|Defining Forage Variability
in Rice Straw - 2005
Project Leader and Principal UC Investigators
Glenn Nader,livestock farm advisor, UC Cooperative Extension Butte/Sutter/Yuba Counties
This project is continuing its examination of how best to utilize rice straw as a forage supplement in livestock feed.
In 2004 researchers obtained a commercial field macerator, a machine that mechanically treats straw to make it more palatable. The straw was treated at harvest when moisture content was 60 percent. It was then dried, baled and stacked. Samples were analyzed in a laboratory. The rice hay was fed to 40 heifers in an experiment that began in October. Rice hay composed about 40 percent of the rations by weight. The balance was primarily alfalfa. The animal’s consumption, weight gain and body condition were observed and recorded.
Initial indications were that maceration did not significantly improve the intake or digestibility of rice straw hay, so researchers modified the experiment’s design in 2005. Cattle numbers increased to eight groups of 10 steers—half the groups being fed the macerated straw, the other half unmacerated straw. Each group was fed a fixed diet of alfalfa, rice bran, cottonseed. Once that was consumed rice hay was fed based on the pen’s consumption. Each pen was fed hay adjusted each day based on the previous day’s consumption and the amounts left in the feed bunk or wasted on the ground. The amount left in the bunk was weighed and the amount wasted on ground was estimated. All feeding took place in the morning, as opposed to the 2004 study where the cattle were fed twice a day.
The trial ran through the end of December 2005. Observations and data were still being analyzed by the project leader at the time of this writing. However, initial indications from laboratory analysis and observed animal response show little impact by in-field maceration. Future research will concentrate on other treatments that will significantly affect the physical properties of field-treated rice straw.
The project leader reports fruitful dialogue with scientists interested in rice hay utilization at other universities domestically and abroad, at the Agricultural Research Service in Albany, and elsewhere in the University of California. A scientific literature review is under way and a new collaborative project is planned for 2006.
Higher forage prices, especially for alfalfa, is creating demand among livestock producers for economical alternatives like rice straw hay. Coupled with the project leader’s UC Cooperative Extension newsletters and news media articles in the Fresno Bee and Modesto Bee, a new market for rice hay is developing with Central Valley dairies. Rice hay is being used for heifer development and in non-lactating cow diets to provide bulk or rumen stimulation with other non-structural byproduct feeds.