Farmers and contractors are to consider crop maturity stage and the type of baler used in whole crop grain silage production as key factors that influence the amount of nutrient losses in the ensiled forage. New research from the Swedish University of Agricultural Science (SLU) shows that nutrient losses increase with crop maturity and that using the right baling equipment can reduce dry matter (DM) losses in bales by 30% to 75%, depending on crop maturity stage.
The research led by Prof. Per Lingvall and supported by Dow, the manufacturer of DOWLEX* Polyethylene (PE) Resins, was presented at the recent ‘Silage Production and Utilisation’ satellite conference in Belfast, as part of the International Grassland Congress 2005.
“The research conducted by the SLU shows that there is still room for improvement to produce quality fodder with enhanced nutritional value at a reasonable profit,” comments Sander van Veen, Silage Market Development Manager at Dow. “In recent years, the focus of Dow and its partners has been to understand as completely as possible what goes on inside the wrapped bale – what influences the process of fermentation, and how to minimise wastage to the lowest possible level.”
To conduct the experiment, winter wheat and spring barley were harvested at three stages of maturity - heading, milk stage and dough stage – using two types of baler. “Research of freshly harvested barley shows that not only the yield per hectare increases with each stage of maturity, nutrient losses increase considerably as well.” explains Prof. Lingvall. “In addition, we registered extra losses of DM during baling and storing the harvested crops. Those losses increased with 45 to 50% between heading and dough stage”.
A significant impact on baling losses was also found by researchers when comparing types of baler. “A tough treatment of mature whole crop grain (dough stage) revealed significant nutrient losses (151 g per kg DM), more than twice the loss with a baler that handles the crop more gently (65 g per kg DM)”, observes Prof. Lingvall. “Concerning the nutrition value of the bale contents, research showed that balers with a limited number of knives and a longer cut length prove to be more beneficial than balers with more knives that cut shorter.”
Part of the research was dedicated to comparing DM losses in bales and silos. “The study indicates that producing well-wrapped bales with eight layers of quality stretch film results in lower DM losses than precision chopping in silos”, comments Prof. Lingvall. The use of silage additives significantly reduces DM losses and is necessary to avoid hygienic problems and clostridia growth”.
To make and preserve quality silage it is important that good quality materials and equipment are used, and that includes the bale wrap film. “The optimal number of layers depends on prevailing conditions. As a general rule the more layers and the better the film quality, the smaller the risk of air entering the bale and allowing moulds to develop”, comments Sander van Veen. “Trying to save costs by using fewer layers at this stage can undermine all previous efforts.”
A complete abstract paper with illustrative figures of the research findings is published in the Spring issue of Silage Insights, now available on www.silageinsights.com. Silage Insights is a newsletter providing practical advice, trends, research, and industry news on bale silage in Europe. Developed by Dow, this informative newsletter is aimed at the farming community and those involved in the agricultural business.
