Effects of lameness, subclinical mastitis and loss of body condition on the reproductive performance of dairy cows     

Peake KA  Biggs AM  Argo CM  Smith RF  Christley RM  Routly JE  Dobson H 《The Veterinary record》2011,168(11):301

A total of 318 cows were monitored in the pre-breeding postpartum period for the presence of three production stressors: lameness, subclinical mastitis and body condition score (BCS) loss. For each stressor, cows were given a classification of severely, moderately or non-affected based on mobility scores, somatic cell counts and BCS change. The number of days from calving to onset of the first luteal phase was greater in cows that had one severe production stressor (median 44 days) or two moderate production stressors (41 days) compared with cows that had no stressors (31 days) (P=0.02 and P=0.04, respectively). More than one severe stressor increased the interval further. There was no difference between cows with one moderate stressor (median 38 days) and those with none (P=0.13). The delay to the first luteal phase was significantly longer in cows with two moderate stressors if the onset of one stressor occurred at the time when resumption of ovarian activity was expected. The presence of these production stressors in early lactation had no effect on the interval from calving to establishment of the next pregnancy or the number of inseminations required despite the negative effect on the onset of the luteal phase.  相似文献   

Associations between trichostrongylid worm egg count and productivity measures in Dorper lambs     

Sweeny JP  Gardner GE  Dobson RJ  Jacobson C  Bell K 《Veterinary parasitology》2011,180(3-4):307-314

Two flocks of pure bred Dorper lambs were managed separately according to sex (283 ewe lambs and 212 ram lambs) in southern Western Australia. Faecal sample collection, weighing and body condition assessments were performed for each lamb on 2 occasions, specifically pre-weaning (approximately 14 weeks of age) and post-weaning (approximately 9 months of age). Body condition score (BCS) was assessed using a scale of 1 (very thin, emaciated) to 5 (excessively fat). Faecal worm egg counts (WECs) were measured using a modified McMaster technique and larval cultures were performed to identify trichostrongylid nematode genera present. Eye muscle and c-site fat depths were measured using ultrasound at post-weaning. Lambs received an abamectin anthelmintic treatment at weaning (18 weeks of age). Worm egg count data was assessed for normality of data distribution and homogeneity of variance. This data was transformed using log(10)(WEC+25) to stabilise variances between groups prior to statistical analyses and general linear models were used to assess relationships between WEC and productivity measures. Mean WECs were 564 eggs per gram of faeces (EPG) and 514 EPG at pre- and post-weaning in the ewe flock and 552 EPG and 480 EPG at pre- and post-weaning in the ram flock. Teladorsagia (Ostertagia) circumcincta, Trichostrongylus spp. and Oesophagostomum spp. larvae were identified. No lambs with WEC<500 EPG pre-weaning had WEC>1000 EPG post-weaning. Ewe and ram lambs with WEC>1000 EPG at pre-weaning were 42 (12-145 95% CI) and 37 (9-153) times more likely to have WEC>1000 EPG at post-weaning than lambs with WEC 501-1000 EPG at pre-weaning. There were no significant relationships between WEC and live weight in the ram flock, while relationships between WEC and live weight were inconsistent in the ewe lamb flock. There was no relationship between WEC and eye muscle or c-site fat depth. Significant negative relationships between WEC and BCS were identified at pre- and post-weaning for both flocks. Lambs with WEC<500 EPG had 0.19-0.61 higher mean BCS than lambs with WEC>1000 EPG at pre- and post-weaning. In conclusion, high WEC was associated with lower body condition in Dorper lambs, however the relationship between WEC and live weight was inconsistent and there was no effect on eye muscle depth.  相似文献   

Lack of LH response to oestradiol treatment in cows with cystic ovarian disease and effect of progesterone treatment or manual rupture.     

A S Nanda  W R Ward  H Dobson 《Research in veterinary science》1991,51(2):180-184

The luteinising hormone (LH) surge in response to 1 mg oestradiol benzoate intramuscular injection was studied on 67 occasions in 45 cows with cystic ovarian disease 20 to 150 days post partum. Cows diagnosed as having luteal cysts were given 500 micrograms cloprostenol intramuscularly 24 hours before oestradiol, to induce luteolysis. Oestradiol benzoate was also given to eight post partum acyclic and eight cyclic cows and in all these cases a control LH response was characterised for comparison. Eight of 17 cows with luteal cysts (47 per cent), and 10 of 21 cows with follicular cysts (48 per cent), released LH in response to oestradiol. Some cows with cysts were given one of two treatments. Seven cows with follicular cysts were treated with a progesterone-releasing device (PRID) for seven days: all responded to a second oestradiol treatment given 24 hours after removal of the PRID. Luteal cysts in three cows and follicular cysts in nine cows were ruptured manually: only one cow (a luteal case) responded to the second oestradiol treatment given 24 hours after manual rupture. In eight cows initially diagnosed with luteal cysts, cloprostenol was not given and plasma progesterone concentration at the time of oestradiol treatment was high (over 0.9 ng ml-1): none released LH in response to oestradiol. As manual rupture did not improve the LH response to oestradiol, it is concluded that the defective LH response to oestradiol in cows with cystic ovarian disease was not influenced in the short-term by cyst fluid contents.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Effects of radiotherapy alone and surgery and radiotherapy on survival of dogs with nasal tumours   总被引：2，自引：0，他引：2  

J. S. Morris  K. J. Dunn  J. M. Dobson  R. A. S. White 《The Journal of small animal practice》1994,35(11):567-573

The case records of 26 dogs with nasal tumours, treated either with radiation alone or surgery and radiation, were compared. One- and two-year actuarial survival rates for 12 dogs treated with radiotherapy were 58 and 13 per cent, respectively, compared to 71 and 38 per cent, respectively, for 14 dogs which were treated with surgery before radiotherapy. Sixty-seven per cent of the dogs treated with radiotherapy had recurrent clinical signs by 52 weeks compared to 36 per cent of the dogs treated with surgery and radiotherapy. The longer disease-free interval of the dogs treated with surgery and radiotherapy was statistically significant. When dogs with sarcomas were compared to those with carcinomas, there was no significant difference in disease-free interval or survival time.  相似文献   

A METHOD OF MOUNTING A GAMMA DETECTOR AND YOKE ASSEMBLY FOR EQUINE NUCLEAR IMAGING     

Lawrence J.  Riddolls  BSc  RTNM  Russell A.  Willoughby  DVM  PhD  Howard  Dobson  BVM&S  DVSc  Cert  E.O. 《Veterinary radiology & ultrasound》1991,32(2):78-81

A scintillation detector assembly capable of providing the range of movement and flexibility needed for the investigation and diagnosis of equine-related health problems was required for the nuclear medicine facility of the Equine Research Centre, Guelph, Ontario. The planning, technique and modifications used to mount the gamma detector and yoke assembly are detailed herein. The system has been successfully used for the nuclear scans in horses, and demonstrates the practicality, safety and usefulness of equipment adaptation for large animal imaging.  相似文献   

Neural angiostrongylosis in three captive rufous bettongs (Aepyprymnus rufescens)     

DP HIGGINS  MS CARLISLE-NOWAK  J. MACKIE 《Australian veterinary journal》1997,75(8):564-566

Neurological disease attributed to migration of the rat lungworm ( Angiostrongylus cantonensis ), is described in three captive rufous bettongs ( Aepyprymnus rufescens ). Clinical signs, including ascending paralysis and multifocal neurological deficits, were similar to those seen in other species. Histologically, the severity of meningoencephalomyelitis ranged from mild to moderate. In one animal cerebrospinal fluid contained a high percentage of eosinophils but peripheral blood cell counts were within normal limits. Treatment with dexamethasone, diazepam and vitamin E was unsuccessful. The prognosis for bettongs with this disease is poor. The susceptibility of this species to this disease has implications for enclosure design.  相似文献   

Use of a uterine pessary to prevent infection of the uterus of the cow after parturition     

D P Dobson  D E Noakes 《The Veterinary record》1990,127(6):128-131

A uterine pessary containing penicillin, streptomycin, formosulphathiazole and ethinyloestradiol, was assessed for its efficacy in reducing the frequency and severity of uterine infections in cows after parturition. Fifteen pluriparous Holstein Friesian cows had pessaries inserted into the uterus within 24 hours after calving. Compared with 14 similar untreated cows there were significant reductions in the number infected by Actinomyces pyogenes and in the number exhibiting abnormal uterine discharges.  相似文献   

Preliminary studies of a platelet function disorder in Simmental cattle.   总被引：1，自引：1，他引：0       下载免费PDF全文

G P Searcy  D Sheridan    K A Dobson 《Canadian journal of veterinary research》1990,54(3):394-396

A bleeding disorder due to abnormal platelet function occurs in Simmental cattle. Whole blood from these animals underwent good clot retraction. Platelet aggregation in response to adenosine diphosphate (ADP) and collagen in a whole blood aggregation system was markedly impaired. Normal bovine platelets in a whole blood aggregation system showed very little aggregation in response to epinephrine and arachidonic acid. Aggregation in platelet-rich plasma was negligible in response to ADP, collagen and thrombin. Dense granule release of radiolabelled serotonin from the platelets of one affected cow was similar to that of normal bovine platelets. Platelet membrane glycoprotein electrophoresis with the platelets of one affected cow revealed no quantitative abnormalities. These findings reveal similarities and differences in thrombopathic Simmental platelet function when compared to human Glanzmann's thrombasthenia and Basset Hound thrombopathia.  相似文献   

Effect of eperythrozoonosis on sow productivity   总被引：3，自引：0，他引：3  

G M Zinn  G W Jesse  A W Dobson 《Journal of the American Veterinary Medical Association》1983,182(4):369-371

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Cutaneous and systemic mycoses from infection with Lecanicillium spp. in captive Guthega skinks (Liopholis guthega)          下载免费PDF全文

TF Scheelings  EC Dobson  C Hooper  P Eden 《Australian veterinary journal》2015,93(7):248-251

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