Summaries of Southeast Milk Check-off Projects Funded in 2015

Productive and high quality forages are critical to the success of dairy operations, but the combination of high yield and excellent quality has been difficult to find among warm-season perennial grasses adapted to the Gulf Coast region. Mulato II brachiariagrass and Jiggs bermudagrass have characteristics that make them attractive to dairy enterprises, but additional research station and on-farm evaluation is needed before they can be recommended to producers. Jiggs bermudagrass establishes rapidly, has fine stems for rapid wilting/drying, is persistent under frequent defoliation, and tolerates poorly drained soils. Mulato II is a productive grass with high nutritive value, but persistence in cooler climates is not documented. For both grasses, it is important to know if they provide advantages over currently used hybrid bermudagrasses in North Florida/South Georgia, environments that are cooler than where they have been most widely tested and used. The objective of this project was to assess the potential of Jiggs and Mulato II for use as warmseason forages on dairies by measuring yield, persistence, and nutritive value in research station experiments and on-farm demonstrations carried out at three dairies. At each dairy, Jiggs and Tifton 85 bermudagrasses and Mulato II brachiariagrass were planted in side-by-side 0.5-acre strips between July 24 and August 6, 2014. Establishment was monitored during the 2014 growing season. On-station, one experiment compared Jiggs and Tifton 85 bermudagrasses, harvested every 28 days during summer at two stubble heights (3 and 6 inches) and fertilized at three levels of K2O (0, 20, and 40 lb/acre/harvest). The second experiment compared Jiggs and Mulato II harvested every 28 days and fertilized at two nitrogen rates. The on-farm demonstrations showed that under producer conditions Jiggs bermudagrass consistently established easier and faster than Tifton 85 or Mulato II. Through two years, onstation experiments showed no evidence that Jiggs is less cold tolerant than Tifton 85 in North Florida, but Jiggs forage is less digestible than Tifton 85 and Mulato II. Mulato II stands survived the first winter after planting with virtually no stand loss and produced higher yields than Tifton 85 in the year after planting due to strong late-season production. However, an average to slightly colder than average second winter killed most of the Mulato II stand indicating that it will not function as a long-lived perennial in North Florida. Based on these studies, we conclude that Jiggs provides rapid establishment and earlier spring growth than most bermudagrasses. Additionally, it has persisted under frequent cutting in North Florida for at least two years, but its forage is less digestible than Tifton 85. Mulato II is not well suited to systems requiring a long-lived perennial, but because it is a seeded forage, it may have some potential as a high digestibility, short rotation forage crop. It could be seeded in spring of one year and produce high yields of high quality forage that growing season and the next. 53rd Florida Dairy Production Conference 190 Gainesville, FL, April 20, 2017 Inoculant Effects on Mycotoxins, Fermentation Characteristics, and Nutritive Value of Bermudagrass Silage – Year 2 Joe Vendramini, Lynn Sollenberger, and Jose C. Dubeux Jr. 3 1 Range Cattle Research and Education Center, Ona, FL 2 Agronomy Department, Gainesville, FL 3 North Florida Research and Education Center, Marianna, FL