Fermentation, stability and degradability of whole-crop oat silage ensiled with a commercial inoculant

[摘要] ENGLISH ABSTRACT: South Africa is well-known for periodic dry periods and uncertain rainfall. Ensiling ofcrops is a method of preserving forage and ensures feed availability during periods whenthe supply of good quality forage is low. Cereal-based silages, especially in the WesternCape, South Africa, represent a significant proportion of feed consumed by ruminantanimals, particularly high-producyion dairy cattle. However, farmers are still concernedabout the technical challenges of ensiling cereal crops. Previous research done on lacticacid bacteria (LAB) inoculants used on cereal based silage has indicated a potential forimproving silage fermentation, stability and degradability, thus enhancing feedconversion and production by ruminants.Two experiments were conducted to determine the effects of inoculating whole-crop oatsilage with Lalsil® Cereal Lactobacilli (Lactobacillus buchneri (NCIMB 40788) andPediococcus acidilactici (CNCM MA 18/5M)) LAB on(1) silage fermentation,(2) aerobic stability and(3) nutritional value of silage ensiled undera. micro-silos conditions andb. in a bunker under outdoor conditions of a Mediterranean summer.Oats (Avena sativa, cv SSH 405) were planted on 60 ha under dryland conditions atElsenburg in the Western Cape province, South Africa. Whole-crop oats were harvestedat the soft dough stage and length of the chopped material was 9 mm (Day of ensiling –Day 0).Chopped whole-crop oats were sampled, mixed thoroughly and divided into two portions.The Inoculant (Lalsil® Cereal) was applied to one portion to provide 5.79 x 109 colonyforming units (CFU) of LAB per gram of fresh material. In the first experiment twenty -four glass silos (1.5 L glass jars) (WECK, GmbH u.Co., Wehr-Ofligen, W. Germany)were filled for each of the control and inoculant treatments. The glass silos were storedin a dark room in the laboratory at ambient temperature. Three glass silos were openedfor each treatment on days 1, 2, 4, 8, 15, 30, 60 and 102 post-ensiling to determinefermentation dynamics.A parallel study was done with the same chopped whole-crop oats using the buried bagtechnique in a bunker silo. Whole-crop oats were ensiled in six net bags per treatmentburied in a bunker filled with the same untreated whole crop oats. Bags, attached withnylon lines (3 m lengths) for easy retrieval were buried at 1m and 2 m depths in the samebunker. The net bags in the bunker were retrieved after 186 days of ensiling.Dry matter (DM), organic matter (OM), neutral detergent fibre (NDF), crude protein(CP), lactic acid levels, pH, water soluble carbohydrates (WSC) and in vitro organicmatter degradability (IVOMD) for both studies were determined. Silage of bothexperiments was exposed to aerobic conditions for ten days to determine aerobicstability. It is concluded that the inoculant Lalsil® Cereal had the effect of reducing therate of consumption of WSC during the anaerobic phase and aerobic exposure for both experiments. Silage spoilage due to yeasts and moulds was however more evident withthe inoculated silage due the presence of sugars in the micro-silos experiment.

[发布机构] Stellenbosch University