Spatial patterns of lacustrine fish assemblages in a catchment of the Mississippi Alluvial Valley

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Mesquite bean (Prosopis juliflora) meal in diets of Nile tilapia (Oreochromis niloticus): Nutritional value,growth, physiological responses and health

Two experiments were conducted to assess the nutritional value and potential use of mesquite bean (Prosopis juliflora) meal (MBM) to substitute corn in extruded diets for Nile tilapia (Oreochromis niloticus). Digestible energy and the content of protein, soluble carbohydrates and amino acids were measured for 160 Nile tilapia juveniles (average weight 25.58 ± 5.52 g), allocated to eight treatment groups (four fed the experimental diet, and four fed a reference diet). To determine the inclusion potential of MBM, 384 fish (average weight 21.85 ± 1.01 g) were used and allocated to 24 tanks (1,000 L capacity). The experimental design was completely randomized with six levels of substitution (0%, 20%, 40%, 60%, 80% and 100%), and four repetitions. After the feeding experiment, tissue samples (blood, liver, muscle and intestine) were used to analyse metabolic and haematological variables. MBM produced apparent digestibility coefficients (ADC) similar to those of traditional diet ingredients: 81.85% dry matter (DM), 83.02% crude energy, 88.57% crude protein, 82.88% lysine and 82.57% methionine. Differences were observed in the digestibility of soluble carbohydrates (p < 0.05), with MBM having higher levels of starch (72.19%) and sucrose (88.99%). A 20% substitution with MBM produced a decrease in zootechnical performance (p < 0.05). Enzymatic activity of amylase and sucrose seemed to be induced in response to the proportion of their respective substrate in the diets. We observed a reduction in the efficiency of dietary protein utilization, with reduced levels of plasma amino acids (p < 0.05), owing to the increase in the enzymatic activity of muscular alanine and aspartate transaminases (ALT and AST) and the deaminase glutamate dehydrogenase in the hepatic and muscular tissues. Haematological variables did not indicate any adverse effects of MBM on the health status or survival of the fish (100%). Therefore, we conclude that MBM may be a viable alternative to corn meal in the diet, enabling substitution of up to 20%.     

Effects of dietary dehydrated lemon peel on some biochemical markers related to general metabolism,welfare and stress in gilthead seabream (Sparus aurata L.)

Dehydrated lemon peel (DLP) at two levels (1.5% and 3%) was included for 30 days in the diet of gilthead seabream (Sparus aurata L.) and after 15 and 30 days the serum and skin mucus of fish were analysed. In serum, both experimental diets led to an initial decrease in glucose and lactate after which the levels became comparable to the control. Dietary DLP modulated the activity of transaminases, alanine aminotransferase and aspartate aminotransferase. The total antioxidant status showed a progressive increase in relation to levels of inclusion of DLP and time of administration (p < .05). In skin mucus, some biomolecular markers related to general stress, oxidative stress and apoptosis exhibited variations that suggest an adaptive response of fish to the new metabolic situation, resulting from the experimental diet. The inclusion of DLP in the diet seems to positively modulate the central metabolism and welfare of gilthead seabream.     

Diversity and stress tolerance in rhizobia from Parque Chaqueño region of Argentina nodulating Prosopis alba

The aim of this work was to investigate the genetic diversity, symbiotic effectiveness, drought tolerance, and indole acetic acid production of indigenous rhizobial populations in the Parque Chaqueño of Argentina able to nodulate Prosopis alba, the dominant forest tree of this region. The populations were sampled at five locations from the Arid, Semi-arid, and Humid Chaco in the Parque Chaqueño region. A set of rhizobial strains able to nodulate P. alba was obtained and selected based on their molecular diversity. Data obtained by BOX-PCR indicated that the highest molecular variability was observed in rhizobial isolates from Semi-arid Chaco. High level of indolic compound production and tolerance to osmotic treatment were significantly (p?≤?0.05) correlated with water restrictions of the environments where the strains belonged. A small set of rhizobial strains that stimulate P. alba growth was selected from a large group of strains. The strains were identified by 16S rDNA sequencing as belonging to the genera Mesorhizobium, Bradyrhizobium, and Ensifer. To our knowledge, this is the first report of P. alba nodulation by strains other than Mesorhizobium chacoense, which was already described for the Parque Chaqueño.     

Assessment of some blood parameters as potential markers of hepatic copper accumulation in cattle.

The increasing frequency of copper (Cu) toxicosis episodes in cattle in recent years, mainly associated with excess Cu supplementation, underscores the need to identify animals in the clinically silent phase of hepatic Cu accumulation. The aim of the study reported here was to evaluate the suitability of various blood parameters as potential early markers of hepatic Cu accumulation in cattle. Paired liver and blood samples from 70 calves aged 6 to 10 months were obtained at slaughter in a region in northwestern Spain where animals usually have hepatic Cu concentration higher than safe values. Neither serum Cu concentration nor ceruloplasmin (CP) concentration, the 2 parameters most commonly used for diagnosis of Cu deficiency, were significantly associated with hepatic Cu concentration. However, whole-blood Cu concentration had a slight but significant correlation with hepatic Cu concentration (r = 0.269, P = 0.026). The use of calculated blood parameters, such as the serum or whole-blood non-CP Cu fraction, or the CP-to-serum Cu ratio, increased the correlation with the hepatic Cu concentration (r = 0.393, P = 0.001, in the case of whole-blood, non-CP Cu concentration), but the strength of the association remained insufficient for accurate prediction of hepatic Cu values. Likewise, hepatic enzyme (aspartate transaminase and gamma-glutamyltransferase) activities were significantly or nearly correlated significantly with hepatic Cu concentration, but the strength of the association remained too low for accurate prediction. It is concluded that direct analysis of Cu concentration in liver biopsy specimens--preferably postmortem liver samples obtained at slaughter--is the best technique currently available for detecting chronic subclinical Cu accumulation in cattle at risk for supraoptimal Cu exposure.     

Recovery efficiency of nitrogen from liquid and solid fractions of pig slurry obtained using different separation technologies

The characteristics of solid (SF) and liquid (LF) fractions resulting from solid–liquid separation of pig slurry depend on the separation technique used. It can be assumed that the separation technique will also affect the nitrogen (N) availability to plants. A pot experiment was performed with ryegrass to compare the N‐recovery efficiency of SFs and LFs obtained with four frequently used separation techniques (centrifugation [Cent], sediment settling during 20 h [Sed], enhanced settling during 20 h by addition of cationic polyacrylamide [Sed+PAM], sieving [Siev], sieving followed by treatment of the resulting liquid fraction by PAM addition [Siev+PAM]) with the untreated slurry (US) and an unfertilized control. Increases (2–17%) of ryegrass dry matter yield (DMY) were obtained in LF treatments relative to US. However, this increase was statistically significant only for the Siev+PAM‐L treatment. A significant decrease of ryegrass DMY was observed in SF treatments relative to US. All treatments with SFs led to similar values of DMY while only small differences were observed between treatments receiving LFs. A significant correlation (R² = 0.968) was observed between the total DMY and the NH$ _4^+ $ ‐ N : N_tot ratio of the fraction applied suggesting that this is a major parameter to be considered when comparing separation techniques. Overall, the separation techniques showed only a weak effect on the dry matter yields and on the N ‐ recovery efficiency from LF and SF although they strongly affected the nutrient concentration and speciation in each fraction.     

Factors Associated with Dog Rabies Vaccination in Bhol,Philippines: Results of a Cross‐Sectional Cluster Survey Conducted Following the Island‐Wide Rabies Elimination Campaign

The Philippines has a long history of rabies control efforts in their dog populations; however, long‐term success of such programmes and the goal of rabies elimination have not yet been realized. The Bohol Rabies Prevention and Elimination Program was developed as an innovative approach to canine rabies control in 2007. The objective of this study was to assess canine rabies vaccination coverage in the owned‐dog population in Bohol and to describe factors associated with rabies vaccination 2 years after implementation of the programme. We utilized a cross‐sectional cluster survey based on the World Health Organization’s Expanded Programme on Immunization coverage survey technique. We sampled 460 households and collected data on 539 dogs residing within these households. Seventy‐seven per cent of surveyed households reported owning at least one dog. The human‐to‐dog ratio was approximately 4 : 1, and the mean number of dogs owned per household was 1.6. Based on this ratio, we calculated an owned‐dog population of almost 300 000. Overall, 71% of dogs were reported as having been vaccinated for rabies at some time in their lives; however, only 64% of dogs were reported as having been recently vaccinated. Dogs in our study were young (median age = 24 months). The odds of vaccination increased with increasing age. Dogs aged 12–23 months had 4.6 times the odds of vaccination compared to dogs aged 3–11 months (95% CI 1.8–12.0; P = 0.002). Confinement of the dog both day and night was also associated with increased odds of vaccination (OR = 2.1; 95% CI 0.9–4.9; P = 0.07), and this result approached statistical significance. While the programme is on track to meet its goal of 80% vaccination coverage, educational efforts should focus on the need to confine dogs and vaccinate young dogs.     

Conventional and functional magnetic resonance imaging features of late subacute cortical laminar necrosis in a dog

Cerebral cortical laminar necrosis (CLN) is a consequence of severe hypoxic, ischemic, or hypoglycemic events. In humans, these cortical lesions show characteristic linear T1‐weighted (T1W) hyperintensity in the late subacute stage. Limited information reporting magnetic resonance imaging (MRI) findings in dogs affected by CLN is available. A 3‐year‐old Belgian Shepherd dog was referred 8 days after sudden onset of blindness after general anesthesia. Neurological examination showed central blindness and mild ataxia. Three‐Tesla MRI examination of the brain revealed bilateral asymmetrical areas of T2‐weighted hyperintensity within the occipital, parietal, temporal, and frontal cortex, involving gray and white matter. Furthermore, linear T1W‐hyperintense lesions were found in the cerebral cortex of the same areas and showed heterogeneous contrast enhancement. Perfusion‐weighted images revealed hyperperfusion in the affected regions. Lesions were compatible with subacute CLN with corresponding edema suspected to be secondary to anesthesia‐related brain hypoxia. Three‐Tesla MRI enabled identification of the laminar pattern of the cortical lesions.     

Prevalence of selected infectious organisms and comparison of two anatomic sampling sites in shelter cats with upper respiratory tract disease

In order to describe the isolation rates of potential pathogens and to compare anatomic sampling site suitability, nasal and pharyngeal swabs were taken from cats with acute clinical upper respiratory disease in a humane society. DNA of feline herpesvirus-1 was amplified from 51 of 52 cats sampled, Mycoplasma species were cultured or detected by PCR in samples from 34 of 42 cats sampled for both culture and PCR, and Bordetella bronchiseptica was isolated from three of 59 cats sampled for aerobic culture. A single swab was positive for calicivirus and no swabs were positive for Chlamydophila felis. Mycoplasma, Pasteurella and Moraxella species were all isolated from at least one cat in which no primary pathogen was identified. With the exception of B. bronchiseptica, which was detected in nasal swabs only, recovery rates for all suspect primary pathogens were comparable between sampling sites.