Harvest method and feeder type effect on corn stover intake and waste

Abstract Text: Thirty non-lactating, mid-gestation crossbred cows (575 ± 59 kg) were used in a 5x5 Latin square to evaluate harvest method and processing effects on corn stover (CS) DMI and waste. Dry CS (90% DM) was harvested prior to baling by mowing and raking (DMR) or raking only (DR) and barn stored. High-moisture CS (58% DM) was mowed, raked (WMR) then baled and wrapped to exclude oxygen. CS bales were offered in a conventional open bottom ring feeder (R) or processed through 20 cm screen and offered in fence-line bunks (B). High-moisture CS feeding was hypothesized to increase DMI and reduce waste. A distillers grain based supplement containing monensin at 200 mg•cow^-1•day^-1 was offered separate from CS at 1.58 kg•cow^-1•day^-1. Stover DMI was calculated by subtracting ORTs and collected waste from DM on offer then divided by number of cows per pen. Daily CS DMI was greater (P < 0.05) for DR-R (9.2 kg, 1.56% BW) and WMR-B (9.0 kg, 1.53% BW) compared to DMR-B (7.2 kg, 1.22% BW) and DR-B (7.5 kg, 1.28% BW); DMR-R (8.3 kg, 1.41% BW) was not different (P > 0.05) from all other treatments. Daily waste was greater (P < 0.05) for DMR-R (10.0 kg) and DR-R (9.1 kg) compared to DMR-B (1.2 kg), DR-B (0.7 kg), and WMR-B (0.4 kg). Daily waste as a percent of DMI was greater (P < 0.05) for DMR-R (127.8%) and DR-R (109%) compared to DMR-B (18.4%), DR-B (9.6%), and WMR-B (4.6%). Stover quality was greater (P < 0.05) for WMR-B initial (65.1% NDF, 37.4% ADF) and waste (65.4% NDF, 38.2% ADF) than all other treatments. Initial CS NDF was greater (P < 0.05) in DMR-R (81.9%) compared to DMR-B (79.3%) and DR-B (78.6%); DR-R (79.9%) was not different (P > 0.05) from all other dry treatments. NDF in CS waste was lower (P < 0.05) in DMR-B (72.7%) compared to DMR-R (79.6%) and DR-R (78.3%); DR-B (75.0%) was not different (P> 0.05) from all other dry treatments. Offering CS in ring feeders allows for selection behavior and resulted in greater DMI and waste. Dry CS bunk feeding was effective at reducing waste but reduced DMI. Feeding processed high moisture, higher quality CS in fence-line bunks resulted in the greatest DMI and least waste.  

Keywords: Corn stover, hay waste, harvest method