A number of iron compounds have been shown to protect sheep against the harmful effects of the facial eczema toxin, sporidesmin. Various salts were found to be effective; the oxidation state of the metal was not important although water-solubility did appear to be a prerequisite for prophylactic activity. The effect of iron salts was additive with that of zinc, and it is suggested that the protective action of these compounds results from their ability to inhibit the absorption of copper, consistent with the previously-proposed freeradical mechanism for sporidesmin toxicity. 相似文献
Four experiments assessed changes in serum IGF-I under various physiologic conditions in postpartum cows. In Exp. 1, anestrous suckled cows (n = 25) were infused for 6 d with either saline or glucose at two different infusion rates. In Exp. 2, anestrous cows (n = 29) received either a saline (weaned and suckled controls) or 3 g/d phlorizin (weaned phlorizin) infusion for 3 d. Calves from the weaned groups were removed from 15 h before and throughout infusions. In Exp. 3, cycling suckled cows (n = 20) received prostaglandin F2 alpha (PGF2 alpha) when the 5-d saline or phlorizin infusion began. In Exp. 4, suckled cows (n = 20) had ad libitum access to feed or received 50% of control feed consumption from 30 to 40 d postpartum. Increasing glucose availability (Exp. 1) increased (P less than .05) serum IGF-I by 30 to 35%. IGF-I remained stable after weaning (Exp. 2) in phlorizin-infused cows (128.8 +/- 12.7 ng/ml), but increased (P less than .05) by 3 d after calf removal in weaned control cows (152.2 +/- 7.5 ng/ml). IGF-I also remained stable in phlorizin-infused cows following PGF2 alpha injection (Exp. 3), but increased in control cows by 2 d after PGF2 alpha (156.8 +/- 18.3 on d 2 vs. 133.7 +/- 9.8 ng/ml pre-injection; P less than .05) and remained elevated (P less than .05) during the periovulatory period. In cows receiving restricted feed intake (Exp. 4), IGF-I decreased by approximately 50% within 4 d of feed restriction (71.3 +/- 9.4 vs 137.4 +/- 16.6 ng/ml; P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
This study tested the hypothesis that the increased glucose requirement of lactation had effects that were independent of the suckling-dependent inhibition of postpartum endocrine function in beef cows. Mature Hereford cows were either suckled ad libitum and infused with saline iv (n = 9) from d 2 through 4 (d 0 = jugular catherization on d 32 +/- 3 postpartum); were nonsuckled and infused with saline from d 2 through 4 (n = 10); or were nonsuckled and infused with phlorizin (3 g/d) from d 2 through 4 (n = 10). Nonsuckled cows infused with phlorizin had lower (P less than .05) plasma concentrations of glucose and amino acid nitrogen (AAN) on d 2 compared with pre-infusion levels (d 1), but their metabolic profile returned to levels similar to the suckled cows by d 3 and 4. Nonsuckled cows infused with saline had elevated glucose and insulin and lower AAN and free fatty acids (FFA) on d 3 and 4 compared with pre-weaning (d 1) levels (P less than .05). Nonsuckled cows infused with phlorizin did not show this weaning-induced elevation in glucose and insulin. The number of luteinizing hormone (LH) pulses was not affected by treatment. However, in contrast to the large LH pulses observed in the nonsuckled cows infused with saline, both the suckled cows and the nonsuckled cows treated with phlorizin had more small and fewer large amplitude pulses (P less than .01). Treatment did not affect serum concentrations of follicle stimulating hormone, gonadotropin release in response to gonadotropin releasing hormone (25 micrograms) or the number of cows ovulating by 55 d after calving. We conclude that the increased glucose clearance caused by phlorizin infusion or lactation results in depression of LH pulse amplitude in suckled postpartum beef cows. 相似文献
AIMS: To report on the long-term outcomes of hydraulic artificial urethral sphincter (HAUS) placement for the correction of urethral sphincter mechanism incompetence (USMI) in New Zealand dogs.
METHODS: Retrospective data were obtained from cases of dogs which had a HAUS placed after failed medical and/or surgical management of USMI between August 2012 and November 2016. Owner assessment of urinary incontinence was evaluated by an online survey in May 2017 using a visual analogue scale (0 being normal, 100 being severely affected) for the frequency, volume and severity of any straining to urinate, immediately prior to the placement of the HAUS and at the time of the survey. The number of days between surgery and the completion of survey were recorded.
RESULTS: Seven females and two male dogs, which were all desexed except for one female, were eligible for inclusion in the study. The period of follow-up following HAUS placement ranged from 206–1,685 days. Following HAUS placement, frequency and volume of urinary incontinence decreased for six dogs and were practically unchanged for three dogs. The median frequency score decreased from 70 to 13 and the volume score decreased from 73 to 12. There was no consistent change in the perceived degree of straining to urinate. Complications occurred in three dogs; one required repositioning of a dislodged injection port, one required management for haematuria and a hypoplastic bladder, and one required surgical removal of fibrous tissue around the HAUS cuff.
CONCLUSIONS AND CLINICAL RELEVENCE: HAUS placement was an effective method for the treatment of persistent USMI in most dogs and provided good clinical results based on owner assessment. The technique was associated with few complications and allowed successful long-term control of urinary incontinence without the need for medical management. 相似文献
A field trial was conducted to assess the efficacy of a combined prostaglandin F2α analogue (cloprostenol) and dexamethasone treatment as an abortifacient in feedlot heifers. Heifers were grouped according to stage of gestation as follows: Group I, one to four months, n = 37: group II, four to six months, n = 40: group III, six to eight months, n = 40: group IV, one to eight months, n = 29. Heifers in groups I, II and III received a simultaneous intramuscular injection of 500 μg cloprostenol and 25 mg dexamethasone at the time of rectal palpation for pregnancy diagnosis. Heifers in group IV were subjected to rectal palpation for pregnancy diagnosis but received no treatments. Heifers were observed daily for two weeks for abortion and rectal palpations were done 50 days after treatment to determine reproductive status. 相似文献
Termination of pregnancy in cows was investigated using sham-operated (SH) or ovariectomized (OV) cows treated with either a saline vehicle (V), cloprostenol (PG), dexamethasone (DEX) or dexamethasone and cloprostenol (DEX+PG). Surgery was done at 210 days of pregnancy and treatment was administered 72 hours later.
Days (mean±S.E.) from treatment to termination of pregnancy for the treatment groups were: sham-operated +vehicle (SH+V): 61.5±11.3; ovariectomized+vehicle (OV+V): 53.4±15.7; sham-operated+cloprostenol (SH+PG): 61.8±1.7; ovariectomized+cloprostenol (OV+PG): 54.5±13.1; shamoperated+dexamethasone (SH+DEX): 74.8±4.8; ovariectomized+dexamethasone (OV+DEX): 2.8±0.4; shamoperated+dexamethasone+cloprostenol (SH+DEX+PG) 26.0±23.0; ovariectomized+dexamethasone+cloprostenol (OV+DEX+PG): 7.2±4.9. Pregnancies in the OV+DEX and OV+DEX+PG groups were terminated significantly earlier than in all other groups (P<0.05) except the SH+DEX+PG group. These findings suggest that dexamethasone will terminate pregnancy in cows near seven months of gestation after the ovarian source of progesterone has been removed by either an injection of prostaglandin or by ovariectomy.
下载免费PDF全文