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Grazing winter cereal pasture with stocker cattle is a common production practice on water‐limited cropland acres in the southern Great Plains. Soil erosion and loss of soil water holding capacity from interactions with tillage operations, wind, and rainfall are common problems with these systems. Despite the environmental and economic benefits reported for no‐till (NT) techniques, clean‐till (CT) establishment remains a common practice in the region. The objectives were to determine the effects of tillage system (CT and NT) on measures of animal performance and net returns, and to determine the sensitivity of net returns to the prices of glyphosate, labor, and fuel. Data representing average daily gain (ADG), steer grazing days (SGD) (ha−1), and total gain (TG) (ha−1) were obtained from a 4‐year (2010–2013) grazing trial conducted in south‐central Oklahoma. Enterprise budgeting was used to determine average revenues, costs, and net returns for each establishment system. Mixed model regression results indicated that SGD ha−1 was 11.1 greater (p < 0.0001) for CT compared to NT but ADG was 0.025 kg day−1 greater (p < 0.0001) for the NT system. The CT system realized a TG of 6.63 kg ha−1 greater (p < 0.0001) than NT. Conversely, the NT system realized a total cost of US$1067.27 ha−1, which was $105.29 ha−1 lower than the cost of the CT system. On average, the NT system realized a $67.63 ha−1 greater net return than CT. The NT system remained the most profitable even with substantial changes in prices of glyphosate, machinery labor, and fuel. Core Ideas: No‐till establishment has been shown to be economical compared to clean‐till.Despite being economical, adoption of no‐till continues to lag expectations.Animal performance and production data were produced in a scientific grazing trial.Results suggest that no‐tilling is US$68 ha−1 more profitable than clean‐till establishment.Relative profitability of no‐till was not overly sensitive to changes in prices of glyphosate, labor, and fuel. [ABSTRACT FROM AUTHOR]

An accurate estimate of feed intake is a critical component in determining individual animal feed efficiency. However, existing feed intake measurement systems are not designed for unprocessed, dry forage diets. Open-circuit gas flux technology measures enteric gas emissions for cattle in a pasture-based setting. If a significant relationship exists between feed intake and gas emissions, this system could be used to rank grazing cattle for forage intake and forage utilization efficiency. Our objective was to develop prediction equations to estimate forage dry matter intake using gas flux and performance data. Angus and Angus x Hereford heifers [n = 71; initial body weight (BW) 329.5 ± 31.1 kg] were used over 3 yr to measure intake, gain, and gas flux. All heifers were subject to a 21-d adaptation and 71-d intake test using individual intake technology (SmartFeed; C-Lock Rapid City, SD) with a stocking rate of 3.3 heifers per feeder. Throughout the study, heifers were fed a long-stem, unprocessed, grass hay diet (≥ 10.8% CP, 2.0 Mcal ME, and 56% TDN) with ad libitum access to a salt/mineral supplement. The GreenFeed system (C-Lock Rapid City, SD) was used to monitor oxygen (O2) consumption (means ± SD; 3364.4 ± 374.8 g/d), methane (CH4; 181.4 ± 24.3 g/d) and carbon dioxide (CO2) production (4,965.3 ± 494.5 g/d). Body weights were collected every 14 d, and average daily gain (ADG) was calculated by regressing BW on day of study. The phenotypic correlations of forage DMI with CO2, CH4, O2, and heat production (HP) were 0.72, 0.66, 0.74, and 0.74, respectively. Average daily gain and midpoint metabolic BW combined with the estimate of daily HP, O2, or CO2 accounted for 60% of the variation in forage DMI. These results suggest that forage intake can be predicted using performance data in conjunction with the GreenFeed gas quantification system. [ABSTRACT FROM AUTHOR]

Four years of feedlot performance and carcass characteristics were pooled on spring-(SPRING) and fall-(FALL) born steers (n=460) into a mixed model to evaluate the effects of calving season, sire breed (Angus [AN], Charolais [CHAR] or Hereford [HER]) and their interaction on feedlot performance and carcass traits. Initial and final BW, DOF, ADG, DMI, and G:F were evaluated as performance measures and HCW, YG, FT, REA, and MS were collected at harvest. There was no season by breed interaction for entry or final BW (P >0.05). SPRING steers (400.2 kg, 686.4 kg) weighed more than FALL (350.9 kg, 668.3 kg) upon entering and leaving the feedyard (P< 0.001). CHAR weighed 14.3 kg less than AN upon feedlot entry (P=0.01) although final BW did not differ by breed (P >0.05). SPRING steers (21.8 kg/d) consumed more feed than FALL steers (18.8 kg/d; P=0.002), but there was no difference in gain:feed due to calving season nor sire breed (P=0.575). A calving season by sire breed interaction was present for ADG and DOF (P=0.014). FALL AN (1.70 kg/d) and FALL HER (1.80 kg/d) gained more than FALL CHAR (1.55 kg/d;P< 0.001) and FALL AN were fed over a shorter period than FALL CHAR and FALL HER (P=0.006). However, average daily gain of SPRING calves did not differ by breed (P >0.05). There was a tendency for FALL (400.9 kg) steers to have lighter carcasses than SPRING steers (407.9 kg; P=0.068). HER carcasses were 18.0 kg heavier than AN carcasses (P< 0.001), but did not differ from CHAR (P=0.13). CHAR had larger REA (93.5 cm2) than both AN (87.7 cm2) and HER steers (88.5 cm2;P=0.001). Fall-born steers had less YG than spring-born steers (P< 0.042). Feedlot performance was generally less for fall-born steers finished during the winter months. Under these conditions, numerous performance and carcass traits were influenced by the interaction of breed and season. [ABSTRACT FROM AUTHOR]

Two experiments were conducted to evaluate the effects of virtual fencing on stress in beef cattle. In both experiments, cattle were contained by either physical, 2-strand electric fencing or by use of a proprietary, GPS-based virtual fencing collar, with no physical interior fencing. In both studies, hair from the tail switch was collected at the end of the experiment, and analyzed for cortisol concentration to measure the accumulated stress experienced by the cattle. Additionally, a subset of cattle were fitted with pedometers to measure behavior responses. In the initial pilot experiment, 55 heifers were grazed for 28 d in either 1 physically-fenced pasture or 1 virtually-fenced pasture. In the second experiment, 59 mature cows and heifers were grazed for 56 d in 1 of 2 physically-fenced or 1 of 2 virtually-fenced pastures (4 pastures total). In the second experiment, blood samples were also collected and NEFA and lactate were quantified in plasma. Only descriptive statistics were summarized for the pilot experiment, which indicated that hair cortisol concentrations were within published ranges for both fence types (0.39 ± 0.32 and 0.37 ± 0.15 pg/mg for physically- or virtually-fenced animals, respectively), and step count and motion index appeared elevated in the first few days of adaptation to virtual fence. The second experiment was analyzed with analysis of variance as a completely random design with pasture as the experimental unit. No effect of fence type was found for behavior (number of steps, standing time, lying bouts, or motion index; P > 0.16). Further, no difference was observed in cortisol, lactate nor NEFA (P > 0.14) concentrations due to fence type. None of this data suggests that virtual fencing is different from physical fencing in the effects on cattle stress and behavior, indicating further research and development of virtual fencing technology are warranted. [ABSTRACT FROM AUTHOR]