Frosted corn silage with or without bacterial inoculants in dairy cattle ration.

摘要

This experiment was conducted to study the effects of different bacterial inoculants on fermentation characteristics and chemical composition of frosted-corn silage and animal performance. The corn crop was harvested at 297.6 g/kg DM after a killing frost. Treatments were frost damaged corn silages: without inoculant (WI), inoculated with Lactisil Maize (LB, contains Enterococcus faecium, Lactobacillus plantarum, Pediococcus pentosaceus, Lactobacillus casei - and Lactobacillus buchneri - in total 1.5x105 cfu/g of fresh forage) or inoculated with LalsilMS01 (LP, L. plantarum and Propionibacterium acidipropionici -1.5x105 cfu from each strain per g of fresh forage). Silages were fed to twelve multiparous lactating Holstein dairy cows in a replicated 3x3 Latin square design experiment. The addition of inoculants did not influence percentages of DM, CP and water soluble carbohydrate of silages. However, higher concentration of lactic acid and NDF was found in silages with inoculants compared with control (P<0.01). Concentration of acetic acid was higher in LB compared with WI and LP (P<0.01). In contrast, concentration of propionic acid was slightly higher in LP compared with LB and WI (P<0.01). LB treatment improved aerobic stability of silage but inoculation with LP produced silage with lower resistance to spoilage (P<0.05). Digestibility of nutrients in total gastric tract was not affected by inoculation. However, inoculated silages decreased DM intake, milk protein (P<0.05) and milk fat (P<0.01) yield. Percentages of milk fat, protein and lactose were lower in LP in comparison with LB and control. Cattle on inoculated silages produced lower FCM and ECM yield (P<0.01). However, ratios of DMI/FCM and DMI/ECM were not affected by inoculation. These results imply that frosted corn silage successfully can be ensiled without inoculants. Using these inoculants has no beneficial effect on feed efficiency of animals.