Effects of dietary molybdenum on nematode and host during Haemonchus contortus infection in lambs.

The addition of molybdenum (0.05 mmol kg-1 dry-matter) to the diet of lambs given a trickle infection of Haemonchus contortus larvae (500 third stage larvae d-1 over six weeks) reduced mean faecal egg counts (epg) from 3952 to 2312 +/- 402 by 32 days (P less than 0.02) and greatly reduced the mean number of worms recovered from the abomasum 14 days after infection ceased (907 compared with 4167: P less than 0.01). Infection reduced haemoglobin concentrations less in lambs given molybdenum although the difference was small relative to the reduction in worm burden. Lambs not given molybdenum had low intraepithelial mast cell counts in the abomasal mucosa and less abomasal hypertrophy than expected from abomasal parasitism. Molybdenum did not consistently reduce the copper status of the host or the parasite. Previous exposure to molybdenum greatly reduced protein but not proteinase activity in, or secreted by, adult worms cultured for eight hours. It is suggested that molybdenum either increased the inflammatory response which preceded worm rejection or that it indirectly enhanced that reaction by reducing the effectiveness of copper-dependent, anti-inflammatory enzymes in the gastrointestinal mucosa.     

Closed reduction and surgical fixation of elbow joint luxation in an adult mare and in a 3-month-old foal using knotless bone anchors and FiberTape

This report describes the successful surgical stabilisation of elbow joint luxation using knotless bone anchors and FiberTape to repair the medial collateral ligament in an 11-year-old mare (Case 1) and both medial and lateral collateral ligaments in a 3-month-old foal (Case 2). Radiography (both cases) and computed tomography (Case 2) were used to diagnose subluxation (Case 1) and complete luxation (Case 2) with suspected rupture of both collateral ligaments. Case 1 was supported in a rescue sling for 7 weeks postoperatively to prevent recumbency. Recovery was good, and the mare was sound at the walk at the time of discharge 8 weeks after surgery and 1 year later at the follow-up visit. Case 2 was discharged 3 weeks after surgery and was sound at the trot when re-evaluated 2 and 6 months postoperatively. Although elbow luxation accompanied by torn collateral ligaments is rare in horses, successful outcomes have been described. In the present case report, joint stabilisation and a successful outcome were achieved, for the first time, with closed reduction and an open approach for placement of knotless bone anchors and FiberTape. Limitations of our study included inability to directly assess the integrity of the implants during healing and relying mainly on clinical signs to assess healing.     

The effect of restricting the individual daily energy intake of caged layers on the efficiency of egg production

Two experiments are described in which the daily metabolisable energy intake of laying hens fed a concentrated diet (ME = 3550 kcal/kg) was restricted on an individual hen basis. Performance on this diet was compared with that of hens fed a high‐energy diet (ME = 2690 kcal/kg). In experiment 1 medium‐weight hybrid pullets were used and in experiment 2 two light‐weight hybrid strains were used.

In both experiments maximum egg production was obtained from the birds fed the high‐energy diet ad libitum. Restriction of the concentrated diet caused a significant reduction of body weight gain and a statistically insignificant fall in the total weight of egg product and in percentage production in both experiments.

Restriction of the concentrated diet caused improvements of 22 and 18 per cent in the efficiency of utilisation of metabolisable energy in experiments 1 and 2 respectively.

The data are discussed in relation to the relevant literature and the current cost of concentrated sources of energy.     

Perchlorate accumulation in forage and edible vegetation

The accumulation of perchlorate in vegetation is becoming a concern, with increasing numbers of sites reporting the presence of perchlorate in groundwater and surface water. This study investigated potential perchlorate uptake and distribution by a variety of forage and edible crops in both the laboratory and the field. Perchlorate concentrations in soybean leaves grown in the greenhouse were significantly higher than perchlorate concentrations in soybean seeds and pods. Perchlorate concentrations in alfalfa grown in sand were significantly lower than those in alfalfa grown in soil. The concentration of perchlorate in tomato was lower in the fruit than the leaves. Commercially grown wheat and alfalfa samples all contained perchlorate, 0.72-8.6 mg/kg of fresh weight (FW) in the wheat stems, 0.71-4.4 mg/kg of FW in the wheat heads, and 2.9 mg/kg of FW in alfalfa. All field garden samples tested (including cucumber, cantaloupe, and tomato) that were irrigated with perchlorate-tainted water contained perchlorate at various concentrations ranging from 0.040 to 1.65 mg/kg of FW. Bioconcentration factors (BCF), ratios of plant fresh weight concentrations to estimated or measured groundwater concentrations [(microg/kg of FW)/microg/L], were all in the same order of magnitude ranging from 215 +/- 126 for wheat stems to 233 +/- 264 for wheat heads and to 380 +/- 89 for alfalfa. BCF for garden fruit samples were much lower (0.5-20). Results from this study highlight the potential for perchlorate exposure by routes other than drinking water.     

Reproductive characteristics of the fishery important temperate demersal berycid Centroberyx gerrardi indicate greater reproductive output in regions of upwelling

The reproductive biology of Centroberyx gerrardi (Günther) was investigated across ~2,000 km of its southern Australian distribution, encompassing different jurisdictions and varying environmental features. Greater gonad mass and prevalence of spawning fish, along with lower ratios of lengths at maturity:maximum lengths and ages at maturity:maximum ages, were identified at the western‐most (Capes) and eastern‐most (Great Australian Bight; GAB) regions. Across the study region, spawning peaks in summer/autumn, when water temperatures are warmest. Regional differences in potential “reproductive output,” while not consistent with the eastward decline in mean monthly water temperature, may instead be related to summer upwelling in the Capes and GAB, driving greater oceanic productivity prior to peak spawning, supporting larval survival. In autumn, the prevailing southward and eastward flowing, downwelling Leeuwin Current (LC) strengthens, providing a dispersal mechanism along the west and south Australian coasts, but limiting upwelling effects. Predicted changes in environmental conditions and their potential impacts on C. gerrardi are discussed, in particular how these factors may affect recruitment to stocks and fisheries, requiring a better understanding of source‐sink relationships for this species. As environmental changes occur, management strategies to sustain fish resources must adapt to spatially variable and changing reproductive output and be collaborative across jurisdictions.     

Regulation of blood and lymphatic vascular separation by signaling proteins SLP-76 and Syk

Lymphatic vessels develop from specialized endothelial cells in preexisting blood vessels, but the molecular signals that regulate this separation are unknown. Here we identify a failure to separate emerging lymphatic vessels from blood vessels in mice lacking the hematopoietic signaling protein SLP-76 or Syk. Blood-lymphatic connections lead to embryonic hemorrhage and arteriovenous shunting. Expression of slp-76 could not be detected in endothelial cells, and blood-filled lymphatics also arose in wild-type mice reconstituted with SLP-76-deficient bone marrow. These studies reveal a hematopoietic signaling pathway required for separation of the two major vascular networks in mammals.     

The Effects of Salivary Gland Extracts from <Emphasis Type="Italic">Boophilus microplus</Emphasis> Ticks on Mitogen-stimulated Bovine Lymphocytes

The effect of salivary gland extract (SGE) from the tick Boophilus microplus was examined in mitogen-stimulated lymphocytes in vitro. SGE was added to lymphocytes of seven cattle together with the mitogens concanavalin A (ConA), phytohaemagglutinin (PHA) and pokeweed mitogen (PWM). Semi-purified B cells from another seven cattle were stimulated with the mitogen lipopolysaccharide (LPS). PHA and ConA stimulated proliferation of lymphocytes to the same extent, but the inhibition due to SGE of Boophilus microplus on the proliferative response stimulated by PHA (39.0% ± 9.3%) was less than the inhibition of proliferative response stimulated by ConA (75.4% ± 6.9%). In contrast, SGE of B. microplus stimulated the proliferation of B cells in the presence of LPS in a dose-dependent manner. Enhanced stimulation of B cells by SGE at >4 μg in culture was greater than twice that observed when B cells were stimulated by LPS alone. SGE does not have a direct suppressive effect on bovine B cell proliferation; however, in vivo the effectiveness of B cell responses might be influenced by other immune factors, such as cytokine profiles.     

Nonneurogenic urinary incontinence in a canine female pseudohermaphrodite

Nonneurogenic incontinence was observed in a 1-year-old Pekingese X Poodle with female pseudohermaphroditism. The dog had male external genitalia as well as a well-developed vagina, uterus, and ovaries. Urinary incontinence was caused by an anomalous communication of the prostatic urethra with the vagina. Ovariohysterectomy and surgical correction of the urethrovaginal fistula was followed by remission of urinary incontinence. Subsequently, the dog developed estrogen responsive urinary incontinence. Nonneurogenic incontinence to be a common finding in canine pseudohermaphroditism associated with abnormalities of the vagina or urethra (or both). Surgical correction should be considered to correct anomalous communications between the genital and lower urinary tracts.