Factors associated with Ontario dairy producers' management and care of down dairy cattle.

The objective of this study was to better understand current management practices for down cows in Ontario, Canada, and to identify factors associated with the adoption of acceptable practices. An online survey was distributed to all dairy producers in Ontario, Canada (n = 3,367) and was available from November 2020 to March 2021, inclusive. Dairy producers were identified through their provincial dairy organization and contacted via email, and the survey was also promoted via social media. The survey was comprised of 134 questions, 31 of which were related to down cow management. Descriptive statistics were evaluated, and 2 logistic regression models were generated using Stata 17, exploring factors associated with 1) relocating down cows with hip lifters and 2) assisting cows to stand within an hour after discovering a down cow. A total of 226 producers responded (7.4%). Participants were predominantly male (68%), farm owners (78%), and 30-39 years old (29%). Producers reported relocating down cows with a boat or sled (32.6%), front-end loader bucket (31.4%), hip lifters (28.0%), or 'other' (with a text box to further describe) (8.0%). The median time to relocating a down cow after identifying her was 1 h (range 0 - 17h). Farms that relocated a down cow sooner after identifying her as down, were more likely to use appropriate methods to move the cow. However, we also found that farms that provided feed and water sooner to down cows, were more likely to use an inappropriate method (hip lifters) to move her. Farms that used hip lifters to move cows had higher odds of assisting a cow to stand within an hour following the discovery of recumbency. Additionally, producers who waited longer to relocate a down cow were less likely to assist the cow to stand within one hour of finding them down. Research has identified effective management practices for down cows, yet there remains a gap in understanding the implementation and the decision-making process of producers. Data from this study will be helpful in designing future research that further explores the barriers and motivations of producers when implementing evidence-based management plans to care for down dairy cows and may help inform current industry extension efforts.

Spring-summer net community production, new production, particle export and related water column biogeochemical processes in the marginal sea ice zone of the Western Antarctic Peninsula 2012-2014.

New production (New P, the rate of net primary production (NPP) supported by exogenously supplied limiting nutrients) and net community production (NCP, gross primary production not consumed by community respiration) are closely related but mechanistically distinct processes. They set the carbon balance in the upper ocean and define an upper limit for export from the system. The relationships, relative magnitudes and variability of New P (from 15NO3- uptake), O2 : argon-based NCP and sinking particle export (based on the 238U : 234Th disequilibrium) are increasingly well documented but still not clearly understood. This is especially true in remote regions such as polar marginal ice zones. Here we present a 3-year dataset of simultaneous measurements made at approximately 50 stations along the Western Antarctic Peninsula (WAP) continental shelf in midsummer (January) 2012-2014. Net seasonal-scale changes in water column inventories (0-150 m) of nitrate and iodide were also estimated at the same stations. The average daily rates based on inventory changes exceeded the shorter-term rate measurements. A major uncertainty in the relative magnitude of the inventory estimates is specifying the start of the growing season following sea-ice retreat. New P and NCP(O2) did not differ significantly. New P and NCP(O2) were significantly greater than sinking particle export from thorium-234. We suggest this is a persistent and systematic imbalance and that other processes such as vertical mixing and advection of suspended particles are important export pathways.This article is part of the theme issue 'The marine system of the west Antarctic Peninsula: status and strategy for progress in a region of rapid change'.

Global sea-surface iodide observations, 1967-2018.

The marine iodine cycle has significant impacts on air quality and atmospheric chemistry. Specifically, the reaction of iodide with ozone in the top few micrometres of the surface ocean is an important sink for tropospheric ozone (a pollutant gas) and the dominant source of reactive iodine to the atmosphere. Sea surface iodide parameterisations are now being implemented in air quality models, but these are currently a major source of uncertainty. Relatively little observational data is available to estimate the global surface iodide concentrations, and this data has not hitherto been openly available in a collated, digital form. Here we present all available sea surface (<20 m depth) iodide observations. The dataset includes values digitised from published manuscripts, published and unpublished data supplied directly by the originators, and data obtained from repositories. It contains 1342 data points, and spans latitudes from 70°S to 68°N, representing all major basins. The data may be used to model sea surface iodide concentrations or as a reference for future observations.