the production of antibody to S. typhimurium in several animals whose humoral system had been activated by previous exposure to this organism.

Validation of a non-invasive device to measure intracavernous pressure as an index of penile rigidity

Many authors agree with the importance of developing devices to measure penile rigidity. The devices that have been developed over recent years have defined penile rigidity in terms of stiffness. Penile stiffness, however, is believed to result from an increase in intracavernous pressure. The device presented here was therefore designed to estimate intracavernous pressure, rather than penile stiffness, as an index of penile rigidity. Validation of the penile cuff device was achieved by simultaneously recording penile cuff pressure and intracavernous pressure on patients undergoing artificial erections. The results showed a linear relationship and highly positive correlation coefficients between the 2 measures. The results demonstrate that the penile cuff may be used to estimate intracavernous pressure as an index of penile rigidity. The findings are discussed in terms of the possible applications of the cuff as a clinical tool to measure both penile tumescence and penile rigidity.

Type of dietary lipids exerts a major influence on the secretory activity of the exocrine pancreas: medium-term studies

A possible influence of the type of dietary lipids on the pancreas exocrine function was tested on rats. For this purpose, four groups of rats were fed on different diets comprising 5% of different types of lipids: fish oil, evening primose oil, hydrogenated beef tallow, and a mixture of fish oil and evening primose oil. After a 6 week feeding period, the secretory activity of the pancreas was measured. Under resting conditions, rats fed hydrogenated beef tallow release different proportions of amylase, lipase, and serine proteases as compared to rats fed unsaturated lipids. In stimulated conditions, there was no significant difference in the relative proportions of enzymes secreted by the pancreas among the different groups of rats but the secretory response to cerulein stimulation from rats fed saturated lipids was increased by more than 40%. These results demonstrate that the type of dietary lipids exerts a major influence on the secretory activity of the pancreas.

Influence of steroids on the exocrine pancreas: presence of laminated bodies in the acinar lumen following castration and adrenalectomy

The influences of combined adrenalectomy and castration and of a replacement therapy with estradiol and glucocorticoids were examined in the rat pancreas. At the light microscope level, the surgical treatment changed the overall shape of the acini and caused widening of intralobular and interlobular spaces as well as partial depletion of zymogen granules. A significant reduction of the acinar lumen size was observed in castrated-adrenalectomized (CasX-AdreX) animals. This could be reversed by a replacement therapy with glucocorticoids. Moreover, triamcinolone even caused a significant lumen enlargement as compared to sham-operated animals. Such an enlargement was not observed with dexamethasone. Both these glucocorticoids caused an increase in zymogen granule content of the acinar cell. At the ultrastructural level, hitherto undescribed type of precipitates was observed in the acinar lumen of CasX-AdreX rats. Precipitates that exhibited a laminated aspect were identified as luminal laminated bodies. The latter could have some interest from the etiological point of view of certain pancreatic diseases, such as cystic fibrosis and pancreatitis. Replacement therapy with estradiol did not affect the frequency of these precipitates, but glucocorticoid had a significantly inhibitory effect. From our observation, it is clear that some steroid exert a profound influence on the acinar cell and that a replacement therapy with glucocorticoids or estradiol do not totally restore the normal aspect of the pancreas acinar tissue. It suggests that some unknown factors from adrenals or testis are still required in addition to glucocorticoids and estrogens for the maintenance of the structural integrity of the gland.

Bulbocavernosus reflex: its validity as a diagnostic test of neurogenic impotence

Measurement of the bulbocavernosus reflex is used widely to diagnose underlying neurogenic disorders in erectile dysfunction. A prolonged bulbocavernosus reflex latency (that is more than 45 msec.) or the absence of a reflex response of the bulbocavernosus muscles during electrical stimulation of the glans penis is considered a sign of neurological disease. Since only a few experimental studies have been performed in man related to the neurophysiological mechanism of erection, and since the results of these studies were contradictory the diagnostic validity of bulbocavernosus reflex measurement was reassessed. We determine whether men with abnormal bulbocavernosus reflex latencies have concomitant organic erectile dysfunction as confirmed by nocturnal plethysmographic and rigidity recordings. The bulbocavernosus reflex was recorded in 90 subjects and 19 had abnormal bulbocavernosus reflex latencies. Of these 19 subjects 8 had normal nocturnal erections, thus, confirming a diagnosis of psychogenic impotence. These results cast some doubts on the validity of bulbocavernosus reflex measurement for the diagnosis of organic erectile dysfunction due to a neurological disease.

Reflex contractions of the ischiocavernosus muscles following electrical and pressure stimulations

In a previous study, we have demonstrated that voluntary muscular contractions of the ischiocavernosus muscles (IC) correlate with changes in intracavernous pressure and, therefore, with penile rigidity. The purpose of our current research project was to verify whether reflex contractions of the IC muscles exist and under what conditions. Our results confirm that reflex contractions occur following electrical or pressure stimulations. Following electrical stimulation, the mean latency of the reflex contractions was 67.5 ms for the IC muscles and 34.9 ms for the bulbocavernosus muscles (BC). Following pressure stimulation, the pressure threshold necessary to elicit contractions of the IC muscles varied between 18.2 mm. Hg and 34.8 mm. Hg. We also observed that pressure variation (increase and decrease) rather than a relatively constant pressure is necessary to produce this reflex response. We interpret these results to suggest that pressure stimulations on the glans penis during coitus contribute to the erectile process and, specifically, to the increase in intracavernous pressure. These findings suggest the possibility of a physiotherapeutic management for patients with penile rigidity problems.

Relationship between perineal muscle contractions, penile tumescence, and penile rigidity during nocturnal erections

The mechanism of penile erection and erectile dysfunction is still unclear and widely debated. The role of the perineal muscles in the erectile process, especially in changes in intracavernous pressure, is increasingly being studied on the hypothesis that perineal muscular contractions are essential to full penile rigidity. In a previous investigation we studied the correlation between voluntary perineal muscle contractions and intracavernous pressure during artificially induced erections. The purpose of the current study was to examine whether under normal conditions of nocturnal erection a similar relationship exists between the electromyographic activities of perineal muscles and changes in penile rigidity. Nocturnal penile recordings were made of seven volunteers with psychogenic erectile dysfunctions. During nocturnal erections simultaneous computerized recordings were made of penile tumescence, penile rigidity, and electromyographic activities of perineal muscles. The peaks for the three variables were reached simultaneously. The results of this study suggest the existence of two different physiologic phases: a vascular phase and a muscular phase. Furthermore, in cases of dysfunctions, specific diagnostic assessment and therapeutic management will be required for both penile tumescence and penile rigidity.

Effect of intraruminally administered, selenium soluble-glass boluses on selenium status in cows and their calves

Intraruminal selenium soluble-glass boluses were administered by balling gun to 65 of 125 crossbred beef cows (Shorthorn X Charolais) during the last trimester of pregnancy. Elevated (P less than .01) whole blood glutathione peroxidase (GSH-Px) concentrations were observed monthly for the next 10 mo following initiation of treatment, reaching the maximum magnitude (263 vs 41) at the fourth month. Monthly milk samples showed elevated selenium concentrations (P less than .01, April through August; P less than .05 through September). Intraruminal, selenium soluble-glass bolus administration to gestating cows was highly effective in raising the selenium status of their progeny. Although the control calves were in low-selenium status, no acute cases of nutritional muscular dystrophy were observed during this experiment.

The Successful Management of Leptospirosa hardjo Infection in a Beef Herd in Northern Ontario

Abortion, premature calving, hemolytic anemia and fatal hematuria were associated with high levels (titer > 10(-4)) of antibody to Leptospira interrogans serovar hardjo and with isolation of hardjo in a herd of 265 beef cattle in the Great Clay Belt of northern Ontario. This herd was bred by artificial insemination, after heat detection by vasectomized bulls. The antibody prevalence rate in the herd was 54 to 60% over a five year period. The rate tended to reach 100% by age three years and to be below 5% in yearlings, which were raised in isolation from older cattle. Hardjo was isolated from the urine of a cow that aborted in the eighth month of pregnancy, and from kidneys of yearling steers which had been exposed to an older cow. Maternal antibody levels in calves paralleled those in their dams, protecting calves while they were being naturally exposed to infection, thus contributing to the achievement of balance between host and parasite. A controlled vaccination trial was conducted in 50 initially seronegative yearling steers and heifers. Serological response to vaccine was limited to a maximum agglutinin titer of 10(-2) in 8% of vaccinated cattle. Vaccination reduced the infection rate from 86% in the controls to 46% in the treated group, indirectly reducing the number of calves for which colostral antibody against hardjo would be available. A vaccination program was not implemented in the herd. Hardjo infection appeared to die out over a period of six years following the initial five year study period, with antibody prevalence falling from 60% to 0.7% and reactors persisting only in two eight year old cows. Decline in infection was coincident with changes in management which protected heifers from exposure to infection until their third pregnancy, and which probably lowered the reservoir of infection by increased culling from older age classes.

Induction of Parturition in the Cow using Cloprostenol and Dexamethasone in Combination

Two experiments were designed to test the hypothesis that induction of parturition in the cow would be more predictable with the simultaneous use of a combination of cloprostenol and dexamethasone than with either hormone used alone.In experiment I all 19 beef cows treated with 500 mug cloprostenol and 25 mg dexamethasone in combination calved within 72 hours whereas dexamethasone (n = 19) or cloprostenol (n = 16) treatments alone each resulted in two induction failures. In those cows successfully induced, the mean interval from treatment to birth was 34.6 +/- 1.4 hours for the cloprostenol plus dexamethasone group, 43.3 +/- 2.4 hours for the dexamethasone group and 44.9 +/- 2.1 hours for the cloprostenol group. Control cows (n = 15) did not calve during the first 72 hours after treatment with saline. The incidence of retained placenta ranged from 19 to 53% in induced groups whereas placentae were not retained by cows in the control group.In experiment II all 30 beef cows in the cloprostenol plus dexamethasone group calved within the 72 hour limit, with a mean interval of 39.1 +/- 1.0 hours. Twenty-six of 31 cows calved within 72 hours with a mean interval of 51.9 +/- 3.4 hours after a single injection of cloprostenol and 29 of 33 cows calved within 72 hours with a mean interval of 52.6 +/- 3.3 hours after two injections of cloprostenol, 12 hours apart. Five of 34 control cows calved within 72 hours of time of treatment. The incidence of retained placenta was again high in induced cows. Results indicate that the simultaneous administration of cloprostenol and dexamethasone does constitute a safe, reliable and effective method of inducing parturition in the cow.

Intraruminal selenium pellet for control of nutritional muscular dystrophy in cattle

Administration of an intraruminal selenium pellet to a herd of pregnant crossbred cows was evaluated for controlling nutritional muscular dystrophy in an area of northern Ontario with numerous losses of calves. Cows were winter-fed grass silage. Each spring cows and calves went to pasture. A single dose of intraruminal selenium pellet was given to 80 cows during last 3 mo of pregnancy the 1st yr only while the remaining 80 were controls. During 3 consecutive years, efficacy of intraruminal selenium pellet was evaluated by selenium status of recipient cows and their offspring as well by the incidence of nutritional muscular dystrophy. Selenium in plasma, as well as glutathione peroxidase in whole blood, in the cows administered intraruminal selenium pellet, were higher than in the deficient controls. Ten months after intraruminal selenium pellet treatment, selenium in tissues was higher in treated than in untreated cows but within normal ranges. Before cows were turned out to pasture the 1st yr, milk selenium of intraruminal selenium pellet cows were higher than controls. This technique of selenium dosing was effective in raising the selenium status of the progeny. There was no evidence of nutritional muscular dystrophy in calves from selenium-dosed cows, while 15 calves born of the untreated cows showed clinical symptoms of nutritional muscular dystrophy.

[Early and late outcome after aortocoronary bypass: experience in 500 cases]

Between 1971 and 1976, 500 patients underwent aortocoronary bypass surgery. There were 15 operative deaths (3%) and the total frequency of perioperative infarction was 7%. The operative mortality was 7.4% in unstable angina, as compared with 1.1% in stable angina (P less than 0.01). The proportion of grafts patent at 2 weeks was 92% and at 18 months 87.6%. Postoperative follow-up was complete for 99% of the patients. There were 15 late deaths (3%) and the rates of survival at 2 and 4 years were 94.4% and 92.1% respectively. The actuarial curve of survival after surgery was not significantly different from that of the general population. After a mean follow-up of 27 months 73% of the patients were completely free of angina and 19% were markedly improved. The rate of recurrence of angina averaged 10% per year and the annual infarction rate was 0.7%. Fourteen patients (3%) underwent reoperation during the follow-up period. Thus, coronary revascularization surgery offers effective and sustained relief of incapacitating angina and might also improve survival if the operative mortality is low.

You are what you wear

Uniforms and professional roles are frequently tied in the minds of both staff and patient, so it may be advisable to return to greater use of uniforms by hospital professional staffs.