PROGRESS ON IMPROVING AGRICULTURAL NITROGEN USE EFFICIENCY: UK-CHINA VIRTUAL JOINT CENTERS ON NITROGEN AGRONOM

● Virtual joint centers on N agronomy were established between UK and China. ● Key themes were improving NUE for fertilizers, utilizing livestock manures, and soil health. ● Improved management practices and technologies were identified and assessed. ● Fertilizer emissions and improved manure management are key targets for mitigation. Two virtual joint centers for nitrogen agronomy were established between the UK and China to facilitate collaborative research aimed at improving nitrogen use efficiency (NUE) in agricultural production systems and reducing losses of reactive N to the environment. Major focus areas were improving fertilizer NUE, use of livestock manures, soil health, and policy development and knowledge exchange. Improvements to fertilizer NUE included attention to application rate in the context of yield potential and economic considerations and the potential of improved practices including enhanced efficiency fertilizers, plastic film mulching and cropping design. Improved utilization of livestock manures requires knowledge of the available nutrient content, appropriate manure processing technologies and integrated nutrient management practices. Soil carbon, acidification and biodiversity were considered as important aspects of soil health. Both centers identified a range of potential actions that could be taken to improve N management, and the research conducted has highlighted the importance of developing a systems-level approach to assessing improvement in the overall efficiency of N management and avoiding unintended secondary effects from individual interventions. Within this context, the management of fertilizer emissions and livestock manure at the farm and regional scales appear to be particularly important targets for mitigation.     

Effects of adrenaline on ionic equilibria in red blood cells of rainbow trout (Salmo gairdneri)

Effects of adrenaline on the equilibrium distributions of Na⁺ , K⁺ , H⁺ , Cl^– , and H₂O across the cell membrane of rainbow trout (Salmo gairdneri) erythrocytes were determinedin vitro, as a function of P CO₂ (1.76–7.77 torr). CO₂-carrying capacity of the blood was also examined. Plasma catecholamine concentrations inunanaesthetized, unrestrained trout were 3.1 nM adrenaline and 1.2 nM noradrenaline. Elevation of the plasma adrenaline concentrationin vitro to 4.6 × 10³ nM resulted in net gains of Na⁺ , Cl^– and H₂O by red cells, a net loss of H⁺ from red cells, and a pronounced red cell swelling. Adrenaline also reduced the CO₂-carrying capacity of trout bloodin vitro. The magnitudes of these effects increased with P_CO2 and, thus, were sensitive to blood HCO₃ ^– concentrations. The distribution of K⁺ between red cells and plasma was unaffected by adrenaline. Adrenergic-mediated ion movements and red cell swelling were sensitive to both propranolol and SITS. These results are consistent with the symport NaCl uptake model for adrenergic-mediated swelling of Baroinet al. (1984). The adrenergic response of fish erythrocytes may function to ameliorate the effects of blood acidoses on O₂-carrying capacity by maintaining red cell pH in the face of a decrease in plasma pH.     

Understanding the economic and farming practices driving species selection in aquaculture within the Mymensingh division of Bangladesh

Aquaculture is a major supplier of animal protein for Bangladesh’s population, and the Mymensingh division is a major contributor to finfish aquaculture, producing 43% of the total pond pangasius and 9% of the total amount of tilapia (figures from 2018). We conducted a finfish farmer survey covering Netrokona, Jamalpur and Mymensingh districts to understand current finfish farming practices and identify factors that drive farmers in their species choice between pangasius or tilapia cultivation. We found that most finfish farmers in Mymensingh are experienced practitioners and practise polyculture with a range of stocking densities for each species. Using an economic model of polyculture practice, we have shown that over a production cycle, pangasius gain body mass at a rate nearly 4 times greater than that for tilapia, resulting in substantially larger revenues and providing a strong incentive for their culture. High levels of tilapia aquaculture likely persist due to their short production cycle and an associated decreased economic risk due to crop loss from disease, both factors providing a strong incentive for their culture. Our findings also indicate production yield differences through different species selection in polyculture systems. For example, co-culturing pangasius, tilapia and carp together was less productive than co-culture of pangasius with tilapia. Furthermore, higher yields of tilapia were obtained when co-cultured with carp compared with pangasius, the reasons for which are not known and warrant further investigation. Our study uses information provided by finfish farmers to produce a useful guide on fish species choices to maximise production yields, and therefore food production, from their ponds.

     

Supplemental feeds containing coffee pulp for rearing Tilapia in Central AmericaAlimento suplementario conteniendo pulpa de café para la crianza de Tilapia en Centro America

A supplementary feed containing 30% coffee pulp was evaluated for use in the culture of Tilapia aurea in El Salvador, Central America. A comparison of the coffee pulp feed with a feed containing all of the same ingredients except coffee pulp was made with T. aurea raised in 1.0-m³ cages suspended in a fertilized earthen pond. Survival was high in all treatments and there was no significant difference in average weight gain between groups of fish receiving the two experimental feeds. Production trials were conducted in 100-m² fish pens and in 0.05-ha earthen ponds. Pen-raised fish receiving coffee pulp feed grew faster throughout the experiment, and total production was approximately twice that in control treatments. Highest production in pens was 1.25 kg/m² per year. Results of production pond trials using T. aurea at 9 000/ha and stocked with the piscivorous Cichlasoma managuense yielded an estimated 3 392 kg/ha per year in fed treatments and 2 049 kg/ha per year in controls. Low feed conversion (1.92) and low feed cost resulted in an increase in net annual earnings of $251.00/ha.     

Determination of the quality parameters of pike perch <Emphasis Type="Italic">Sander lucioperca</Emphasis> caught by gillnet,longline and harpoon in Turkey

ABSTRACT:   The effects of the different catching methods (gillnet, longline, harpoon) on sensory, chemical (pH, total volatile base nitrogen, K -value) and microbiological (total viable count [TVC]) changes in pike perch Sander lucioperca stored in ice were investigated. The same soaking time was used for both gillnet and longline fishing. The catching method had considerable influence on the freshness quality of pike perch. The acceptable shelf life was 15 days for pike perch caught by gillnet, and 22 days for longline and harpoon. The initial concentrations of inosine monophosphate (2.4 μmol/g) in pike perch caught by gillnet were significantly lower ( P  < 0.05) than longline (4.1 μmol/g), and especially by harpoon (16.7 μmol/g). However, the initial K -values for fish caught by harpoon were significantly ( P  < 0.05) lower (24.36%) than fish caught by longline and gillnet (57.69%, 64.41%, respectively). The average K , Ki, G and H -values at rejection day in terms of sensory assessment were approximately 90, 98, 156 and 40%, respectively, for all catching methods during ice storage. However, TVC reached 7.0 log cfu/g after approximately 11 days of storage for fish caught by gillnet, 19 days for fish caught by longline and 8 days for fish caught by harpoon. The result of this study suggests that the best catching method for preserving the freshness of pike perch is longline, based on the data obtained from the sensory and microbiological analysis.     

Post-release movement and diel activity patterns of hatchery-reared and wild black-spot tuskfish <Emphasis Type="Italic">Choerodon schoenleinii</Emphasis> determined by ultrasonic telemetry

ABSTRACT:   Post-release movement and diel activity patterns of hatchery-reared and wild black-spot tuskfish were examined using ultrasonic telemetry. Five hatchery-reared and four wild fish were released in the sandy bottom of Urasoko Bay, Ishigaki Island, Okinawa, Japan, and monitored using automated monitoring receivers from November 2005 to February 2006. Both hatchery-reared and wild fish tended to stay near the release site for over two weeks, before leaving the release site. Both hatchery-reared and wild tuskfish showed diurnal rhythm intermittently; signals were recorded more frequently in the daytime and less frequently in the nighttime, suggesting that the fish of both origins were active during the day and inactive during the night. These findings indicate that the one-year-old hatchery-reared tuskfish have some consistent behavioral characteristics with those of the wild.     

An investigation of the effects of ketoprofen following rumen fistulation surgery in lactating dairy cows

Post-operative pain management following rumen surgery is not common practice. We examined the effect of providing the pain medication ketoprofen to dairy cattle following the first stage of a rumen cannulation surgery, which involves an incision in the body wall and exteriorizing and clamping the rumen. The results of this study provide clear evidence that the first stage of the surgery was painful and ketoprofen at the time of and 24 h following surgery, alleviated some, but not all, of the post-surgical pain. Pain mitigation should be included when performing flank surgery in cattle.     

Genomic analysis of influenza A virus from captive wild boars in Brazil reveals a human-like H1N2 influenza virus

Influenza is a viral disease that affects human and several animal species. In Brazil, H1N1, H3N2 and 2009 pandemic H1N1 A(H1N1)pdm09 influenza A viruses (IAV) circulate in domestic swine herds. Wild boars are also susceptible to IAV infection but in Brazil until this moment there are no reports of IAV infection in wild boars or in captive wild boars populations. Herein the occurrence of IAV in captive wild boars with the presence of lung consolidation lesions during slaughter was investigated. Lung samples were screened by RT-PCR for IAV detection. IAV positive samples were further analyzed by quantitative real-time PCR (qRRT-PCR), virus isolation, genomic sequencing, histopathology and immunohistochemistry (IHC). Eleven out of 60 lungs (18.3%) were positive for IAV by RT-PCR and seven out of the eleven were also positive for A(H1N1)pdm09 by qRRT-PCR. Chronic diffuse bronchopneumonia was observed in all samples and IHC analysis was negative for influenza A antigen. Full genes segments of H1N2 IAV were sequenced using Illumina's genome analyzer platform (MiSeq). The genomic analysis revealed that the HA and NA genes clustered with IAVs of the human lineage and the six internal genes were derived from the H1N1pdm09 IAV. This is the first report of a reassortant human-like H1N2 influenza virus infection in captive wild boars in Brazil and indicates the need to monitor IAV evolution in Suidae populations.