Large Round Bales Research Articles

Nutritive value and storage characteristics of large-round bales of alfalfa-grass or perennial-grass hays treated with a propionic acid–based preservative at elevated application presets

Our objectives were to evaluate the storage characteristics and changes in nutritive value for large-round bales of alfalfa (Medicago sativa L.)-orchardgrass (Dactylis glomerate L.) or perennial-grass [orchardgrass; tall fescue (Festuca arundinacea Shreb.); meadow fescue (Festuca pratensis Huds.)] hays treated with a propionic acid–based preservative. Applicator delivery presets were increased by 50% relative to standard factory settings, and hays were compared against untreated control hays. In Exp. 1, 21 large-round bales (1.2 × 1.5 m; 30.5 ± 1.40% moisture; 88% alfalfa, 12% grass) were produced in a completely randomized design with 2 treatments. Bales either received a propionic acid–based preservative at 1.0 ± 0.41% of wet bale weight (n = 11), or no preservative (n = 10), and were stored outdoors on wooden pallets for 131 d. Experiment 2 was conducted similarly; 26 bales of mixed, perennial-grass hay (1.2 × 1.5 m; 18.4 ± 1.40% moisture) were either treated with a preservative at 0.25 ± 0.104% of wet bale weight (n = 15) or were untreated (n = 11) and stored in an identical manner for 40 d. In Exp. 1, application of the preservative reduced maximum internal bale temperatures during the first 30 d of storage compared with untreated control hays (51.8 vs. 60.6°C; P < 0.001); similarly, heating degree days >30°C (HDD) were less for treated hays during the same initial (30-d) time interval (441 vs. 716 HDD; P = 0.001). However, total HDD after 131 d of storage did not differ across treatments (P = 0.426), largely because of the tendency for greater accumulated HDD in treated bales from 31 to 131 d in storage (1,105 vs. 761 HDD; P = 0.085). Final energy density (NEl) was greater (P = 0.030) for treated hays compared with untreated control hays (1.26 vs. 1.21 Mcal/kg DM), but both treatments were depressed from initial prestorage estimates (overall mean = 1.37 Mcal/kg DM). For Exp. 2, there were no differences (P ≥ 0.185) between treatments for any poststorage measure of nutritive value. For bales made at 30.5% moisture, application of a propionic acid–based preservative with elevated delivery presets effectively reduced spontaneous heating during the first month of bale storage, and modestly improved poststorage energy density; however, any nutritional benefit from treatment was modest, and energy density was still subject to measurable reductions relative to prestorage estimates.

Nitrogen balance and blood urea nitrogen by gestating sheep offered alfalfa silage wrapped with or without an enhanced oxygen barrier plastic after time delays up to three days

Exposing ensiling forage to oxygen can result in dry matter deterioration and reduce silage intake by animals. This study was conducted to investigate the effects of two different wrapping sources and time intervals between baling and wrapping on N utilization in gestating sheep offered alfalfa silage. Alfalfa silage was baled in large round bales (moisture concentration = 591 ± 43.0 g/kg), then wrapped with plastic using either an enhanced oxygen-limiting barrier (EOB) or no additional barrier (conventional wrap; CW) on the day of baling or 1, 2 or 3 d after baling. After 5 months of storage, silages were chopped, then offered randomly for ad libitum consumption to 16 gestating ewes [63.5 ± 1.71 kg body weight] to provide 2 observations per treatment for each of 3 experimental total collection periods. Each study period consisted of a 10-d dietary adaptation period followed by 7 d of total fecal and urine collection. Blood was collected immediately prior to feeding and four hours after feeding on the last day of each period. Data were analyzed using PROC MIXED of SAS for a 2 × 4 factorial treatment arrangement, while blood data were treated as repeated measures. When expressed as a portion of total N, neutral detergent insoluble N (NDIN) content of silage increased (P ≤ 0.02) linearly and quadratically, and acid detergent insoluble N (ADIN) concentrations increased (P < 0.01) linearly with longer wrapping delays. Nitrogen apparent absorption (g/d and g/kg N intake) and urinary N (g/d) decreased (P ≤ 0.04) linearly with extended time delays between baling and wrapping. Retained N (g/kg of N intake and of absorbed N) was greater (P = 0.04) from silage wrapped with EOB. Blood urea N concentrations (mg/dL) decreased (P = 0.02) quadratically with extended delay between baling and wrapping. Digestion of NDIN (g/kg NDIN intake) increased (P = 0.03) linearly with extending time delay when silage was wrapped with EOB and linearly and quadratically (P < 0.01) when wrapped with CW. Digestion of ADIN increased (P = 0.02) quadratically with increasing delay between baling and wrapping averaged across wrap types. Therefore, management practices to limit oxygen exposure during packaging and ensiling can prevent a decline in N utilization by ruminants.

Storage characteristics and nutritive value of moist large-round bales of alfalfa or alfalfa–grass hay treated with a propionic acid–based preservative

ABSTRACT Objectives Our objectives for 2 experiments were to evaluate storage characteristics and changes in nutritive value for large-round bales of alfalfa or alfalfa–grass hays made with or without a propionic acid–based preservative. Materials and Methods In Exp. 1, 18 large-round bales (83% alfalfa, 17% mixed grass) were produced (20.6% moisture) in a randomized complete block design with a 2 × 3 factorial arrangement of bale diameters (1.2 or 1.5 m) and preservative-application strategies (fully automated, fully automated assuming a constant baling rate, or control). For Exp. 2, 28 (1.5-m diameter) large-round bales of alfalfa hay were produced in an unbalanced, completely randomized design (20.2% moisture; 16 acid treated, 12 controls). Results and Discussion For Exp. 1, all measures of spontaneous heating differed (P ≤ 0.037) between the 1.2- and 1.5-m bale diameters, with the larger diameter exhibiting greater maximum internal bale temperatures (46.1 vs. 41.6°C; P = 0.012) and greater total heating degree days >30°C (HDD) during storage (334 vs. 106 HDD; P = 0.024). In Exp. 2, all 16 acid-treated bales initially exhibited heating suppression relative to control hays but differed only numerically for total HDD (450 vs. 628 HDD; P = 0.223) after storage; within acid-treated hays, 9 of 16 bales incurred a secondary heating response, primarily after 25 d in storage. Implications and Applications Bale size has a strong effect on preservative effectiveness, and the secondary and extended heating responses exhibited by some acid-treated hays partially explains the mixed overall responses to preservative application noted in some previous experiments.

Effect of Alfalfa Cultivar and Bale Wrap Type on Dry Matter and Forage Quality of Large Round Bales in Outdoor Storage

HighlightsTime to bind a round bale was longest for twine (56 s) compared to B-Wrap® (28 s) and net wrap (18 s).Alfalfa cultivar had minimal effects on changes in dry matter and forage quality of round bales stored outdoors.Dry matter losses were 7% for twine bales, 5% for net wrap bales, while B-Wrap® bales maintained DM in outdoor storage.Deleterious changes in forage quality were generally observed after =180 days of outdoor storage. Abstract. Large round bales are commonly fed to livestock; however, it has been well documented that outdoor storage can negatively impact dry matter (DM) and forage quality. To reduce storage losses and improve feeding value, new wrap types and alfalfa cultivars have been developed; however, these options have not been extensively investigated. Therefore, the objectives of this research were to evaluate the time required to bind large round bales, determine changes in DM and forage quality, and examine the economics of reduced-lignin and conventional alfalfa hay bound in twine, net wrap, and B-Wrap® while in outdoor storage. Hay was baled into 24 large round bales; 12 bales each of reduced-lignin and conventional alfalfa. Within each cultivar, four replicates were bound with each wrap type. Using stopwatches, the time to bind each bale was recorded. At the time of harvest, and every 90±3 days for 365 days, individual bales were weighed and cored to determine changes in DM and forage quality. Significance was set at P = 0.05. Time to bind a bale was longest for twine, intermediate for B-Wrap®, and shortest for net wrap (P &amp;lt; 0.01). Alfalfa cultivar had minimal effects on the parameters measured; therefore, the interaction between wrap type and storage length was reported. After 365 days in outdoor storage, DM losses were 7% for twine bales, 5% for net wrap bales, while B-Wrap® bales maintained DM. Changes in forage quality were observed at =180 days of storage where nonstructural carbohydrates were decreased and insoluble fiber components were concentrated. B-Wrap® bales had a higher value compared to net wrap and twines bales at 180 and 270 days in storage. These results suggest that B-Wrap® was better able to shed precipitation which preserved forage quality and bale value compared to large round bales bound in net wrap and twine in long term, outdoor storage. Keywords: B-Wrap®, Bale value, Net wrap, Reduced-lignin alfalfa, Twine.

Intake and digestibility by gestating sheep of alfalfa silage wrapped with or without an enhanced oxygen barrier plastic after time delays up to three days

Poor silage fermentation can affect its acceptance by livestock. Alfalfa from 3 field blocks were baled in large round bales (moisture concentration = 591 ± 43.0 g/kg) and then wrapped with 7 layers of plastic either with (EOB) or without (CW) an enhanced oxygen barrier on the day of baling, or 1, 2 or 3 d after baling in order to examine those effects on subsequent intake and digestibility by gestating sheep. Alfalfa was chopped after approximately 5 mo. of fermentation, and then offered for individual ad libitum consumption by 16 gestating ewes [63.5 ± 1.71 kg avg. body weight (BW)] in a 3-period (63-day) digestion study. Silage moisture and nitrogen (N) decreased linearly (P < 0.05), acid-detergent fiber (ADF) increased linearly (P < 0.05), and neutral-detergent fiber (aNDF) increased at a decreasing rate (linear; quadratic P < 0.05) with wrapping delay within EOB but not CW (P ≥ 0.23). Lactic acid expressed as g/kg of total silage acids decreased linearly (P < 0.05) within CW and decreased at an increasing rate (linear; quadratic P < 0.05) within EOB with increasing wrapping delay, likely because of aerobic deterioration. Digestible organic matter intake (DOMI) decreased linearly (P = 0.03) within EOB and quadratically (P = 0.02) within CW (wrap type × wrapping time after baling interaction; P = 0.04), but other intake and digestibility measurements were not affected (P ≥ 0.15) by wrap type or its interaction with wrapping time after baling. Intake of DM and OM (DMI and OMI, g/kg BW) as well as digestible DMI (g/kg BW) responded linearly and quadratically (P ≤ 0.03) with wrapping delay after baling by initially increasing to 1 d after baling, then declining sharply thereafter. Digestibility of aNDF increased linearly (P = 0.04) with wrapping delay which was likely related to reduced DMI. These values align somewhat closely with those for forage quality and fermentation profiles. Therefore, managing alfalfa silage to ensure more desirable fermentation should also result in higher digestible OMI, which will improve the overall energy status of ruminants.

Fluctuant storage temperature increased the heterogeneous distributions of pH and fermentation products in large round bale silage

AbstractIn practical of silage production, variations in the fermentation parameters of silage might be attributable to changes in weather data, especially for ambient temperature. The objective of this study was to investigate how the changed temperature of outside weather condition affects distributions of pH and fermentation products in large round bale silage. The bale silages (1.22 m × 1.25 m ø; density, about 168.9 kg dry matter [DM]/m3) were produced by BR6090 Combi from New Holland Agriculture, wrapped with six layers of stretch film, stored at ambient temperature (2–20°C) and constant temperature (10°C; 15°C; 25°C) for 3, 9, 15, 45 and 90 days. Compared with other silages, silage stored at 25°C had higher (p &lt; 0.05) lactic acid content, lower (p &lt; 0.05) pH, butyric acid content and ammonia‐nitrogen (N) ratio of total N. Fluctuant storage temperature limited lactic acid fermentation process with delayed pH decline and continuous butyric production and crude protein (CP) degradation. The differences of pH, lactic acid, propionic acid and ammonia‐N were considerably less evident in the centre of silages stored at different temperatures, and they increased towards the boundaries. The data shows that fluctuant storage temperature had undesirable effect on the fermentation quality of silage, especially for the external part of silo; relatively high and stable storage temperature for initial stage of ensiling process was necessary, but did not promote a positive response to the homogeneous distributions of pH and fermentation products in large round bale silage.

Factors Affecting Hay Prices at Auction: A Hedonic Analysis

Core Ideas Marketing hay in small square bales was found to add significant economic value to the forage. TDN and RFV were both significant drivers of economic hay value. Quality measures had more price impact on small square bales than large round bales. An inverse relationship was found between square bale weight and sale price per metric ton. Despite hay’s significance as a driver of the agricultural economy and its role as a major input into the livestock sector, it has generally received less attention in marketing literature than many other commodities. This work examined sale results from a hay auction in Central Kentucky where information on hay weights and quality were made available to prospective buyers prior to sale. Utilizing this data, a hedonic analysis was employed to examine specific factors that impacted sale prices for individual lots of hay. This work built on existing literature by evaluating the price impact of large round bales compared to small square bales, hay quality measures of Total Digestible Nutrients (TDN) and Relative Feed Value (RFV), lot size, and bale weight. Hay sold in small square bales was found to net a significantly higher price than hay sold as large round bales, even when holding other factors constant. This work also confirmed the importance of hay quality measures as a price driver, even in a market environment without significant dairy influence. Finally, quantitative evidence was found to support a negative relationship between price and small square bale weight, such that price and revenue would likely decrease as small square bales become larger. This work has implications for producers and sellers of hay as they consider marketing strategies and hay buyers as they attempt to understand what drives prices of hay in their region.

94 Effect of Forage Type and Supplement Frequency on Heifer Growth and Reproductive Performance.

In each of 2 yr a 2 by 2 factorial design of forage type Tifton-85 or Coastal bermudagrass large round bale silage and supplement frequency of daily or 3 d/wk (3X) was used to evaluate growth and reproductive performance in heifers. In each year, heifers (n = 123, BW = 272 ± 3.7 kg) were blocked by breed, BW, and BCS and randomly assigned to 1 of 4 pens (15 heifers/pen) for a 112 d development period. Heifers were pen fed silage and supplement fed daily or 3X, mean amount was 2.96 kg•heifer-1•d-1. Weekly blood samples were collected for analysis of plasma progesterone concentration. Heifer BW and BCS were collected every 28 d. On d 112, heifers were synchronized using a CIDR and time-AI. Ten d following AI, heifers were exposed to a bull for 60-d. Pregnancy status was determined at 30 and 60 d intervals. Statistical analysis used pen as the experimental unit and PROC MIXED to analyze BW, BCS, and GENMOD for reproductive performance. Fixed effects included forage, frequency, and interactions, random effects included year and heifer. Final BW and 112-d ADG were not different (P > 0.31) for Coastal than Tifton-85 (351 vs 345 ± 7.4 kg and 0.69 vs 0.65 ± 0.11 kg/d). Final BW and 112-d ADG did not differ (P > 0.84) between Daily and 3X supplemented heifers (348 vs 348 ± 4.8 kg and 0.67 vs 0.68 ± 0.12 kg/d). There was no forage x frequency interaction (P = 0.20) for final BW and 112-d ADG. Body condition score on d 112 did not differ (P > 0.05, 5.4 ± 0.11). Cycling status at the initiation of the breeding season tended (P = 0.10) to be greater for Daily (46%) compared to 3X (31%) heifers. Artificial insemination pregnancy exhibited a forage x frequency interaction (P < 0.009). Tifton-85/daily supplemented heifers (73%) had similar (P > 0.05) AI pregnancy rate compared to Coastal/3X (55%), but greater (P < 0.05) than Tifton-85/3X (42%) and Coastal/daily (39%). Coastal/3X and Tifton-85/3X both had greater (P < 0.05) AI pregnancy rate than Coastal/daily. However, 30-d and 60-d pregnancy rates did not differ (P > 0.05) among treatments (73% and 85%, respectively). Similarities in heifer final BW and ADG among forage types and supplement frequency resulted in similar heifer 30-d or 60-d pregnancy rate. However, Tifton-85 did result in greater 30- and 60-d pregnancy rates.

Nutritive value and fermentation characteristics of alfalfa-mixed grass forage wrapped with minimal stretch film layers and stored for different lengths of time

A key aspect of managing baled silages is to quickly achieve and then rigorously maintain anaerobic conditions within the silage mass. The concept of inserting an O2-limiting barrier (OB) into plastic commercial silage wraps has been evaluated previously, yielding mixed or inconclusive results. Our objective for this study was to maximize the challenge to a commercial polyethylene bale wrap, or the identical wrap containing an OB, by using minimal plastic (4 layers), and then extending storage periods as long as 357 d. Forty-eight 1.2 × 1.2-m large-round bales of alfalfa (Medicago sativa L.) and mixed grass forage (66.3 ± 8.66% alfalfa; DM basis) were made at 2 moisture concentrations [47.5 (ideal) or 36.1% (dry)], wrapped with 4 layers of plastic containing an OB or no OB, and then stored for 99, 243, or 357 d. After storage, yeast counts within the 0.15-m deep surface layer were not affected by treatment (mean = 5.85 log10 cfu/g); mold counts could not be analyzed statistically because 26 bales were nondetectable at a 3.00 log10 cfu/g detection limit, but means among detectable counts were numerically similar for OB (4.74 log10 cfu/g) and no OB (4.77 log10 cfu/g). Fermentation characteristics were most affected by initial bale moisture, resulting in a more acidic final pH for ideal compared with dry bales (5.52 vs. 6.00). This was facilitated by greater concentrations of total fermentation acids (3.80 vs. 1.45% of dry matter), lactic acid (2.24 vs. 0.71% of dry matter), and acetic acid (1.07 vs. 0.64% of dry matter) within ideal compared with dry silages. Plastic wrap type had no effect on final concentrations of any fermentation product. During fermentation and storage, we noted greater change in concentrations of fiber components and whole-plant ash within the 0.15-m deep surface layer than in the bale core, and these changes always differed statistically from 0 (no change) based on pre-ensiled baseline concentrations. Overall, concentrations of water-soluble carbohydrates were reduced (mean = 2.3 percentage units) during fermentation and storage, which resulted (indirectly) in increased concentrations of fiber components and crude protein, as well as an overall energy cost of 2.2 percentage units of total digestible nutrient. It remains unclear under what conditions an OB plastic wrap will consistently benefit the fermentation and preservation of baled silages.

Switchgrass Biomass Quality as Affected by Nitrogen Rate, Harvest Time, and Storage

Core Ideas Switchgrass, being an efficient perennial biofuel crop, can be used as an alternative to fossil fuels and help in the sustainability of energy. Thus, it is important that we understand the effect of storing switchgrass for extended periods of time. Storing switchgrass for an extended period may have an impact on quality and yield. Storing switchgrass in bales or as a standing crop in the field are two storage methods assessed in this study. The purpose of this study was to assess the changes in switchgrass (Panicum virgatum L.) biomass quality as affected by N rate, harvest time, and storage. This research was conducted near Bristol, SD, in 2010 and 2011. Treatments included three N rates (0, 56, and 112 kg N ha−1) applied annually and each N rate replicated four times. After a killing frost, all of the plots were harvested and baled in large round bales in October 2010 and November 2011. An area of about 30 m2 from each plot was left unharvested to represent storage of standing switchgrass over the winter and to determine dry matter yields. Switchgrass was analyzed for hemicellulose, cellulose, lignin, mineral elements, N, and C. In the first season, storage of the fall harvested switchgrass bales numerically increased the concentrations of hemicellulose, lignin, and N. In the second season, they increased significantly. Mineral elements significantly increased in both sampling seasons. Delaying harvest until spring decreased lignin, N, and mineral elements concentration, and increased cellulose and hemicellulose concentrations, but also reduced biomass yield. Results from this study suggest that delaying the switchgrass harvest until spring increased the overall feedstock quality for ethanol production, but yield reductions must be considered to determine the overall economic impact of a delayed harvest.

Planning the Collection and Transportation of Rice Straw in Nantou County, Taiwan

Abstract. The purpose of this study was to design a rice straw collection and transportation method. Four bale forms were designed for processing 75,474 tons of rice straw produced in Nantou County: large large-round bale, small large-round bale, large small-round bale, and small small-round bale. Nine trucks, individually weighing 2, 3, 3.49, 6.2, 7.5, 11, 15.5, 17, and 24 tons, were used for transportation analysis. This study proposed six hypothetical scenarios for rice straw collection and transportation. For each scenario, centralized and noncentralized transportation were implemented, in which centralized transport involves a route from various townships to neighboring farmers‘ associations to the final rice-straw treatment site, and noncentralized transport is direct delivery from various townships to the final treatment site. A geographic information system was consulted to construct a map for the locations of various townships and to assess the optimal routes for rice straw collection and transport. Considering the trucks of varying weights, the transportation costs of various rice straw delivery methods were calculated to determine the optimal collection and transportation locations. The results revealed that the optimal plant locations for rice straw processing and distribution are the rice straw production areas in Caotun Township, Nantou, Mingjian Township, and Jhushan Township. A centralized transportation of small large-round bale was the optimal method and form. The cost of rice straw collection and transportation is US$31.66 and US$20.7 per ton, respectively. A 3.49-ton truck was used for first-stage transportation, traveling an average distance of 15.9 km; a 15.5-ton truck was used for second-stage transportation, traveling an average distance of 24.9 km. Additionally, US$1.5776 million is required annually for collecting and delivering rice straws in Nantou County. In this study, a rice straw collection and transportation method was devised for Nantou County and plant establishment at the final sites for rice straw treatment was assessed. In the future, a decision-supporting system for rice straw collection and transportation can be further developed.

Reshaping and Recompressing Round Biomass Bales

<abstract> <b><i>Abstract. Recompressing bales to achieve greater density can reduce biomass storage and transportation costs, but researchon recompressing round biomass bales is limited. Bi-axial compression in the radial direction of wheat straw, cornstover, switchgrass, and reed canarygrass was used to reshape round bales into a rectangular cross-section. The processwas conducted as a three-stage progression: vertical reshaping to cuboid shape, followed by vertical and then horizontaldensification. Density increased by 13% to 23% during vertical densification, and the pressure-density relationship wasmodeled as a linear function. Linear, power, and exponential models were fit to the pressure-density data collected duringhorizontal compression, during which density increased by an additional 68% to 83%. The linear and power functions bestmodeled the horizontal compression data. Although the power model underpredicted the initial density, it closely predictedthe final bale density, so this model would have greater utility for future design applications. The target density of 240 kgDM m-3 was achieved at the end of compression with all four crops. Corn stover had significantly greater final density thanthe other three crops and achieved the target density with less applied pressure. Bales were restrained with polyester strappingprior to removal from the chamber. Bale density decreased 19% to 30% due to re-expansion after pressure was released.Although the forces applied were great, the specific energy requirements were low because compression took placeover a relatively long time (~30 s). Differences in specific energy between crops were not statistically significant. Reshapingand recompressing large round bales could be an alternative to high-density large square baling to achieve weight-limitedtransport of baled biomass. </i></b> <p />

Implications of Round Bale Dimensions on Hay Use

The dimensions of large round bales make a difference in many cases. Bale size determines the amount of hay in a purchased bale, the amount of nutrients in pounds, and the extent of spoilage during storage and feeding. Large round bales, the predominant form of hay made and fed to cattle, are under discussion. This 3-page fact sheet is a new document that examines the significance of bale dimensions, volume, density, and weight as well as the relationship of these factors to hay prices. Written by Matt Hersom, Todd Thrift, and Joel Yelich, and published by the UF Department of Animal Sciences, June 2016. AN326/AN326: Implications of Round Bale Dimensions on Hay Use (ufl.edu)

Engineering Economics of Cotton Stalk Supply Logistics Systems for Bioenergy Applications

Cotton stalk (CS), which is usually left in the field, can be a potential bioenergy feedstock if it can be economically harvested and delivered to a bioenergy plant. The objectives of this study were to systematically assess the spatial and temporal availability of harvestable quantities of CS and evaluate the least expensive supply system among various biomass supply logistics options. The availability of harvestable CS in the U.S. was estimated at the county level using cotton yield data with the best farm management practices. Six supply logistics options for CS were evaluated to estimate delivered cost and energy usage for each option: large rectangular bale (LReB), large round bale (LRoB), small round bale (SRoB), chops, modules, and single-pass bio-baler. The average annual availability of CS in the U.S. was estimated as about 14.4(±0.05) dry Tg, with an economically harvestable amount of 5.6 (±0.03) dry Tg and a minimal harvestable stalk yield of 2.5 dry Mg ha -1 . Among the six supply logistics options evaluated, LReB was the least expensive option, with an average delivered cost of $60 dry Mg -1 (100 km round trip) and energy input of 462 MJ dry Mg -1 . Sensitivity analysis of the LReB supply logistics system demonstrated that the total delivered cost can be further reduced by up to 30% if the overall machine capacity, field efficiency, and bale bulk density can be increased by 20%.

359 Effect of delayed wrapping and wrapping source on intake and digestibility of alfalfa silage in sheep

Delays often occur between baling and wrapping during production of baled silage that increases exposure time of the forage to oxygen. This study was conducted to investigate the effect of 2 different wrapping sources and time intervals between baling and wrapping on intake and digestibility of alfalfa silage by gestating sheep. Alfalfa silage was baled in large round bales, and then wrapped with plastic either with or without an oxygen-limiting barrier; wrapping occurred either the day of baling, or 1, 2 or 3 d after baling. Beginning in January, silages were chopped and packed into plastic-lined trash containers, and then offered randomly for ad libitum consumption to 16 gestating ewes (n = 16; 63.5 ± 1.71 kg BW) to provide 2 ewes per treatment for 3 experimental periods. Each period consisted of a 10-d dietary adaptation period followed by 7 d of total fecal and urine collection. Ewes were housed in individual 1 × 1.5-m pens with plastic coated expanded metal flooring and were re-randomized to different treatments each period such that ewes were not offered the same treatment in any subsequent period. Data were analyzed using PROC MIXED of SAS for a 2 × 4 factorial treatment arrangement and orthogonal polynomial trend analyses were used to assess effects of time delay for wrapping after baling. Intakes of DM responded with linear, quadratic, and cubic effects (P < 0.05), while OM responded with linear and quadratic effects (P < 0.05) as wrapping was delayed after baling. Digestibility of DM and OM responded cubically (P < 0.05), that of NDF increased linearly (P < 0.05), and digestible DM and OM intake (g/kg BW) responded linearly, quadratically, and cubically (P < 0.05) with time delay between baling and wrapping. In general, intake and digestibility were greatest in silage wrapped the day following baling. Type of wrap tended (P = 0.10) to affect DM digestibility, and digestible OM intake was affected (P < 0.05) by the wrap type × wrapping time after baling interaction, but other intake and digestibility measurements were not affected (P ≥ 0.15) by wrap type and the interaction of wrap and wrapping time after baling. Therefore, delaying wrapping alfalfa silage bales beyond 1 d after baling may have detrimental effects on energy status in gestating ewes. The study was supported in part by USDA-ARS specific cooperative agreement 58–3655–4-052.

Storage characteristics, nutritive value, and fermentation characteristics of alfalfa packaged in large-round bales and wrapped in stretch film after extended time delays

The production of baled silage is attractive to producers because it offers advantages over dry hay, particularly by limiting risks associated with wet or unstable weather conditions. Our objectives were to test the effects of delayed wrapping on silage fermentation, storage characteristics, and the nutritive value of baled alfalfa silages. To accomplish this, large-round bales of alfalfa were wrapped in plastic film within 4h of baling (d 0), or after delays of 1, 2, or 3 d. A secondary objective was to evaluate a prototype bale wrap containing an O2-limiting barrier (OB) against an identical polyethylene wrap without the O2 barrier (SUN). Sixty-four 1.19×1.25-m bales of alfalfa were made from 4 field blocks at a mean moisture concentration of 59.1±4.3% with a mean initial wet bale weight of 473±26.4kg. Two bales per field block were assigned to each combination of bale wrap (SUN or OB) and wrapping time (0, 1, 2, or 3 d postbaling), and one bale of each pair was fitted with a thermocouple placed in the geometric center of each bale. All bales were sampled after a 97-d storage period. Internal bale temperatures, recorded at the time bales were wrapped, were greater for all bales with wrapping delays compared with bales wrapped on d 0 (54.9 vs. 34.9°C), and increased to a maximum of 63.9°C after a 3-d delay exhibiting a linear effect of time delay. Total silage fermentation acids (lactic, acetic, propionic, butyric, and isobutyric) were greatest when bales were wrapped on d 0 compared with all bales wrapped with time delays (4.64 vs. 2.26% of DM), and declined with linear and quadratic effects of wrapping delay. Total fermentation acids also were related quadratically to internal bale temperature by regression [y (% of DM)=0.0042x2 – 0.50x + 17.1; R2=0.725]. Similar responses were observed for lactic acid, except that trends were linear, both for orthogonal contrasts evaluating length of wrapping delay, and in regressions on internal bale temperature [y (% of DM)=−0.046x + 3.5; R2=0.663]. Butyric acid also was detected, regardless of treatment, but was greatest within bales wrapped on d 0 compared with those with wrapping delays (0.99 vs. 0.38% of DM), and a similar response (0.68 vs. 0.52% of DM) was observed for NH3-N, suggesting that clostridial activity occurred during silage fermentation. Based on these results, silage fermentation characteristics and the nutritive value declined with time delays before wrapping, but responses were exacerbated when delays exceeded 1 d.

Nutritive value and in situ digestibility of pearl millet hay as affected by moisture concentration and bale sampling depth

Seven hectares (ha) of pearl millet [Pennisetum glaucum (L.) R. Br.] were divided into 3 blocks with 3 whole plots each to evaluate the effects of moisture (165, 187, and 274 g/kg of DM) and sampling depth (0.2, 0.4, and 0.6 m) in round bales on chemical composition and in situ disappearance. Plots were assigned randomly to moisture treatments. Round bales (n = 3 per plot; 1.2 × 1.5 m, 568 kg) were obtained and sampled at 3 different depths within each bale (n = 81) before and after 71 d of storage. Duplicate in situ bags (10 × 20 cm) were incubated in 6 ruminally cannulated cows (BW = 585 ± 37.8 kg) up to 120 h. Residual DM for each sampling time was fit to a nonlinear model using PROC NLIN of SAS to determine DM degradation kinetics. Data were analyzed as a split-plot design using Proc Mixed procedures of SAS and tested for moisture, depth, and their interactions. Bale temperature and concentrations of ADL were greater (P 0.10) any of the digestion variables, but the water-soluble fraction, potentially degradable fraction, and effective ruminal disappearance as well as concentrations of OM, NDF, and acid-detergent insoluble nitrogen were affected (P < 0.05) by the moisture × sampling depth interaction. Therefore, a greater range in sampling depth should be used to accurately assess heat damage in large round bales.

Corn stover for bioenergy production: Cost estimates and farmer supply response

A lot of attention is being paid to potential use of corn stover as a feedstock for bioenergy production. In addition to meeting renewable energy goals, use of corn stover for energy production may provide a new source of income for corn growers. This study estimates the costs of corn stover harvest and supply, and then uses that information to estimate farm production decisions and changes to farm profit at varying corn stover prices. In this study, corn stover is collected in large round bales using a raking, baling, and staging method. Harvest cost includes payments for fuel, labor, equipment ownership and repair, net wrap, and nutrient replacement. Supply costs include storage, loading and unloading, and transport. The total cost of harvest and supply is estimated between 82.19 $ Mg−1 (dry) and 100.56 $ Mg−1 (dry). Costs will vary considerably from farm to farm and from year to year depending on weather conditions.A linear programming model was used to estimate the willingness of corn growers to harvest corn stover at varying stover prices. Corn stover supply, farm profit, and land allocation was analyzed under multiple scenarios. At a price of 88.19 $ Mg−1, farms in the base case harvested corn stover at a rate of 2.49 Mg ha−1 using a 33% removal rate. At this price, stover provided enough additional profit to entice farmers to shift to more continuous corn production. Future research is needed to determine the overall impacts of a viable stover market on corn and soybean production and price.

Effects of Harvest and Storage of Switchgrass on the Recovery of Carbohydrates during Dilute Acid Pretreatment and Enzymatic Hydrolysis

Perennial forage grasses have potential as cellulosic feedstocks. Outside storage as round bales is a likely mode of storage; however, little is known of storage effects. The objective of this study was to determine the effects of baled storage method on saccharification, namely the recovery of glucose and xylose, and production of inhibitors after dilute acid pretreatment and enzymatic hydrolysis. Mature switchgrass (Panicum virgatum L. cv. Alamo) was harvested in Fayetteville, AR and packaged in large round bales in October 2010. There were two baling times: one soon after cutting when there was no rainfall and the other after a rainfall event. The bales that did not receive rain were stored either in an open barn or unprotected in the field. Bales made from rained-on switchgrass were only stored unprotected in the field. Samples were taken from the windrows right before baling, and after a maximum 65-day storage period. Field storage increased lignin content in biomass relative to barn storage, but carbohydrate constituents were not affected. Field storage decreased production of hydroxymethylfurfural and increased production of furfural relative to barn storage. Results indicate that protected storage conditions for switchgrass biomass in round bales can lead to greater preservation of fermentable sugars and reduced production of the important inhibitor furfural.

Cattle preference for hay from round bales with different wrap types

Three different methods of wrapping and storing alfalfa hay in round bales were used to explore possible differences in preferential consumption. Large round bales of alfalfa were stored indoors, outdoors with conventional net wrap, or outdoors with a new wrap that incorporates a breathable film. This film is intended to better conserve hay in round bales by shedding precipitation but allowing internal moisture to exit the bale through microscopic pores. Five separate preference trials, each of 18-d duration with six 3-d periods, were conducted using beef cattle. In all 5 preference trials, hay wrapped with breathable film was preferred over net-wrapped hay stored outdoors. For instance, in trial 1 hay wrapped with breathable film was preferred over net-wrapped hay stored outdoors in all 18 pairings (P < 0.001), and consumption of the film-wrapped hay was significantly greater (78 vs. 28% of total hay offered, P = 0.05). Results suggest that when bales are stored outdoors, cattle will strongly prefer to consume hay from bales wrapped with breathable film compared with net-wrapped bales. Although in 2 trials hay wrapped with breathable film was preferred over hay stored indoors, when considered across all trials and pairings, preference of hay from breathable film bales did not differ from that stored indoors.