Utilizing an electronic feeder to measure individual mineral intake, feeding behavior, and growth performance of cow-calf pairs grazing native range

Crossbred Angus cow-calf pairs ( = 28 pairs) at the Central Grasslands Research Extension Center (Streeter, ND) were used to evaluate an electronic feeder to monitor individual mineral intake and feeding behavior and their relationship with growth performance and liver mineral concentrations. Cows and calves were fitted with radio frequency identification ear tags that allowed access to an electronic feeder (SmartFeed system; C-Lock Inc., Rapid City, SD) and were provided ad libitum minerals (Purina Wind and Rain Storm, Land O'Lakes, Inc., Arden Hills, MN). Mineral intake, number of visits, and duration at the feeder were recorded over a 95-d monitoring period while pairs were grazing native range. Liver biopsies were collected from a subset of cows on the final day of monitoring and analyzed for mineral concentrations. Data were analyzed with the GLM procedure in SAS for mineral intake and feeding behavior with age class (cows vs. calves), intake category (high vs. low), and the interaction between class and category in the model. Correlations were calculated among cow feeding behavior and calf intake and growth performance with the CORR procedure, and a comparison of liver mineral concentrations among cows of high (>90 g/d; average 125.4 g/d) and low (50 g/d; average 72.2 g/d) consumed greater ( < 0.001) amounts of minerals than low-intake calves (