Submitted to: Animal Feed Science And Technology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/4/2013
Publication Date: 11/15/2013
Publication URL: http://handle.nal.usda.gov/10113/58016
Citation: Caldwell, J.D., Philipp, D., Coffey, K.P., Hardin, L.A., Bass, A.E., Young, A.N., Rhein, R.T., Coblentz, W.K. 2013. Intake and digestibility by sheep, and in-situ disappearance in cannulated cows, and chemical composition of crabgrass hayed at two moisture concentrations and treated with a non-viable lactobacillus-lactic acid additive. Animal Feed Science And Technology. 186:27-35. Interpretive Summary: Crabgrass is a high-quality warm-season annual grass that can be used as hay throughout the southern U.S., but field curing time may be lengthy compared with other forages. Our objective was to assess the effects of moisture concentration at baling with or without application of a non-viable Lactobacillus-lactic acid preservative on the subsequent heating characteristics of bales during storage, pre- and post-storage forage nutritive value, voluntary dry matter intake and digestibility by sheep, as well as kinetics of ruminal disappearance in beef cows. Based on the results, treating crabgrass at the time of mowing with the non-viable Lactobacillus-lactic acid hay preservative may not retain hay nutritive value throughout storage. However, the hay preservative may be effective in improving recovery of dry matter in crabgrass hays baled at greater than recommended moisture concentrations. Some positive effects of treatment also were observed for intake and digestibility by sheep, as well as kinetics of ruminal disappearance within beef cows. However, it was difficult to relate these positive results to the chemical composition of the hays. More research is needed to confirm our findings.
Technical Abstract: Crabgrass [Digitaria ciliaris (Retz.) Koel.] is a high-quality warm-season annual that can be used as hay, but field curing time may be lengthy compared with other forages. A 1.6-ha field of common crabgrass was divided into 12 plots that were used in a randomized complete block design with a 2 × 2 factorial treatment arrangement to determine the effects of a non-viable Lactobacillus-lactic acid preservative and moisture concentration at baling on heating characteristics and pre- and post-storage forage nutritive value. Half of the plots within each block were treated with 81 mL/Mg dry matter (DM) of a solution containing 110 g/kg lactic acid and non-viable Lactobacillus acidophilus at the time of mowing (T) and half were not treated (U). Within T and U plots, half were baled at 175 g/kg (L) and half at 278 g/kg (H) of moisture. Six bales per plot were selected at random, weighed, and stored in separate insulated 6-bale stacks. Core samples were taken from 3 bales initially and 3 bales post-storage. Initial bale moisture concentrations were greater (P<0.05) and initial neutral-detergent fiber (NDF) concentrations were lower (P<0.05) from H vs. L. Recovery of DM was greater (P<0.05) from L compared with H and tended (P<0.10) to be greater from HT compared to HU. Post-storage concentrations of NDF and acid-detergent insoluble N (ADIN; g/kg DM and g/kg N) were greater (P<0.05) from H vs. L. Treating crabgrass with the preservative at mowing may not affect forage chemical composition, but may improve DM recovery in hay baled at elevated moisture levels. Dry matter intake in sheep was unaffected (P>0.05) by either treatment, but DM digestibility and digestible DM intake were both positively affected (P<0.05) by the spray treatment. In addition, DM digestibility also was affected (P<0.05) by moisture, with H>L. In-situ DM disappearance was largely affected by spray treatment × moisture interactions. Fractions A, U, and ED were greater (P<0.05) for HT compared to HU, indicating a positive relationship between applied hay preservative and digestibility of high-moisture crabgrass.