GEM and the UW Silage Breeding Project

1. GEM and the UW Silage Breeding Project J.G. Coors D. Majee D.T. Eilert P.J. Flannery Department of Agronomy University of Wisconsin with acknowledgements to: J.G. Lauer UW Department of Agronomy R.D. Shaver UW Department of Dairy Science

2. Outline • Silage quality – what is it? • UW silage breeding system • GEM contributions – silage germplasm • GEM contributions – starch degradability • Summary

3. Dry Matter Protein Carbohydrate Degradable protein Sugars & starch Cell wall Bound Unavailable starch Sugar and Starch Bugs Bound with Lignin Undegradable protein Fiber Bugs Digestible energy & protein Absorbed Metabolizable energy & protein Maintenance Growth Pregnancy Lactation

5. Milk2000

6. Processed Unprocessed Adapted from Schwab and Shaver, unpublished. Based on data of Bal et al., 2000; Dhiman et al., 2000; Rojas-Bourrillon et al., 1987

7. GEM Contributions – Silage Germplasm Phase I Silage evaluation of elite GEM topcrosses (~15-25) that were identified in prior years by other GEM cooperators as having high grain yield and suitable maturity for Wisconsin (<120RM). Phase 2 For those topcrosses with high forage yield and good nutritional quality in Phase 1 trials, the respective GEM breeding population is included in the UW inbred development nursery for further inbreeding and selection Phase 3 Inbred development – testcrosses at S2 to S6 generations using two to four inbred testers

8. 2004 UW GEM Program Phase I 17 breeding populations or early generation GEM inbred families crossed to LH185, LH198, LH200, LH244, or LH287 were evaluated for silage potential (GEMNEW). Phase 2 Gem inbreeding nursery included ~400 inbred families from 10 breeding populations. Most inbred families (~170) were derived from CUBA164 background. Phase 3 160 advanced generation inbreds from six populations were crossed to two testers each for evaluation in 2005. Evaluated ~50 S3+ families topcrosses to two testers (GEM198, GEM244). 27 promising S4+ families evaluated in topcrossed to two to four testers each (GEMADV).

9. Forage yield for GEMNEW trial in 2004 Entries marked with “*” will be analyzed for nutritional quality

10. 2004 UW GEM Program Phase I 17 breeding populations or early generation GEM inbred families crossed to LH185, LH198, LH200, LH244, or LH287 were evaluated for silage potential (GEMNEW). Phase 2 Gem inbreeding nursery included ~400 inbred families from 10 breeding populations. Most inbred families (~170) were derived from CUBA164 background. Phase 3 160 advanced generation inbreds from six populations were crossed to two testers each for evaluation in 2005. Evaluated ~50 S3+ families topcrosses to two testers (GEM198, GEM244). 27 promising S4+ families evaluated in topcrossed to two to four testers each (GEMADV).

11. 2004 UW GEM Program Phase I 17 breeding populations or early generation GEM inbred families crossed to LH185, LH198, LH200, LH244, or LH287 were evaluated for silage potential (GEMNEW). Phase 2 Gem inbreeding nursery included ~400 inbred families from 10 breeding populations. Most inbred families (~170) were derived from CUBA164 background. Phase 3 160 advanced generation inbreds from six populations were crossed to two testers each for evaluation in 2005. Evaluated ~50 S3+ families topcrosses to two testers (GEM198, GEM244). 27 promising S4+ families evaluated in topcrosses to two or four testers each (GEMADV).

12. Forage yield for GEM198 and GEM244 trials in 2004

13. Forage yield for GEMADV trial in 2004

15. WQS/GQS  Season 1 (winter) S1 families (~500) Evaluate &  Season 2 (summer) S2 families (~150) Testcross (1 tester) Season 3 (winter)  S3 families (~150) S2 testcrosses (~150) Season 4 (summer) Evaluate & select  S2 families (20 selects) S4 families (~20-40 selects) Recombine Season 5 (winter) Testcross (2-3 testers)  S4 testcrosses (~75-100) S5 families Season 6 (summer) Evaluate & select  S4 selected families S6 lines Season 7 (winter) Testcross (2-3 testers) Increase Inbred release Sample hybrids for distribution

16. Components of GEM Quality Synthetic (GQS) 2003 trial, LH279 topcrosses

17. GEM Contributions – Starch Degradability

18. Rumen Degradability of Starch

19. Starch Degradability Oh43 o2 CHO5015:N12-387-1-B

20. [Correa et al., 2002]

21. Starch Degradability Studies Objectives • Determine whether there is genetic variation for starch • degradability • Determine the extent to which kernel vitreousness is related • to starch degradability

22. Harvest dates: ½ milkline (ML, ~35% DM) Black layer (~15 d post ½ ML) Experiment design (field): RCB with 3 replicates Madison - 2002, 2003 1 self-pollinated row – 3.04 x 0.76 m 10 plants per row Starch Study 32 inbred lines and 1 population (2002) 19 hybrids (2003) Entries:

23. Procedure – Two-Stage Starch Digestion (Pioneer Hi-Bred International, Inc.) • STAGE 1 - in-situ ruminal incubation • Two steers with ruminal cannula – 2 wk adaptation to 70% (DMB) corn silage diet • In-situ procedure: • Corn kernels ground with Wiley Mill (6mm screen) • 1.5g ground material placed in 5 x 5 cm dacron bag • Eight replicate bags incubated for each sample • Placed in rumen for 0 and 14 h, • Removed, rinsed and dried at 62oC for 24 h • STAGE 2 - post-ruminal in-vitro incubation • 14-h ruminal residue subjected to 8 h incubation • intestinal enzymatic cocktail (pepsin + pancreatic enzymes) • Removed, rinsed and dried at 62oC for 24 h • Final Action • Eight replicates for DM disappearance • Eight replicated bags composited for a single starch analysis

24. ½ milk-line stage

25. Black layer stage

26. Black layer stage W64A X Oh43 su2 W64A X Oh43 o2 W64A X Oh43 fl2

27. Black layer stage – hybrids

29. Summary GEM has contributed greatly to the UW silage breeding program by providing: 1) Superior and unique germplasm 2) Better understanding of nutritional properties of silage http://silagebreeding.agronomy.wisc.edu