Progress 10/01/02 to 09/30/06
Outputs
We developed an enzymatic lab assay, Degree of Starch Access (DSA), which is sensitive to differences in particle size, moisture content, and vitreousness of corn-based feeds (Blasel et al., 2006). We developed W64A x Oh43 fl2/fl2, o2/o2, and normal endosperm near-isogenic lines based upon our earlier in vitro work within this project of Ngonyamo-Majee (2005). We produced these lines at the UW Arlington Research Station and fed in 2005 for evaluation of intake, digestion, and milk production in a corn silage feeding trial with lactating dairy cows. Kernel vitreousness was 0, 0 and 87% at black-layer for o2, fl2 and normal lines, while ruminal in situ DM degradation for 6-mm grind kernels was 51.4, 55.7 and 35.6% at black-layer for o2, fl2 and normal lines (Ngonyamo-Majee, 2005). The Wisconsin Quality Synthetic hybrid characterized by its high stover digestibility was also included in the study. Intake and milk production did not differ among treatments. Ruminal 48-h in
situ DM and NDF disappearance were greater for WQS and tended to be greater at 24 h. Ruminal in situ starch disappearance did not differ among treatments. Apparent total-tract NDF digestibility was lower for ISO than FL2, which disagreed with previous in vitro and current in situ results. Total-tract starch digestibility tended to differ, (89.1, 84.8 and 81.5% for FL2, ISO and WQS, respectively) which disagreed with in situ but agreed with previous in vitro and vitreousness measurements. The decrease in total tract NDF digestibility may have been related to an increased intake of ruminally degraded starch from corn silage, which differed among the treatments. The W64A x Oh43 fl2/fl2, o2/o2, and normal endosperm near-isogenic lines were again grown in 2006 and harvested as dry grain. The three treatment corn grains will be coarse and fine ground to provide 6 treatments for evaluation in a grain feeding trial to evaluate intake, digestion and milk production in lactating dairy cows
during 2007. This design will be repeated with high-moisture corn in 2007-2008.
Impacts
Developing hybrids for specific starch and endosperm characteristics is likely to improve ruminal starch degradation and the utilization of corn grain and silage by dairy cattle.
Publications
- Blasel, H.M., P. C. Hoffman, and R. D. Shaver. 2006. Degree of starch access: An enzymatic method to determine starch degradation potential of corn grain and corn silage. J. Anim. Feed Sci. Technol. 128:96-107.
- Shaver, R. D. 2006. Forage intake, digestion and milk production by dairy cows. J. Dairy Sci. 89(Suppl.1): 298(Abstr.). Invited symposium paper at ADSA/ASAS Annual National Mtg.
- Shaver, R. D, and P. C. Hoffman. 2006. Applied aspects of starch in dairy cattle feeding programs. J. Dairy Sci. Abstr. Invited symposium paper at ADSA/ASAS Annual Midwest Mtg.
- Goeser, J. P., R. D. Shaver, and J. G. Coors. 2006. Corn silage genotype effects on intake, digestion, and milk production by dairy cows. J. Dairy Sci. 89(Suppl. 1): 193(Abstr.)
- Shaver, R. D., and J. G. Lauer. 2006. Review of Wisconsin corn silage milk per ton models. J. Dairy Sci. 89(Suppl. 1): 282(Abstr.)
- Shaver, R., J. Lauer, J. Coors, and P. Hoffman, 2006. MILK2006 Corn Silage: Calculates TDN-1x, NEL-3x, Milk per ton, and Milk per acre. milk2006corn silagev1.xls http://www.wisc.edu/dysci/uwex/nutritn/spreadsheets/sprds.htm
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Progress 01/01/05 to 12/31/05
Outputs
We developed W64A x Oh43 fl2/fl2, o2/o2, and normal endosperm near-isogenic lines (Ngonyamo-Majee, 2005) that we produced at the UW Arlington Research Station and fed in 2005 for evaluation of intake, digestion, and milk production in a corn silage feeding trial with lactating dairy cows. Kernel vitreousness was 0, 0 and 87% at black-layer for o2, fl2 and normal lines, while ruminal in situ DM degradation for 6-mm grind kernels was 51.4, 55.7 and 35.6% at black-layer for o2, fl2 and normal lines (Ngonyamo-Majee, 2005). The Wisconsin Quality Synthetic hybrid characterized by its high stover digestibility was also included in the study. Eight multiparous Holstein cows between 50-80 days in milk at the start of the trial were assigned randomly to a replicated 4x4 Latin square design with 21-d periods. All cows were fitted with rumen cannulae for ruminal digestion measurements. Diets contained 70% forage of which 75% was one of the respective traetment corn silages (DM
basis). Diets were formulated to contain 17.5% crude protein (CP) and to meet or exceed NRC (2001) mineral and vitamin requirements, and fed as total mixed rations (TMR) twice daily. The feeding trial has been completed and data summary is in progress. We also developed an enzymatic lab assay, Degree of Starch Access (DSA), which is sensitive to differences in particle size, moisture content, and vitreousness of corn-based feeds (Blasel et al., 2005).
Impacts
Developing hybrids for specific starch and endosperm characteristics is likely to improve ruminal starch degradation and the utilization of corn grain and silage by dairy cattle.
Publications
- Blasel, H. M., P. C. Hoffman, R. D. Shaver, and S. M. Offer. 2005. Degree of starch availability: An index to define relative starch digestion potential in corn based feeds. Abstr. Midwest ADSA. J. Dairy Sci. 88(5):1924(abstr.).
- Goeser, J., B. A. L. Justen, J. Coors, and R. Shaver. 2005. Potential of NIR spectroscopy to predict grain vitreousness using whole-plant corn samples. J. Dairy Sci. 88(Suppl. 1): 190(abstr.).
- Ngonyamo-Majee, D., R. Shaver, J. Coors, D. Sapienza, J. Lauer, and X. Mhike. 2005. Evaluation of kernel hardness parameters and degradabilities of Zimbabwean commercial and research corn hybrids. J. Dairy Sci. 88(Suppl. 1): 185(abstr.).
- Ngonyamo-Majee, D., R. Shaver, J. Coors, D. Sapienza, J. Lauer, and P. Flannery. 2005. Evaluation of near infrared calibrations for corn kernel hardess parameters and relationship to degradabilities. J. Dairy Sci. 88(Suppl. 1): 394(abstr.).
- Blasel, H.M., P. C. Hoffman, and R. D. Shaver. 2005. Degree of starch access: An enzymatic method to determine starch degradation potential of corn grain and corn silage. J. Anim. Feed Sci. Technol. (In press).
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Progress 01/01/04 to 12/31/04
Outputs
Trial 1--Correlations between kernel vitreousness (V) and in vitro ruminal (RDMD) and total tract dry matter degradability (TDMD) were evaluated using 33 germplasm sources. Germplasm sources included 17 lines from the Germplasm Enhancement of Maize project, 6 flint lines, 6 near-isogenic inbreds of Oh43 carrying o2, fl2, su2, ae1, h1 and wx1su2 alleles affecting endosperm composition, an experimental breeding population (WQS C2), and three check inbreds (B73, Oh43, and W64A). Inbreds were harvested at two growth stages; half milk-line (ML) and black-layer (BL). Vitreousness of the 33 germplasm, determined by near infrared reflectance spectroscopy (NIRS) in a previous study, was better correlated to DMD at BL stage (R2=0.66; 0.52; and 0.36) than ML (R2=0.38; 0.44; and 0.14) for RDMD, 0-hr disappearance and TDMD, respectively. Inbreds su2(Oh43) and wx1su2(Oh43) were outliers with high %V and also high RDMD. This suggests that endosperm characteristics other than V may
affect corn degradability. Trial 2--Combined effects of single gene mutations, harvest stage (HS), and sample drying technique (DT) on the proportion of corn dry matter (DM) and starch degraded ruminally and post-ruminally in vitro was evaluated using four near-isogenic lines in Oh43 inbred background (fl, o2, su2 genes and straight OH43). Inbred by DT interactions were observed for zero-bag losses (p<0.0001), RDMD (p=0.0024) and total DMD (p=0.0089). Harvest stage by DT interactions were observed for bag losses (p<0.0001), RDMD (p=0.0031) and total DMD (p=0.0551). Inbred by HS interactions were observed for bag losses only (p=0.0208). Freeze dried samples were more highly degraded than OD samples, especially for earlier harvested samples (HS1 and HS2), 0-hr losses, and RDMD versus TDMD. The ranking of inbreds for decreasing RDMD and TDMD was o2(Oh43)>fl2(Oh43)=su2(Oh43)>Oh43. When compared to FD, OD corn samples at 40oC reduced 0-hour DM loss through bag pores, particularly for early
harvested samples.
Impacts
Developing hybrids for specific starch and endosperm characteristics is likely to improve ruminal starch degradation and the utilization of corn grain and silage by dairy cattle.
Publications
- Frey, T.J, J.G. Coors, R.D. Shaver, J.G. Lauer, P.J. Flannery, and D.T. Eilert. 2004. Selection for silage quality in the Wisconsin Quality Synthetic and related maize populations. Crop Sci. 44:1200-1208.
- Justen, B.A.D., Majee, R.D. Shaver, and J.G. Coors. 2004. Digestion kinetics and starch degradability for the Wisconsin Quality Synthetic. Report of the North Central Corn Breeding Research Committee (NCR 167). Feb. 9-11, St. Louis, MO.
- Ngonyamo-Majee, D., R D. Shaver, D. Sapienza, J.G Coors, J.G Lauer, and C. Venhaus. 2004. Effect of freeze drying versus oven drying on dry matter and starch digestibility of corn mutants with Oh43 inbred line background harvested at four growth stages. J. Dairy Sci. 87(Suppl. 1):216(Abstr.).
- Ngonyamo -Majee, D., R.D. Shaver, J.G. Coors, D. Sapienza, J.G. Lauer, and C. Venhaus. 2004. Effect of kernel vitreousness on ruminal and total tract dry matter digestibility of diverse corn germplasm sources. J. Dairy Sci. 87(Suppl. 1):216(Abstr.).
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Progress 01/01/03 to 12/31/03
Outputs
Characterization of corn endosperm properties of 33 germplasm sources for future development of corn hybrids with high ruminal starch degradability was performed. The germplasm included 17 lines from the Germplasm Enhancement of Maize (GEM) project at Iowa State University; six flint lines from North Carolina State University (NCSU) and CIMMYT; six near-isogenic inbreds of Oh43 carrying o2, fl2, su2, ae1, h1 and wx1su2 alleles that affect endosperm composition; an experimental breeding population developed for improved silage quality (WQS C2) and three check inbreds; B73, Oh43, and W64A. Harvesting was done at half milkline (ML) and black-layer (BL) stages. The BL samples had higher (P<0.05) weight of 1000 dried seeds (252.5 vs. 209.7g LSD=3.8). Dried kernels from middle portions of ears were used to determine % vitreousness (V) using a light box. Hardness was determined from a 20g sample using a Stenvert micro hammer-cutter mill that measured time to collect ground
sample to a set receptacle height (T); total column height (TH); and height ratio of course to fine (C/F) particles. The ML samples had lower %V compared to BL samples (66.9 vs 72.4% LSD=0.8). Inbreds with softer endosperm (P<0.05) from BL samples were o2(Oh43) (0% V; 11.2s T; 82mm TH; 0.02 C/F ratio); fl2(Oh43) (0% ; 9.8s; 86mm; 0.01 C/F ratio); and h1(Oh43) (20%; 15.3s; 81mm; 0.04 C/F ratio), compared to inbred check B73 (50%; 23.7s; 71mm; 0.37 C/F ratio). The remaining germplasm ranged from medium to hard (60-95% V and 0.47-0.90 C/F ratio). Correlations between %V and hardness factors were higher for BL samples compared to ML; TH (R2= 0.79 vs. 0.39); C/F ratio (R2=0.67 vs. 0.67); and T (R2=0.66 vs. 0.42). These data show that a wide range of corn genetic material has potential for improving ruminal starch degradability and that visual rating of vitreousness on corn harvested at BL stage can determine corn hardness properties with relative accuracy.
Impacts
Developing hybrids for specific starch and endosperm characteristics is likely to improve ruminal starch degradation and the utilization of corn grain and silage by dairy cattle.
Publications
- Majee, D., R. D. Shaver, and J. G. Coors. 2003. Characterization of corn endosperm properties in 33 germplasm sources for potential improvements in ruminal starch degradability. J. Dairy Sci. 86 (Suppl. 1):232 (abstr.)
- Majee, D., R. Shaver, J. Coors, and J. Lauer. 2003. Relationship between starch properties of corn and starch digestion. Page 10-18 in Proc. 2nd Forage Teaching & Technol. Conf. UW Extension Team Forage. Arlington, WI.
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Progress 01/01/02 to 12/31/02
Outputs
Corn kernel dry matter, 1000-kernel dry weight, vitreouness, and hardness are being determined in the laboratory on 33 inbred lines grown at Univ. of WI West Madison and Marshfield Experiment Stations and harvested at half milk-line and black layer maturities to characterize endosperm properties for future development of corn hybrids with improved ruminal starch degradability.
Impacts
Developing corn hybrids for starch and endosperm characteristics is likely to improve ruminal starch degradation and the utilization of corn grain and silage by dairy cattle.
Publications
- Shaver, R. D., and D. Majee. 2002. Relationship between corn vitreousness and starch digestion. Pages 153-158 in Proc. of 64th Cornell Nutr. Conf. For Feed Manuf., East Syracuse, NY. Cornell Univ., Ithaca, NY.
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