Grazing warm‐season grass pastures with stocker cattle (Bos taurus) is an important economic activity in the southern Great Plains, and substantial increases in the price of N fertilizer have negatively affected profitability of forage producers. The goal of the study was to determine if bermudagrass [Cynodon dactylon (L.) Pers.] pastures interseeded with either annual or perennial legumes are more profitable than the conventional method of fertilizing with 112 kg N ha−1 commercial fertilizer. A completely randomized design grazing study was conducted in south‐central Oklahoma during the spring and summer months of 2008, 2009, and 2010. Preconditioned stocker cattle (260 ± 47 kg head−1) were randomly assigned to pastures (1.42 ± 0.10 ha; three replicates per system) at 2.32 ± 0.40 animals ha−1, beginning when measured standing forage reached 2000 kg ha−1 and grazing continuously until forage mass declined to 1000 kg ha−1. Results of the 3‐yr grazing study show that under continuous stocking for the growing conditions common to the south‐central Great Plains, the legume systems could not compete economically with the common practice of fertilizing bermudagrass pastures with synthetic inorganic N fertilizer. Results are most sensitive to number of grazing days, price of N, and prices of legume seed.

Rotational grazing management is commonly recommended to improve persistence of legumes interseeded into bermudagrass, but impacts on animal performance are poorly understood. Steers (n = 365, BW = 249 ± 22.9 kg) grazed mixed alfalfa (Medicago sativa L.)/bermudagrass (Cynodon dactylon [L.] Pers.) pastures (n = 10; 1.6-ha) with either continuous grazing (CONT) or rotational grazing (ROT) management over 3 yr. Initial stocking rate was set at 6.25 steers/ha. When forage allowance of CONT became limiting in mid-July each year, 2 randomly selected steers were removed from all pastures to maintain equal stocking rates in CONT and ROT. Rotational grazing pastures were divided into 8 paddocks with 3-d grazing and 21-d rest between grazing events. Initial, final, and interim (28-d) BW were collected following a 16-h removal from feed and water. Data were analyzed as a repeated measures experiment with completely random design using the mixed procedure of SAS (SAS Inst. Inc., Cary, NC) using pasture within treatment by year in the random statement. Across years, steer BW did not differ (P ≥ 0.47) at the midpoint or end of the grazing season. Daily BW gains during the early summer period tended (P = 0.10) to be 0.11 kg greater for CONT than ROT in yr 1, but did not differ (P ≥ 0.24) in yr 2 and 3. In the late summer, ADG was 0.15 kg less (P < 0.01) for CONT than ROT in yr 1, were not different (P = 0.23) in yr 2, and were 0.29 kg less (P < 0.01) for CONT than ROT in yr 3. Over the entire experimental period, ADG did not differ (P ≥ 0.67) in yr 1 or 2, but tended (P = 0.09) to be 0.10 kg greater for ROT than CONT in yr 3. Forage mass of ROT was greater (P < 0.01) than CONT throughout the grazing season. Because stocking rates were maintained at the same level, ROT pastures provided greater (P < 0.01) forage allowance during the grazing season than CONT explaining differences in ADG between treatments. Alfalfa stand percentage did not differ (P = 0.79) at the beginning of the experiment, but was less (P ≤ 0.03) for CONT than ROT at all other sampling dates. These data indicate that at equal stocking rates, ROT can maintain greater alfalfa persistence, forage nutritive quality, and forage allowance compared with continuous grazing and provided increased animal performance during the late summer when the alfalfa stand was reduced in CONT pastures.

Estimating forage availability is important in optimizing livestock stocking rates. The rising plate meter was developed to estimate forage availability. It needs a calibration equation to convert its measurement to a prediction of forage mass, and predictions can vary across crops, seasons, and locations. Our research objective was to derive new calibration equations for wheat (Triticum aestivum L.) and rye (Secale cereale L.). Most past literature used a linear model, but recent literature has suggested that using a quadratic model without an intercept could improve predictions. A non-nested test was used to test among these two non-nested models for wheat and rye calibration equations. The results favored the more encompassing model of a quadratic with an intercept; however, with wheat the quadratic with no intercept was not rejected. A pooling test indicated different equations were needed for species, seasonality (winter and non-winter), and tillage type (tilled or no-till).

Integration of switchgrass (Panicum virgatum L.) into livestock production systems has potential to improve farm economics and encourage development of a biofuel industry in the Southern Great Plains. The objectives of this study were to determine the economics of seven alternative switchgrass grazing and bioenergy feedstock systems and to determine how sensitive the results are among the systems for a range of cattle and feedstock prices. Data were collected from a completely randomized designed grazing study in south-central Oklahoma in 2008, 2009, and 2010. Stocking density treatments [0, 2.5, 4.9 and 7.4 hd ha −1

Fifteen introduced and native warm-season perennial grasses were evaluated for yield, yield distribution, and quality in southcentral Oklahoma. These grasses have production potential for forage and/or biofuel. Each was harvested one to four times per year. "Alamo" switchgrass (Panicum virgatum) had a two-year average dry matter yield of 17690 kg ha −1 . Over 1/3 of this production occurred in May with a crude protein (CP) range of 97-115 g kg −1 . Alamo's high yield potential and early spring growth make it attractive for spring forage production and fall biomass production. Other grasses with two-year average dry matter yields over 11200 kg ha −1 and 1/3 of yearly production occurring early in the growing season that have potential dual purpose use include "Selection 75" kleingrass (Panicum coloratum), "Midland 99" bermudagrass (Cynodon dactylon), johnsongrass (Sorghum halepense), "Carostan" flaccidgrass (Pennisetum flaccidum), and "Ermelo" weeping lovegrass (Eragrostis curvula).