Effect of harvest method and ammoniation of baled corn residue on intake and digestibility in lambs

Abstract

To determine the effect of harvest method and ammoniation on both in vivo and in vitro digestibility of corn residue, six corn residue treatments consisting of three different harvest methods either with or without anhydrous ammonia chemical treatment (5.5% of dry matter [DM]) were evaluated. The harvest methods included conventional rake-and-bale (CONV) and New Holland Cornrower with eight rows (8ROW) or two rows (2ROW) of corn stalks chopped into the windrow containing the tailings (leaf, husk, and upper stem) from eight rows of harvested corn (ammoniated bales of each harvest method resulted in treatments COVAM, 8RAM, and 2RAM). Nine crossbred wether lambs (49.2 ± 0.5 kg BW) were fed 64.2% corn residue, 29.8% wet corn gluten feed, 3.3% smooth-bromegrass hay, and 2.8% mineral mix (DM basis) in a 9 × 6 Latin rectangle metabolism study with a 3 × 2 factorial treatment to measure total tract disappearance. Six 21-d periods consisted of 14-d adaptation and 7-d total fecal collection, and lambs were fed ad libitum (110% of the previous day’s DM intake [DMI]) during days 1 to 12 and reduced to 95% of ad libitum intake for days 13 to 21. There was a harvest method by ammoniation interaction (P < 0.01) for ad libitum DMI (days 7 to 11). Ammoniation increased (P < 0.01) intake across all harvest methods, where 2RAM DMI was 4.1%, COVAM was 3.6%, and 8RAM was 3.1%, which were all different (P < 0.01) from each other, but all untreated residues were consumed at 2.6% of BW (P ≥ 0.92) regardless of harvest method. There were no interactions (P > 0.34) between harvest method and ammoniation for any total tract or in vitro digestibility estimate. Harvest method affected (P < 0.04) DM, neutral detergent fiber (NDF), and acid detergent fiber (ADF) digestibility, where 2ROW was greater than both CONV and 8ROW, which did not differ. The organic matter (OM) digestibility (P = 0.12) and digestible energy (DE; P = 0.30) followed the same numerical trend. Both in vitro DM digestibility (IVDMD) and in vitro OM digestibility (IVOMD) of the residue were affected (P < 0.01) by harvest method, with 2ROW being greater (P < 0.01) than both CONV and 8ROW. For IVDMD, 8ROW was not (P = 0.77) different from CONV, but 8ROW IVOMD was lower (P = 0.03) than CONV. Ammoniation improved (P < 0.01) DM, OM, NDF, and ADF digestibility of all harvest methods, resulting in a 26% increase (P < 0.01) in DE due to ammoniation. Similar digestibility improvements were observed in vitro with ammoniation improving IVDMD and IVOMD by 23% and 20%, respectively. Both selective harvest methods and ammoniation can improve the feeding value of baled corn residue.

Effect of ammoniation and harvest method on waste and consumption of corn residue bales fed to cows in a round bale feeder

“…Alternatively, baled corn residue can offer low-cost forage to cattle producers who may not have access to grazing acres. Previous work has evaluated baled corn residues when fed after grinding and mixing into a total mixed ration ( King et al, 2017 ; Conway et al, 2019 ). Little information is available on the feeding value and waste of whole bales of corn residue fed in ring feeders, which may be more feasible for cattle producers who cannot graze corn residue and who do not have access to grinding and ration-mixing equipment.…”

“…Inherent differences in the nutritive value of the different corn plant parts have been previously noted, with husk being the most digestible, leaf being intermediate, stem being the least digestible, and cob being highly variable ( Fernandez-Rivera and Klopfenstein, 1989b ; Gutierrez-Ornelas and Klopfenstein, 1991 ). Selective harvest methods can change the plant part proportion in the corn residue bales, changing the digestibility of the baled corn residue (King et al, 2017; Conway et al, 2019 ). Furthermore, ammoniation has also been shown to increase intake, digestibility, and crude protein (CP) content of low-quality forages ( Saenger et al, 1982 ; Fahmy and Klopfenstein, 1994 ) and there is some evidence that it will differentially affect individual corn plant parts ( Ramirez et al, 2007 ; Conway et al, 2019 ).…”

“…Selective harvest methods can change the plant part proportion in the corn residue bales, changing the digestibility of the baled corn residue (King et al, 2017; Conway et al, 2019 ). Furthermore, ammoniation has also been shown to increase intake, digestibility, and crude protein (CP) content of low-quality forages ( Saenger et al, 1982 ; Fahmy and Klopfenstein, 1994 ) and there is some evidence that it will differentially affect individual corn plant parts ( Ramirez et al, 2007 ; Conway et al, 2019 ). The objective of this study was to quantify the effects of three different harvest methods and ammoniation on the intake and waste of corn residue when fed to dry cows as a whole bale in a ring feeder.…”