5704

Performance and economic analyses of year-round forage systems for forage-fed beef production in the Gulf Coast1

G. Scaglia,*2 J. Rodriguez,* J. Gillespie,† B. Bhandari,† J. J. Wang,‡ and K. W. McMillin§

*Iberia Research Station, Louisiana State University Agricultural Center, Jeanerette 70544; †Department of Agricultural Economics and Agribusiness, Louisiana State University Agricultural Center, Baton Rouge 70803; ‡School of Plant,

Environmental and Soil Sciences, Louisiana State University Agricultural Center, Baton Rouge 70803; and §School of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge 70803

ABSTRACT: On a global scale, most beef is pro-duced from grazing pastures or rangelands. Certain limitations exist, however, such as not having adequate animal rates of gain for marbling and availability of adequate forage nutritional value and quantity for con-stant animal weight gains. In the last 20 yr, there has been an increased interest in forage-fed beef for mul-tiple reasons (health related, environmental concerns, and welfare issues). Starting on June 5, 13, 14, and 8 in 4 consecutive yr, 54 steers (initial BW = 259 ± 5.6 kg; average of 9 mo of age) were randomly allotted to 3 yr-round forage systems. Each system occupied 6 ha/replicate and had the same stocking rate. System 1 had annual ryegrass (Lolium multiflorum) for winter graz-ing and bermudagrass (Cynodon dactylon) for summer grazing; while Systems 2 and 3 added rye and a clover mix to the ryegrass and diversified the use of pastures in the fall (dallisgrass [Paspalum dilatatum] and clo-vers [Trifolium spp.]). System 3 added the use of annual summer forages. During their respective growing season for each forage or forage mix, mass and height did not limit animal performance; however, there was a sam-pling date effect (P < 0.05) for nutritive value variables

since it decreased as forages became mature. The ADG observed (0.44 kg) for all systems (P = 0.78) during summer was lower than expected and might have been limited by the observed temperature as well as forage nutritive value. Systems 1 and 2 had more grazing days (P = 0.03) during summer (155 and 146 d, respectively) compared to System 3 (132 d) due to the greater pasture area of bermudagrass in those systems. Steers in System 3 were fed more hay for a longer period of time (P < 0.05) than on the other 2 systems. System 1 and 2 pro-duced more hay per hectare than System 3 (P < 0.05). No differences (P > 0.05) were detected between sys-tems in ADG year round, during the winter season, or carcass characteristics. Return over total direct costs and total specified expenses were greater for Systems 1 and 2, while System 3 was the lowest. Hay making and bale sales played a major role in explaining the economic results of this study. Where possible, year-round for-age systems are a viable alternative for forage-fed beef production; however, the low gains during summer and forage availability during the transition period when hay is necessary deserve further research to find alternatives to improve productivity during those times of the year.

Key words: carcass characteristics, forage-fed beef, forage systems, steers

© 2014 American Society of Animal Science. All rights reserved. J. Anim. Sci. 2014.92:5704–5715 doi:10.2527/jas2014-7838

INTRODUCTION

Consumer interest in the benefits of forage-finished beef has led to increased demand for this product and prompted the USDA-AMS to define forage-fed beef (USDA-AMS, 2007). The definition of forage-fed beef published in USDA-AMS (2007) indicates that it is con-sidered such “when grass and forage are the feed source consumed for the lifetime of the ruminant animal, with the exception of milk (milk replacer) consumed before

1Partially funded by NIFA. This manuscript was approved by the Director of the Louisiana Agricultural Experiment Station as manuscript number 2014-268-15557. Funds provided in part by Southern SARE (LS09-221) and NIFA/AFRI (2011-67023-30098). The authors would like to thank P. Loza, J. Wuenschell, M. Hotard, A. Hebert, and all the staff at the Iberia Research Station for their hard work and daily care of the experimental animals.

2Corresponding author: gscaglia@agcenter.lsu.eduReceived March 11, 2014.Accepted September 23, 2014.

Published December 12, 2014

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weaning.” Additional labeling claims are usually made since forage-fed beef is typically associated with the pro-duction of beef without using growth promoters, iono-phores, or sub-therapeutic use of antibiotics (USDA-AMS, 2007; AGA, 2013). Over 40 yr ago, a “systems approach” was proposed to better understand interrelationships of all the production aspects of the beef industry (Purcell, 1977) for accommodating positive environmental effects and ac-ceptable well-being of animals (Allen et al., 2007).

In the southeastern United States, extended grazing is practical, and year-round grazing systems are possible. Previous research on different physiographic regions of the South (Spooner and Ray, 1977; Coombs et al., 1990; Allen et al., 1996) showed the feasibility of finishing cat-tle on forages. The objective of the present study was to evaluate 3 different year-round 100% forage systems dif-fering in level of inputs used on the profitability and beef produced from steers harvested at an average of 18 mo of age without the use of supplemental concentrate feeds, growth promotants, or ionophores.

MATERIALS AND METHODS

The present study was conducted in 4 consecutive yr (2009–2013; grazing period extended from June of one year to May of the following year) at the Louisiana State University Agricultural Center (LSU AgCenter) Iberia Research Station (IRS) located in Jeanerette, LA (29° 57’ 54” W latitude; 91° 42’ 54” N longitude; altitude 5.5 m). The soil type is classified as Iberia silty clay loam with risk of flooding, although the experimental area had pre-viously been shaped to improve drainage. All procedures involving animals were approved by the LSU AgCenter Institutional Animal Care and Use Committee.

Weather Data

Monthly information on maximum, minimum, and average temperatures (°C) and rainfall (mm) was ob-tained from a weather station located at the IRS approxi-mately 230 m from the center of the experimental sites used. Monthly average weather data for the last 30 yr (1981–2010) were obtained from www.nws.noaa.gov/cli-mate/xmacis.php?wfo = lch (select Jeanerette, LA).

General Description of the Systems

Systems 1 and 2 had 3 paddocks (Paddocks A, B, and C, which had 2.7, 2.1, and 1.2 ha, respectively), and System 3 had 5 paddocks (Paddocks A, B, C, D, and E, which had 1.2, 1.2, 2.7, 0.45, and 0.45 ha, respectively). Bermudagrass hybrids were already established before the study and were present in all systems. Forages were

drilled into the soil after herbicide application unless oth-erwise stated. Forage systems were designed as follows.

Forage System 1Paddock A: bermudagrass hybrid (Cynodon dac-tylon “Alicia,” “Jiggs,” and “Tifton 85,” BG); Paddock B: annual ryegrass (Lolium multiflorum cv. “Marshall,” RG; seeding rate of 33.7 kg/ha); Paddock C: BG+RG drilled into the bermudag-rass sod (seeding rate of 33.6 kg/ha) without pre-vious herbicide application.

Forage System 2Paddock A: BG; Paddock B: RG (seeding rate of 33.6 kg/ha) + rye (Secale cereale cv. “Elbon”; seeding rate of 33.7 kg/ha) + berseem (Trifolium alexandrium cv. “BigBee”; seeding rate 22.5 kg/ha), red (Trifolium pretense cv. “Kenland”; seed-ing rate 16.8 kg/ha) and white (Trifolium repens cv. “Ladino”; seeding rate 5.6 kg/ha) clovers; Paddock C: dallisgrass (Paspalum dilatatum Poir.; seeding rate 13.5 kg/ha) + berseem, red, and white clovers (same varieties and seeding rates).

Forage System 3Paddock A: BG; Paddock B: dallisgrass + ber-seem, red, and white clovers; Paddock C: RG + rye + berseem, red, and white clovers; Paddock D: forage soybean (Glycine max cv. “Laredo,” seed-ing rate 67 kg/ha)/RG (for summer and winter, respectively); Paddock E: brown midrib (BMR) sorghum (Sorghum bicolor (L.) Moench.) × su-dangrass (Sorghum sudanese Piper cv. “Sweet Sunny”) hybrid (seeding rate 18 kg/ha)/RG (for summer and winter, respectively).

The 3 forage systems (treatments) represented sys-tems with different degrees of management complexity and expertise required for appropriate utilization of re-sources. System 1 represented a very common forage system for the Gulf Coast region with the inclusion of a perennial summer grass and an annual winter grass. System 2 used mixed swards with winter annual grasses and clovers and dallisgrass with clovers, with the goal to extend the grazing season and reduce the requirement of hay feeding. System 3 included summer annuals to in-crease nutritive value to satisfy calves’ nutrient require-ments. Figure 1 shows the 4-yr-average use of the dif-ferent forages by system throughout the grazing season (June to May of the following year).

Only Paddock C in System 1 and Paddocks D and E in System 3 had summer and winter grazing; the rest were dedicated specifically to those pastures assigned to each of them.

As summer pastures, 3 bermudagrass hybrids (“Alicia,” “Jiggs,” and “Tifton 85”) were already established before the study, and one replicate per system was assigned to each variety so that there was no effect of a specific variety

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on animal performance on any system. In May of each year, all pastures with bermudagrass were fertilized with 100 units/ha of N as urea, and throughout the grazing season, they received an average of 200 units N/ha. All bermu-dagrass pastures were scouted for armyworm (Spodoptera frugiperda) infestation especially after hay was made and new growth occurred. If there was a need for application (the threshold considered was 25 armyworms/m2), mala-thion (diethyl 2-[(dimethoxyphosphorothioyl) sulfanyl] butanedioate) at 2.3 L/ha was applied for its control due to no restrictions for grazing. Stands were not affected during the 4 yr of this experiment, but in 2011, there was a need to apply malathion 3 times.

The pasture assigned for sorghum-sudan hybrid was sprayed with Ranger Pro (41% Glyphosate, 4.7 L/ha; Monsanto, St. Louis, MO), while the pasture assigned for soybean was sprayed with Roundup Power Max (48.7% Glyphosate, 4.7 L/ha; Monsanto, St. Louis, MO) to sup-press or kill existing forages. “Sweet Sunny” sorghum-sudan and “Laredo” soybean were planted using a John Deere no-till drill JD 1590, with 4.5 m of planting width (25.4 cm between rows and at a planting depth of 1.9 cm) and clover seedboxes. A single dose of urea (50 units N/ha) was applied on the sorghum-sudan pasture, but none was applied on the soybean pasture. Because of the presence of armyworms in the area, these 2 pastures were sprayed once with Sevin (Carbaryl [1- naphthyl N-methylcarbamate] 43.0%; Bayer, Research Triangle Park, NC) at a rate of 1.4 kg/ha in August 2009, 2011, and 2012.

The areas designated for dallisgrass/clover mix were sprayed with 4.7 L/ha of Gramoxone (Paraquat dichlo-ride [1,1’-dimethyl-4,4’-bipyridinium dichloride] 30.1%; Syngenta, Greensboro, NC), 9.35 L/ha of Gly Star (Glyphosate, N-[phosphonomethyl] glycine, in the form of

its isopropylamine salt 41.0%; Albaugh, Ankeny, IA), 9.35 L/ha of Grazon P+D (picloram: 4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid, triisopropanolamine salt 10.2%; 2,4-dichlorophenoxy acetic acid, triisopropanolamine salt 39.6%; Dow Agrosiences, Indianapolis, IN), and 0.1 kg/ha of Outrider (Sulfosulfuron 75%; Monsanto, St. Louis, MO) to suppress or kill existing forages in an effort to establish the desired species in the pastures. Dallisgrass was planted in April 2009 using the same no-till drill. In November of every year, after the grazing period, the clover mix was planted with the same equipment at the rates described above. In the second year of the project (2010), dallisgrass was replanted in August at the same rate. No fertilization was applied to these pastures in any year.

In late August of every year, all paddocks where only winter pastures (Paddock B in System 1 and Paddocks B and C in Systems 2 and 3, respectively) would be planted were sprayed with N-(phosphonomethyl) glycine (glypho-sate; 2.34– 4.7 L/ha) to eliminate the volunteer grasses pres-ent. They were all planted with the same no-till drill and specifications (space between rows and planting depth) de-scribed above. Urea (60, 60, and 40 units N/ha) was split-applied in November, late January, and March of every year.

In December of every year, “Marshall” ryegrass was sod-seeded into bermudagrass (“Alicia”) in Paddock C of System 1 using the same equipment and seeding rate as described above. These pastures received 2 applica-tions (December and February, respectively) of urea (both of 60 units of N/ha).

Experimental Animals

For 4 consecutive yr, 54 spring-weaned steers (3/8 Gelbvieh, 3/8 Red Angus, and 1/4 Brahman; average frame

Figure 1. Forage utilization by month for each system based on the average of 4 yr of grazing records.

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size of 5 and muscle score of 1 to 2) were selected (from a yearly average of 132 steers) and purchased every year from the same single source to minimize animal variation across years. Steers were transported to the IRS in May of each year. Within 2 d, steers were weighed and vacci-nated against infectious bovine respiratory syncytial virus, infectious bovine rhinotracheitis, bovine viral diarrhea vi-rus, parainfluenza, and leptospirosis with Bovi-Shield FP 4+VL5 (Pfizer Animal Health, New York, NY). They were also vaccinated with Vision 8 (Merck Corporate, Animal Health, Summit, NJ) for prevention of Clostridium sp. Lastly, bovine Pneumonic pasteurellosis was prevented with Once PMH (Bayer Corporation, Agriculture Division, Animal Health, Shawnee Mission, KS). Internal and ex-ternal parasite control was maintained with a single dose of Cydectin pour-on (Boehringer-Ingelheim Vetmedica, Inc., St. Joseph, MO) in July and 2 doses of Ivomec Plus (Merial Inc., Duluth, GA) in October and February of each year. Steers were allowed ad libitum access to water and to a mineral and vitamin supplement. Vigortone 3V5 S (Ca 20–24%, P 3.5%, NaCl 18.2–21.8%, Mg 1%, K 0.1%, Cu 2000 ppm, Se 26.40 ppm, Zn 7500 ppm, vitamins A 881,057 IU/kg, vitamin D 44,052 IU/kg, and vitamin E 441 IU/kg; Provimi North America, Brookville, OH) was used for all systems during the summer. During the winter, Purina Range Mineral (Ca 8.0–9.6%, P 4.0%, NaCl 5.5–6.5%, Mg 14%, K 0.4%, Mn 1750 ppm, Cu 1100 ppm, Co 50 ppm, I 43 ppm, Se 23 ppm, Zn 3300 ppm, vitamins A 110,132 IU/kg, vitamin D 11,013 IU/kg, and vitamin E 50 IU/kg; Purina Mills, Gray Summit, MO) was used for all cattle. No additional supplements were used.

Steers were blocked by weight (BW = 259 ± 5.6 kg; average of 9 mo of age) into 9 groups (6 steers/group). Each group was randomly assigned to 1 of 3 forage sys-tem treatments, which were replicated 3 times. Steers remained in the treatment-replicate during the entire ex-perimental period. All systems occupied the same area (18 ha/each with 6 ha/replicate; 54 ha total) and had the same stocking rate (1.0 steer/ha). This might be seen as a low stocking rate, but for year-round systems, it is needed so that it is possible to maximize grazing days, hence reducing hay feeding or costs.

On d 0, and every 28 d thereafter, all steers were weighed without shrink starting at 0800 h. From June to October, shade was provided in all pastures where animals were grazing using portable shades (metal frames and black woven polypropylene cloth providing 80% shade). Each year at the end of grazing period (age of steers was 17–19 mo), 2 steers from each treatment-replicate (n = 18; 6 steers/treatment) were randomly selected and har-vested at a commercial plant (Roucher’s Meat Supply, Plaquemine, LA; situated 147 km or approximately 2 h away from the IRS) by humane procedures under meat inspection supervision. Time of harvest or endpoint was

determined based on forage availability and was from late April to the beginning of May. Immediately after harvest-ing, HCW of each steer was taken and the carcasses were placed in a 2 ± 1°C cooler. Dressing percentage was cal-culated as (hot carcass weight/live weight) * 100.

At 24 h postmortem, each individual carcass was ribbed between the 11th and 12th ribs, and a trained grader evaluated backfat at 3/4 length of longissimus dorsi muscle; preliminary yield grade; longissimus dor-si area; kidney, pelvic, and heart percentage; adjusted backfat at 3/4 length of longissimus dorsi muscle; lean color and marbling 24 h after harvesting for determina-tion of quality and yield grades (USDA, 1997).

Grazing Management and Hay Production

Grazing period started in June of each year. At that time, all 9 groups of steers started grazing bermudagrass. Pastures had enough forage mass and height so that dry matter intake of steers was not restricted (Paterson et al., 1994). All systems were managed for maximal grazing days and minimal days of hay feeding. All pastures were rotationally stocked and grazed to a predetermined stubble height (7 to 10 cm for bermudagrass, 15 to 20 cm for sor-ghum-sudan, 15 to 20 cm for forage soybeans, and 10 to 15 cm for ryegrass, ryegrass/rye/clover mix, dallisgrass/clover mix) through the grazing period. Electrified polytapes were used to allocate grazing areas depending on time of the year and forage mass. Regardless of forage type (annual or pe-rennial summer forages or annual winter forage), the size of the paddocks varied from 1.2 to 2 ha each; hence, there were multiple paddocks available for each group of steers. On average, from June to August (on bermudagrass), the grazing area was 0.22 ha, which gave a stocking density of 27 steers/ha or 7,722 kg BW/ha. Grazing period was of 3 to 4 d with 20 to 25 d of resting period. When forage mass and nutritive value of the bermudagrass started to decrease (September), the grazing area increased on average to 0.44 ha. At this point, the stocking density was 13.5 steers/ha or 4,198 kg BW/ha. During the hay feeding period, each of the 9 groups of cattle remained on a 1.34 ha paddock of bermudagrass (4.5 steers/ha or 1,453 kg BW/ha). In the winter period, the area of the grazing paddocks (pure stands of ryegrass or mixed swards) was 0.26 ha, resulting in a stocking density of 23 steers/ha or 8,970 kg BW/ha. The grazing period was 2 to 5 d with 20 to 28 d of resting period.

Hay was harvested during the summer (June to August) in all the systems whenever there was an excess of grass (estimated by visual observation according to forage availability for the animals until next regrowth), but always maximizing grazing days and minimizing days of hay feeding. Round hay bales were made (1.52 × 1.52 m) using a John Deere JD 275 disc mower and a John Deere JD 567 round baler (Deere & Company, Moline,

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IL) Individual round bales weighed an average of 460 kg were labeled with the forage system and replicate origin from which they came and were individually sampled when fed. Hay was fed using circular hay feeders (2.6 m in diameter, 1.3 m in height, with 18 feeder openings; Southern States Cooperative, Inc., Richmond, VA) when there was no available forage mass (estimated by visual observation to be less than 6 cm of canopy height and/or less than 800 kg/ha of forage mass available).

Forage mass and height were determined on d 0 and every 28 d thereafter in paddocks where cattle were graz-ing or immediately before cattle entered into a new pad-dock. Standing herbage mass and height were estimated every 28 d by randomly clipping five 1-m2 quadrats to a 2.5-cm stubble height using hand clippers. Pastures were not sampled when visual observation of canopy height was considered to be less than 6 cm and/or available for-age was lower than 800 kg/ha; in these cases, hay bales were sampled instead. Only on winter pastures, vegetative cover was estimated using transects. On d 0 and every 30 d thereafter, five 10-m transects were randomly located within each treatment replicate. At 10-cm intervals (100 points in each transect) along each transect, a sharpened point was lowered from above the vegetation, and the first plant species intercepting the point was recorded (Heady and Torell, 1959). Samples for nutritive value analyses (both forage and hay) were dried in an air oven at 55°C for 48 h and weighed to determine the percentage of DM. They were then ground in a laboratory mill (Model 4, Arthur H. Thomas Co. Philadelphia, PA) and passed through a 2-mm screen. Forage samples from each system/replicate and sampling date were submitted to a commercial laboratory (DairyOne; Ithaca, NY) for analysis using near-infrared reflectance spectroscopy (989.03; AOAC, 1996).

Economic Analyses

For each pasture each year, detailed input, costs, and returns records were kept. These records allowed for es-timation of costs and returns for each replication within treatment. Total income was the sum of steer income and hay income. Hay income represents the value of hay cut from pastures within a specific replication within treat-ment, but not used to feed steers within that replication within treatment. Each was estimated on a per-steer ba-sis. Direct costs included fertilizer, pesticides, livestock, twine for hay, seed, minerals and medication, diesel cost, repair and maintenance on fencing and equipment, and interest on operating cost. Quantities assumed for each of the income and direct cost categories are reflective of those found (outputs) and used (inputs) in the experi-ment. The weekly Texas Hay Report (USDA-TX, 2010, 2011, 2012, 2013) was used to determine hay prices, assuming fair quality hay in east Texas, the first week

of April. Grass-fed steer prices were calculated using USDA-ERS (2013) published prices for fed steers, ad-justed upward by $0.44/kg, observed in the industry as a typical premium received for grass-fed beef.

Statistical Analyses

Data were analyzed by using PROC MIXED (SAS Inst. Inc., Cary, NC) as a randomized complete block de-sign with 3 replicates. Year or period within year were the repeated measures used for the overall analysis or for with-in-year analyses, respectively. Forage system was the fixed effect, and replicate within forage system was the experi-mental unit. Mean separation was conducted using Tukey (α = 0.05). The covariance structure selected was compound symmetry, and values reported are least square means.

For forage management and nutritive value analyses, data were divided into 3 different periods of summer, hay feeding, and winter for statistical analyses. The sum-mer period extended from start of grazing (d 0) until the bermudagrass was grazed out; from then until the win-ter, when forages were available for grazing was the hay feeding period, and from the time winter annuals were available for grazing until the end of the experiment was considered the winter period. Response variables were forage mass and height, %CP, %ADF, %NDF, %TDN, % lignin, % nonfiber carbohydrates (NFC), and % water soluble carbohydrates (WSC). Hay samples were taken and analyzed for nutritive value. Response variables of interest for pasture management were grazing days for summer and winter periods and as annual total, days on hay, and amount of hay produced and fed per system. Animal performance data were divided on an annual ba-sis and into the same 3 periods previously described for forage management. Variables of interest for animal per-formance were ADG and initial and final BW. Carcass data were also analyzed following the same model.

Economic Analysis. With 4 yr of data and 9 sets of re-cords per year, a total of 36 cost and return estimates were developed for this study. Using a mixed model with fixed treatments and year as fixed repeated measure effects, the Kenward-Roger Degrees of Freedom method was used to determine differences in costs, returns, and return over cost by treatment (Kenward and Roger, 1997).

RESULTS AND DISCUSSION

Weather InformationIn Fig. 2 and 3, there are some extreme situations to

note. Even though annual rainfall in yr 1 was average (Fig. 2), monthly precipitations in October and December were 2 and 3 times greater, respectively, than the historic average for those months (Fig. 3). Rainfall in the win-

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ter season in yr 4 was notably greater than the average. Rainfall in January and April was twice the historic aver-age for those months, while rainfall in February and May were 84% and 48% greater (Fig. 3); however, no nega-tive effects on pastures and animal performance were ob-served. Winter periods (January to April) for yr 1 and 3 were approximately 5°C colder and warmer, respectively, than average (Fig. 3). The colder temperatures and heavy rainfall in the fall of yr 1 affected planting time and early growth of winter pastures, which affected the amount of forage available at the beginning of the grazing period.

Forage Characteristics and Nutritive Value

Depending on the time of the year, different forages were available, and the length of the grazing period for each varied. As planned, bermudagrass was the most important forage base for all 3 systems from June to late October/early November followed by a hay feed-ing period until winter forages were available for graz-ing (January to May). Due to this utilization of forage resources (Fig. 1), data will be presented separately for summer (Table 1) and winter (Table 2).

Sampling date had an effect (P < 0.05) on bermu-dagrass mass and height as well as on most of the nutri-tive value characteristics, but forage system (treatment) did not affect (P > 0.05) any of these variables (Table 1).

Systems 2 and 3 presented other alternatives such as dallisgrass/clovers mix, sorghum-sudan, and forage soy-beans. Dallisgrass and clovers mix in Systems 2 and 3 was used in late fall and early spring, as well as during the winter months. Winter grazing was primarily due to the excellent production of berseem clover. It needs to be noted that the stand of dallisgrass was poorer than expected in all replica-tions regardless of system. In pasture composition data tak-en using transects, dallisgrass represented only an average of 8% of the DM produced (data not shown). On average, dallisgrass/clover mix pastures were grazed only for 7 d in the late fall (when bermudagrass was less active), and only

dallisgrass was available. Stands of dallisgrass were poor, and hence forage production limited; however, in spring, due to the addition of the clover mix, grazing days increased to an average of 21 d. Dallisgrass is a high nutritive value C4 grass (Henderson and Robinson, 1982a,b), widely used in different regions of the world such as Uruguay, Argentina, and Australia (common dallisgrass originated in eastern Argentina, Uruguay, and Southern Brazil; Burson, 1991; as cited by Evers and Burson, 2004) to finish beef cattle on, but it is very difficult to establish (Burton, 1945; Bennett and Marchbanks, 1969). Dallisgrass establishment is difficult because of poor seed quality, slow and erratic germination, and poor seedling vigor (Evers and Burson, 2004).

In System 3, summer annuals (sorghum-sudan hybrid and forage soybeans) were used for an average of 31 d over 2 periods (21 and 10 d in August and September, respec-tively). The sorghum-sudan hybrid provided this second and short (10 d) grazing period as the forage soybeans re-growth was very poor. The main reason for using this hy-brid was that forage chemical composition and ruminal in situ disappearance are improved in the BMR sorghum × sudangrass hybrids (Beck et al., 2007). They also tend to have less risk associated with prussic acid than the forage sorghums; however, yield reductions are commonly re-ported for BMR hybrids, although Beck et al. (2007) de-termined they were not reduced if harvested at a similar phenological growth stage. In the present study, sorghum-sudan grass had greater (P < 0.05) nutritional value than bermudagrass, including CP (14.1%), ADF (35.5%), and NDF (56%) concentrations. The goal of grazing should be to keep the forage in an early vegetative stage to maximize quality. It is often difficult to stock pastures heavy enough to take advantage of the rapidly growing forage such as the sorghum-sudan hybrid used. This rotational system al-lows for maximum production and better utilization. In yr 2, 3, and 4, the ADG of the steers grazing sorghum-sudan was 1.1 kg (although, as indicated before, for only a short period of time), while those steers in Systems 1 and 2 graz-ing bermudagrass gained during the same period of time (0.75 kg). Banta et al. (2002) evaluated a sorghum × sudan

Figure 2. Annual precipitation during the years of the experiment and historic data (1981–2010).

Figure 3. Monthly average temperatures and precipitation for each year of the project’s lifetime.

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hybrid in continuous or rotational grazing and the ADG in both treatments were very similar (1.1 kg) to the present study, although the numbers of grazing days (72 and 80 d for continuous and rotational, respectively) were greater. Similar performance data were obtained by McCuistion et al. (2011) using BMR and photoperiod-sensitive sorghum-sudangrass hybrids. Forage soybean was used for an aver-age of 5 d across the years. The main reason was the low productivity and regrowth capacity (after grazing it) that it showed during this time; however, based on nutritive value analyses, it can be a very productive and nutritious forage for stockers (Rao et al., 2005). It should be noted that forage soybean stands were affected by weed pressure, mainly crabgrass (Digitaria sanguinalis), brown-top mil-let (Brachiaria ramose [L.] Stapf), vaseygrass (Paspalum urvillei), yellow foxtail (Setaria glauca), and itchgrass (Rottboellia cochinchinensis). Based on these data, it can be concluded that animal performance can be greatly in-creased using summer annuals due to their nutritive value and, in the case of the sorghum-sudan BMR, its greater DM production. Since the grazing periods on them were short in the present study, these performance differences were di-luted when season-long data were considered.

Botanically diverse pastures can extend the grazing season to meet nutritive demands of the cattle and improve system stability (Tilman et al., 1996) and help meet sea-son-long nutritive demands of cattle. Intensive rotational pasture stocking can improve forage nutritive value and herbage distribution over the grazing season. Additionally, grazing animals distribute manure across the field with

minimal attention needed by the farmer or rancher, which contributes to soil fertility and reduces purchased fertil-izer inputs (Ball et al., 2007); however, the N to energy ratio in grazed herbage is often not balanced for efficient capture of forage N by livestock. Forage combinations can be created to improve the N to energy ratio (Allen et al., 1996). Legumes added to forage-based diets improve overall weight gain of ruminants. Cattle background and finished on alfalfa-orchardgrass pastures had greater gains and more desirable carcass traits than those finished on tall fescue-based pastures with and without legumes (Allen et al., 1996). However, little is known about specific contri-butions of forage species or combinations on performance and carcass characteristics (Allen et al., 1996).

In the present study, ryegrass, rye, and clover mix pas-tures had ryegrass and berseem clover as the major forage components. The 2 represented approximately 80% of the forage produced from the time grazing started to early April, at which time red clover became more productive. White clover was the last of the 3 clovers to contribute to the total of forage produced, increasing in the canopy after the grazing period was concluded. Notably, rye’s growth rate was visibly greater than that of ryegrass. This fact al-lowed Systems 2 and 3 to have greater forage mass (1,893 and 2,099 kg DM/ha, respectively) at the beginning of the grazing period when compared to System 1 (1,631 kg DM/ha); early grazing in Systems 2 and 3 was possible in 3 out of the 4 yr, although not enough for a difference to be de-tected (P > 0.05). Table 2 shows that forage mass, height, and all nutritive value variables, except CP concentration,

Table 1. Least square means for the effect of sampling day on forage (bermudagrass) mass, height, and nutritive value characteristics

Item4Sampling day1

SEMForage system2

SEMP-value3

0 28 56 84 112 140 1 2 3 TRT DAY TRT × DAYFM, kg DM/ha 2,210b 3,764a 4,791a 4,121a 3,890a 2,310b 479 2,890 2,991 2,709 398 0.70 0.02 0.51FH, cm 31.1b 40.9a 41.9a 36.7ab 31.9b 19.9c 3.3 28.6 31.1 34.2 2.91 0.09 0.01 0.79CP, % DM 14.9a 12.8a 12.0b 11.9b 10.1b 8.2c 0.64 11.3 10.9 11.8 1.52 0.45 0.001 0.61ADF, % DM 37.0c 42.1b 42.0 b 43.1b 44.8 ab 47.0a 0.90 40.1 39.0 41.7 0.99 0.31 0.004 0.08NDF, % DM 69.9 b 73.1 a 70.9 b 71.9 ab 72.1 a 73.1a 0.71 70.1 70.8 68.7 1.80 0.11 0.001 0.49TDN, % 60.8a 58.7a 57.1ab 59.0a 55.1b 54.9b 1.92 57.2 58.1 56.9 1.77 0.21 0.001 0.33Lignin, % DM 3.6b 5.1a 5.3a 5.6a 5.5a 5.6a 0.27 4.5 4.7 4.6 0.18 0.09 0.009 0.31NFC, % DM 12.1b 11.8b 14.7ab 14.5 ab 15.9 ab 16.1a 1.98 13.9 12.8 13.5 1.13 0.27 0.005 0.17WSC, % DM 5.1 5.4 5.2 5.4 5.7 5.1 0.27 5.2 5.3 5.3 0.07 0.32 0.86 0.43

1Average sampling date during the grazing season.2Forage System 1; Paddock A: bermudagrass hybrid (Cynodon dactylon “Alicia,” “Jiggs,” and “Tifton 85,” BG); Paddock B: annual ryegrass (Lolium mul-

tiflorum cv. “Marshall,” RG; seeding rate of 33.7 kg/ha); Paddock C: BG+RG (seeding rate of 33.6 kg/ha). Forage System 2; Paddock A: BG; Paddock B: RG (seeding rate of 33.6 kg/ha) + rye (Secale cereale cv. “Elbon”; seeding rate of 33.7 kg/ha) + berseem (Trifolium alexandrium cv. “BigBee”; seeding rate 22.5 kg/ha), red (Trifolium pretense cv. “Kenland”; seeding rate 16.8 kg/ha) and white (Trifolium repens cv. “Ladino”; seeding rate 5.6 kg/ha) clovers; Paddock C: dal-lisgrass (Paspalum dilatatum Poir.; seeding rate 13.5 kg/ha) + berseem, red and white clovers (same varieties and seeding rates). Forage System 3; Paddock A: BG; Paddock B: dallisgrass + berseem, red, and white clovers; Paddock C: RG + rye + berseem, red, and white clovers; Paddock D: forage soybean (Glycine max cv. “Laredo,” seeding rate 67 kg/ha)/RG (for summer and winter, respectively); Paddock E: brown midrib (BMR) sorghum (Sorghum bicolor (L.) Moench.) × sudangrass (Sorghum sudanese Piper cv. “Sweet Sunny”) hybrid (seeding rate 18 kg/ha)/RG (for summer and winter, respectively).

3TRT = forage system effect; DAY = sampling day effect.4FM = forage mass; FH = forage height; NFC = non-fiber carbohydrates; WSC = water soluble carbohydrates.a–cWithin a row means without a common superscript differ (P < 0.05).

Systems for forage-fed beef production 5711

were affected by sampling period (P < 0.05). Forage mass, ADF, NDF, and lignin concentration increased linearly (P < 0.05), while TDN, WSC, and NFC concentration decreased linearly (P < 0.05). Fractions included in NFC are simple sugars, starch, fructans, soluble fiber, and organic acids; the main difference with WSC is the presence of organic acids (Hall, 2007). Forage height presented a quadratic response (P < 0.05), and it was greater on d 84 (Table 2). There was a treatment effect (P < 0.05) on CP and ADF concentration. Crude protein and ADF concentration in the mixed swards (Systems 2 and 3) were different (P < 0.05) from the pure stands of ryegrass in System 1 (Table 2). Crude protein concentration was greater and ADF smaller on mixed swards (Systems 2 and 3) than on ryegrass (System 1). Legumes usually contain greater concentration of CP than grasses, and as the frequency of legumes on any particular sward increases, CP levels will linearly increase (Ball et al., 2007). Similarly, ADF concentration is always greater in grasses (Ball et al., 2007). Buxton and Redfearn (1997) compared forage species at similar maturity and reported leaves of alfalfa and red clover plants (mid-flowering ma-turity) were approximately 25% NDF and stems were 40% to 55% NDF. In contrast, the leaves and stems of tall fescue, smooth bromegrass, and orchardgrass were approximately 50% and 70% NDF, respectively. Regardless of differences between the nutritive value of pastures and the decline in these characteristics that occur as plant maturity advances, nutrient concentration throughout the grazing season was enough to meet (and exceed) the requirements of this class of cattle (NRC, 2000).

Pasture Management

The greater number of grazing days in summer in Systems 1 and 2 (Table 3) than System 3 was due to the greater area of bermudagrass available in those systems. Bermudagrass comprised 65% of the area in System 1 (Paddocks A and C), 45% in System 2 (Paddock A), and only 20% of the area in System 3. Increasing the nutritive value of forage available in Systems 2 and 3 had the trad-eoff that less bermudagrass was available. The issue is that bermudagrass provided System 1 with the advantage of having greater area with enough forage available (al-though less nutritive value) and with a greater capacity to produce hay. Consequently, for System 3, the number of grazing days during summer and kg/ha of hay produced were smaller while the kg of hay fed and days on hay were greater when compared to System 1 (Table 3). System 2 was intermediate for days on hay, but similar to System 1 on kg/ha of hay produced and kg of hay fed (Table 3).

Animal Performance and Carcass Information

Due to the known uneven forage distribution through-out the year and between years (Evers, 2008), the present study was designed to use what can be considered to be a low stocking rate (number of steers/ha). As indicated before, forage mass and height were never limiting, something that assured the greatest possible animal performance. The pro-posed idea of using spring-weaned calves was based on the objective of reaching a target final weight of 500 to 545

Table 2. Least square means for the effect of sampling day on forage (winter annuals) mass, height, and nutritive value characteristics

Item4

Sampling Day1 SEM

Forage System2 SEM

P- value3

0 28 56 84 112 1 2 3 TRT DAY TRT × DAYFM, kg DM/ha 1,711c 1,921bc 2,371b 3,513a 3,669a 337 2,453 2,690 2,871 289 0.08 0.03 0.08FH, cm 21.7c 18.8c 28.1b 34.4a 17.9c 2.01 25.2 27.9 28.2 3.11 0.53 0.02 0.15CP, % DM 15.7 14.9 16.1 12.7 11.8 1.51 12.9b 18.8a 17.8a 0.70 0.02 0.08 0.06ADF, % DM 20.8d 24.7cd 25.8c 33.0ab 38.9a 1.77 29.2a 26.9b 25.9b 1.02 0.03 0.04 0.07NDF, % DM 38.1c 40.1c 43.1c 53.8b 61.1a 2.01 48.9 43.6 47.1 2.88 0.07 0.01 0.21TDN, % 63.3a 61.8a 59.8ab 58.0ab 54.1b 3.59 57.0 60.1 59.2 3.13 0.46 0.03 0.78Lignin, % DM 5.3ab 4.8b 5.3ab 6.3a 5.9a 0.66 5.8 5.5 5.7 0.81 0.86 0. 01 0.24NFC, % DM 37.1a 29.8b 30.1b 26.8bc 22.1c 2.76 28.8 26.1 27.3 1.32 0.13 0.01 0.08WSC, % DM 20.4a 19.8a 17.1ab 16.4ab 13.8b 2.49 18.9 17.1 18.4 1.92 0.76 0.05 0.62

1Average sampling date during the grazing season.2Forage System 1; Paddock A: bermudagrass hybrid (Cynodon dactylon “Alicia,” “Jiggs,” and “Tifton 85,” BG); Paddock B: annual ryegrass (Lolium mul-

tiflorum cv. “Marshall,” RG; seeding rate of 33.7 kg/ha); Paddock C: BG+RG (seeding rate of 33.6 kg/ha). Forage System 2; Paddock A: BG; Paddock B: RG (seeding rate of 33.6 kg/ha) + rye (Secale cereale cv. “Elbon”; seeding rate of 33.7 kg/ha) + berseem (Trifolium alexandrium cv. “BigBee”; seeding rate 22.5 kg/ha), red (Trifolium pretense cv. “Kenland”; seeding rate 16.8 kg/ha) and white (Trifolium repens cv. “Ladino”; seeding rate 5.6 kg/ha) clovers; Paddock C: dallisgrass (Paspalum dilatatum Poir.; seeding rate 13.5 kg/ha) + berseem, red and white clovers (same varieties and seeding rates). Forage System 3; Paddock A: BG; Paddock B: dallisgrass + berseem, red, and white clovers; Paddock C: RG + rye + berseem, red, and white clovers; Paddock D: forage soybean (Glycine max cv. “Laredo,” seeding rate 67 kg/ha)/RG (for summer and winter, respectively); Paddock E: brown midrib (BMR) sorghum (Sorghum bicolor (L.) Moench.) × sudangrass (Sorghum sudanese Piper cv. “Sweet Sunny”) hybrid (seeding rate 18 kg/ha)/RG (for summer and winter, respectively).

3TRT = forage system effect; DAY = sampling day effect.4FM = forage mass; FH = forage height; NFC = non-fiber carbohydrates; WSC = water soluble carbohydrates.a–cWithin a row means without a common superscript differ (P < 0.05).

Scaglia et al.5712

kg at 17 to 19 mo of age after cattle grazed for 100–140 d on high nutritive value winter pastures. It can also be ar-gued whether or not the genetic base of the steers used was appropriate. The primary goal was to have a maximum of 25% Brahman influence to have a genotype that could tol-erate high temperatures and humidity during the summer months without compromising performance (Brown et al., 2005; Buchanan and Frahm, 2005; Ferrell et al., 2005), car-cass characteristics, and beef chemical and organolopetic characteristics (Torrico et al., 2012; McMillin et al., 2013).

No difference (P > 0.05) in animal performance was observed (Table 4). Even though there were differences in ADG for a short period of the summer grazing season (when steers in System 3 grazed sorghum-sudan hybrid/forage soybeans vs. steers in Systems 1 and 2 grazing ber-mudagrass), the overall animal performance during that time of the year was not different between systems. Based on the genetic potential for growth of the steers and forage availability, ADG during the summer (0.44 kg) seems low; however, high nutrient requirements (NRC, 2000) of this class of cattle (recently weaned 9 mo of age steers), the me-dium to low nutritive value of bermudgrass (Table 1) and the high temperature and relative humidity (Fig. 3) may have adversely affected their performance. As expected, the ADG of steers in the 3 systems during the winter sea-son were over 1 kg, making an overall year-round ADG of approximately 0.66 kg. Steers in System 3 were lighter (P

< 0.05) at the beginning of the winter grazing period (316 kg) when compared to those grazing in Systems 1 (327 kg) and 2 (323 kg). This mainly reflects the ADG achieved dur-ing the hay feeding period (Table 4). Similarly, no effect of forage system (P > 0.05) was detected on any of the carcass characteristics (Table 5). Many reports about “for-age-finishing” refer to short periods of time, usually during a single season (Bidner et al., 1985; Schmidt et al., 2013; Duckett et al., 2013). It also needs to be noted then that di-rect comparisons of the present study with these and other research studies conducted in the United States are very difficult because of different factors, such as breeds of cat-tle and forage types used, the use of spring-born instead of fall-born calves, calves reared at different locations within the same project (Bagley et al., 1987; Coombs et al., 1990), use of some kind of supplement (corn, corn silage, soy-bean meal, etc.) during the lifetime of the animal (Bidner et al., 1981; 1986; Bagley et al., 1987; Coombs et al., 1990; Allen et al., 1996; Neel et al., 2007; Roberts et al., 2009), cattle receiving implants (Bagley et al., 1987; Roberts et al., 2009), animals harvested at a younger age (Duckett et al., 2013) or much older (Bidner et al., 1986; Orellana et al., 2009), cattle were on grass for a shorter period of time (Bidner et al., 1985), cattle harvested at different times of the year due to different (although appropriate) objectives for that particular study (Schmidt, 2009), or combinations of these and other factors. Regardless of all these differenc-es, dressing percentage, hot carcass weight, and yield grade data were consistent with other studies in which cattle were forage-fed finished (Bowling et al., 1977; Bidner et al., 1986; Bennett et al. 1995; Roberts et al., 2009). Fat thick-

Table 3. Least square means for number of days graz-ing on summer (June to October) and winter (January to May) or hay fed and kilograms per hectare of hay produced and kilograms of hay fed to steers

Item

Forage System1 SEM

P-value1 2 3

Summer grazing, days 155a 146a 132b 4.1 0.03Winter grazing, days 131 128 130 1.8 0.70Days on hay 55b 65ab 77a 8.1 0.02Hay produced, kg/ha 8,730a 8,441a 6,658b 413 0.02Hay fed, kg 2,150b 2,407b 3,290a 201 0.03

a,bWithin a row means without a common superscript differ (P < 0.05).1Forage System 1; Paddock A: bermudagrass hybrid (Cynodon dactylon

“Alicia,” “Jiggs,” and “Tifton 85,” BG); Paddock B: annual ryegrass (Lolium multiflorum cv. “Marshall,” RG; seeding rate of 33.7 kg/ha); Paddock C: BG+RG (seeding rate of 33.6 kg/ha). Forage System 2; Paddock A: BG; Paddock B: RG (seeding rate of 33.6 kg/ha) + rye (Secale cereale cv. “Elbon”; seeding rate of 33.7 kg/ha) + berseem (Trifolium alexandrium cv. “BigBee”; seeding rate 22.5 kg/ha), red (Trifolium pretense cv. “Kenland”; seeding rate 16.8 kg/ha) and white (Trifolium repens cv. “Ladino”; seeding rate 5.6 kg/ha) clovers; Paddock C: dallisgrass (Paspalum dilatatum Poir.; seeding rate 13.5 kg/ha) + berseem, red and white clovers (same varieties and seeding rates). Forage System 3; Paddock A: BG; Paddock B: dallisgrass + berseem, red, and white clovers; Paddock C: RG + rye + berseem, red, and white clo-vers; Paddock D: forage soybean (Glycine max cv. “Laredo,” seeding rate 67 kg/ha)/RG (for summer and winter, respectively); Paddock E: brown midrib (BMR) sorghum (Sorghum bicolor (L.) Moench.) × sudangrass (Sorghum sudanese Piper cv. “Sweet Sunny”) hybrid (seeding rate 18 kg/ha)/RG (for summer and winter, respectively).

Table 4. Least square means for final BW and ADG by period and for the entire period

Item

Forage System1 SEM

P-value1 2 3

Final BW, kg 500.8 505.9 497.8 11.2 0.63Summer ADG, kg 0.44 0.44 0.42 0.05 0.78Hay feeding ADG, kg 0.04 -0.02 -0.10 0.14 0.40Winter ADG, kg 1.26 1.34 1.30 0.06 0.40Annual ADG, kg 0.67 0.67 0.66 0.03 0.89

1Forage System 1; Paddock A: bermudagrass hybrid (Cynodon dactylon “Alicia,” “Jiggs,” and “Tifton 85,” BG); Paddock B: annual ryegrass (Lolium multiflorum cv. “Marshall,” RG; seeding rate of 33.7 kg/ha); Paddock C: BG+RG (seeding rate of 33.6 kg/ha). Forage System 2; Paddock A: BG; Paddock B: RG (seeding rate of 33.6 kg/ha) + rye (Secale cereale cv. “Elbon”; seeding rate of 33.7 kg/ha) + berseem (Trifolium alexandrium cv. “BigBee”; seeding rate 22.5 kg/ha), red (Trifolium pretense cv. “Kenland”; seeding rate 16.8 kg/ha) and white (Trifolium repens cv. “Ladino”; seeding rate 5.6 kg/ha) clovers; Paddock C: dal-lisgrass (Paspalum dilatatum Poir.; seeding rate 13.5 kg/ha) + berseem, red and white clovers (same varieties and seeding rates). Forage System 3; Paddock A: BG; Paddock B: dallisgrass + berseem, red, and white clovers; Paddock C: RG + rye + berseem, red, and white clovers; Paddock D: forage soybean (Glycine max cv. “Laredo,” seeding rate 67 kg/ha)/RG (for summer and winter, respectively); Paddock E: brown midrib (BMR) sorghum (Sorghum bicolor (L.) Moench.) × sudangrass (Sorghum sudanese Piper cv. “Sweet Sunny”) hybrid (seeding rate 18 kg/ha)/RG (for summer and winter, respectively).

Systems for forage-fed beef production 5713

ness was similar to those reported by Bowling et al. (1977), Bidner et al. (1986), and Mandell et al. (1998). Longissimus muscle areas for animals in this study (62 to 64 cm2) were similar to those reported by Bowling et al. (1977), who harvested their animals at the same USDA quality grade, and Bidner et al. (1985), who harvested their animals at the same final weight. However, Crouse et al. (1984), Bennett et al. (1995), and Mandell et al. (1998), who harvested their animals to a common backfat, reported greater values (69.6, 70.8, and 70.8 cm2, respectively) for forage-fed beef. Marbling scores were similar to those found by Bidner et al. (1985, 1986) and Mandell et al. (1998).

Economic Analyses

Table 6 presents a listing of the prices used for all inputs and outputs. Fixed costs included depreciation and interest on fencing and equipment. At the 5% significance level, to-tal income differed by treatment, with System 3 yielding lower income than either Systems 1 or 2 (Table 7). This was due to less hay being made and sold in System 3 than in the other 2 treatments. Total direct costs did not differ by treatment. Although System 3 incurred greater seed cost

due to the planting of a wider variety of forages, fertilizer costs and costs associated with making hay (diesel and re-pair and maintenance of equipment) were lower on System 3, offsetting the higher seed cost. Return over total direct cost was lowest for System 3. Fixed costs were highest for System 1, followed by System 2, and finally System 3, due primarily to the greater equipment usage for hay making in System 1. Total expenditures did not differ significantly by system. Return over total specified expenses was lowest for System 3. These cost estimates do not include labor costs.

Table 5. Least square means for carcass characteristics of steers harvested (24 steers/treatment; 6 steers/treat-ment/yr) with an average of 18 mo of age

Item

Forage System1 SEM

P-value1 2 3

Hot carcass weight, kg 268.0 275.2 273.5 8.07 0.32Dressing, % 53.2 54.4 54.9 1.2 0.05Lean color 180.9 167.3 203.3 14.7 0.05Marbling score 217.9 228.3 196.9 28.2 0.26Fat thickness, mm 5.7 6.2 4.8 4.1 0.13Preliminary yield grade, % 2.5 2.6 2.4 0.03 0.89Ribeye area, cm2 65.2 62.5 66.7 1.6 0.12Kidney, pelvic and heart fat, % 1.63 1.58 1.58 0.25 0.98Ribeye area/HCW, cm2/kg 1.72 1.60 1.72 0.04 0.05Quality grade 2 148 166 140 22.0 0.31Yield grade 2.39 2.61 2.27 0.15 0.08

1Forage System 1; Paddock A: bermudagrass hybrid (Cynodon dactylon “Alicia,” “Jiggs,” and “Tifton 85,” BG); Paddock B: annual ryegrass (Lolium multiflorum cv. “Marshall,” RG; seeding rate of 33.7 kg/ha); Paddock C: BG+RG (seeding rate of 33.6 kg/ha). Forage System 2; Paddock A: BG; Paddock B: RG (seeding rate of 33.6 kg/ha) + rye (Secale cereale cv. “Elbon”; seeding rate of 33.7 kg/ha) + berseem (Trifolium alexandrium cv. “BigBee”; seeding rate 22.5 kg/ha), red (Trifolium pretense cv. “Kenland”; seeding rate 16.8 kg/ha) and white (Trifolium repens cv. “Ladino”; seeding rate 5.6 kg/ha) clovers; Paddock C: dallisgrass (Paspalum dilatatum Poir.; seeding rate 13.5 kg/ha) + berseem, red and white clovers (same varieties and seeding rates). Forage System 3; Paddock A: BG; Paddock B: dallisgrass + berseem, red, and white clovers; Paddock C: RG + rye + berseem, red, and white clovers; Paddock D: forage soybean (Glycine max cv. “Laredo,” seeding rate 67 kg/ha)/RG (for summer and winter, respectively); Paddock E: brown midrib (BMR) sorghum (Sorghum bi-color (L.) Moench.) × sudangrass (Sorghum sudanese Piper cv. “Sweet Sunny”) hybrid (seeding rate 18 kg/ha)/RG (for summer and winter, respectively).

2Quality grade: Select 50 = 100, Select 75 = 150, Select 90 = 180.

Table 6. Prices (dollars) of inputs and outputs by yr used in the economic analysis

Item

Unit

Year1

1 2 3 4Inputs

Weanling calf kg 2.20 2.20 2.65 2.76Urea fertilizer kg 0.40 0.35 0.42 0.42Gramoxone Max herbicide2 liter 10.50 11.54 11.54 11.54Grazon p+d herbicide3 liter 8.47 10.44 8.18 8.79Roundup Max herbicide4 liter 13.86 15.32 15.22 12.85Outrider herbicide5 liter 676.28 N/A N/A N/AMalathion insecticide liter N/A 8.98 8.94 8.94Sevin 80% insecticide6 kg 13.51 15.01 16.20 16.20Bovishield vaccine7 dose 2.50 2.50 2.50 2.50Vision 8 vaccine8 dose 0.40 0.40 0.40 0.40Once PMH9 dose 2.50 2.50 2.50 2.50Dewormers dose 3.45 3.45 3.45 3.45Minerals mix bag 17.13 17.13 17.13 17.13Twine, hay roll 0.75 0.75 0.75 0.75Berseem clover seed kg 4.72 4.74 7.72 7.72Red clover seed kg 5.51 6.61 2.65 2.65White clover seed kg 5.51 7.05 6.83 6.61Rye seed kg 0.49 0.97 0.97 0.99Ryegrass seed kg 1.34 1.54 1.10 1.06Soybean seed kg 1.23 1.17 1.32 1.32Sorghum-sudan seed kg 1.04 1.76 1.76 1.85Fence, electric km 23.61 23.61 23.61 23.61Fence, 5-wire km 130.49 130.49 130.49 130.49Shade, structure unit 3.48 3.48 3.48 3.48Shade cloth unit 5.30 5.30 5.30 5.30Water tank unit 40.00 40.00 40.00 40.00

OutputsHay bale 45.00 40.00 82.50 37.50Steers at harvest kg 2.56 2.93 3.13 3.24

1Year 1 = June 2009 to May 2010; Year 2 = June 2010 to May 2011; Year 3 = June 2011 to May 2012; Year 4 = June 2012 to May 2013.

2Syngenta, Greensboro, NC.3Dow Agrosiences, Indianapolis, IN.4Monsanto, St. Louis, MO.5Monsanto, St. Louis, MO.6Bayer, Research Triangle Park, NC.7Pfizer Animal Health, New York, NY.8Merck Corporate, Animal Health, Summit, NJ.9Bayer Corporation, Agriculture Division, Animal Health, Shawnee

Mission, KS.

Scaglia et al.5714

This is the first report of year-round forage systems for production of forage-fed beef following USDA-AMS (2007) definition of the product adding the concept of not using growth promotants or ionophores. All 3 systems al-lowed the production of steers weighing 520 kg at 18 mo of age with similar carcass characteristics. Even though short-term differences in ADG of animals between sys-tems occurred, these disappeared when considered the en-tire grazing season. The evaluation of these systems at a low stocking rate allowed for maximum individual animal performance and hay production, the latter of which, when considered in economic analyses, made the difference in the profitability between the evaluated systems. The evalu-ation of (animal and forage) alternatives to ameliorate the low summer performance as well as to reduce the length of the “transition period” or “forage gaps” is warranted.

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Bagley, C. P., T. D. Bidner, D. F. Coombs, G. M. Hill, D. C. Huffman, J. W. Knox, A. F. Loyacano, K. W. McMillin, W. M. Oliver, A. M. Saxton, and W. E. Wyatt. 1987. Year-round production of slaughter beef using optimum levels of forages. LAES, Bull. No. 781. 127 p.

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Banta, J. P., F. T. McCollum III, L. W. Greene, K. W. McBride, G. Scaglia, J. J. Williams, B. Bean, and R. Van Meter. 2002. Performance of stocker cattle grazing a brown midrib sorghum x sudan hybrid in either a continuous or rotational grazing sys-tem. Available at http://animalscience.tamu.edu/wp-content/up-loads/sites/14/2012/04/nutrition-performance-stocker.pdf.

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Table 7. Revenue, expenses, and profit per treatment (dollars/steer)

Item

Forage System1

1 2 3IncomeSteers sold 1,378.33 1,384.22 1,377.01Hay sold 742.72a 596.28b 402.53c

Total income 2,121.07a 1,980.50a 1,779.54b

Direct costFertilizer 290.56a 231.13b 193.69c

Pesticides 56.89 44.35 51.76Livestock 636.00 637.92 637.99Twine 3.64a 2.69b 2.18b

Seed 59.93a 146.79b 205.49c

Minerals and medication 22.17a 22.69b 22.65b

Diesel 72.32a 55.36b 46.21c

Repair and maintenance 61.18a 49.90b 45.74b

Interest on operating capital 43.72 46.07 43.75Total direct cost 1,237.07 1,238.26 1,250.17Return over total direct cost 883.96a 742.97a 529.28b

Fixed cost 204.53a 164.31b 140.60c

Total expenditures 1,441.64 1,401.83 1,390.88Return over total specified expenses 702.39a 578.60a 388.60b

1Forage System 1; Paddock A: bermudagrass hybrid (Cynodon dactylon “Alicia, “Jiggs,” and “Tifton 85,” BG); Paddock B: annual ryegrass (Lolium mul-tiflorum cv. “Marshall,” RG; seeding rate of 33.7 kg/ha); Paddock C: BG+RG (seeding rate of 33.6 kg/ha). Forage System 2; Paddock A: BG; Paddock B: RG (seeding rate of 33.6 kg/ha) + rye (Secale cereale cv. “Elbon”; seeding rate of 33.7 kg/ha) + berseem (Trifolium alexandrium cv. “BigBee”; seeding rate 22.5 kg/ha), red (Trifolium pretense cv. “Kenland”; seeding rate 16.8 kg/ha) and white (Trifolium repens cv. “Ladino”; seeding rate 5.6 kg/ha) clovers; Paddock C: dal-lisgrass (Paspalum dilatatum Poir.; seeding rate 13.5 kg/ha) + berseem, red and white clovers (same varieties and seeding rates). Forage System 3; Paddock A: BG; Paddock B: dallisgrass + berseem, red, and white clovers; Paddock C: RG + rye + berseem, red, and white clovers; Paddock D: forage soybean (Glycine max cv. “Laredo,” seeding rate 67 kg/ha)/RG (for summer and winter, respectively); Paddock E: brown midrib (BMR) sorghum (Sorghum bicolor (L.) Moench.) × sudangrass (Sorghum sudanese Piper cv. “Sweet Sunny”) hybrid (seeding rate 18 kg/ha)/RG (for summer and winter, respectively).

a–cWithin a row means without a common superscript differ (P < 0.05).

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