Determination of depletion and statistical distribution of morantel-related residues in bovine milk following administration of morantel tartrate to dairy cows

Residue depletion studies were conducted in dairy cattle to monitor morantel-related residues in milk following oral administration of morantel tartrate (Rumate. Eleven lactating cows of various ages, periods of lactation, and known milk production were orally dosed with the bolus formulation of morantel tartrate with an actual dose range of 8.4-9.8 mg/kg body weight. Representative samples of milk were collected at 10-14 h intervals post-dose, and subsamples were assayed for the major and minor hydrolysis products of morantel-related residues, MAPA and CP-20,107. Residues assayed as precursors of MAPA peaked at the second milking (24 h post-dose) and were below 25 ppb (range: less than 12-24 ppb). Precursors of CP-20,107, which confirm the identity of morantel, also peaked at 24 h post-dose (range: 2.1-3.3 ppb) and declined rapidly thereafter. A statistical model was used to project the level of residues at the upper limit of 99% of the total target animal (i.e., dairy cattle) population with 95% confidence. The calculated peak levels from this model were 50 and 5.0 ppb for morantel-related residues convertible to MAPA and CP-20,107, respectively.     

Oxygen activation and reduction in respiration: involvement of redox-active tyrosine 244

Cytochrome oxidase activates and reduces O(2) to water to sustain respiration and uses the energy released to drive proton translocation and adenosine 5'-triphosphate synthesis. A key intermediate in this process, P, lies at the junction of the O(2)-reducing and proton-pumping functions. We used radioactive iodide labeling followed by peptide mapping to gain insight into the structure of P. We show that the cross-linked histidine 240-tyrosine 244 (His240-Tyr244) species is redox active in P formation, which establishes its structure as Fe(IV) = O/Cu(B)2+-H240-Y244. Thus, energy transfer from O2 to the protein moiety is used as a strategy to avoid toxic intermediates and to control energy utilization in subsequent proton-pumping events.     

Procedure for Maximizing Oocyte Harvest for In Vitro Embryo Production in Small Ruminants

Possible effects of repeated hormonal treatments and laparoscopic ovum pick-up (LOPU) on the efficiency of oocyte recovery rate and quality were determined in sheep and goats. In six adult Merino sheep and five Criolla goats, ovarian status was synchronized by a prostaglandin F(2 alpha) analogue and the insertion of an intravaginal sponge 48 h later. Follicle development was stimulated by a single dose of FSH (60 mg NIH-FSH-P1) plus a single dose of equine chorionic gonadotrophin (eCG; 300 UI). The first FSH/eCG doses were administered 48 h after the sponge insertion, being repeated every 4 days to complete a total of four treatments in sheep and three in goats. Follicles in both ovaries were categorized according to their diameter and follicular fluid was aspirated under laparoscopic observation without a vacuum pump. In sheep, during a 12-day-period, a total of 347 follicles were aspirated with a recovery rate of 46.9%. In goats, during an 8-day-period, 219 follicles were aspirated with a recovery rate of 45.6%. In both species, there were no significant differences in the number of aspirated follicles, oocyte recovery rate and good quality oocyte recovery rate. However, in sheep the oocyte recovery rate was higher for large follicles, whereas in goats no such effect was detected. In summary, current results indicate that retrieval of oocytes can be maximized, without affecting oocyte quality, by repeating 'oneshot' FSH/eCG regimes and LOPUs at intervals as short as 4 days.     

Salmonella monitoring programs in Australian feed mills: a retrospective analysis

The availability of safe, commercially prepared stock feed for production animals is an important step in ensuring animal health and welfare and the safety of food animal products for human consumption. Animal feed quality assurance programs include microbiological monitoring of raw materials, mill equipment and finished feed. Over a period of 16 years, 23,963 samples for Salmonella culture and serotyping were collected from 22 stock feed mills. A multivariable generalized linear mixed model (GLMM) was used to identify mill and sample type factors that increase the odds of detecting Salmonella. The odds of detecting a Salmonella positive sample was greatest in samples from raw materials and in mills that processed restricted animal material (RAM). The percentage of positive samples ranged from 7.2% in 2003 to 2.8% in 2017. Of the 1,069 positive samples, 976 were serotyped with 61 different Salmonella serotypes isolated. The serotype most frequently isolated from raw materials was S. Agona, (n = 108) whilst S. Anatum was the serotype most frequently isolated from equipment and finished feed (n = 156). The diversity of Salmonella serotypes differed between mills and different stages of the production line. Microbiological monitoring in the commercial preparation of animal feed in Australian stock feed mills guides the implementation of quality control measures and risk mitigation strategies thereby reducing the prevalence and diversity of potentially zoonotic bacteria such as Salmonella, enhancing food safety for both animal and consumer.     

Potential movement of fish and shellfish stocks from the sub‐Arctic to the Arctic Ocean

An assessment of the potential for 17 fish or shellfish stocks or stock groups to move from the sub‐Arctic areas into the Arctic Ocean was conducted. A panel of 34 experts was convened to assess the impact of climate change on the potential movement of the 17 stocks or stock groups. The panel considered the exposure of species to climate change, the sensitivity of species to these changes and the adaptive capacity of each stock or stock group. Based on expert opinions, the potential for expansion or movement into the Arctic was qualitatively ranked (low potential, potential, high potential). It is projected that the Arctic Ocean will become ice‐free during the summer season, and when this happens new areas will open up for plankton production, which may lead to new feeding areas for fish stocks. Five stocks had a low potential to move to, or expand in, the high Arctic. Six species are considered as potential candidate species to move to, or expand in, the high Arctic. Six stocks had a high potential of establishing viable resident populations in the region. These six stocks exhibit life history characteristics that allow them to survive challenging environmental conditions that will continue to prevail in the north. This study suggests that several life history factors should be considered when assessing the potentiality of a species moving in response to changing climate conditions.     

Discovery and characterization of sulfoxaflor, a novel insecticide targeting sap-feeding pests

The discovery of sulfoxaflor [N-[methyloxido[1-[6-(trifluoromethyl)-3-pyridinyl]ethyl]-λ(4)-sulfanylidene] cyanamide] resulted from an investigation of the sulfoximine functional group as a novel bioactive scaffold for insecticidal activity and a subsequent extensive structure-activity relationship study. Sulfoxaflor, the first product from this new class (the sulfoximines) of insect control agents, exhibits broad-spectrum efficacy against many sap-feeding insect pests, including aphids, whiteflies, hoppers, and Lygus, with levels of activity that are comparable to those of other classes of insecticides targeting sap-feeding insects, including the neonicotinoids. However, no cross-resistance has been observed between sulfoxaflor and neonicotinoids such as imidacloprid, apparently the result of differences in susceptibility to oxidative metabolism. Available data are consistent with sulfoxaflor acting via the insect nicotinic receptor in a complex manner. These observations reflect the unique structure of the sulfoximines compared with neonicotinoids.