Nutritive Characteristics of Dried Potato By-Product Meal for Ruminants

Dried potato by-product meal was analyzed by official procedures, compared with dried potato pulp in a reversal feeding trial for dairy cows, and total digestible nutrients and digestible energy were determined with both sheep and dairy heifers. This feed was variable in composition but averaged 8.6% moisture, 7.4% crude protein, 4.9% ether extract, 4.6% crude fiber, 16.0% ash and 58.5% nitrogen-free extract. Analyses of the ash showed 11.0% calcium oxide, 1.54% potash, .487% phosphate and lesser amounts of other minerals.Digestibility of protein was zero for dairy heifers and 7.3% for sheep. Total digestible nutrients and digestible energy were 52.5 to 53.9% and 2.0 to 2.3 Mcal/kg. When dried potato by-product meal was fed to high producing dairy cows at 22% in a grain mixture containing nearly 15% protein, the cows ate significantly less grain and more alfalfa-grass hay than similar cows fed the same amount of dried potato pulp. This resulted in significantly less dry matter and protein but more fat and mineral intake by those cows fed the dried potato by-product meal ration. There were no significant differences in milk or major milk constituents produced or body weight changes of the cows during the reversal experiment.