Effects of Movement and Activity Behavior in a Pasture System Compared to Time

During the summer of 2016 seventeen cows were fitted with Global Positioning System (GPS) tracking collars to evaluate activity characteristics of cattle on rangelands. Data collected included daily distance traveled, average distance from water, daily time spent at water, daily area covered, and percent of day spent active (traveling or grazing). These variables were analyzed weekly to assess changes in behavior as time within pastures increased during three time periods of the growing season. Based on data collected from mid-May to mid-September, cattle showed little changes throughout the grazing season as to levels of activity through different periods of a 24-hour day. Daily patterns indicate that cattle are most active during mid-morning and evening hours. Periods of greatest inactivity occur during early morning hours and late afternoon prior to an evening grazing bout. Distance traveled showed a general downward trend as week within pasture progressed with the exception of the early grazed pasture. Average distance of cattle from water increased, and average time at water decreased at the end of the growing season. There were no statistical differences in activity levels or average area covered as time within a pasture increased. The greater distance traveled at the beginning of grazing on a pasture suggests that cattle are more selective in their grazing patterns and go to more grazing locations

Estimates of genetic parameters and genetic change for reproduction, weight, and wool characteristics of Columbia sheep

Genetic parameters from both single-trait and bivariate analyses for prolificacy, weight and wool traits were estimated using REML with animal models for Columbia sheep from data collected from 1950 to 1998 at the U.S. Sheep Experiment Station (USSES), Dubois, ID. Breeding values from both single-trait and seven-trait analyses calculated using the parameters estimated from the single-trait and bivariate analyses were compared with respect to genetic trends. Number of observations were 31,401 for litter size at birth and litter size at weaning, 24,741 for birth weight, 23,903 for weaning weight, 29,572 for fleece weight and fleece grade, and 2,449 for staple length. Direct heritability estimates from single-trait analyses were 0.09 for litter size at birth, 0.06 for litter size at weaning, 0.27 for birth weight, 0.16 for weaning weight, 0.53 for fleece weight, 0.41 for fleece grade, and 0.55 for staple length. Estimate of direct genetic correlation between litter size at birth and weaning was 0.84 and between birth and weaning weights was 0.56. Estimate of genetic correlation between fleece weight and staple length was positive (0.55) but negative between fleece weight and fleece grade (−0.47) and between staple length and fleece grade (−0.70). Estimates of genetic correlations were positive but small between birth weight and litter size traits and moderate and positive between weaning weight and litter size traits. Fleece weight was lowly and negatively correlated with both litter size traits. Fleece grade was lowly and positively correlated with both litter size traits, while staple length was lowly and negatively correlated with the litter size traits. Estimates of correlations between weight traits and fleece weight were positive and low to moderate. Estimates of correlations between weight traits and fleece grade were negative and small. Estimates of correlations between staple length and birth weight (0.05) and weaning weight were small (−0.04). Estimated breeding values averaged by year of birth from both the single-trait and multiple-trait analyses for the prolificacy and weight traits increased over time, but were unchanged for the wool traits. Estimated changes in breeding values over time did not differ substantially for single-trait and multiple-trait analyses, except for traits highly correlated with another trait that was responding to selection

Pyrethroid Exposure Reduces Growth and Development of Monarch Butterfly (Lepidoptera: Nymphalidae) Caterpillars

Insecticide exposure has been identified as a contributing stressor to the decline in the North American monarch butterfly Danaus plexippus L. (Lepidoptera: Nymphalidae) population. Monarch toxicity data are currently limited and available data focuses on lethal endpoints. This study examined the 72-h toxicity of two pyrethroid insecticides, bifenthrin and β-cyfluthrin, and their effects on growth and diet consumption. The toxicity of bifenthrin to caterpillars was lower than β-cyfluthrin after 72 h. Survival was the most sensitive endpoint for bifenthrin, but diet consumption and caterpillar growth were significantly reduced at sublethal levels of β-cyfluthrin. Using AgDRIFT spray drift assessment, the aerial application of bifenthrin or β-cyfluthrin is predicted to pose the greatest risk to fifth-instar caterpillars, with lethal insecticide deposition up to 28 m for bifenthrin and up to 23 m for β-cyfluthrin from treated edges of fields. Low boom ground applications are predicted to reduce distances of lethal insecticide exposure to 2 m from the treated field edge for bifenthrin and β-cyfluthrin. Growth and survival of fifth-instar monarch caterpillars developing within the margins of a treated field may be significantly impacted following foliar applications of bifenthrin or β-cyfluthrin. These findings provide evidence that pyrethroid insecticides commonly used for soybean pest control are a potential risk to monarch caterpillars in agricultural landscapes

Impact of Increasing Level of Milk Production on Cow-Calf Performance in Nebraska Sandhills

In a 2-yr study, data were collected on 118 crossbred cow-calf pairs from March and May-calving herds. On approximately 30, 60, 90, 120, and 210 d postpartum, individual cow 24-h bilk yield was estimated through weigh-suckle weigh techniques. Cow body weight (BW) and body condition score (BCS) were collected weekly through breeding. Calf BW was recorded at each milking. Individual cow milk area under the curve (AUC) values were calculated and data were analyzed using linear regression analysis. Results from this study illustrate that increasing total milk produced throughout the lactation period had minimal influence on the cow production parameters assessed in the Nebraska Sandhills forage environment. However, the lack of differences found in this study may be due to years of selecting for low milk production genetics and the cowherd may not represent the US average for milk production

Morphological and genetic analyses in the Melanoplus packardii group (Orthoptera: Acrididae)

Melanoplus packardii Scudder was described in 1897. Three additional closely-related species were later described and their status as species has been questioned on numerous occasions. We examined morphology from specimens collected in Nebraska which fit descriptions of three of the four forms and specimens that appeared to be hybrids. We found distinct morphological characters suggesting species status for M. foedus and M. packardii, but not for M. foedus fluviatilis. Examination of aedeagi of these three forms suggests that M. foedus and M. packardii are each distinct, but that the aedeagi of M. f. fluviatilis and M. f. foedus cannot be distinguished. Molecular analyses of the three groups did not produce clear separations and suggest gene exchange between these three forms may be ongoing. Together, these data suggest that M. foedus and M. packardii should be recognized as sibling species, but M. foedus fluviatilis is best considered a form of M. foedus, typically found in low lying areas

Effect of Methionine Supplementation During Late Gestation in Beef Females

Some amino acids are known to be essential to cattle and effect protein availability to the animal, especially during gestation when nutrient requirements are higher. Methionine is found to be one of the most limiting in low quality forage diets. Two 3-yr studies were performed to evaluate the impact of methionine supplementation during late gestation on intake, body weight, average daily gain, and subsequent calf performance in primiparous and multiparous females. In exp 1, 120 artificially inseminated pregnancy heifers were placed in a Calan gate feeding system (n=40/yr) and assigned 1 of 3 treatments during late gestation and fed ad libitum grass hay with either: no supllement, 2 lbs. distillers based supplement with 1 oz of rumen protected methionine. In exp 2, multiparous cows on upland winter range were fed 1 of 5 treatments; no supplement, ad libitum meadow hay, 1 lb. of a distiller\u27s based cube, 2 lb. of a distiller\u27s based cube, or 2 lb. of a distiller\u27s based cube plus 1 oz of a rumen protected methionine. Body weight, body condition score, reproductive responses, and subequent calf performance were recorded in both studies. No differences were observed in calving performance or progeny carcass characteristics in either experiment in response to methionine supplementation, so it may not be a necessary supplementation strategy

Impact of Feeding Syngenta Enogen® Feed Corn Compared to Control Corn in Different Diet Scenarios to Finishing Beef Cattle

The objective of this pooled statistical analysis was to evaluate Syngenta Enogen® Feed Corn (EFC) versus conventional corn (CON) when fed as either dry-rolled corn (DRC) or highmoisture corn (HMC) for effects on finishing beef cattle performance and carcass characteristics. Corns were evaluated in diets with byproduct inclusion rates of 0, 15, 18, 20, and 30% distiller grains or 25 and 35% Sweet Bran® (a commercial corn gluten feed product). Seven trials (n = 1856) consisting of 200 pen means comparing 26 diet treatments were analyzed using regression in a pooled analysis. When EFC was processed as DRC, the gain efficiency (G:F) improved compared with CON, but the response to feeding EFC decreased from a 4.8% improvement to no improvement compared to CON as distiller grains increased from 0 to 30%, but was significantly improved due to feeding EFC in diets with 0 to 18% distiller grains. Feeding cattle EFC as DRC increased the average daily gain (ADG) and G:F by 4.5% compared with CON corn in diets containing Sweet Bran®. No improvements in animal performance were observed when cattle were fed EFC compared to CON when processed as HMC in any situation. Feeding Enogen® corn improved the gain efficiency of finishing cattle compared with conventional corn when processed as dry-rolled corn and fed in diets with less than 20% distillers or diets that include Sweet Bran®

Morphological and genetic analyses in the Melanoplus packardii group (Orthoptera: Acrididae)

Melanoplus packardii Scudder was described in 1897. Three additional closely-related species were later described and their status as species has been questioned on numerous occasions. We examined morphology from specimens collected in Nebraska which fit descriptions of three of the four forms and specimens that appeared to be hybrids. We found distinct morphological characters suggesting species status for M. foedus and M. packardii, but not for M. foedus fluviatilis. Examination of aedeagi of these three forms suggests that M. foedus and M. packardii are each distinct, but that the aedeagi of M. f. fluviatilis and M. f. foedus cannot be distinguished. Molecular analyses of the three groups did not produce clear separations and suggest gene exchange between these three forms may be ongoing. Together, these data suggest that M. foedus and M. packardii should be recognized as sibling species, but M. foedus fluviatilis is best considered a form of M. foedus, typically found in low lying areas

Effect of distillers grains moisture and inclusion level in livestock diets on greenhouse gas emissions in the corn-ethanol-livestock life cycle

A model was previously developed (Biofuel Energy Systems Simulator; www. bess.unl.edu) to predict greenhouse gas (GHG) emissions and net energy yield when ethanol is produced from corn. The model also predicts feedlot cattle, dairy cattle, and swine performance and feed replacement value of ethanol coproducts. Updated equations that predict performance of feedlot cattle fed 0 to 40% of dietary DM as corn wet (WDGS), modified (MDGS), or dry (DDGS) distillers grains plus solubles replacing dry-rolled and high-moisture corn were developed and incorporated into the model. Equations were derived from pen-level performance for 20 finishing studies evaluating WDGS, 4 evaluating MDGS, and 4 evaluating DDGS conducted at the University of Nebraska. Feeding value of WDGS was 145 to 131% of corn replaced when included at 20 to 40% of diet DM due to a quadratic (P \u3c 0.01) increase in G:F. The feeding value of MDGS was 124 to 117% with a quadratic (P \u3c 0.01) increase in G:F and 112 to 110% for DDGS with a linear (P \u3c 0.01) increase in G:F. Midwest corn-ethanol-livestock life cycle GHG reduction relative to gasoline (97.7 g CO2 equivalent/MJ of ethanol) was 61 to 57% when WDGS was fed to feedlot cattle for 20 to 40% diet inclusion. Feeding MDGS and DDGS to feedlot cattle reduced GHG emissions from the corn-ethanol-cattle system by 53 to 50% and 46 to 41%, respectively. Feeding WDGS to feedlot cattle was the optimum feed use of distillers grains plus solubles based on feeding performance and GHG reduction

Wet Distillers Grains Plus Solubles or Solubles in Feedlot Diets Containing Wet Corn Gluten Feed

Effects of the addition of 0% to 40% wet distillers grains plus solubles (WDGS) or 0% to 20% condensed corn distillers solubles (CCDS) to feedlot diets containing high moisture corn (HMC) and 35% wet corn gluten feed (WCGF) were evaluated. As WDGS replaced HMC, average daily gain (ADG) decreased linearly and dry matter intake (DMI) tended to decrease. Replacement of HMC with WDGS in the 35% WCGF diet caused a linear decrease in ADG and a trend for a linear decrease in DMI. When CCDS replaced HMC, no difference in steer performance was observed. The sulfur content, rather than fat content, of WDGS may be the limiting factor with feeding WDGS in combination with WCGF, and solubles may effectively reduce the dietary inclusion of corn by up to 20% of diet DM in finishing diets containing 35% WCGF