Effects of zeranol implants on post-castration response in calves

SUMMARY Suckling and yearling calves were surgically castrated and one half of each group implanted with 36 mg zeranol at time of castration. Both treated and control cattle of each class were maintained as a group and evaluated for swelling of the scrotum, inflammation and healing, plasma prostaglandin levels and weight gain. Swelling and inflammation of the scrotum were less in treated suckling calves than in controls at both 7 and 14 d after castration, though this difference was not statistically significant. In yearlings at 7 d after castration, treated cattle had more swelling than controls; however at 14 d, treated cattle had less swelling and inflammation with only one treated yearling having an open scrotal wound versus 6 (P <.03) in the control group. Plasma prostaglandin levels as indicated by plasma malondialdehyde increased from d 0 to 14; however no significant treatment differences were observed for either age group. Suckling calves treated with zeranol gained 9.79 kg more (P <.03) than non-treated calves during the 97 d of trial while the yearlings treated with zeranol gained 16.78 kg more (P <.01) than controls during 102 d. It is concluded from the increased growth and reduced scrotal swelling and inflammation in treated cattle that zeranol implantation could possibly have a beneficial effect in improving the healing process after castration.     

Results of Transsphenoidal Hypophysectomy in 52 Dogs With Pituitary-Dependent Hyperadrenocorticism

Objective —To evaluate microsurgical transsphenoidal hypophysectomy in dogs with pituitary-dependent hyperadrenocorticism (PDH). Study Design —Prospective study to evaluate the results (survival and disease-free interval, remission, recurrence) and complications of microsurgical transsphenoidal hypophysectomy by clinical follow-up, computed tomography (CT), and urinary corticoid-to-creatinine (C/C) ratios in dogs with PDH. The effect of surgical experience was investigated by comparing results of hypophysectomy cases 1 through 26 and 27 through 52. Animals or Sample Population—52 dogs with PDH. Results —Preoperative CT enabled accurate assessment of pituitary size (24 nonenlarged and 28 enlarged) and localization relative to intraoperative anatomic landmarks. Treatment failures included procedure-related mortalities (five dogs) and incomplete hypophysectomies (four dogs). The 1-year estimated survival rate was 84% (95% confidence interval [CI], 71% to 92%). The 2-year estimated survival rate was 80% (95% CI, 65% to 90%). In 43 dogs, the hyperadrenocorticism went into remission. Hyperadrenocorticism recurred in five dogs. The 1-year estimated relapse-free fraction was 92% (95% CI, 76% to 97%). The main complications were transient, mild, postoperative hypernatremia; transient reduction or cessation of tear production (25 eyes in 18 dogs); permanent (five dogs) or prolonged (nine dogs) diabetes insipidus; and secondary hypothyroidism. Normal tear production had resumed in all but one case after a median period of 10 weeks. In the second case series (27 through 52), the hospitalization period was shorter, the number of dry eyes fewer, the survival fraction greater, and the postoperative mortality lower than in the first series. In 15 dogs in which remission was obtained, postoperative CT images suggested the presence of small pituitary remnants; in 1 of these, hyperadrenocorticism recurred. In 46 dogs, the histological diagnosis was pituitary adenoma. Conclusions —Microsurgical transsphenoidal hypophysectomy in dogs with PDH is an effective method of treatment in specialized veterinary institutions having access to advanced pituitary imaging techniques. Postoperative CT findings do not correlate well with remission or subsequent recurrence of hyperadrenocorticism. Clinical Relevance —The neurosurgeon performing hypophysectomies must master a learning curve and must be familiar with the most frequent complications of the operation to recognize them as early as possible and to treat them immediately and effectively. Urinary C/C ratios are sensitive indicators for the assessment of remission and recurrence of hyperadrenocorticism.     

Triacontanol: a new naturally occurring plant growth regulator

Alfalfa meal and chloroform extracts of the meal have increased the growth and yield of several plant species. A crystalline substance isolated from the active fraction of alfalfa meal increased the dry weight and water uptake of rice seedlings when sprayed on the foliage or applied in nutrient culture. The substance was identified as triacontanol by mass spectrometry. Sprays containing this compound also increased the growth of corn, and barley grown in soil. Authentic triacontanol produced a similar response over a wide range of concentrations on rice grown in nutrient cultures and tomatoes grown in soil.     

A coherent signature of anthropogenic nitrogen deposition to remote watersheds of the Northern Hemisphere

Humans have more than doubled the amount of reactive nitrogen (Nr) added to the biosphere, yet most of what is known about its accumulation and ecological effects is derived from studies of heavily populated regions. Nitrogen (N) stable isotope ratios ((15)N:(14)N) in dated sediments from 25 remote Northern Hemisphere lakes show a coherent signal of an isotopically distinct source of N to ecosystems beginning in 1895 ± 10 years (±1 standard deviation). Initial shifts in N isotope composition recorded in lake sediments coincide with anthropogenic CO(2) emissions but accelerate with widespread industrial Nr production during the past half century. Although current atmospheric Nr deposition rates in remote regions are relatively low, anthropogenic N has probably influenced watershed N budgets across the Northern Hemisphere for over a century.     

Fixed‐time post‐cervical artificial insemination in weaned sows following buserelin use combined with/without eCG

Fixed‐time post‐cervical artificial insemination (FTAI) drastically reduces labour requirements and increases the use of boars with higher genetic merit. This study evaluated the efficiency of eCG administration combined with/without the GnRH agonist buserelin for the induction and synchronization of ovulation in weaned sows submitted to FTAI. The sows were allocated into three groups. In the control group, the first artificial insemination was performed at the onset of oestrus and repeated every 24 hr. In the eCG+GnRH group, sows received 600 IU eCG at weaning and buserelin (10 μg) after 86–89 hr of eCG, and in the GnRH group, sows received only buserelin after 86–89 hr of weaning. The hormone‐treated sows received a single FTAI after 30–33 hr of buserelin application. All the sows were inseminated with homospermic doses (1.5 × 10⁹ sperm cells/50 ml). The interval between weaning and ovulation was shorter (p < .05) in the eCG+GnRH (133.3 hr) and GnRH (135.9 hr) groups than the control (141.5 hr) group. In the eCG+GnRH group, the sows ovulated earlier (p < .05) than those in the GnRH group (44.5 vs. 48.2 hr after buserelin administration). The reproductive performance of GnRH sows was not compromised when only sows exhibiting oestrus at the time of insemination were considered, but lower farrowing rate and smaller litter size were observed in eCG+GnRH sows. The reproductive performance of eCG+GnRH sows was primarily compromised because the insemination was performed outside the optimal time relative to ovulation; therefore, it is advisable to inseminate them before 116–122 hr after weaning.     

Fibrin–alginate hydrogel supports steroidogenesis,in vitro maturation of oocytes and parthenotes production from caprine preantral follicles cultured in group

This study aimed to establish a culture system that improves the in vitro development of caprine preantral follicles. In a first experiment, follicles were encapsulated as a single unit per bead and cultured singly or in groups or with five follicles in the same alginate (ALG) bead for 18 days. In a subsequent experiment, the “five follicles per bead” design was chosen to culture in ALG, fibrin–alginate (FA) or hyaluronate (HA) for 18 days. In a third experiment, we chose the five follicles per bead in FA to culture for 30 days. The culture set‐up of five follicles per ALG bead increased antrum formation and follicle diameter compared to the other culture designs (p < .05). Moreover, under this condition, 44.44% of the oocytes from in vitro cultured preantral follicles reached meiotic resumption. A significant increase of follicle diameter occurred in attachment system and FA (p < .05), but the ALG condition reached the highest among all groups on day 18 (p < .05). Follicles encapsulated in matrix produced more estradiol and progesterone than attachment system (p < .05). The expression of MMP‐9 mRNA was higher in FA than in other groups (p < .05) and similar to antral follicles from in vivo control (p > .05). Only FA group resulted in oocytes matured. After 30 days, oocytes from preantral follicles in vitro grown in FA developed to eight‐cell parthenotes. In conclusion, a culture system using FA supported the development of caprine preantral follicles cultured in group and included in the same bead of hydrogel, improving the oocyte maturation and producing parthenotes.