1. Low Lignin Alfalfa for Reducing Labor and Increasing Yield Dr. Dan Undersander University of Wisconsin

2. Dan Undersander-Agronomy © 2009 Importance of Lignin in Alfalfa Provides strength to plants Allows the plant vascular system to transport water in the plant without leakage. Increases with advanced maturity in alfalfa Is indigestible and reduces fiber digestibility Lignin Subunits

3. Dan Undersander-Agronomy © 2009 Effect of low lignin genes on in vivo digestibility Digestibility of low lignin alfalfa types and controls fed to lambs, diet was 100% alfalfa hay fed ad libitum. 100% alfalfa hay dietaNDF % DM ADL % DM NDFD % NDF DMD % DM COMT Inactive38.25.357.5*67.5* COMT Active (Control)39.05.849.164.5 CCOMT Inactive39.45.250.165.3 CCOMT Active (Control) 39.45.946.463.7 *Significant, P < 0.05 SOURCE: Mertens et al. 2008. J. Dairy Sci. Supple. 1

4. Dan Undersander-Agronomy © 2009 Effect of low lignin genes on milk production Lactating cow responses to alfalfa hays with down- regulated lignin biosynthesis Alfalfa hay type 1 CP % DM NDF % DM NDFD %NDF Milk lb/day COMT Inactive18.131.1 53.5**84.7* COMT Active (Control)18.429.3 42.582.1 CCOMT Inactive18.142.5 48.6**84.5 CCOMT Active (Control)18.331.1 44.586.7 1 TMR diets - 50 % alfalfa hay, 10 % corn silage, 40 % concentrate *Significant, P < 0.10; ** significant P <0.01 (different from control) SOURCE: Weakley et al. 2008. J. Dairy Sci. Supple. 1

5. Dan Undersander-Agronomy © 2009 Low lignin study Studies were conducted at Davis, CA and Tulelake, CA, Becker, MN, Arlington, WI, and West Salem, WI.

6. Dan Undersander-Agronomy © 2009 Planted at 5 locations to determine response in harvest system

7. Dan Undersander-Agronomy © 2009 Planted at 5 locations to determine response in harvest system

8. Dan Undersander-Agronomy © 2009 Planted at 5 locations to determine response in harvest system

9. Dan Undersander-Agronomy © 2009 Yield Curve of Alfalfa Yield

10. Dan Undersander-Agronomy © 2009 Yield and Quality Curve of Alfalfa YieldForage Quality

11. Dan Undersander-Agronomy © 2009 Yield and Quality Curve of Alfalfa YieldForage Quality Low Lignin Quality

12. Dan Undersander-Agronomy © 2009 3 vs 4 cutting by Sept 1 effect on alfalfa yield, Arlington, Wisconsin 1 st cutting 2 nd cutting 3 rd cutting 4 th cutting Season Total 2 nd year3 cut2.972.432.15----7.55 4 cut1.661.481.711.686.53 3 rd year3 cut2.321.531.24----5.09 4 cut1.311.180.750.834.07 17% 25%

13. Dan Undersander-Agronomy © 2009 Summary Low lignin lines had lower lignin and higher fiber digestibility. The CCOMT line stood (lack of lodging) as well in space plantings at the commercial alfalfa line. Low lignin lines could be harvested later to get the same quality as standard lines but at higher yields.