Comparing the behavioural thermoregulation response to heat stress by Atlantic salmon parr (Salmo salar) in two rivers

Climate change is expected to increase the frequency and magnitude of extreme thermal events in rivers. The Little Southwest Miramichi River (LSWM) and the Ouelle River (OR) are two Atlantic salmon (Salmo salar) rivers located in eastern Canada, where in recent years, water temperatures have exceeded known thermal limits (~23°C). Once temperature surpasses this threshold, juvenile salmon exploit thermal heterogeneity to behaviourally thermoregulate, forming aggregations in coolwater refuges. This study aimed to determine whether the behavioural thermoregulation response is universal across rivers, arising from common thermal cues. We detailed the temperature and discharge patterns of two geographically distinct rivers from 2010 to 2012 and compared these with aggregation onset temperature. PIT telemetry and snorkelling were used to confirm the presence of aggregations. Mean daily maximum temperature in 2010 was significantly greater in the OR versus the LSWM (p = 0.005), but not in other years (p = 0.090–0.353). Aggregations occurred on 14 and 9 occasions in the OR and LSWM respectively. Temperature at onset of aggregation was significantly greater in the OR (T_onset = 28.3°C) than in the LSWM (T_onset = 27.3°C; p = 0.049). Logistic regression models varied by river and were able to predict the probability of aggregation based on the preceding number of hours >23°C (R² = 0.61 & 0.65; P₅₀ = 27.4°C & 28.9°C; in the OR and LSWM respectively). These results imply the preceding local thermal regime may influence behaviour and indicate a degree of phenotypic plasticity, illustrating a need for localised management strategies.     

Inflammatory mammary carcinoma in dogs: 33 cases (1995-1999).

OBJECTIVE: To determine epidemiologic, clinical, and pathologic characteristics of inflammatory mammary carcinoma (IC) in dogs. DESIGN: Retrospective study. ANIMALS: 33 dogs with IC and 153 dogs with malignant mammary tumors other than IC. PROCEDURES: Medical records were reviewed, and signalment, history, physical examination findings, and results of thoracic radiography and necropsy were obtained. RESULTS: 33 of 436 (7.6%) dogs examined at a veterinary teaching hospital because of dysplasia or tumors of the mammary glands and 33 of 186 (17.7%) dogs with at least 1 malignant tumor had IC. Thirty-two of the 33 dogs were sexually intact. Dogs with IC were significantly older than were dogs with other malignant mammary tumors, and in dogs with IC, the tumor was initially noticed a mean of 52 days after the beginning of the last observed estrus, whereas in dogs with other mammary tumors, the tumor was initially noticed a mean of 137 days after the beginning of the last observed estrus. Dogs with IC were more likely to be anorectic and to have generalized weakness, weight loss, and thoracic metastases. Dogs with IC survived a mean of 25 days with palliative treatment. Histologically, involvement of dermal lymphatic vessels was identified in 14 of 19 (74%) dogs with IC. Two clinical forms of IC (primary and secondary) were identified. Dogs with primary IC had a worse clinical condition. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that IC is an uncommon but distinct entity in dogs. A histologic finding of dermal lymphatic involvement should be considered a hallmark for the pathologic diagnosis of IC in dogs.     

Incidence of Salmonellae in Captive and Wild Free‐Living Raptorial Birds in Central Spain

A total of 595 faecal samples from raptorial birds, either captive or free‐living, residing in GREFA Wildlife Hospital were bacteriologically examined using various selective media and an Automated Diagnostic Assay System for Salmonella detection. Serotype and phage type of the strains identified as Salmonella was determined. In the captive group, of the 285 samples examined, 21 (7.36%) were positive for Salmonella. Serotyping revealed that most of the individuals were infected by Salmonella serotype Havana. This result suggested that there could be a source of contamination in the Hospital although it could not be established. In the wild free‐living group, over 310 samples examined (4.19%) were positive for Salmonella. The Salmonella isolates showed a major variety of serotypes: Enteritidis, Adelaide, Brandenburg, Newport, Typhimurium, Hadar, Saintpaul and Virchow. Most of them are similar to those commonly described in isolates from human and domestic animals. These results indicate that wild birds could be involved in the dissemination of Salmonella in humans or domestic animals or vice versa.     

Determination of sulfamethazine and trimethoprim in liquid feed premixes by HPLC and diode array detection, with an analysis of the uncertainty of the analytical results.

Sulfamethazine (SMZ) and trimethoprim (TMP) are antibacterials used in veterinary practice. This paper describes a method for their determination in veterinary liquid feed premixes that is based on liquid chromatography with diode array detection. Gradient elution with methanol and ammonium acetate achieved excellent separation of the two analytes within 15 min without any interference from the matrix. Absorbance of the column effluent was monitored at 264 nm for SMZ and at 230 nm for TMP. Detailed analyses of the uncertainties of determinations afford estimated expanded uncertainties of, respectively, 0.2 and 0.1 w/v % for typical SMZ and TMP concentrations of 10.7 and 2.1 w/v %, respectively. At the lower end of the calibrated range of the method, the dominant source of uncertainty is the preparation of standards and the construction of the calibration line.     

Effect of dietary protein content on live and carcase performance of heterozygous naked neck and normally feathered broilers

1. An experiment was conducted to determine the effect of different dietary protein contents on the performance of naked neck (Na/na) and normally feathered (na/na) broilers.

2. Chicks from the two genotypes were reared in wire‐floored cages and divided at random into 3 groups. Birds were fed on high protein (HP, 12.99 MJ ME, 238 g crude protein/kg and 12.94 MJ ME, 216 g crude protein/kg from 0 to 3 and 3 to 7 weeks, respectively), medium protein (MP, 12.99 MJ ME, 219 g crude protein/kg and 12.87 MJ ME, 201 g crude protein/kg from 0 to 3 and 3 to 7 weeks), and low protein (LP, 12.94 MJ ME, 205 g crude protein/kg and 12.75 MJ ME, 184 g protein/kg from 0 to 3 and 3 to 7 weeks) diets.

3. The LP diets resulted in a significantly lower daily body weight gain of males from 0 to 3 weeks. Dietary protein content had no effect on body weight gain from 3 to 7 weeks, body weight at 7 weeks, and the food intake of birds. Carcase composition of birds from both genotypes was unaffected by dietary protein.

4. Naked neck birds had significandy higher body weights at 7 weeks. Yields of carcase and breast of Na/na males were significantly higher than those of na/na males. There were no significant differences between females from the two genotypes as regards carcase yield.

5. It was concluded that the dietary protein requirements of naked neck birds were similar to those for normally feathered birds.     

Biological features and life table parameters of the mealy plum aphidHyalopterus pruni on different apricot cultivars

Development, survival, reproduction rate, and population growth parameters of the mealy plum aphidHyalopterus pruni (Geoffroy) (Hom.: Aphididae) were evaluated on four different apricot cultivars (Tyrinte, Sakıt, Colomer, and Bebeco) under field conditions in the Van region of Turkey. Experiments were carried out on exterior leaves of trees, 1.5–2 m above the ground. Plexiglas clip-cells (25×6 mm) with the upper side covered by muslin were used in the experiments. The mealy plum aphid performed better on Tyrinte than on the other cultivars tested. The fastest development time (first instar to adult; 9.4 days), highest daily reproduction rate (2.6 offspring/aphid/day), and highest total fecundity (48.1 offspring/aphid) were obtained on Tyrinte. The intrinsic rate of increase — a good indicator of the growth potential of a population — of individuals fed on Tyrinte was significantly greater than that of individuals fed on cvs. Colomer and Bebeco. While mean generation times (T _o ) of populations on different cultivars were close to each other, the net reproductive rate was the highest (29.45 offspring/aphid/generation) on Tyrinte and the population doubling time on Tyrinte was 18.7%, 25.2% and 26.3% faster than those of individuals on other cultivars tested. The results obtained in this study indicated that Tyrinte appeared to be the most susceptible to the mealy plum aphid among the cultivars tested. http://www.phytoparasitica.org. posting Nov. 23, 2004.     

Effect of diet composition and slaughter weight on animal performance, carcass and meat quality, and fatty acid composition in veal calves

The effect of true milk use in the diet of Spanish Brown Swiss male calves on animal performance, carcass and meat quality, and fatty acids composition was studied. In experiment 1, the effect of milk intake [ad libitum continuous (ADLIB) feed vs. restricted 0.7 during 75 days followed by ad libitum feed (RESTR)] and slaughter endpoint (225 kg vs. 5 month) were studied. In experiment 2, ad libitum concentrate feeding [grain-fed (GF)] was compared with milk supplementation until slaughter [milk-fed (MF)] in calves slaughtered at 345 kg. As regards to milk intake, carcass weight and degree of fatness were higher in the ADLIB group (P<0.05). The RESTR group revealed a higher percentage of saturated fatty acids (P<0.05). In experiment 2, the MF group exhibited a higher fat percentage (P<0.05), lower press and cooking losses (P<0.05), and higher scores for tenderness and juiciness (P<0.05) than the GF group. The percentage of saturated fatty acids was higher in the MF group (P<0.05). The results suggest that true milk use in veal production could be an advantageous alternative in terms on production costs, animal performance, and carcass and meat quality.     

C-reactive protein measurement in canine saliva.

An established time-resolved immunofluorometric assay designed for measurement of C-reactive protein (CRP) in canine blood was evaluated and validated for use in canine saliva. C-reactive protein was measured in saliva specimens from 5 healthy dogs before and after the injection of casein and in 37 dogs with different disease conditions. The analytical and functional limits of detection were 0.000053 microg/ml and 0.0091 microg/ml, respectively, and intra- and interassay coefficients of variation ranged between 6.7-9.9% and 8.5-16.5%, respectively. A recovery experiment showed no significant disagreement between detected values and expected ones, and saliva CRP concentration was measured in a linear and proportional manner. A positive correlation was found between CRP levels obtained in saliva and serum samples in the experimental (R2 = 0.76) and clinical studies (R2 = 0.70). The assay was able to detect significant differences between salivary CRP levels in healthy dogs and dogs with inflammatory processes. These results suggest that saliva can be used for CRP measurement in dogs. The use of saliva presents the advantage of an easier and less stressful sampling method for the animals, which might be performed outside of hospital environments.     

The effects of agricultural fields and human settlements on the use of rivers by wildlife in the mid-Zambezi valley,Zimbabwe

After the eradication of the Tse-Tse fly in the Mid-Zambezi valley, human settlements and fields extended mainly along the main rivers. In order to investigate the consequences of this human development on wildlife diversity we monitored three rivers of the Mid-Zambezi valley in Zimbabwe: Angwa, Manyame and Kadzi. The rivers were divided in segments of 200 m which were checked for spoors in order to assess the number of species and the number of individuals that used the segments. Human settlements were also recorded. We used a GIS to define the spatial characteristics of the fields present along the rivers, and related them to the distribution and abundance of wild species spoors in the river beds and banks. Our results show that the number of species in one segment of the river decreased with the increasing size of the field area bordering the segment. For all the major ungulate species, the numbers of individuals recorded per segment decreased with increasing field area. A similar trend was observed for small and medium-sized carnivores, though they were in lower numbers when present. Our analyses thus confirm that the extension of human agriculture in wildlife areas has an impact on most wild species, but we also define some threshold value of field size above which there seem to be an acceleration of the decrease in wildlife density and diversity: 3.2 ha for medium and small herbivores and carnivores; only the elephant seem to tolerate larger field area with a threshold value of 32 ha.This revised version was published online in May 2005 with corrections to the Cover Date.