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Cowpeas [Vigna unguiculate (L) Walp] as a summer cover crop have the potential to provide N to a cool-season crop. The objectives of this study were to evaluate two cowpea cultivars grown as a cover crop to supply N for forage rye (Secale cereale L.) and to document cowpea N and C contributions to the soil. The 2-yr study was conducted at the Texas A&M AgriLife Research Center at Overton on a Darco loamy fine sand (loamy, siliceous, semiactive, thermic Grossarenic Paleudult) during 2014-2016. Treatments were arranged in a splitplot design with four replicates with cover crop as the main plot and N rate as subplot. Cover crop treatments included 'Combine' (COM) and 'Iron and Clay' (IAC) cowpeas and summer fallow. In late summer, cowpeas were incorporated as green manure, and four rates of fertilizer N were applied to rye. Total 2-yr cowpea biomass incorporated as green manure was similar at 4,596 kg ha-1 and 5,058 kg ha-1 for IAC and COM, respectively. Cowpeawas not effective as a green manure crop at providing N for rye biomass. Total soil N showed no difference (P ≥ .34) between cowpea entries or N rate within a soil depth. Each N rate increased rye biomass (P < .01) linearly (P < .001) in each year. Soil organic C from cowpeas increased about 6-8% over 2 yr. The extent of decomposition of cowpeas on the deep, sandy Darco soil limited nutrient transfer from cowpeas during this 2-yr period. [ABSTRACT FROM AUTHOR]

Sixteen forage cowpea [Vigna unguiculata (L.) Walp.] plant introduction (PI) lines were evaluated for agronomic traits and pest resistance in field and greenhouse experiments to enhance double cropping and cover crop rotation systems in northeast Texas and the southeastern United States. Cowpea cultivars 'Iron and Clay' and 'Combine', and one cowpea breeding line, TX-3, were included as controls. Cowpea lines were planted in a Darco loamy fine sand soil (a loamy, siliceous, semiactive, thermic Grossarenic Paleudult) in a randomized complete block design. Data collected in 2015 and 2016 included biomass, seed yield, and maturity stage. Plant introduction lines differed in biomass and seed production (P < .05) in both years. Biomass production ranked highest at 2,695 lb dry matter (DM) acre-1 for PI 175963 in 2015 and 2,582 lb DMacre-1 for PI 367863 in 2016. Seed yield ranked highest at 305 lb acre-1 for PI 175963 in 2015 and 2,071 lb acre-1 for PI 208845 in 2016. In a greenhouse study, 14 PI lines and two cowpea breeding lines, TX-505 and TX-3, were evaluated for susceptibility to the southern rootknot nematode (Meloidogyne incognita). Based on nematode reproduction and root galling, most of the PI lines were susceptible, while PI 367863 and TX-505 were resistant. Several PI lines were identified with improved biomass and seed production and one PI line and one breeding line with resistance to the southern root-knot nematode. These lines could be used in cowpea breeding programs to develop improved forage cowpea cultivars for double-cropping and crop-rotation systems in Texas and the southeastern United States. [ABSTRACT FROM AUTHOR]

The perennial forage model in the Decision Support System for Agrotechnology Transfer (DSSAT) suite is a newly developed model. Studies involving the use of the forage model for predicting biomass production for a perennial grass such as bermudagrass [Cynodon dactylon (L.) Pers.] are few. By conducting a series of simulation investigations, we examined the DSSAT forage model for simulating 'Coastal' bermudagrass biomass response to N as affected by soil and climate variability in the southern United States. The simulation results indicated that the DSSAT forage model predicted the biomass response to N reasonably well. However, the accuracy of simulations was linked primarily to the water holding capacity (WHC) of the soil used. A seemingly small difference in WHC, such as 0.03 mm mm-1, made a significant difference in the biomass response to N rate by a margin of about 3 Mg ha--1. These results indicated that providing more leverage to WHC than to the soil name, texture, or type being used for simulations could provide more accurate results. The simulations further indicated that bermudagrass production in the southern United States could be impacted by El Niño-Southern Oscillation (ENSO), with the La Niña and El Niño phases providing above-normal and below-normal production, respectively. The rate of increase in biomass with an increase in N rate was higher under La Niña than under El Niño. The impact of ENSO was greater on a soil with a coarser texture. [ABSTRACT FROM AUTHOR]

Winter wheat (Triticum aestivum L.) is an important component of pastures in the southern United States. This study examined winter wheat biomass responses to N application rate as influenced by soil type, planting date, drought, and El Niño-Southern Oscillation (ENSO) for the Pineywoods region of Texas using a new forage wheat model that had been incorporated into the Decision Support System for Agrotechnology Transfer suite of crop models. Biomass was simulated for various scenarios comprising two soils, three planting dates, seven N rates, and 74 yr of weather data. The biomass response to N rate was represented by a one-phase exponential association. Biomass generally peaked at 135 kg N ha-1 on the finer, more fertile Lilbert soil and at 269 kg N ha-1 on the coarser, less fertile Darco soil. Biomass decreased with a delay in planting date at N rates =135 kg N ha-1 for Lilbert and =202 kg N ha-1 for Darco. The effect of drought during September to October was greater for a higher N rate, the Darco soil, and an earlier planting date. The effect of drought during March to April was greatest at 135 kg N ha-1 and greater on Darco, with up to 45% reduction in biomass compared with 35% on Lilbert. Biomass reduction was up to 45% for the mid-October planting and 32% for the mid-September planting. Winter wheat biomass yield was not significantly affected by ENSO. These findings might assist winter wheat forage growers in this region in identifying soil type-, planting date-, and weather-specific N rates to optimize forage production. [ABSTRACT FROM AUTHOR]

Management of bermudagrass [Cynodon dactylon (L) Pers.] pastures on Coastal Plain soils in the southeastern United States incorporates multiple strategies for N fertilization, liming, and stocking rate (SR). This study documented longterm changes in soil pH and extractable NO3-N K, Ca, and Mg in Coastal and common bermudagrass pastures continuously stocked at different intensities for 37 yr (1969-2004). Soil fertility regimens were established in 1985 and consisted of (i) inorganic nitrogen fertilizer with overseeded annual ryegrass (Lolium multiflorum Lam.) (NRYG) and (ii) no nitrogen with overseeded clover (Trifolium spp.) (NoNCLV). Soil samples (0-120-cm depth) were collected in 1985, 1989, 1994, 1996, and 2004 and analyzed for pH and extractable NO3-N, K, Ca, and Mg levels. Fertility regimen showed significant effects on soil NO3-N concentration (0-15 cm) with greater values generally observed in the pastures receiving N (average NO3-N concentration of ~ 4 mg kg-1 in NoNCLV vs. 14.15 mg kg-1 in NRYG treatments). Differences in N fertilizer application levels throughout the study period also affected soil NO3-N concentration. Conversely, bermudagrass pastures receiving no inorganic N and overseeded with clover showed relatively constant soil NO3-N concentrations during the study period. Soil K levels increased (42 to 48%) over time and were generally greater in the NoNCLV pastures. It was concluded that overseeding clover without N fertilization onto bermudagrass pastures can be a viable, long-term management strategy to sustain adequate soil nutrient levels while achieving satisfactory forage and animal production. [ABSTRACT FROM AUTHOR]

Grazing systems research includes a wide array of component experimentation to assess plant-animal responses on pastures during short-term, seasonal, and long-term periods. pasture-animal experiments seek to assess forage growth responses to grazing and to quantify relationships between forage growth and nutritive value to gains per animal and per hectare. These experiments have used fixed and variable stocking rate management, continuous or rotational methods of stocking, and other stocking strategies to evaluate levels of production efficiencies. Stocking strategies require the integration of periodic and total forage mass, associated nutritive attributes, specific defoliation regimen responses, and incorporation of weather conditions to meet end-point objectives. The flexible integration processes includes forageanimal databases, availability of land resources, and intuitive experience to accommodate erratic weather conditions. Scientists have the opportunity to develop and validate stocking strategies through long-term, site-specific grazing systems research as well as collaborative, ecoregion research efforts. Documenting the influence of stocking density on nutrient cycling, stand maintenance, ecotype diversity, and watersheds will further define soil-forage-animal responses and impacts. Management prerequisites for application of stocking strategies includes foundational forage-animal interface relationships, land resource limitations, animal husbandry behavior awareness, initiation and termination of stocking sequences, projections and expectations for climatic changes, and biological and economic risk-reward expectations. Scientists involved in grazing system research are challenged to integrate soil, forage, and animal databases to discover and document production efficiencies and stocking strategies for implementation by scientists, students, and stakeholders. [ABSTRACT FROM AUTHOR]

Cancer of the eye in cattle with white faces occurs less frequently in cattle with pigmented eyelids. Corneoscleral pigmentation is related to eyelid pigmentation and occurrence of lesions that may precede cancer. Objectives of this study were to assess 1) variation in the proportion of eyelid and corneoscleral pigmentation in Hereford, Bos taurus, and Bos indicus crossbreds and 2) the occurrence of lesions with the presence of pigmentation in those areas. Hereford and Bos indicus crosses (Brahman or Nellore with Angus and Hereford and straightbred Brafords) and Bos taurus crosses (Angus-Hereford) were included in the study (n = 1,083). Eyelid pigmentation proportions were estimated by pixel quantification and were evaluated as total proportions and for upper and lower eyelids distinctly for each eye. Fixed effects included breed type, age categories, and sex of the animal. Lesion presence (1) or absence (0) was obtained by visual appraisal of image and was assumed to be binomially distributed. Eyelid pigmentation proportions (overall, upper, and lower eyelids) for Hereford ranged from 0.65 ± 0.03 to 0.68 ± 0.03 and were significantly lower than Bos indicus (range from 0.93 ± 0.02 to 0.95 ± 0.02) or Bos taurus (ranged from 0.88 ± 0.02 to 0.92 ± 0.02) crosses. Corneoscleral pigmentation in Hereford cows (0.17 ± 0.06) did not differ (P = 0.91) from Hereford calves and yearlings (0.16 ± 0.07). Bos indicus and Bos taurus crossbred cows had larger corneoscleral pigmentation (0.38 ± 0.05 and 0.48 ± 0.04 for left eyes and 0.37 ± 0.05 and 0.53 ± 0.04 for right eyes, respectively) than all calves (P < 0.001), and their corneoscleral pigmentations were greater than that of Hereford cows (P < 0.003). Bos indicus and Bos taurus cows had greater proportions of left eye corneoscleral pigmentation (0.38 ± 0.05 and 0.48 ± 0.04, respectively) than Hereford cows (0.17 ± 0.06) and all young animal breed types (P < 0.05). Right eye proportions differed for all cow groups (P < 0.05; 0.53 ± 0.04, 0.37 ± 0.05, and 0.17 ± 0.06). Among calves and yearlings, Hereford had a lower right eye corneoscleral pigmentation proportion (0.16 ± 0.07) than Bos taurus (P = 0.02). The lesion proportion for Hereford (0.08 ± 0.03) was significantly greater than that of either Bos indicus (0.01 ± 0.005) or Bos taurus (0.01 ± 0.003). Crossbreeding with Bos taurus or Bos indicus animals appears to increase eye pigmentation, which may help reduce the occurrence of cancer in eyes of cattle with white faces. [ABSTRACT FROM AUTHOR]

Pasture management affects soil properties, but information concerning the effects of long-term stocking and fertility regimens on soil P in pastures is limited. This study investigated changes in extractable soil P concentrations from Coastal and common bermudagrass [Cynodon dactylon (L) Pers.] pastures stocked for 37 yr at different intensities on an Ultisol. From 1969 through 2004, pastures were continuously stocked during February to September to achieve high, medium, and low herbage mass. Annual fall-applied P averaged 44 kg ha-1 from 1969 to1984 and 51 kg ha-1 from 1998 to 2004. Extractable soil P concentrations in the 0- to 15-cm depth increased (P ≤ 0.0001) from 5 mg kg-1 (very low) in 1975 to 43 mg kg-1 in 2004 (high), and deeper depths showed 14 to 36% increased P levels. Elimination of P fertilizer for 13 yr, 1985 to 1997, decreased (P ≤ 0.0001) extractable soil P in the 0- to 15-cm depth by 30 and 47% in common and Coastal bermudagrass pastures, respectively. An interaction between year and stocking rate was evident as extractable P levels increased after 20 yr at high stocking rates. After 37 yr, extractable P levels at the 0- to 120-cm soil depth followed the order high > medium ≥ low stocking rate. Despite the effect of stocking rate on soil P, 37 yr of continuous stocking showed no evidence of excessive P accumulation at levels that may pose an environmental threat. Phosphorus recycled through the soil-forage-animal system sustained adequate forage and animal productivity. [ABSTRACT FROM AUTHOR]

Field observations revealed greater retention of green leaf area and growth of 'Tifton 85' compared to common and 'Coastal' bermudagrass [Cynodon dactylon (L.) Pers.] underwaterstress.Ourobjective was to compare phenotypic and physiological responses to increased water stress between Tifton 85 and Coastal and between Tifton 85 and 'Tifway' bermudagrass under greenhouse conditions. Bermudagrass green leaf area, shoot and root dry weights, leaf C02 exchange rate (CER), H20 exchange rate (WER), and conductance were measured under well-watered and reduced watering in two experiments. Tifton 85 retained greater green leaf area than Tifway under water stress in Exp. 1. The CER, WER, and conductance were less for Tifton 85 than Tifway, but water stress over 8 d reduced each variable for Tifway only. In Exp. 2, soil water content and green leaf area declined more for Tifton 85 than for Coastal bermudagrass over 14 d after watering ended. Greater root dry weight below the 13-cm depth indicated Tifton 85 depleted water content of the finite pot volumes more rapidly than Coastal under reduced watering. After 14 d without watering during Exp. 2, mean CER of green leaves was less than well-watered pots for Tifton 85 but not for Coastal bermudagrass. Similar to phenotypic traits, leaf CER, WER, and conductance responses of Tifton 85 differed between experiments. These greenhouse experiments documented variation of responses to reduced soil water supply among bermudagrass and revealed the need to evaluate traits affecting water access and use for Tifton 85 and other bermudagrass under field conditions. [ABSTRACT FROM AUTHOR]

Forage-animal production agriculture is implementing infrastructure changes and management strategies to adjust to increased energy-related costs of fuel, feed grains, fertilizers, and seeds. The primary objectives of this position paper are to assess future research and extension scientific needs in forage utilization, financial support for the discipline, and changing status and number of scientists. A survey questionnaire returned from 25 land-grant universities in the eastern half of the United States rated the top 4 research needs as 1) pasture systems and efficiency of production; 2) interfacing with energy concerns; 3) forage cultivar evaluations and persistence; and 4) environment impacts. Plant-animal future research needs at 11 USDA-ARS regional locations are targeted at sustainable management and improved livestock performance, ecophysiology and ecology of grasslands, environment impacts, and improved technologies for nutritive value assessments. Extension scientists from 17 southern and northeastern states listed the top 3 needs as forage persistence, soil fertility and nutrient management, and pasture systems and efficiency of production. Grant funds currently provide more than 40% of land-grant university research and extension efforts in forage utilization, and scientists estimate that this support base will increase to 55 to 60% of the funding total by 2013. Reduced allocation of state and federal funding has contributed to a reduction in the number of full-time equivalent (FTE) scientists engaged in forage utilization research and extension activities. The current 25 state FTE conducting research number about 2.8 per state. This includes 10 states with >3, 11 states with <2, and 3 states with <1 FTE. Increased interest in cellulosic energy, climate change, and environmental impact may offer new opportunities for these FTE to participate in integrated cross-discipline research Extension programming, and technology transfer methods will change to accommodate reduced funding but with increasing numbers of novice, recreation-oriented landowners. [ABSTRACT FROM AUTHOR]

Supplementation of cattle on pasture is a well-known viable strategy for increased performance per animal and per ha. Ethanol has been proclaimed as a sustainable alternative to fossil fuels, and the vast supply of dried distillers' grains with solubles (DDGS) generated from ethanol production provides opportunities for addition to feedlot rations and supplementation of grazing cattle. A large percent of the cattle in the United States are located in the Southeast, where bermudagrass is the primary introduced forage species. Since relatively few research studies have been conducted using DDGS as a supplementation on actively-growing warm-season pastures, this research represents a significant and critical knowledge database for the pasture-beef industry. The first objective of this research was to evaluate performance of stocker calves grazing 'Tifton 85' (TIF) bermudagrass with varying rates of DDGS supplementation. Steers (n = 112, 364 ± 3.5 kg BW) were stratified by BW and allocated randomly to each of 16 pastures (0.7 ± 0.01 ha) across 2 years (2014, 2015). The TIF pastures were allocated randomly to each of 4 rates of DDGS: 0, 0.25, 0.5, or 1% BW hd-1 d-1. Average daily gain was greatest (P < 0.05) from steers offered 1% BW (1.3 kg/d), and least from non-DDGS steers (0.8 kg/d), with 0.25 and 0.5% BW intermediate (1.1 and 1.2 kg/d, respectively). There were supplemental feed to additional gain ratios of 3.7, 6.0 and 9.0, respectively, for 0.25, 0.5 and 1% BW. The second objective was to evaluate performance of Bos indicus versus B. taurus stocker calves grazing 'Coastal' (COS) bermudagrass with varying rates of DDGS. Steers within a breed type (n = 117, 343 ± 4.5 kg BW) were stratified by BW and allocated randomly to each of 9 pastures (1.3 ± 0.17 ha) across 2 years (2014, 2015). Pastures were allocated randomly to each of 3 rates of DDGS: 0, 0.25, or 1% BW hd-1 d-1. Across breed types, ADG was greater (P < 0.05) from steers offered 1% BW (1.0 kg/d) than either from non-DDGS steers or 0.25% BW (0.7 kg/d each). There was no difference (P = 0.70) in ADG between breed types. The third objective of the study was to evaluate any carryover effects in long yearling stockers previously stocked on TIF or COS with varying rates of DDGS. Following the pasture x DDGS phase in the first 2 objectives, steers were shipped 693 km to a commercial feedlot for an approximate 140-d finishing phase. At finishing, animals were transported 59 km and harvested at a commercial abattoir. There was no effect (P ≥ 0.36) of DDGS for either TIF or COS during the feedlot phase. Likewise, there was no effect of DDGS on percent Low Choice for TIF (P = 0.74) or COS (P = 0.86). The fourth objective was to evaluate in vitro digestion kinetics and methane production potential of TIF or COS with varying rates of DDGS. Hand-plucked plant parts of TIF and COS were mixed independently with DDGS to represent the intake of cattle at various rates of DDGS (0, 0.25, 0.5 or 1% for TIF; 0, 0.25 or 1% for COS) in each of the first 2 objectives. Newly-generated laboratory samples were incubated in an in vitro anaerobic fermentation chamber. In vitro true degradation (IVTD) and in vitro NDF degradation (IVNDFD) were greater (P < 0.05) from TIF (69% IVTD, 57% IVNDFD) than from COS (62% IVTD, 44% IVNDFD). Treatment of DDGS did not differ (P > 0.05) within TIF for IVTD, but 1% DDGS was greater (P < 0.05) than 0%, with 0.25% DDGS intermediate to the 2 for COS. Concentration of CH4 was also greater (P < 0.05) TIF (14 mM) than COS (12 mM), and CH4:H2 ratio was less (P < 0.05) from TIF (3:1) than from COS (2:1). The fifth and final objective was to evaluate the ruminal in situ digestion kinetics of TIF as affected by forage seasonality and DDGS. Samples of TIF were harvested in June, August and October 2014. Ruminally-fistulated steers (n = 6) were stratified by BW to 3 pens, and pens were allocated randomly to 1 of 3 rates of DDGS: 0, 0.25, or 1% BW hd-1 d-1. Samples were incubated for 2, 4, 8, 12, 24, 72, and 96 h. A trend of decreasing degradation of DM, NDF, and ADF was observed with both increasing seasonality (P ≤ 0.01) and increasing DDGS (P ≤ 0.04). The undegraded fraction (UDG) of DM from TIF was least (P < 0.05) from June (19%), followed by August (34%), and greatest from October (41%). The UDG from TIF DM was not different (P = 0.47) based on DDGS, and averaged 31%. Low rates of DDGS may be feasible using TIF but not COS at our vegetational region. Rate of DDGS on pasture did not affect feedlot performance nor carcass characteristics. Increased rates of DDGS may increase forage digestibility and decrease CH4 production, but this was cultivar-dependent. Reduction of DM degradation was dependent upon seasonality more so than DDGS rate. Overall, DDGS represented a viable option for stocker production systems, and economic assessments for each specific operation-location will be required prior to implementation of a supplementation program.. [ABSTRACT FROM AUTHOR]

Supplementation of cattle on pasture is a well-known viable strategy for increased performance per animal and per ha. Ethanol has been proclaimed as a sustainable alternative to fossil fuels, and the vast supply of dried distillers' grains with solubles (DDGS) generated from ethanol production provides opportunities for addition to feedlot rations and supplementation of grazing cattle. A large percent of the cattle in the United States are located in the Southeast, where bermudagrass is the primary introduced forage species. Since relatively few research studies have been conducted using DDGS as a supplementation on actively-growing warm-season pastures, this research represents a significant and critical knowledge database for the pasture-beef industry. The first objective of this research was to evaluate performance of stocker calves grazing 'Tifton 85' (TIF) bermudagrass with varying rates of DDGS supplementation. Steers (n = 112, 364 ± 3.5 kg BW) were stratified by BW and allocated randomly to each of 16 pastures (0.7 ± 0.01 ha) across 2 years (2014, 2015). The TIF pastures were allocated randomly to each of 4 rates of DDGS: 0, 0.25, 0.5, or 1% BW hd-1 d-1. Average daily gain was greatest (P < 0.05) from steers offered 1% BW (1.3 kg/d), and least from non-DDGS steers (0.8 kg/d), with 0.25 and 0.5% BW intermediate (1.1 and 1.2 kg/d, respectively). There were supplemental feed to additional gain ratios of 3.7, 6.0 and 9.0, respectively, for 0.25, 0.5 and 1% BW. The second objective was to evaluate performance of Bos indicus versus B. taurus stocker calves grazing 'Coastal' (COS) bermudagrass with varying rates of DDGS. Steers within a breed type (n = 117, 343 ± 4.5 kg BW) were stratified by BW and allocated randomly to each of 9 pastures (1.3 ± 0.17 ha) across 2 years (2014, 2015). Pastures were allocated randomly to each of 3 rates of DDGS: 0, 0.25, or 1% BW hd-1 d-1. Across breed types, ADG was greater (P < 0.05) from steers offered 1% BW (1.0 kg/d) than either from non-DDGS steers or 0.25% BW (0.7 kg/d each). There was no difference (P = 0.70) in ADG between breed types. The third objective of the study was to evaluate any carryover effects in long yearling stockers previously stocked on TIF or COS with varying rates of DDGS. Following the pasture × DDGS phase in the first 2 objectives, steers were shipped 693 km to a commercial feedlot for an approximate 140-d finishing phase. At finishing, animals were transported 59 km and harvested at a commercial abattoir. There was no effect (P ≥ 0.36) of DDGS for either TIF or COS during the feedlot phase. Likewise, there was no effect of DDGS on percent Low Choice for TIF (P = 0.74) or COS (P = 0.86). The fourth objective was to evaluate in vitro digestion kinetics and methane production potential of TIF or COS with varying rates of DDGS. Hand-plucked plant parts of TIF and COS were mixed independently with DDGS to represent the intake of cattle at various rates of DDGS (0, 0.25, 0.5 or 1% for TIF; 0, 0.25 or 1% for COS) in each of the first 2 objectives. Newly-generated laboratory samples were incubated in an in vitro anaerobic fermentation chamber. In vitro true degradation (IVTD) and in vitro NDF degradation (IVNDFD) were greater (P < 0.05) from TIF (69% IVTD, 57% IVNDFD) than from COS (62% IVTD, 44% IVNDFD). Treatment of DDGS did not differ (P > 0.05) within TIF for IVTD, but 1% DDGS was greater (P < 0.05) than 0%, with 0.25% DDGS intermediate to the 2 for COS. Concentration of CH4 was also greater (P < 0.05) TIF (14 mM) than COS (12 mM), and CH4:H2 ratio was less (P < 0.05) from TIF (3:1) than from COS (2:1). The fifth and final objective was to evaluate the ruminal in situ digestion kinetics of TIF as affected by forage seasonality and DDGS. Samples of TIF were harvested in June, August and October 2014. Ruminally-fistulated steers (n = 6) were stratified by BW to 3 pens, and pens were allocated randomly to 1 of 3 rates of DDGS: 0, 0.25, or 1% BW hd-1 d-1. Samples were incubated for 2, 4, 8, 12, 24, 72, and 96 h. A trend of decreasing degradation of DM, NDF, and ADF was observed with both increasing seasonality (P ≤ 0.01) and increasing DDGS (P ≤ 0.04). The undegraded fraction (UDG) of DM from TIF was least (P < 0.05) from June (19%), followed by August (34%), and greatest from October (41%). The UDG from TIF DM was not different (P = 0.47) based on DDGS , and averaged 31%. Low rates of DDGS may be feasible using TIF but not COS at our vegetational region. Rate of DDGS on pasture did not affect feedlot performance nor carcass characteristics. Increased rates of DDGS may increase forage digestibility and decrease CH4 production, but this was cultivar-dependent. Reduction of DM degradation was dependent upon seasonality more so than DDGS rate. Overall, DDGS represented a viable option for stocker production systems, and economic assessments for each specific operation-location will be required prior to implementation of a supplementation program.. [ABSTRACT FROM AUTHOR]