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New research has fueled an update to the berry processing score (BPS) metric that determines the adequacy of berry processing in sorghum silage. Thanks to the latest study reviewing the dynamics of starch digestibility after processing and after ensiling sorghum, the determining factors of BPS have been updated to more accurately account for this relationship. Previously measured as the percentage of starch passing through a 1.7 mm sieve, the project led key scientists from Texas A&M University, University of Wisconsin-Madison, and Rock River Laboratory, Inc. to update this standardized measurement to a 2.36 mm sieve screen.
“This step in BPS understanding has the potential to radically improve uptake and use of sorghum silage within dairy rations,” shares Katie Raver, Rock River Laboratory animal nutrition and field support specialist. “Expanding the sieve from the former value of 1.7 mm - which was too restrictive for halved and quartered berries - to 2.36 mm size gives a good barometer that the berry is cracked and opens the door for further fermentation.”
Sieve size changes may not seem that exciting, but BPS’s cousin - kernel processing score (KPS) - would say otherwise. The adoption and regular use of KPS by much of the dairy industry to determine adequate kernel processing in corn silage has driven the significant improvement in harvest management and in turn, corn silage digestibility in dairy animals since first put into practice.
Combined with the dawn of new kernel processor technologies, such as Scherer Inc.’s new Durracut processor for inclusion on harvesting equipment, this BPS update has impressive opportunities. Compared to not using KPS, in situ starch digestibility is increased by 20 to 40 units in ensiled sorghum - which translates to a rough estimated return on investment of $8.00/ton. Before berry processing equipment, sorghum growers harvested early at the soft dough stage, sacrificing both potential tonnage and starch. In turn, they only captured 20 percent of the plants’ starch at harvest, and only 10 percent was available to the cows. That level of starch - about 2.5 pounds unavailable - translates to around $0.50 per head per day in lost nutritive value. A BPS above 50 percent with the 2.36 mm screen is the new goal that will allow growers and harvesters to begin benchmarking and constantly improving their harvest.
“Initial results from our study are quite promising,” shares Raver. “Roughly 66 percent of the starch in sorghum silage that has fermented for three months is digestible after seven hours in the rumen."
While the project’s results are promising, the data capture is ongoing - including information regarding interactions with hybrids and management. Dr. Juan Piñeiro of Texas A&M, Dr. Luiz Ferraretto of the University of Wisconsin-Madison, and the team at Rock River Laboratory hope to include an additional 100 samples which will continue to assess the link between starch digestibility and processing. The current recommendations are based on over 300 commercial and research samples.
As dairy producers in arid regions of the US face further water scarcity challenges, sorghum technology and research are constantly evolving to provide opportunities for further replacement of corn silage with this water-conserving crop. A step forward in both berry processing and scoring this key to harvest could become a major leap for crop and ration efficiencies for these dairies.
Founded in 1976, Rock River Laboratory is a family-owned laboratory network that provides production assistance to the agricultural industry through the use of advanced diagnostic systems, progressive techniques, and research-supported analyses. Employing a team of top specialists in their respective fields, Rock River Laboratory provides accurate, cost-effective, and timely analytical results to customers worldwide, while featuring unsurpassed customer service.
