Effect of Chemical Conditioning of Alfalfa on Drying Rate and Nutrient Digestion in Ruminants

Abstract

Solutions of K2CO3 or KOH were sprayed on freshly cut, third harvest alfalfa. Drying rates of treated alfalfa were faster than control in both laboratory and field trials. Two 3 × 3 Latin square digestion trials were conducted with sheep and dairy cows to evaluate the effects of chemical treatment on digestion of field dried alfalfa hay. Forage composition and DM intake of hays were not influenced by treatment in either sheep or cows. Apparent digestibility of dietary constituents did not differ between control and treated hay in the sheep trial, except for decreased digestibility of NDF with hay treated with KOH. However, digestibility of DM, CP, NDF, and ADF was improved in cows with potassium carbonate treatment of hay. Potassium hydroxide treatment only increased ADF digestion in cows. Extent of NDF digestion in vitro was increased at 12, 24, and 48 h of incubation with both chemical treatments; both treatments decreased the proportion of indigestible NDF. When incubated in situ, particle-associated carboxymethylcellulase activity was greater with potassium carbonate treatment of field dried hay. Treatment with either KOH or K2CO3 increased drying rate of alfalfa hay, but only potassium carbonate treatment improved nutrient digestibility. © 1988, American Dairy Science Association. All rights reserved.