Use of radio-frequency identification technology to assess the frequency of cattle visits to mineral feeders

Effects of electrolyte supplementation on performance and physiological responses of preconditioning beef calves

The objective of this study was to evaluate the effects of electrolyte solution supplementation on the performance and physiological responses of beef calves during a 45-d preconditioning phase. Forty Angus × Hereford steers (230.4 ± 4.8 kg body weight [BW]) were sorted into 20 pens (2 steers/pen) following weaning (day 0). Treatments were randomly assigned to pens: (1) control: access to water only and (2) electrolyte: access to water and electrolyte solution supplementation (10% of total daily water intake) from days 1 to 14. Calf BW and blood samples were collected on days 0, 1, 3, 7, 14, 21, and 44 of the study. Blood samples were analyzed for sodium, potassium, albumin, haptoglobin, ceruloplasmin, and cortisol. All variables were analyzed using the MIXED procedure of SAS. Electrolyte solution consumption was estimated at 0.70 kg/calf daily (SEM ± 0.21). Calves assigned to the Electrolyte treatment had greater water and total liquid intake than control (P < 0.05). No effects of treatment were observed on ADG or BW (P > 0.05). Effects of day (P < 0.004), but not treatment or treatment × day were observed for sodium, potassium, albumin, cortisol, ceruloplasmin, and haptoglobin. Electrolyte solution supplementation during the preconditioning period did not improve performance nor influenced stress-related markers, however improved liquid intake.

Update on copper and selenium in Canadian cow-calf herds: regional differences and estimation of serum reference values

Trace mineral supplementation of beef cattle is essential for efficient reproduction and herd health. Understanding regional differences in cow trace mineral status could inform decisions about risks of deficiencies and supplementation management. Cow-calf surveillance projects provided three opportunities to evaluate the trace mineral status of Canadian beef cow herds. Blood samples were collected at pregnancy testing in 2014 from 102 cow-calf herds and in 2016 from 86 cow-calf herds in Western Canada. In 2019, blood samples were collected at pregnancy testing from cows in 163 cow-calf herds from Eastern and Western Canada. Serum samples were analyzed for copper, selenium, and molybdenum concentrations using a plasma mass spectrometer. The prevalence of copper deficient cows sampled from the Western provinces ranged from 24% to 43% across the three periods, and was 20% from Eastern Canada in 2019. The prevalence of selenium deficient cows ranged from 0.2% to 0.4% across the three projects in Western Canada, but was higher in Eastern Canada at 4.6% in 2019. High serum molybdenum was identified in 9.4% to 14% of cows across the three periods in Western Canada and in 15% of cows sampled in Eastern Canada in 2019. Serum copper, selenium, and molybdenum concentrations varied by cow age and month of sample collection. Serum selenium and molybdenum concentrations, but not copper, varied by soil type associated with the location of the farm. A subsample of samples from cows from Western Canadian herds provided body condition score (BCS) data, pregnancy status, and calf survival data and were used to estimate updated serum reference values for adequate concentrations. Age-specific values were required for selenium and molybdenum. Reference intervals (80%) were estimated from 2,406 pregnant beef cows from 99 herds with each cow having a BCS ≥ 2.5/5 and a live calf at 3 wk with no retained placenta: copper for all cows (0.379 to 0.717 ppm), selenium for cows <4 yr (0.052 to 0.152 ppm), and selenium for cows ≥4 yr (0.064 to 0.184 ppm). Upper 90% reference limits were also estimated for serum molybdenum for cows <4 yr (>0.104 ppm) and cows ≥4 yr (>0.110 ppm). The lower limits for the reference intervals for adequate copper and selenium are below those previously reported; nevertheless, they represent a large sample that was specifically applicable to extensively managed beef animals in western Canada.

Trace Mineral Nutrition of Grazing Beef Cattle

Simple Summary

The trace mineral nutrition of grazing beef cattle is an essential, but often complicated component of the management program. Throughout the annual cycle, forage is the primary source of trace mineral supply to grazing cattle, but concentrations vary depending on a multitude of factors. Trace mineral deficiencies are common when relying solely on forage to meet cattle requirements. Selenium, Cu, Zn, Mn, Co, and I are the trace minerals most commonly found to be deficient in forage. Trace mineral antagonists, such as Fe, Mo, and S, are commonly found in forage and exist in varying concentrations further complicating the success of satisfying the requirement of grazing cattle. Trace mineral-fortified, salt-based, free-choice supplements are the most common supplementation strategies available. Cattle voluntarily consume these supplements to satisfy their salt craving and thus indirectly receive supplemental trace minerals. Managing salt inclusion and seasonal variation in voluntary intake are essential to the success of this management system. Supplements can be formulated with a variety of trace mineral ingredients available to the industry, which are generally grouped into different source categories. Other supplementation strategies to supply trace minerals to grazing cattle include fortification of energy and protein supplements, biofortification, injectable trace minerals, and boluses.

Abstract

The trace mineral requirements of grazing beef cattle are often complicated by different environmental factors, such as the lack of specific trace minerals or the presence of trace mineral antagonists in forage. Nearly every region of the world has specific implications related to trace mineral nutrition of grazing cattle. Since forage is the most significant contributor to trace mineral nutrition, it is important to consider the concentrations of trace minerals and antagonists and how they may impact the performance of cattle consuming them. This review attempts to provide an update on the trace minerals commonly found to be inadequate in forage, supplementation strategies to address deficiency including a discussion on supplemental trace mineral source, and the complications presented by mineral antagonists. Although the review focuses on beef cattle grazing systems of the United States, the information herein is derived from both extensive native range and intensive planted pasture.