Sally Flis, Ph.D. - Feed and Crop Support Specialist - Dairy One
From March to June 2015
he Dairy One Forage Lab collaborated with Allenwaite Farm in Schaghticoke, NY to run a 12 week study feeding shredlage
The Shredlage® processor rips the forage longitudinally, opens up the
of the plant, and smashes the corn kernels
resulting in higher corn silage processing scores (CSPS) than conventionally processed corn silage. In recent years
studies have found varying responses to feeding
and Shaver, 2012; Shaver, 2014;
In order to help the farm make a decision on how to proceed in the future with corn silage processing, we worked with the farm to design a project to compare the corn silage harvested on the farm as shredlage
a conventional corn silage processing unit.
Working with Russ Saville and Sue Greth from Cargill Animal Nutrition, diets were formulated to have 22.4 lbs (38 % of diet DM) of dry matter from either conventionally processed corn silage (CCS) or shredlage (SCS). All other ingredients were the same. Diets were fed to two pens of 2+ lactation cows with 152 cows per pen. The cows in the conventional (C) pen averaged 120 DIM
and the cows in the
shredlage (S) pen averaged 115 DIM at the start of the project.
Milk production was recorded daily for all cows. Feed delivered and refused by each pen was recorded daily using FeedWatch. Milk quality measures (Fat %, Protein %, SCC, and MUN) were measured at week 6 and week 12. During week 6 and week 12, TMR and ORTS (refusal) samples were taken for analysis with the Penn State Shaker and nutrient composition. The CCS and SCS were sampled and tested weekly.
Forage analysis was very similar between weeks three and nine (Table 1), therefore dry matter intake and milk production in the two pens is focused on these weeks. Dry matter intake was similar between weeks three and nine, averaging 56.0 ± 1.2 lbs/cow/day on the SCS diet and 55.8 ± 1.2 lbs/cow/day on the CCS diet (Table 2). The similarity of chemical analysis for SCS and CCS with different milk production responses leads to the second objective of the project:
In the C pen, 136 of the cows were in the pen for all 12 weeks of the study, and in the S pen, 143 cows were in the pen for all 12 weeks of the study
to examine other methods for evaluating corn silage.
|Table 1. Forage analysis results for Conventionally Processed Corn Silage (CCS) and Shredlage (SCS).
While DMI bounced back and forth between the two groups (Table 2), cows in the S Pen produced between 2.2 and 3.2 lbs/day more milk (Figure 1). The milk production response to shredlage was greater in this project than has been reported in earlier studies. In the UW 1 trial, a 1.76 lbs/day increase in milk production was reported when shredlage was fed versus conventional corn silage (
and Shaver, 2012)
. Milk production response to shredlage varied by week in the UW 2 study (Shaver, 2014). A recent Cornell study found no difference in milk production when shredlage replaced conventionally processed corn silage (
). Additionally, during week 6 and week 12, TMR and ORTS samples were analyzed with the Penn State Shaker Box and no evidence of sorting was seen.
|Table 2. Average dry matter intake per cow by week, lbs/cow/day
|Figure 1. Average milk production by week, lbs/cow/day
Milk quality did not differ between diets at 6 weeks or 12 weeks. In week 6, fat % averaged 3.69 ± 0.78, protein % averaged 3.03 ± 0.42, SCC x 1,000 averaged 61.5 ± 208, and MUN mg/dL averaged 13.0 ± 2.2. In week 12, fat % averaged 3.71 ± 0.67, protein % averaged 3.09 ± 0.33, SCC x 1,000 averaged 81.9 ± 214, and MUN mg/dL averaged 13.0 ± 2.0. Previous shredlage studies have reported any difference in milk quality measures when shredlage was fed (Ferraretto and Shaver, 2012; Shaver, 2014).
Fecal starch was 2% or less, indicating very good starch digestion in both diets and no difference between treatments. In week 6, fecal starch averaged 2.18 ± 1.16 % DM and 1.95 ± 0.78 % DM for the S Pen and the C pen, respectively. In week 12, fecal starch was 1.46 ± 0.64 % DM and 1.66 ± 0.86 % DM for the S Pen and the C pen, respectively.
The percentage of material on the top screen of the Penn State Shaker Box was higher for shredlage (36.8 %) than conventional corn silage (13.9 %). The CSPS averaged 62.2 ± 2.8 for shredlage and 56.2 ± 4.0 for the conventional corn silage. However, milk production in the study was not correlated with the CSPS results. We found better relationships to milk production when we measured the starch and NDF concentrations in the fractions of the CSPS and plan to further explore these measures in 2016.
Overall results of this project were similar to what has been reported in other studies. Milk quality measures were not different, cows did not sort diets, and fecal starch was not different. Milk production response in this study was greater than reported other studies (Shaver, 2014; Ferraretto and Shaver, 2012; and Chase, 2015).
Thank you to the Allenwaite Farm and Staff, Sue Greth and Russ Saville from Cargill Animal Nutrition, the Dairy One Forage Lab Staff, Dairy One DHIA technicians, and Heather Dann, Ph.D. of the William H. Miner Agricultural Research Institute.
Ferraretto, L.F. and R.D. Shaver, 2012. Effect of corn shredlage on lactation performance and total tract starch digestibility by dairy cows. The Professional Animal Scientist 28:639-647.
Shaver, R.D. 2014. CCP Harvest: Shredlage vs. processed corn silage, does the cow care?. Proceedings of the 2014 Penn State Dairy Cattle Nutrition Workshop. P. 1-10.
Chase, L.E. 2015. Shredlage in dairy cattle rations. Proceedings of the 2015 Cornell Nutrition Conference for Feed Manufacturers. P. 215-220.