This Is AuburnElectronic Theses and Dissertations

Fermentation Characteristics of Different Cool-Season Annuals With or Without Silage Inoculant




Shoup, Sarah

Type of Degree

Master's Thesis


Animal Sciences


Feed and forage costs make up the greatest portion of costs for beef cattle operations in the Southeast. In the Southeast, the most common method of preserving forages for the winter months is dry hay. Dry hay can be troublesome to conserve at optimum maturity due to rain delays that increase dry matter loss in the field. Barn storage of hay decreases available space and can result in fires if not stored at the correct moisture; furthermore, outside storage of dry hay results in further dry matter loss and nutritive quality decline. Baleage is a high-moisture feed that offers flexibility for timing of harvest and baling, and alleviates the need for storage space in the barn. The research related to southeastern forages for baleage production is limited. However, there is a growing interest among beef and forage producers to grow cool-season annuals for baleage production. Therefore, a study was conducted to determine 1) nutritive value of three cool-season annual mixtures ensiled as baleage, and 2) whether use of bacterial silage inoculants altered the forage nutritive value and fermentation characteristics of the baleage. The goal of this study was to be able to provide Alabama and southeastern beef cattle producers information regarding the practicality of baleage for conserving forages from different cool-season annual forage mixtures as an alternative to traditional, dry hay production. Three cool-season annual mixtures were planted at the E.V. Smith Research Center in Shorter, AL. Forage treatments were 1) wheat (Triticum aestivum L.) + crimson clover (Trifolium incarnatum L.; WC), 2) wheat + T-raptor brassica hybrid (Brassica rapa L. × B. napus L.; WT), and 3) annual ryegrass (Lolium multiflorum Lam.) + oats (Avena sativa L.) + crimson clover; ROC). This study was designed as a 3 × 2 × 8 factorial design (n = 3). Forage treatments were subdivided into two silage inoculant treatments [inoculated (I) or not inoculated (N)] and forages were ensiled in individual mini-silos for 0, 7, 14, 21, 28, 45, 60, or 120 days. Prior to ensiling, data were collected to determine forage yield and nutritive value. After baleage harvest and inoculant application, mini-silos were sampled at 0, 7, 14, 21, 28, 45, 60, and 120 d after packing, and samples were analyzed for nutritive value and fermentation parameters. Crude protein concentration of WC was greater (P ≤ 0.005) than all other forage treatments (17.1%). The CP concentration of WC-I was greater (P = 0.024) than WC-N (17.7 and 16.4%, respectively); however, ROC–N was greater (P = 0.033) than ROC–I by 1.5%. Wheat + T-raptor had the lowest (P ≤ 0.003) pH after ensiling while ROC had the greatest (P ≤ 0.001; 4.5 and 5.4, respectively). Forage treatments WC and WT did not differ (P = 0.140) in lactic acid concentration (3.7%); however, both were greater (P ≤ 0.001) than ROC (0.9%). There were no differences (P ≥ 0.128) in acetic acid concentration among all forage treatments (3.5%). For in situ cumulative NDF digestibility, all forage treatments differed (P ≤ 0.001) with WT having the greatest cumulative digestibility, WC intermediate, and WT the least (62.3, 60.1, and 35.8%, respectively). The results from this study are interpreted to mean that WC had the greatest nutritive quality, but do not indicate an advantage over using silage inoculant to benefit fermentation parameters.