A reconnaissance survey of farmers’ awareness of hypomagnesaemic tetany in UK cattle and sheep farms

Abstract

Hypomagnesaemic tetany (HypoMgT) in ruminants is a physiological disorder caused by inadequate intake or impaired absorption of magnesium (Mg) in the gut. If it is not detected and treated in time, HypoMgT can cause the death of the affected animal. A semi-structured questionnaire survey was conducted from July 2016–2017 to assess farmers’ awareness of HypoMgT in cattle and sheep in the UK. The questionnaire was distributed to farmers at farm business events and agricultural shows, and through a collaborative group of independent veterinary practices to their clients. Farmers were asked about (i) the incidence of presumed HypoMgT (PHT); (ii) their strategies to treat or prevent HypoMgT; (iii) mineral tests on animals, forage and soil, and (iv) farm enterprise type. A total of 285 responses were received from 82 cattle, 157 mixed cattle and sheep, and 46 sheep farmers, of whom 39% reported HypoMgT in their livestock, affecting 1–30 animals. Treatment and/or prevention against HypoMgT was reported by 96% respondents with PHT and 79% of those without. Mineral tests on animal, forage, and soil was conducted by 24%, 53%, and 66% of the respondents, respectively, regardless of PHT. There was a highly significant association between the use of interventions to tackle HypoMgT and the incidence of PHT (p < 0.01). The top three treatment/prevention strategies used were reported as being free access supplementation (149), in feed supplementation (59) and direct to animal treatments (drenches, boluses and injections) (45) although these did vary by farm type. Although some (9) reported using Mg-lime, no other pasture management interventions were reported (e.g., Mg-fertilisation or sward composition). Generally, the results indicate that UK farmers are aware of the risks of HypoMgT. A more integrated soil-forage-animal assessment may improve the effectiveness of tackling HypoMgT and help highlight the root causes of the problem.

Hypomagnesemia in beef cattle

“…These pastures are more productive and allow to increase the stocking rate (Saravia et al 2011). Prevention of hypomagnesemia in beef cattle raised in improved pastures should include a comprehensive assessment of the soil, forage, animal and the environment (Kumssa et al 2019), and effective prevention is achieved by ensuring adequate blood Mg levels by supplementing with dietary Mg (Martens & Blume 1986, Moseley & Baker 1991, Wittwer et al 1997, Martín-Tereso & Martens 2014. Additionally, the growing practice of improving natural grasslands to intensify beef cattle production, suggests the need to include nutritional measures to prevent the disease, mainly in late autumn, winter and early spring.…”

“…The concentration of Mg in the plant is partially determined by the level of exchangeable Mg in the soil (Metson 1974) and dietary Mg deficiency is associated with grasses in soils that have 0.2-0.3meq of exchangeable Mg/100g of plant roots (Welte & Werner 1963). The use of fertilizers with nitrogen (N), phosphorus (P) and potassium (K) reduces the exchangeable Mg in the soil and the availability of Mg for the plants and, consequently, for the animals (Kemp et al 1961, Grunes et al 1970, Fox & Piekielek 1984, Cohen et al 2004, Elliott 2008, Kumssa et al 2019.…”

“…Prophylactic measures for hypomagnesemic tetany include an integrated assessment of soil, forage, animals, and the environment to implement prevention strategies (Kumssa et al 2019). Beef cows of British breeds (i.e.…”

Revisiting variation in leaf magnesium concentrations in forage grasses for improved animal health

“…The Mg nutrition of intensive ruminant systems in the UK is usually controlled by supplements in the form of blocks, licks, drenches and boluses (Kumssa et al 2019a). Increasing the ability of forages to supply adequate Mg through crop breeding or use of Mg fertilisers has been a relatively neglected area of research (Kumssa et al 2019b).…”

A Spatial Analysis of Lime Resources and their Potential for Improving Soil Magnesium Concentrations and pH in Grassland Areas of England and Wales

“…If Mg de ciency could be prevented, it would be of bene t to both animal welfare and economic productivity. Recent research has con rmed that whilst hypomagnesaemia is commonly reported by UK farmers, the reported use of preventative measures is low, and the use of pasture interventions is lower still 4 . Pasture interventions can include the application of Mg-rich fertiliser or lime products, or selection of sward species with a propensity to take-up elevated Mg concentrations 4,5 .…”