Somatic energy of sockeye salmon Oncorhynchus nerka at the onset of upriver migration: a comparison among ocean climate regimes

We examined somatic energy patterns in two stocks (Chilko and Early Stuart) of adult Fraser River (British Columbia, Canada) sockeye salmon (Oncorhynchus nerka), collected at the end of their ocean residency, spanning years across different climate regimes. Both stocks had high levels of somatic energy in years with high open ocean productivity (1956, 1957, 2001 and 2002), and relatively low levels in years with poor open ocean productivity (1999 and 2000). For Early Stuart sockeye, energy levels in 1999 and 2000 were approximately 15% lower (～1.5 MJ kg^?1) than that in the 1950s, an amount of energy equivalent to that necessary for migrating 600 km upriver. In recent years (2001 and 2002), energy levels have increased by about 9% for both stocks. Low energy levels at the onset of upriver migration, particularly in years of energetically demanding in‐river conditions, such as high flows or temperatures, are likely to contribute to prespawning and en route mortality in Fraser sockeye.     

Retrospective study of 108 foals with septic osteomyelitis

Objective   To determine the clinical characteristics, short-term outcome and future athletic performance of foals with septic osteomyelitis.
Design   Retrospective clinical study of 108 Thoroughbred foals with radiographic evidence of bone infection that were presented at the Scone Veterinary Hospital between August 1995 and December 2001. Medical records were reviewed and information concerning signalment, the clinical, laboratory and radiographic findings, treatment and outcome was obtained. Racing records were obtained and evaluated for surviving foals that had reached racing age.
Results   Mean age of foals at initial evaluation was 39 days (range 1–180 days); 21 foals had multiple radiographic bone lesions (19.4%), and 76 had concurrent septic arthritis (70.4%). The most frequently affected bones were the femur, tibia and distal phalanx. In total, 87 foals were discharged from the hospital (80.6%), 79 survived long-term to reach racing age and 52 raced (65.8%). Overall, 48% (52/108) of the foals treated for osteomyelitis raced. Foals less than 30 days of age at the time of diagnosis, critically ill foals and those with multiple bones or joints affected were significantly less likely to be discharged from hospital. Multiple septic joints, but not multiple bone involvement, had an unfavourable prognosis for racing.
Conclusions   The prognosis for survival of foals with septic osteomyelitis or osteitis is favourable. Multiple bone or joint involvement is an important short-term prognostic indicator; however, the involvement of multiple joints, but not multiple infected bones, is associated with an unfavourable prognosis for racing.     

Monochorial diamniotic dizygotic twins in a German Shepherd Dog: A case report

Case report: A 6.5‐year‐old clinically healthy German Shepherd Dog with regular oestrous cycles of 6 months was presented for pregnancy diagnosis on day 38 after ovulation (p.ov.). Ultrasonography revealed three individual placental sites in progressed resorption and two vital adequately developed foetuses sharing a joint placenta. On days 41 and 48 p.ov., sonographic signs indicated normal development of both foetuses, but on day 52 p.ov., both foetuses were found to be dead. A caesarean section was performed the same day. Examination of the removed uterus confirmed the diagnosis of a “twin” pregnancy with two foetuses sharing the same placental site but separate amniotic membranes. One foetus showed generalized oedema (anasarca). Bacterial culture of swabs taken from inside the placental cavity was negative. At histological examination of the uterus, no signs of inflammation were found. Serum relaxin concentrations (day 38, 41, 48 and 52. p.ov.) were consistent with those of bitches with normal pregnancies. Cytogenetic analysis of the two foetuses revealed dizygotic twins, one male and one female according to SRY‐PCR. By genotyping 17 high‐polymorphic canine microsatellites, it could be demonstrated that the two foetuses developed from two different oocytes.     

Evaluation of an ultrasonic Doppler probe for pregnancy diagnosis in cattle

SUMMARY The use of an ultrasonic Doppler probe for pregnancy diagnosis was evaluated. Data from the examination of 1115 cattle were analysed. Comparison of the probe with manual rectal palpation by an experienced clinician yielded a sensitivity of 92.8 ± 1.6% (± 95% confidence interval) and a specificity of 75.8 ± 7.4%. This level of accuracy was found to be insufficient to recommend the probe be used by farmers for the diagnosis of pregnancy.     

Epidemiological studies of pig diseases: 2. Post-weaning diarrhoea and performance in Western Australian pigs

Objective To determine in Australian pig herds the accuracy of French protocols for risk factor assessment of post-weaning diarrhoea and illthrift.
Procedure French protocols for the collection of data on health indicators and risk factors for post-weaning diarrhoea were conducted on 54 batches of weaner pigs from 28 Western Australian pig herds during three years.
Results Large variations in post-weaning performance were found. About one-third of the batches were growing at <200 g/day during the 3 weeks after weaning, and 54% had growth rates of <250 g/day. Weaning age and weight of at least 30 days and 7.9 kg, respectively, optimised weaner performance. Other risk factors associated with little post-weaning diarrhoea and good weaner performance were high creep feed intakes, relatively little diarrhoea as suckers, and, contrary to expectations, large temperature fluctuations.
Conclusion Overall, the 'predictability' of post-weaning problems as assessed by measurement of risk status, was good. However, the model was less accurate at predicting the performance of a single batch of pigs.     

Effect of extrusion processing on the nutritive value of canola meal for chinook salmon (Oncorhynchus tshawytscha) in seawater

This study was conducted to evaluate three canola protein products as partial replacements of steam-dried whole herring meal (HM) in a practical diet for juvenile chinook salmon in seawater. Groups of 30–40 g chinook salmon held in 9.5–12°C seawater on a natural photoperiod were fed one of seven equivalent protein (390 g kg⁻¹) and isoenergetic (20 MJ gross energy kg⁻¹) diets to satiation. Each of three test protein sources, namely, commercial canola meal (CM), low-temperature extruded CM (90°C; LT), and high-temperature extruded CM (150°C; HT) comprised about 120 and 240 g kg⁻¹ of dietary protein by replacement of 15 and 30%, respectively, of the HM protein in the control diet. Chinook salmon growth and feed intake were markedly depressed by replacing HM protein with a high level of CM, but these responses were not lowered by replacement with LT and HT. The phytic acid content in commercial canola meal was reduced by about 10 and 30% from the original level by extrusion cooking at low (90°C) and high (150°C) temperature, respectively. Therefore, the diets containing HT still had significant amounts of phytic acid. Terminal whole-body zinc contents were inversely related to the dietary levels of the different canola protein products. Thyroid function was altered by CM but this effect was offset by heat treatment. The results suggest that extrusion cooking of CM improves its nutritive value for chinook salmon in seawater. Indeed, it was found that HT could comprise 240 g kg⁻¹ of the dietary protein without adversely affecting performance.     

Effects of dietary canola oil level on growth, fatty acid composition and osmoregulatory ability of juvenile fall chinook salmon (Oncorhynchus tshawytscha)

This study assessed refined canola oil (CO) as a supplemental dietary lipid source for juvenile fall chinook salmon, Oncorhynchus tshawytscha, parr with respect to possible effects on their growth and osmoregulatory performance and body composition. Diets with equal protein ( 57%) and lipid ( 19%) content (dry weight basis) were supplemented with lipid from either anchovy oil (AO) or CO with AO so that CO comprised 0 (0CO), 11% (11CO), 22% (22CO), 33% (33CO), 43% (43CO) or 54% (54CO) of the dietary lipid content. Triplicate groups of juvenile chinook salmon were fed their prescribed diets for 104 days in freshwater (FW) and 31 days in seawater (SW) after a 4-day transition period. Dietary fatty acid compositions reflected the different proportions of AO and CO in the supplemental lipid. Diet treatment had no effect on fish growth, feed intake, feed efficiency, protein utilization, fish mortality or terminal whole body water and ash percentages. Whole body lipid percentages were higher in 11CO and 43CO fish than in 33CO fish and in 11CO fish versus 22CO fish. Whole body protein percentages were highest in 33CO, 43CO and 54CO fish and lowest in 0CO and 22CO fish. Terminal whole body fatty acid compositions were influenced strongly by the dietary fatty acid compositions. Haematocrit and muscle water percentages were not affected consistently and plasma Na⁺ and Cl⁻ concentrations were unaffected by diet treatment in FW or 24-h seawater challenges during FW residency. Also, diet treatment had no effect on the physiological parameters after SW residency. We conclude that dietary treatment had no effect on fish growth performance under our experimental conditions. Also, the dietary inclusion of CO neither facilitated nor impaired the transfer of chinook salmon parr to seawater. Thus, CO was found to be an excellent and cost-effective source of supplemental dietary lipid for culture of juvenile fall chinook salmon during freshwater residency.