Cool-season Annual Grass, Grass-Forb, and Grass-Legume Forage Systems for Southeastern Beef Cattle Production

Cool-Season Annual Forage Variety Selection Tool For The Southeastern United States

Cool-season annual forage varieties of annual ryegrass (Lolium multiflorum), cereal rye (Secale cereale), wheat (Triticum aestivum), and triticale (Triticale hexaploide Lart.) are often chosen on the basis of availability and affordability rather than performance. The objective of this study was to create a source of collaborative data that would aid producers in selection of superior varieties of cool-season annual forages that perform well across varying years, geographic regions, and environments. Forage yield data was collected from forage variety trials conducted in the years of 2015 – 2020 by University of Georgia, University of Tennessee, Pennsylvania State University, University of Kentucky, and Mississippi State University. Testing occurred at 18 different sites and across 7 states in the Eastern United States. Data from 166 annual ryegrass, 35 cereal rye, 93 wheat, and 48 triticale individual varieties were collected and standardized by expressing yields as a percentage of the mean within a given testing site-year. Standardized means were averaged across all available site-years for each variety within a species and a coefficient of variation (CV) was calculated. Varieties in each species were categorized by their relative mean yield and CV and varieties that had above average relative means and low CV’s were considered desirable. The desired annual ryegrass varieties included: Marshall, K014-WLS, K0140-WEMA, FL Red 4X LATE, Angusta, RM exp-2013A, and FL AT-3. The limitedly tested but qualifying varieties of cereal rye were Wintergrazer 70, Wrens Abruzzi, NF99362, Bates RS4, and Goku, wheat were FLLA10033C-6, GA-09129-16E55, GA-051207-14E53, GA-04417-12E33, GA-03564-12E6, GA-071518-16E39, W010025-H2, PGX-16-4, AGS 3040, Oglethorpe, AGS 3030, PGX 16-1, SS EXP 8629, W010025R1, GA-09377-16LE18, GoWheat 2032, SRW 9410, and GA-071630-12LE9, and triticale were Wintermax, and TriCal 815. Results from this study will aid producers in the identification of desired cool-season annual forage varieties that consistently perform well in varying environmental conditions. 

Exploring Inoculated Cover Crops For Silage Abstract:

Opportunity exists for cool-season annual forages to extend the grazing season and provide high quality feed for beef cattle in Appalachia.  The objective of this 3-year trial is to determine forage mass, botanical composition, and nutritive value of four cool-season annual grasses seeded with and without crimson clover and ensiled with and without a grass/cereal inoculant. In the fall of 2017, 2018 and 2019, forage treatments of rye, ryegrass, wheat and triticale were seeded in small plots with and without crimson clover. Plots were harvested in the spring when grass reached the flowering stage, and was ensiled with and without Pioneer^TM 11G22 Silage Inoculant into mini pvc silos.  Silage forage mass was greatest for triticale and least for ryegrass (9,292 and 8,037 lb./acre, respectively), but did not differ among any other forage treatment. Clover inclusion had no effect on forage mass. Crude protein (CP) content did not differ among clover or ensiling treatment.  However, wheat had greater CP than rye and ryegrass (9.26, 8.48 and 8.47%, respectively).  Wheat had the greatest total digestible nutrients (TDN; 60.33%), followed by triticale (57.78%) and was least for rye and ryegrass (55.53 and 54.80%, respectively) which did not differ from one another.  The addition of crimson clover also increased TDN concentration compared to plots without clover (57.68 and 56.55%, respectively). Silage fermentation parameters of pH, total volatile fatty acids (VFA), lactic acid and acetic acid were impacted by main treatment effects of grass, clover and inoculant. The results of this study indicate that the benefits of including a legume and silage inoculant are negligible and producers should choose a winter-annual forage species that will best fill a forage gap in their production system.

Grazing Cover Crops Soil Abstract:

Coastal Plain soils are often characterized by low soil organic carbon (SOC) as a result of natural and anthropogenic factors. A rotation of cotton (Gossypium hirsutum L.) and peanut (Arachis hypogaea L.) under conventional tillage is typical in this region, but an opportunity to increase SOC and improve soil health by incorporating winter grazing of cover crops exists for producers with row crop and livestock operations. A study to assess winter grazing impacts on soil health was established in the U.S. Coastal Plain. Three cattle removal dates and an ungrazed control were evaluated for impacts on selected soil health indicators: SOC, permanganate oxidizable carbon (POXC), water stable aggregates (WSA), penetration resistance (PR), microbial biomass C (MBC), and arbuscular mycorrhizal fungi (AMF) colonization rates. After two years, MBC was highest in the control treatments, likely due to greater cover crop biomass on the soil surface at termination. No differences were observed between treatments for SOC, POXC, WSA, PR, or AMF. Increased cotton lint yield was observed in control and mid-February treatments in 2019, likely due to greater cover crop residues on the soil surface following grazing, which may have conserved soil moisture during the growing season. Peanut yields were unaffected by treatments in 2020. Lack of differences in soil health indicators suggests that integrating winter-grazing livestock does not negatively nor positively impact selected dynamic soil properties in the short-term, but more time under grazing treatments is needed to thoroughly evaluate how winter-grazing livestock impacts soil health and crop yield.

Grazing Cover Crops Cattle Abstract:

Grazing of cool-season cover crops has been shown to be a viable tool in extending the grazing season while mitigating environmental risks associated with row crop farming systems. Grazing cover crops is not novel, but most information available on this practice focuses on soil health as opposed to forage production and animal performance. A 3-yr study was conducted in Headland, AL to evaluate the effects of cattle removal date on steer performance, forage yield, and forage quality in grazed cover crop systems. Twelve 1.2-ha pastures were established in a forage mix consisting of ‘Cosaque’ oats (Avena strigose), ‘FL401’ cereal rye (Secale cereal), ‘AU Sunrise’ crimson clover (Trifolium incarnatum), and ‘T-raptor’ brassica (Brassica napus × B. rapa) and randomly allocated to be grazed through either mid-February (FEB), mid-March (MAR), or mid-April (APR) with an un-grazed control (CON). Three tester steers were randomly placed in each paddock with the exception of CON. Put and take steers were added to maintain a forage allowance of 1 kg DM / 1 kg BW. Differences in yield were detected between CON and FEB (P < 0.001), CON and MAR (P < 0.001), and CON and APR (P < 0.001). A difference in CP was detected between MAR and CON (P < 0.02). No differences in animal performance were detected, but multiple regression analysis results indicate that NDF has the greatest influence on ADG of all forage quality and stocking parameters. Results indicate that grazing of cool-season annual cover crops can reduce winter supplementation needs, may not be as advantageous when managed under continuous grazing for stocker cattle production. An additional study conducted at the Auburn University Ruminant Nutrition Laboratory evaluated the digestibility, VFA production, and CH₄ production of cool-season cover crops harvested at the beginning of either January (JAN), February (FEB), March (MAR), or April (APR). The objective of this study was to determine if digestibility and subsequent products of digestion changed as forage physiology changes within a growing season. Samples were digested in vitro for either 2, 4, 8, 24, or 48 h. It was found that JAN harvested cover crops had greater IVDMD than FEB (P = 0.009), MAR (P = 0.008), and APR (P = 0.01) following 48 h digestion. No difference in total VFA production were present, but in was found that JAN harvested forages produced less CH₄ than FEB (P = 0.01), MAR (P = 0.003), and APR (P = 0.01). Data from both studies indicate that cool-season annual cover crops can be a suitable grazing crop for beef cattle. Management of grazing in cover crops must be properly managed properly to maximize efficiency of the system, however.

In vitro digestibility of baleage Abstract (North Carolina Data):

This study evaluated ruminal in situ digestibility and nutritional value of monoculture cool-season annual grass baleage with and with-out combination silage inoculant in beef heifers. Four cool season annual grasses: rye (RY: Secale cereale ‘Wrens Abruzzi’), triticale (TR: Triticum secale ‘NCPT01-1433’), wheat (WT: Triticum aestivum ‘SRW8340 croplan’), annual ryegrass (AR: Lolium multiflorum ‘Jumbo’), were grown and ensiled in Waynesville, NC in cooperation with North Carolina State University. A grass/cereal silage combination inoculant containing Lactobacillus buchneri, Lactobacillus plantarum, and Enterococcus faecium was applied to 50 % of the forages. Forage cut at flower stage of maturity was ensiled in laboratory mini silos for 296 ± 1 days before sampling and sending to Auburn University. Two cannulated beef heifers were used to conduct an in situ ruminal digestibility study in Auburn, Alabama at Auburn University. Forage samples were placed in each cow for 0, 2, 4, 8, 12, 24, 48, 72 hours to determine in situ digestibility. After removal, samples were analyzed for neutral detergent fiber using the Van Soest technique. Ruminal in situ digestion kinetics were statistically analyzed for forage species and inoculant status. Forage nutritive values were statistically analyzed for forage species and inoculant status. Overall, WT baleage had the greatest forage nutritive value and in situ digestibility in this study, and the nutritional value was satisfactory for a dry pregnant cow 60 days pre-calving. Rye baleage was not adequate to feed to cattle with-out supplementation. Annual ryegrass and TR maintained intermediate nutritional values throughout the study. Inoculation treatment had a greater effect on in situ digestibility fractions and mineral concentrations than non-inoculated forages. Non-inoculated forages had a greater effect on energy values and soluble carbohydrates than inoculated forages.    

In vitro digestibility of Baleage (Auburn DATA):

In southeastern USA, the use of baleage has increased as an alternative technology to hay production, thereby allowing for a timelier harvest of the conserved forage. A series of studies were conducted to determine the nutritive value, fermentation parameters, and in situ disappearance of the cool-season annual forage mixtures that were ensiled with or without silage inoculant for up to 120 d. The forage mixtures were wheat (Triticum aestivum L.) + brassica hybrid (Brassica rapa L. × napus L.) (WB), wheat + crimson clover (Trifolium incarnatum L.) (WC), and annual ryegrass (Lolium multiflorum Lam.) + oat (Avena sativa L.) + crimson clover (ROC). The inoculant strategy affected the CP concentration (p < 0.05), with it increasing in WB and decreasing in ROC. Among the mixtures, the DM concentration decreased by up to 5%, and the NDF and ADF concentrations decreased by up to 10% during the ensiling period. The pH averaged 5.0, 5.0, and 5.5 for the WC, WB, and ROC mixtures, respectively. Based on our results, the baleage of the cool-season annual forage mixtures may provide a viable high-quality option to sustain animal growth and performance.