|Kung, Limin - UNIV OF DELAWARE-NEWARK|
Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: February 13, 1997
Publication Date: N/A
Technical Abstract: The effects on animal performance of the principal silage additives in North America (microbial inoculants, enzymes, propionic acid and nonprotein nitrogen) were reviewed. The most common additive is the microbial inoculant, which ensures a high level of homofermentative lactic acid bacteria on the crop at ensiling. In studies published from 1990 through 1995, inoculants had a positive effect on animal intake, gain and milk production in 28, 53 and 47% of the studies. When milk production was improved, the average increase was 1.37 kg/d. The cause of improved animal performance from inoculation is still uncertain. Enzyme additives aim to hydrolyze cell walls making the silage more digestible. However, these additives when added at ensiling were less successful in improving animal performance than inoculants. Milk production and dry matter digestibility were improved in only 33 and 9% of the studies, respectively. .A more promising use of enzymes is through treating the feed just prior to feeding although more research is needed to confirm benefits. Nonprotein nitrogen additives (ammonia, urea) are used to increase the crude protein content of a silage and improve aerobic stability. These additives should improve fiber digestibility and conservation of true protein in the crop, potentially leading to improved animal performance. However, results from published studies are mixed; both improvements and reductions in performance have been observed. Reductions may have been caused by clostridial fermentation, uneven applications, etc. Propionic acid-based additives are used to reduce heating and spoilage of silages. Insufficient animal performance data were found to make conclusions.