Hay desiccation and preservation with potassium sorbate, potassium carbonate, sorbic acid and propionic acid

Abstract

Three experiments were conducted to ascertain the effectiveness of sorbic acid or potassium sorbate in hastening the drying of cut alfalfa, thus decreasing the interval from cutting to baling, and to evaluate the effectiveness of sorbic acid or potassium sorbate compared with dry control or propionic acid as a forage preservative by measuring and comparing storage temperature, dry matter and chemical composition of treated and untreated alfalfa hay before and after storage. Second-harvest alfalfa was cut at the early bud stage, wilted in the field to approximately 30% moisture, and baled with the addition of various treatments. Treatments consisted of wet control 0.25, 0.5, 1, 2 and 4 g potassium sorbate kg −1 dry matter (DM). Addition of potassium sorbate to high-moisture alfalfa hay did not improve preservation when compared with untreated hay, with comparisons based on heating during storage, DM change, and chemical composition of hay obtained from storage. A solution containing 1, 2 or 4 g potassium sorbate kg −1 DM and 4 g potassium carbonate kg −1 DM was sprayed on third-harvest bud-stage alfalfa from a sprayboom mounted on the push-bar of a self-propelled mower conditioner. Forage loss of moisture during drying was monitored at regular intervals, and hay was baled into conventional rectangular bales when moisture reached 30%. Addition of potassium carbonate and potassium sorbate to alfalfa hay at cutting did decrease drying time and improved preservation when compared with untreated hay, with comparisons based on field drying time, heating during storage, DM change and chemical composition of hay obtained from storage. Second-harvest alfalfa was cut at the early-bud stage, wilted in the field to approximately 35% moisture and baled with the addition of various treatments. Treatments consisted of wet control, 5, 10, 15 g sorbic acid kg −1 DM and 15 g propionic acid kg −1 DM. Addition of sorbic acid to alfalfa hay at baling did not improve preservation when compared with untreated hay with comparisons based on heating during storage and DM losses. However, alfalfa hay harvested at 30% and treated with 15 g propionic acid kg −1 DM had interior bale temperatures that followed a similar pattern of dry control.