Effect of strain of Holstein–Friesian and feed system on calving performance, blood parameters and overall survival

The objective of the present study was to quantify the effect of strain of Holstein–Friesian and pasture-based feeding system on calving performance, blood parameters and overall survival within a seasonal calving milk production system. The three strains of Holstein–Friesian compared were high production North American (HP), selected entirely for milk production, high durability North American (HD), selected based on milk production, fertility and muscularity traits, and New Zealand (NZ) selected from a seasonal calving pasture-based system. The three feed systems compared were a high grass allowance feed system typical of spring calving herds in Ireland (MP; control); an increased stocking rate system (HS) and an increased concentrate supplementation system (HC). Data comprised up to 585 lactations on 240 cows. Data were analysed using linear mixed models, generalised estimating equations and survival analysis. Strain of Holstein–Friesian had no significant effect on calving difficulty or rate of stillbirths while the effect of feed system on calving difficulty and rate of stillbirths approached significance. Strain of Holstein–Friesian had no significant effect on plasma metabolite or hormone concentrations around parturition, with the exception of urea concentration. At the beginning of the breeding season the NZ strain had lower plasma concentrations of NEFA (0.20 mmol/l) and higher IGF-I (86.8 ng/ml) than the HD (0.24 mmol/l and 66.9 ng/ml, respectively) and HP (0.26 mmol/l and 64.0 ng/ml, respectively) strains. The higher IGF-I concentration of the NZ strain was maintained during the breeding season. The NZ and HD strains survived longer than the HP strain with median survival days post-first calving of 1372, 1367 and 1033 respectively, while feed system had no significant effect on overall survival rate over the study period.     

Left ventricular remodeling in preclinical experimental mitral regurgitation of dogs

Dogs with experimental mitral regurgitation (MR) provide insights into the left ventricular remodeling in preclinical MR. The early preclinical left ventricular (LV) changes after mitral regurgitation represent progressive dysfunctional remodeling, in that no compensatory response returns the functional stroke volume (SV) to normal even as total SV increases. The gradual disease progression leads to mitral annulus stretch and enlargement of the regurgitant orifice, further increasing the regurgitant volume. Remodeling with loss of collagen weave and extracellular matrix (ECM) is accompanied by stretching and hypertrophy of the cross-sectional area and length of the cardiomyocyte. Isolated ventricular cardiomyocytes demonstrate dysfunction based on decreased cell shortening and reduced intracellular calcium transients before chamber enlargement or decreases in contractility in the whole heart can be clinically appreciated. The genetic response to increased end-diastolic pressure is down-regulation of genes associated with support of the collagen and ECM and up-regulation of genes associated with matrix remodeling. Experiments have not demonstrated any beneficial effects on remodeling from treatments that decrease afterload via blocking the renin-angiotensin system (RAS). Beta-1 receptor blockade and chymase inhibition have altered the progression of the LV remodeling and have supported cardiomyocyte function. The geometry of the LV during the remodeling provides insight into the importance of regional differences in responses to wall stress.     

Sulphate in Sudbury, Ontario, Canada, Lakes: Recent Trends and Status

Sulphur emissions from the Sudbury, Ontario, metal smelting industry have affected thousands of lakes in Ontario, Canada. Reductions in these emissions during the 1970's resulted in reduced lakewater SO₄ concentrations and other water quality changes in the 1970's and 1980's. Further declines in lakewater SO₄ concentrations have accompanied additional recent S emission reductions achieved by 1994. Recent (1997) SO₄ concentrations are still related to distance from the Sudbury smelters. A strong inverse relationship with distance is evident to about 45 km, and is most pronounced in lakes within about 20 km. In lakes beyond 45 km, dissolved organic carbon (DOC), which was correlated with hydrological response time and total phosphorus concentrations, was the best correlate with recent SO₄ concentrations, indicating that some slowly-flushing, oligotrophic lakes still exhibit a "Sudbury" effect. Most lakes beyond 45 km, however, showed SO₄ declines and recent SO₄ concentrations comparable to lakes around Dorset, ～200 km from Sudbury, suggesting that these lakes are now most affected by the long-range atmospheric transport of S.     

Overstorey density influence on the height of Picea abies regeneration in northern Sweden

The study aimed specifically at investigating if canopy opennesswas a better predictor of the height growth of Norway spruce(Picea abies (L.) Karst.) advance regeneration than overstoreybasal area or overstorey standing volume. In 1990, a field experimentwith 3 x 2 factorial design and two replications (blocks) wasestablished in an uneven-aged Norway spruce forest. Plots hada net plot area of 30 x 30 m, each with a 10-m-wide treatedbuffer zone. Three overstorey density levels retained approximately15, 40 and 70 per cent of the pre-harvest overstorey standingvolume and were allotted to the plots. Two types of thinningthat harvested smaller trees or harvested larger trees wererandomly allocated to each pair of overstorey density plots.In mid-June 2000, canopy openness was estimated from hemisphericalphotographs taken at five marked points in the centre of eachof the plots at 0.9 m from ground to the top of the ‘fish-eye’camera lens. Regression results showed that canopy opennesswas a better predictor of height increments of spruce seedlings(0.1< height < 0.5 m), saplings (0.5 height < 2.0m), and small trees (height 2.0 m, diameter at 1.3 m height< 5 cm) than with overstorey basal area (m² ha^–1) oroverstorey standing volume (m³ ha^–1). The height incrementof the spruce advance regeneration was not significantly correlatedto stand basal area or to standing volume. Overstorey basalarea in the net plots was significantly negative (P 0.05) withmean canopy openness estimates, and the r² value was 0.40. Resultsindicated that basal area was not linearly related to canopyopenness as it increased, which might explain the lack of predictivepower of retained basal area on spruce regeneration height indense stands in boreal Sweden.     

Technique for percutaneous pulmonary arterial catheterization in conscious dogs

A technique was developed to allow percutaneous placement and exchange of pulmonary arterial catheters in conscious dogs. Seven dogs were catheterized weekly for 5 weeks, using a 10-gauge over-the-needle cannula. A No. 7 F flow-directed catheter was passed through the cannula to measure right heart and pulmonary arterial pressures and to calculate cardiac output. The flow-directed catheter was removed and replaced with an arteriographic catheter, and a pulmonary arteriogram was performed. Placement in alternate jugular or saphenous veins each week resulted in successful catheterizations in all dogs evaluated.     

Comparative efficacy of four commercially available heartworm preventive products against the MP3 laboratory strain of Dirofilaria immitis

A controlled laboratory study was conducted to evaluate the efficacy of four commercial products administered as a single treatment for the prevention of heartworm disease caused by Dirofilaria immitis in dogs. Forty-four commercially sourced Beagle dogs, 6-7 months of age, were received at the test site (Auburn University, Department of Pathobiology) on Study Day (SD) -72 to begin acclimation. On SD -30, each dog was inoculated subcutaneously with 100 infective, third-stage D. immitis larvae (MP3 strain, TRS Laboratories, Inc., Athens, GA). On SD -1, 40 dogs weighing 18.2-25.3 lbs were ranked by decreasing body weight and randomized to five groups of eight dogs each. On SD 0, the dogs assigned to Group 1 were treated orally with ivermectin/pyrantel pamoate chewable tablets, Group 2 dogs were treated orally with milbemycin oxime flavored tablets, Group 3 dogs were treated with selamectin topical solution, and Group 4 dogs were treated with imidacloprid/moxidectin topical solution. Group 5 dogs remained nontreated. Dosages for dogs in Groups 1-4 were based on the individual body weight of each dog and current labeled dose banding for each commercial product. All dogs were fasted overnight prior to treatment. Food was returned four hours after treatment. Animals were observed for abnormal clinical signs involving eyes, feces, respiration, behavioral attitude, locomotion/musculature, or skin conditions at prescribed intervals immediately after treatment and at twice daily intervals thereafter. On SD 90, whole blood was collected and tested for adult heartworm antigen. On SDs 119/120, the dogs were euthanized and subjected to necropsy examination for recovery of adult D. immitis and/or worm fragments. At necropsy, all 8 dogs in the nontreated group were infected with adult D. immitis (34-70 worms/dog, geometric mean (GM)=51.6 worms/dog). One or more adult D. immitis and/or worm fragments were recovered from 7 of 8 of the dogs each in Groups 1-3 (87.5% were heartworm positive). The respective GM worm burdens/dog for Groups 1-3 was 2.3, 2.4, and 2.3 which resulted in 95.6, 95.4 and 95.5% efficacy, respectively. No worms were recovered from any of the 8 dogs in Group 4 resulting in 100% efficacy.     

Midline Cysts of Colliculus Seminalis Causing Ejaculatory Problems in Stallions

Cystic structures are often seen during ultrasound examination of the internal genitalia of stallions. They are located between the ampullae of deferent ducts, either within the urogenital fold, or under the isthmus of the prostate (uterus masculinus). Occasionally, cystic dilatations are also found more caudally, behind the prostate, at the colliculus seminalis (urethral cyst, utriculus masculinus). These cysts are detected less frequently during routine examinations, possibly because of the fact that this area is screened less carefully for the pathologies than the more proximal portion of the internal reproductive tract of stallions. We have recently noticed that many stallions with ejaculatory problems have large cysts at the colliculus seminalis. This article describes the typical clinical presentation of these cases, diagnostic procedures, and management. In addition, we discuss the discrepancies in the currently used terminology pertinent to this condition, as well as introducing a new term, which seems to best describe the root cause of this disorder. Finally, this article presents new diagnostic and therapeutic options used in human medicine in similar cases, and proposes to investigate the applications of these methods in veterinary medicine.     

Beef cow-calf production.

Cow-calf production occurs in all 50 states over varied resource bases and under vastly different environmental conditions. Multiple breeds exist and management styles and objectives are as numerous as the number of cow-calf producers. There is not one area of the country, one breed of cattle, or one management style that is most profitable for producing cows and calves. There are, however, some common strategies that can be employed by cow-calf producers to enhance profitability. Costs need to be controlled without jeopardizing cow herd productivity or net returns. It appears that the cost associated with purchased and harvested feeds varies considerably across operations. Understanding cyclic and seasonal price patterns, weight-price slides, cattle shrink, and other marketing costs can help producers enhance their profit by marketing (and not by just selling) their cattle. Producers with superior cattle genetics can become part of a specific alliance or, at a minimum, document the performance of their cattle so that they can get paid for the superior genetics. The beef industry is changing and will likely continue to change. Cow-calf producers will need to examine their own management practices to determine whether they are optimal for the current industry. Those producers who are most adept at matching their management abilities to their cattle type, their resource base, and the appropriate market outlet will be the most successful in the future.     

Outcome following surgical removal of nonvisceral soft tissue sarcomas in cats: 42 cases (1992-2000)

OBJECTIVE: To identify factors associated with outcome of cats with nonvisceral soft tissue sarcomas treated with surgery alone. DESIGN: Retrospective study. ANIMALS: 42 cats. PROCEDURE: Medical records were reviewed for clinically relevant data, and histologic samples were examined. Follow-up information was obtained by means of physical examination or through telephone conversations with referring veterinarians and owners. The Kaplan-Meier method was used to construct survival curves. RESULTS: Median survival time was 608 days (range, 85 to 2,291 days), although 24 cats were still alive at the time of the study. Tumor size (ie, diameter) and histologic type were significantly associated with survival time. Median survival time was significantly longer in cats with tumors that were < 2 cm in diameter, compared with cats in which tumors were > 2 cm. Median survival times for cats with a fibrosarcoma or nerve sheath tumor were significantly longer than median time for cats with a malignant fibrous histiocytoma. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that tumor size and type are significantly associated with survival time in cats with nonvisceral soft tissue tumors.     

Right dorsal colitis in the horse: minireview and reports on three cases in Ireland

: Right dorsal colitis (RDC) is an ulcerative inflammatory bowel disorder of the horse that has been associated with the administration of non-steroidal anti-inflammatory drugs (NSAIDs), particularly in horses treated when dehydrated or toxaemic. The acute form of RDC may result in profuse diarrhoea, severe colic, dehydration, endotoxic shock and even death; the chronic form may be manifest by mild to moderate intermittent colic, ventral oedema and weight loss with or without diarrhoea. The most consistent laboratory findings are anaemia, hypoproteinaemia, hypoalbuminaemia and hypocalcaemia. Medical management of RDC requires avoidance of NSAIDs, of stressful experiences and of large-volume diets. Specific medications such as sucralfate and metronidazole have been used to treat RDC in the horse. The use of dietary additions such as psyllium and corn oil has been mentioned in the literature.RDC has not been reported previously in Ireland or Britain; here we report that the condition was diagnosed in three horses in Ireland on the bases of a history of phenylbutazone therapy, clinical signs, clinical pathology and ultrasonography. In two of the three horses the diagnosis was confirmed by direct inspection of the affected colon at celiotomy.