The Malnutrition Phenomenon
The North Carolina Veterinary Diagnostic Laboratory System has diagnosed a significant number of starvation deaths in North Carolina livestock this winter, which unfortunately is an annual problem. This winter the submissions of starved animals started in November in all areas of the state after the first extended cold and wet weather. The frequency of starvation cases has decreased in January in the Eastern third of the state due to warmer weather, however the laboratories in Fletcher and Elkin are continuing to see numerous starved animals of all species due to the continuing cold and wet weather. Gastrointestinal parasitism has also played a role, at least in the November cases.
At necropsy the vertebrae, the spine of the scapula, and the pelvic bones of these starved animals are very prominent. There is no internal fat or maybe still a scant amount around the kidneys and heart that is in active catabolism (serous atrophy). Serous atrophy of bone marrow fat is also present and it indicates that the animal has reached to its last store of fat to try to stay alive.
It is important to remember that animals have a critical temperature point that when the ambient temperature (including wind chill) falls below it, animals need to consume additional energy every day to keep from losing weight. For cattle, the critical temperature is 32°F degrees with a dry winter coat. So for every degree below 32°F, 1% more energy (TDN) needs to be consumed to prevent weight loss and that is in addition to gestational or lactational needs. However, when they have a wet winter coat the critical temperature is now 60F! So on a wet 35°F winter days; cattle need an additional 25% of energy every day. The ration for most herds diagnosed with starvation is untested hay, free choice minerals and usually a protein tub. The affected cattle are usually cows heavily pregnant or had calved in the fall. Older cows (10+ years) in the herd often die first.
Based on conversations with producers, hay was often cut this past summer when it was very mature, which means a higher level of indigestible fiber and poor nutritional quality. The Rollins Laboratory has diagnosed 2 cases of forestomach rupture due to abomasal impaction, which is believed to be due to poorly digestible hay.
Laboratory veterinarians are recommending that producers contact their County Extension agent to request core sampling of hay and forage analysis at the NC Forage Lab to determine the quality of hay and then work with the Extension agent or their veterinarian to determine what additional feed is needed to reverse starvation and reduce the fatalities.