Spring calving season is a good time to visually see the nutritional plane and parasite load of first calf heifers and older cows on pasture. Glistening coats of dams and calves indicates an abundance of sun generated grass delivered vitamins like A & E, protein and essential soil or supplement block nutrients like selenium and copper.
Later in the growing season if the pasture’s are predominantly fescue, endophyte toxicity maybe the cause of rough hair coat and laminitis in cattle.
In early spring, dull coats on cows that have not shed their winter hair or have a rough appearance to their coats may be in need of spring deworming and, or mineral supplementation.
These are the cows that are also most likely to lose condition once warble fly season begins. Warble flies or gad flies are more likely to stress younger dams which then adds stress to their nursing calf. This stress starts to occur when the flies are chasing cattle to lay eggs. Cattle spend a considerable amount of time trying to avoid these flies.The stress then continues for nearly a year as the flies eggs hatch and burrow into the cow’s hide to complete the rest of their life cycle.
For more information on this common cattle grub see the fact sheet by Hussein Sanchez-Arroyo, of the University of Florida’s entomology and nematology department http://entnemdept.ufl.edu/creatures/livestock/cattle_grub.htm
If cattle have been wormed, and if more than one animal in the herd is showing signs of dull coat, and calves are unthrifty looking (lack sheen on coat), it is time to take soil tests, pasture grass forage analysis and blood tests for selenium and copper levels from sympomatic and non-symptomatic cows to get a baseline.