Fly Prepupae as a Feedstuff for Rainbow Trout, Oncorhynchus mykiss

Fly larvae may provide an effective method to mitigate two large and growing global concerns: the use of fish meal derived from capture fisheries in aquaculture diets and manure management in livestock and poultry facilities. A 9‐wk feed trial was conducted to determine whether fly larvae could be used as a partial fish meal and fish oil replacement in rainbow trout, Oncorhynchus mykiss, diets. A trout diet was formulated to contain 40% crude protein and 15% fat. Sixty‐seven percent of the protein in the control diet was derived from fish meal, and all the fat was derived from fish oil. Two of the test diets included using the black soldier fly, Hermetia illucens, prepupae, which are 40% protein and 30% fat, as 25 and 50% replacement for the fish meal component of the control diet. The total protein derived from black soldier fly prepupae in these two test diets was 15 and 34%, respectively. A third test diet included using housefly, Musca domestica, pupae, which is 70% protein and 16% fat, as 25% replacement for the fish meal component of the control diet. Data suggest that a rainbow trout diet where black soldier fly prepupae or housefly pupae constitute 15% of the total protein has no adverse effect on the feed conversion ratio of fish over a 9‐wk feeding period. In addition, the diet with black soldier fly prepupae permitted a 38% reduction in fish oil (i.e., from 13 to 8%); however, fish fed black soldier fly diets low in fish oil had reduced levels of omega‐3 fatty acids in their muscle fillets. The findings from this study suggest that either the black soldier fly or the housefly may be a suitable feedstuff for rainbow trout diets.     

Fish Offal Recycling by the Black Soldier Fly Produces a Foodstuff High in Omega-3 Fatty Acids

Abstract.— The black soldier fly, Hermetia illucens , has the potential to reduce animal waste on livestock facilities and produce an animal-grade feedstuff high in protein and fat. The lipid content of insects is largely dependent on their diet. Data from this study suggest that black soldier fly prepupae incorporate α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) when fish offal is included in their diet. Fly larvae were fed three different proportions of fish offal and cow manure diets over a 21-d trial. An additional group of larvae were fed 22% fish offal diet within 24 h of their pupation. Larvae fed fish offal were, on average, 30% lipid, which was 43% more than the controls fed cow manure only, and approximately 3% of this lipid was omega-3 fatty acids (EPA, DHA, and ALA). Furthermore, this concentration of omega-3 fatty acids was achieved within 24 h of feeding fish offal. These omega-3 fatty-acid-enhanced prepupae may be a suitable fish meal and fish oil replacement for carnivorous fish and other animal diets. In addition, they may provide a method of reducing and recycling fish offal from processing plants.     

Effect of proline‐enriched abalone feed on selected metabolite levels of slow‐growing adult Haliotis midae

Abalone is currently considered South Africa's most successfully produced aquaculture export product, with a 76% share of the total value generated by the aquaculture sector. A major risk factor for this sector is slow growth rates experienced during farming. Abalone feeds are often supplemented with amino acids in an attempt to enhance abalone growth. This is a first investigation of the effect of added proline to standard abalone feed, on the metabolite profile of slow‐growing abalone. A targeted liquid chromatography tandem mass spectrometry metabolomics research approach was followed to recognise the metabolic response of abalone showing slower growth performance. The addition of proline to the standard abalone diet was found to serve as a substrate for amino acid catabolism in slower growing abalone, by means of proline breakdown to assist with energy production via the tricarboxylic acid cycle. Other amino acids and urea cycle intermediates, that is, arginine, asparagine, ornithine and creatine further support energy production via the action of protein catabolism in slow‐growing abalone. Additionally, the importance of understanding how abalone respond metabolically to modified feed highlights the use of metabolomics to answer abalone aquaculture farming questions.     

Assessment of cardiac output measurement in dogs by transpulmonary pulse contour analysis

Objective – To determine if metatarsal artery pressure (COmet) is comparable to femoral artery pressure (COfem) as the input for transpulmonary pulse contour analysis (PiCCO) in anesthetized dogs, using the lithium dilution method (LiDCO) as a standard for cardiac output (CO) measurement. Design – Prospective randomized study. Setting – University research laboratory. Animals – Ten healthy purpose‐bred mixed breed dogs were anesthetized and instrumented to measure direct blood pressure, heart rate, arterial blood gases, and CO. Interventions – The CO was measured using LiDCO and PiCCO techniques. Animals had their right femoral and left distal metatarsal artery catheterized for proximal (COfem) and distal (COmet) PiCCO analysis, respectively. Measurements were obtained from each animal during low, normal, and high CO states by changing amount of inhalant anesthetics and heart rate. Measurements were converted to CO indexed to body weigh (CI_BW=CO/kg) for statistical analysis. Agreement was determined using Bland and Altman analysis and concordance correlation coefficients. Measurements and Main Results – Thirty paired measurements were taken. The LiDCO CI_BW (± SD) was 68.7 ± 30.3, 176.0 ± 53.0, and 211.1 ± 76.5 mL/kg/min during low, normal, and high CO states, respectively. There was a significant effect of CI_BW state on bias and relative bias with COmet (P<0.001 and P=0.003, respectively). Bias of the COmet method (± SD) was ?116.6 (70.5), 20.1(76.4), and 91.3 (92.0) mL/kg/min at low, normal, and high CI_BW, respectively. Bias of the COfem (± SD) was ?20.3 (19.0), 8.6 (70.9), and ?2.9 (83.0) mL/kg/min at low, normal, and high CI_BW, respectively. The mean relative bias for COfem was ?6.7 ± 44% (limits of agreements: ?81.2 to 67.9%). Conclusion – Compared with lithium dilution, the pulse contour analysis provides a good estimation of CO, but requires femoral artery catheterization in anesthetized dogs.     

Herd-level risk factors for Neospora caninum seroprevalence in dairy farms in southern Brazil

A cross-sectional study was used to test the relationship between herd seroprevalence to Neospora caninum and various potential herd-level risk factors in 60 dairy farms located in two distinct regions in southern Brazil. Thirty farms were randomly selected from within each region. A questionnaire was designed to summarize each farm's production system as it might relate to N. caninum transmission. The questionnaire contained 105 closed questions relating to general characteristics of the farms, farm facilities, management, source of food and water, herd health, environment and biosecurity, which included questions relevant to N. caninum transmission, including presence and number of dogs and other animals, purchase of animals and contact with man. Serum samples were collected from 40% of animals in each farm and N. caninum antibodies were detected by immunofluorescent antibody test (IFAT). The association between potential risk factors and the probability of an animal being seropositive was modeled using a generalized estimation equations (GEE) logistic regression model. The model accounted for multilevel correlation of data from multiple animals within herds. The mean (+/-S.D.) number of animals in the 60 herds was 64.5 (+/-45.6), ranging from 20 to 280 females. Blood samples were collected from 1549 animals. The size of the farms varied from 4 to 100 ha (mean 30.1+/-25.9 ha). At least one dog was found in 57 of the 60 dairy farms (95%). The mean number of dogs was 3.1 (+/-1.9), ranging from 0 to 10. All females were raised on pasture. For all cattle sampled, N. caninum seroprevalence was 17.8%. Overall, 93.3% of herds (56/60) had at least one seropositive animal identified. Four variables were significantly associated with N. caninum sero-response in the 57 dairy farms, which were included in the final multivariable model: the number of dogs on the farm, farm area (hectares), feeding pooled sources of colostrum and region. The odds of a cow being seropositive increased 1.13 times for each additional dog present on the farm (P=0.021). Cattle from farms that fed calves colostrum pooled from multiple cows had 1.79 times greater odds for being seropositive for N. caninum (P<0.003). The probability of being seropositive was inverse to the area of the farms, such that cattle had 0.92 times the odds to be seropositive (P=0.014) for each additional 10 ha of farmland. Finally, cattle from farms in region one had 0.71 times the odds to be seropositive than cattle from region two (P=0.035). Results of this study suggest that several risk factors may explain why dairy cattle in Brazil may become exposed to N. caninum. However, further investigation of these factors is necessary because the purpose of this study was to refine and generate hypotheses on N. caninum transmission.     

Comparison of the effects of caffeine and doxapram on respiratory and cardiovascular function in foals with induced respiratory acidosis

OBJECTIVE: To determine and compare the effects of caffeine and doxapram on cardiorespiratory variables in foals during isoflurane-induced respiratory acidosis. ANIMALS: 6 clinically normal foals (1 to 3 days old). PROCEDURES: At intervals of > or = 24 hours, foals received each of 3 IV treatments while in a steady state of hypercapnia induced by isoflurane anesthesia (mean +/- SD, 1.4 +/- 0.3% endtidal isoflurane concentration). After assessment of baseline cardiorespiratory variables, a low dose of the treatment was administered and variables were reassessed; a high dose was then administered, and variables were again assessed. Sequential low- and high-dose treatments included doxapram (loading dose of 0.5 mg/kg, followed by a 20-minute infusion at 0.03 mg/kg/min and then 0.08 mg/kg/min), caffeine (5 mg/kg and 10 mg/kg), and saline (0.9% NaCl) solution (equivalent volumes). RESULTS: Administration of doxapram at both infusion rates resulted in a significant increase in respiratory rate, minute ventilation, arterial blood pH, PaO(2), and arterial blood pressure. These variables were also significantly higher during doxapram administration than during caffeine or saline solution administration. There was a significant dose-dependent decrease in PaCO(2) and arterial bicarbonate concentration during doxapram treatment. In contrast, PaCO(2) increased from baseline values after administration of saline solution or caffeine. The PaCO(2) value was significantly lower during doxapram treatment than it was during caffeine or saline solution treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that doxapram restored ventilation in a dose-dependent manner in neonatal foals with isoflurane-induced hypercapnia. The effects of caffeine on respiratory function were indistinguishable from those of saline solution.     

Protoplasts in the analysis of early plant-pathogen interactions: current applications and perspectives

Transient gene expression in protoplasts has been applied to the analysis of gene expression, promoter activity, subcellular localization of proteins, and genome editing. Its advantages have been realized in recent years in various physiological, biochemical, genetic, and molecular biological studies. The omics and systems biology studies of plant development and their interactions with the environment have revitalized this approach. Early plant-pathogen interaction represents one of the most unique signalling research areas. Here, we try to discuss some developments and current applications of the protoplast system. It is for sure that the system will significantly bridge the gap between high throughput approaches and functional analysis in the study of plant-pathogen interactions in the omics era.     

Cardiopulmonary effects of a new inspiratory impedance threshold device in anesthetized hypotensive dogs

ObjectiveTo compare the hemodynamic and respiratory effects of an inspiratory impedance threshold device (ITD) in anesthetized normotensive and hypotensive dogs.Study designProspective randomized study.AnimalsTen adult dogs.MethodsDogs were anesthetized with propofol followed by isoflurane. During spontaneous ventilation, tidal volume ( $\dot{\mathrm{V}}$), systolic (SAP), mean (MAP) and diastolic arterial blood pressure, central venous pressure, gastric PCO₂ as an indicator of gastric perfusion, subcutaneous oxygen tension, subcutaneous blood flow, cardiac index (CI), systemic vascular resistance and blood lactate were monitored. To monitor respiratory compliance (RC) and resistance (ResR), animals were briefly placed on mechanical ventilation. Dogs were studied under four different conditions: 1) normotension (MAP > 60 mmHg) with and without the ITD and 2) hypotension (target MAP = 40 mmHg) with and without ITD. These four conditions were performed during one anesthetic period, allowing for stabilization of parameters for each condition. Data were analyzed by anova repeated measure mixed models.ResultsNo cardiovascular changes were detected between no ITD and ITD in the normotensive state. During hypotension, CI was higher with the ITD (5 ± 1.0 L minute^?1 m^?2) compared with no ITD (4 ± 1.3 L minute^?1 m^?2). During hypotension, SAP was increased with ITD (80 ± 14 mmHg) versus without ITD (67 ± 13 mmHg). There was an increase in ResR and decreased RC with the ITD in both normotensive and hypotensive state.Conclusion and clinical relevanceImpedance threshold device in dogs during isoflurane-induced hypotension improved CI and SAP but had negative effects on RC and ResR.     

Characterisation of BaYMV and BaMMV Pathotypes in France

The reaction of thirty-four barley cultivars from European and Asiatic origin was analysed in six soils infected with barley yellow mosaic virus complex (BaYMV, BaMMV). These soils were selected from 16 sites for their differences in cultivar response. Amongst the six cultivars carrying the ym4 gene (Esterel, Express, Labéa, Majestic, Réjane, Vanoise), only cv Majestic was infected at one site with BaYMV and BaMMV. Concerning BaYMV, three cultivars were infected on all the soils and 19 on none of them. Twelve cultivars were differentially infected depending on the soil. In the case of BaMMV, four cultivars were infected on all the soils and 19 on none of them. Eleven cultivars were differentially infected depending on the soil. ELISA tests revealed the presence, in these soils, of variants of BaYMV and BaMMV that were able to overcome at least seven of the 12 known resistance genes (ym3, ym4, ym6, ym8, ym9, ym10, ym11) and the resistance of three varieties (Tosan Kawa 73, OU1 and Taihoku A) in which the genetic basis is unknown. Amplification by RT-PCR of the N-terminal region for three of BaYMV variants was performed. Nucleotide and amino acid sequences were determined and compared with the corresponding sequence of a common strain of BaYMV-G. A few nucleotide differences were detected between all the French isolates, but there were no strain specific amino acid differences.