Preservation of Alfalfa Hay by Microbial Inoculation at Baling

Abstract

Baling hay at higher moistures reduces harvest losses, but increases storage losses due to microbial deterioration. This study investigates the potential of microbial inoculants in preserving the appearance and chemical quality of hay during storage. Alfalfa ( Medicago sativa L.) hay grown by 17 cooperating producers in Canada and the USA during 1987 was treated with either normal hay microflora [ Bacillus pumilus (Bergeys)] or a silage inoculant: a mixture of [ (Lactobacillus plantarum (Bergeys)] and [ Streptococcus faecium (Bergeys)]. Bales were prepared at moisture contents between 17 and 31% to reduce harvest loss. Internal bale temperatures were measured throughout the 60‐d storage period and appearance and chemical analyses were determined after the storage period. Both treatments improved color, odor, and visual assessment of feed value, and reduced mold and dust, particularly at moistures greater than 20%. In general B. pumilus treated hay was higher in quality over a broader moisture range than the L. plantarum and S. faecium treated hay. Hay treated with B. pumilus had about 0.1% higher N concentration and higher calculated feed values for available protein and daily intake. Feeding trials are needed to confirm this suggested nutritional benefit. Environmental factors, such as moisture at baling and ambient temperature during storage had a major effect on hay quality.