Animal Sciences Commons^™

Amphibian And Small Mammal Assemblages In A Northern Virginia Forest Before And After Defoliation By Gypsy Moths (Lymantria Dispar), Joseph C. Mitchell

Virginia Journal of Science

The introduced European gypsy moth (Lymantria dispar) caused substantial defoliation and mortality of oak trees along the North Fork of Quantico Creek in Prince William Forest Park, Prince William County, Virginia, U.S.A., in 1989 and the early 1990s. Results of a drift fence/pitfall study conducted in 1988 were compared to those obtained from the same technique in the same areas in 1993 to elucidate whether the amphibian and small mammal assemblages had changed over time. Number of Lithobates sylvaticus increased significantly in 1993, but the numbers of Lithobates clamitans and Plethodon cinereus were significantly higher in 1988. Total …

The Complexities Of Female Mate Choice And Male Polymorphisms: Elucidating The Role Of Genetics, Age, And Mate-Choice Copying, Kasey D. Fowler-Finn, Laura Sullivan-Beckers, Amy M. Runck, Eileen A. Hebets

Eileen Hebets Publications

Genetic, life history, and environmental factors dictate patterns of variation in sexual traits within and across populations, and thus the action and outcome of sexual selection. This study explores patterns of inheritance, diet, age, and mate-choice copying on the expression of male sexual signals and associated female mate choice in a phenotypically diverse group of Schizocosa wolf spiders. Focal spiders exhibit one of two male phenotypes: ‘ornamented’ males possess large black brushes on their forelegs, and ‘non-ornamented’ males possess no brushes. Using a quantitative genetics breeding design in a mixed population of ornamented/non-ornamented males, we found a strong genetic basis …

Octopamine Levels Relate To Male Mating Tactic Expression In The Wolf Spider Rabidosa Punctulata, Eileen A. Hebets, Matthew Hansen, Thomas C. Jones, Dustin J. Wilgers

Eileen Hebets Publications

In the wolf spider Rabidosa punctulata, upon encountering a female, males use one of two distinct strategies: (1) they court the female in an attempt to elicit a mating, or (2) they engage in a direct-mount tactic that involves extensive grappling with the female until a mating is achieved. The latter tactic appears more sexually aggressive, and both tactics come with the risk of being cannibalized. We explored the physiological mechanisms underlying this behavioral variation by assessing the relationship between circulating levels of the biogenic amine octopamine (OA), a neuromodulator suggested to play a role in “fight or flight” responses …

Functional Approach To Condition, Dustin J. Wilgers, Eileen A. Hebets

Eileen Hebets Publications

Animal signaling is commonly thought to be costly. Signaling costs can arise via a variety of avenues, including energy expenditure, predator attraction, and so on (reviews in Zuk and Kolluru, 1998; Kotiaho, 2001), and are predicted to increase with signal expression (e.g., size, amplitude, and intensity; Johnstone, 1997). Due to these costs, signaler condition, which is hypothesized to be a reflection of a signaler’s genetic quality, is expected to influence the level of signal expression one can afford (Zahavi, 1975), resulting in a positive correlation between signaler condition and signal expression – that is, condition-dependent signaling (Zahavi, 1977; West-Eberhard, 1979; …

Clues To Aquatic Beetle Research In Southeast Asia: A Multitude Of Ecological Niches, Microhabitats And Deduced Field Sampling Techniques, Hendrik Freitag

Biology Faculty Publications

The basic ecological classification of Southeast Asian beetle families that are associated with aquatic habitats is reviewed. The microhabitat preferences of the taxa are examined on family level with generic examples. Suitable collection methods for quantitative and qualitative sampling are suggested which take into account the different ecological adaptation patterns and microhabitat preferences.

Mineral Composition Of Beef Cattle Carcasses, Andrea K. Watson, Jana L. Harding, Matt P. Mccurdy Curdy, Matt J. Hersom, Kristin E. Hales, Clint R. Krehbiel, Galen E. Erickson

Nebraska Beef Cattle Reports

Mineral retention was measured in 76 beef steers. Cattle were grown at different rates of gain and then finished on a common diet. Calcium and P retention were not affected by treatment and were similar between the growing and finishing periods averaging 4.2 g P and 10.8 g Ca /100 g protein gain across both experiments. As ADG during the growing period was decreased, K, Mg, and S mineral retention during the finishing period were increased. Expressing mineral retention as g/100 g protein gain reducedvariation due to animal size and ADG and suggests that current NRC predictions are accurate.

Anaerobic Digestion Of Feedlot Manure, Andrea K. Watson, Adam L. Shreck, Amy M. Schmidt Schmidt, Terry J. Klopfenstein, Galen E. Erickson

Nebraska Beef Cattle Reports

Cattle diet can impact manure quality and quantity but has minimal impacts on methane production from anaerobic digestion of manure. Quality of manure, measured as OM, does affectmethane production and is largely impacted by the environment cattle are housed in and methods used to collect manure. As the amount of ash contamination of manure was increased, or OM content of the manure was decreased, organic matter degradation and methaneproduction were decreased. With adequate daily cleanout of ash from digesters, open-lot beef cattle manurecan be used for anaerobic digestion.

Mineral Composition Of Serial Slaughter Holstein Carcasses, Andrea K. Watson, Trent J. Mcevers, Lee-Anne J. Walter Walter, Nathan D. May, Jacob A. Reed, N. Andy Cole, Ty E. Lawrence, James C. Macdonald, Galen E. Erickson

Nebraska Beef Cattle Reports

Carcasses of 115 Holstein steers were divided into lean, bone, internal cavity, hide, and fat tissues for analysis of P, Ca, K, Mg, and S retention. Every 28 days, five steers from each of two treatments, fed Zilmax for 20 days prior to harvest or not fed Zilmax, were harvested. There were no differences due to treatment or days on feed when mineral retention was expressed as g/100 g of protein gain. Expressing mineral retention relative to protein gain reduced variation due to rate of gain and animal size.

2015 Beef Cattle Report (Complete)

Nebraska Beef Cattle Reports

Table of Contents

Cow/Calf

Impact of Heifer Development System on Subsequent Gain and Reproduction 5

Genetic Parameter Estimates for Calving Difficulty and Birth Weight in a Multibreed Population 8

Estimation of British- and Continental-Specific Heterosis Effects for Birth, Weaning, and Yearling Weight in Cattle 10

Using Sugar Beet Pulp to Replace Wheat Straw when Limit Feeding Late Gestation Beef Cows 12

Supplementing Cow-Calf Pairs Grazing Smooth Bromegrass 14

Effects of Calf Age at Weaning on Cow and Calf Performance and Feed Utilization in an Intensive Production System 16

An Economic Analysis of Conventional and Alternative Cow-Calf Production Systems 19

Effect …

An Economic Analysis Of Conventional And Alternative Cow-Calf Production Systems, Jason M. Warner, Andrea K. Watson, K. H. Jenkins Jenkins, Rick J. Rasby, Kate Brooks, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

Profitability through weaning was predicted for conventional and alternative cow-calf production systems using various input price scenarios. At base input price levels, conventional systems were more economical than alternative systems. As pasture price increased, alternativesystems became cost effective. Feeding cows year-round in a confinement setting appeared the least economical; however, an alternative system combining summer drylot feeding with cornstalk grazing is projected to be economically competitive given an increasing abundance of corn residue.

Effects Of Calf Age At Weaning On Cow And Calf Performance And Feed Utilization In An Intensive Production System, Jason M. Warner, Curtis J. Bittner, Karla H. Jenkins Jenkins, Rick J. Rasby, Matt K. Luebbe, Galen E. Erickson, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

The effects of calf weaning age on cow and calf performance, reproduction, and feed utilization were investigated in a two-year study. Early weaning increasedcow BW in January. Pregnancy rates were not impacted by calf age at weaning. Dry matter intake (DMI) was similar between normal-weaned cow-calf pairs and early-weaned cows and calves. Feed requirements and utilization were comparable between early- and normal-weaned pairs when fed high energy diets, implying weaning decisions should be made on the basis of management rather than feed efficiency.

Evaluation Of The Impact Of An Alternative Corn Residue Harvest Method On Performance And Methane Emissions From Growing Cattle, Janessa J. Updike, Anna C. Pesta, Robert G. Bondurant Bondurant, James C. Macdonald, Samodha Fernando, Galen E. Erickson, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

A growing study was conducted to evaluate the impact of alternative corn residue harvesting methods and inclusion of Rumensin® on performance and methane to carbon dioxide ratio (CH₄:CO₂) of steers. Use of the alternative harvesting method resulted in greater ADG and improved F:G ratio than traditionally harvested cornstalks. Rumensin increased ADG and improved DMI; however, it did not have an impacton F:G ratio. Altering the composition of baled corn residue did affect CH₄:CO₂, while inclusion of Rumensin, whether included in the diet on a constant or rotational basis, had no impact.

Effect Of Corn Plant Maturity On Yield And Nutrient Quality Of Corn Plants, Cassandra A. Row, Adam L. Shreck, Robert G. Bondurant Bondurant, Curtis J. Bittner, Jana L. Harding, James C. Macdonald, Terry J. Klopfenstein, Galen E. Erickson

Nebraska Beef Cattle Reports

Two corn plots (short season, 102-day, and normal season, 111-day corn) were serially harvested to evaluate nutrient, digestibility, and yield change over the duration from half-milk line through black layer. Digestibility of the corn plant decreased as corn plant maturity and NDF content increased. The lower leaf in the normal season plot decreased in digestibility, but did not change in the short season plot. Little change was observed in the digestibility of the internodes across time. The NDF content of the upper plant increased in both plots. The internodes increased in NDF content across time in both plots. The results …

Digestibility Of Calcium Oxide Treated Corn Residue With De-Oiled Distillers Grains, Sarah J. Peterson, Meredith L. Bremer, Adam L. Shreck Shreck, James C. Macdonald, Galen E. Erickson

Nebraska Beef Cattle Reports

A digestion study was conducted to evaluate diets containing calcium oxide treated corn residue in combination with de-oiled distillers grains in forage based growing diets. Chemical treatment did not affect digestibility of DM, OM, or NDF. However, concentration of distillers grains did improve DM and OM digestibility. The use of chemically treated residue in combination with distillers grains in growing diets may not impact diet digestibility.

Effects Of Dietary Fat Source And Monensin On Methane Emissions, Vfa Profile, And Performance Of Finishing Steers, Anna C. Pesta, Andrea K. Watson, Robert G. Bondurant Bondurant, Samodha C. Fernando, Galen E. Erickson

Nebraska Beef Cattle Reports

A finishing study was conducted to evaluate the effects of dietary fat source and presence or absence of monensin on performance, methane (CH4) emissions, and ruminal VFA profile of cattle. No effects on performance or VFA profile were observed. Inclusion of modified distillers grain plus solubles (MDGS) in the diet tended to increase measures of CH4 production when compared to other fat sources (corn oil or tallow), while inclusion of monensin in the finishing diet was not significant for CH4 production.

Impact Of Heifer Development System On Subsequent Gain And Reproduction, Hazy R. Nielson, John D. Harms, Adam F. Summers Summers, Rebecca A. Vraspir, Rick N. Funston

Nebraska Beef Cattle Reports

Replacement heifers from 2 different calving herds (March and May) were fed ad libitum hay and 4 lb of supplement/day, or were allowed to graze meadow and received 1 lb of supplement/day from mid-January to mid-April prior to both breeding seasons. Heifers from both calving herds that received hay had a greater average daily gain during the treatment period compared with meadow grazing heifers. However, heifers grazing meadow experiencedcompensatory gain during their respective breeding season, resulting in similar body weights at pregnancy diagnosis for March-calving heifers. The proportion of heifers that attained pubertybefore breeding and became pregnant was similar between …

A Comparison Of Two Implant Protocols: Synovex-Choice/Synovex-Plus Vs. Synovex-S/Revalor-S On Steer Feedlot Performance And Carcass Characteristics, Hazy R. Nielson, Adam F. Summers, Rick N. Funston Funston

Nebraska Beef Cattle Reports

In a 2 year study, implant strategies were compared utilizing Synovex® Choice followed by Synovex Plus® or Synovex® S followed by Revalor® S. Spring-born crossbred steers were blocked by BW and randomly assignedto receive either Synovex Choice or Synovex S as the initial implant. Approximately100 days later, steers were reimplanted with Synovex Plus or Revalor S. Steers were slaughtered after 205 days on feed. There was no difference in average daily gain or hot carcass weight between treatment groups. Furthermore, there were no differences in yield grade, marbling score, or proportion of steers grading USDA Choice. Both implant regimens resulted …

Effects Of Ingestion And Collection Bag Type On Nutrient Composition Of Forage Samples From Esophageally Fistulated Cattle, Jacqueline A. Musgrave, Jared Judy, Aaron Stalker Stalker, Terry Klopfenstein, Karla Jenkins

Nebraska Beef Cattle Reports

Ingestion and mastication of forage samples adds ash. Generally, levels of CP were lower and NDF and IVOMD were similar for post-ingested versus pre-ingestedforage. Bag type (screen vs. solid) generally did not affect ash, NDF, or IVOMD. Bag did not affect CP of alfalfabut CP of grass samples from screen bags was lower than solid bags. More fresh than dry forage was recovered through the esophageal opening.

Effect Of Diet On The Rumen Microbial Community Composition Of Growing Cattle And The Role It Plays In Methane Emissions, Allison L. Knoell, Christopher L. Anderson, Anna C. Pesta Pesta, Galen E. Erickson, Terry J. Klopfenstein, Samodha C. Fernando

Nebraska Beef Cattle Reports

To understand the relationship betweenmicrobial community and methane, the microbial community of the rumen was examined by esophageally tubing cattle on a common diet and on 10 treatment diets. Microbial community analysis via 16S taq sequencing displayed structuring of microbial communities (Bacteria and Archaea) by diet. This study demonstrates that diet influences microbial community composition within the rumen, and the potential capacity to develop dietary interventionstrategies for methane mitigation and animal performance.

Effects Of Grazing On Nebraska Sandhills Meadow Forage Nutrient Content, Jared V. Judy, Jacki A. Musgrave, L. Aaron Stalker Stalker, Karla H. Jenkins, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

Nebraska Sandhills subirrigated meadow pastures were used to measure the effects of grazing on forage nutrient content in summer pastures. Non-grazed pastures had greater diet CP content than grazed pastures early in the grazing season. By late July, grazed vs. non-grazed pastures did not differ in diet CP content. Non-grazed pastures had greater in vitro organic matter disappearance compared with grazed pastures from late July through September; however, early summer pastures were not affected. Observed results indicate the greatest differences in nutrient content between grazed and non-grazed meadow pastures occur early and late in the grazing season when the majority …

Dried Distillers Grains Supplementation Of Calves Grazing Irrigated Corn Residue, Mandi Jones, James C. Macdonald, Galen E. Erickson Erickson, Terry J. Klopfenstein, Robby Bondurant

Nebraska Beef Cattle Reports

Steer calves grazing irrigated corn residue received supplementation of dried distillers grains plus solubles (DGS) at 0.3, 0.5, 0.7, 0.9, or 1.1% of body weight. Steers were individually supplemented daily through Calan gates. Daily gain improved linearly (0.77 lb/head/day to 2.21 lb/head/day) with increasing supplementation (1.5 lb/day to 7 lb/day). Supplementing DGS to calves grazing corn residue increased gain during the winter period.

Evaluation Of Changes In Nutritional Quality Of Corn Residue Over Time, Mandi Jones, James C. Macdonald, Terry J. Klopfenstein Klopfenstein, Galen E. Erickson, Keith Glewen, Andrea K. Watson

Nebraska Beef Cattle Reports

Irrigated corn residue was sampled across time in order to determine changes in quality and proportion of corn residue as the plant dried and was exposed to effects of weathering. Corn plants from two hybrids were planted on two different planting dates and harvested at periodic intervals from August 2012 to December 2012. Proportions of stem, blade/sheath, husk/shank, and cob made up smaller components of total plant DM as it matured, with the largest relative reduction occurring in the blade/sheath or stem. Hybrid impacted TDN values primarily because the 119 day hybrid was less mature at the early sampling dates.

Efficacy Of Bovatec 2.2 Mineral Blocks For Cattle Grazing Crested Wheatgrass Pastures, Karla H. Jenkins, Jacob A. Hansen, Matt K. Luebbe Luebbe

Nebraska Beef Cattle Reports

A grazing study was conducted to determine if providing Bovatec® in a trace mineralized salt block would improve cattle performance over cattle provided a trace mineralized salt block without an ionophore while maintaining block consumption below 2 oz/head/day. Average daily block intake was 1.40 and 1.25 oz/day for the Bovatec and control cattle, respectively. Lasalocid consumption was 193 mg/head/day. Although cattle consuming the Bovatec block gained 5% more than the control cattle, this was not significant (1.75 vs 1.67 lb/day, respectively). Supplying an ionophore through a self-feeding block may not improve gain compared to supplying mineral alone in a self-feeding …

Using Enspira To Improve Fiber Digestion, Jana L. Harding, Adam L. Shreck, Melissa L. Jolly-Breithaupt Breithaupt, Galen E. Erickson, James C. Macdonald

Nebraska Beef Cattle Reports

A metabolism study was conducted to evaluate the effects of supplementing a fibrolytic enzyme (Enspira™) on total tract digestion of a finishing diet. In situ NDF digestibilities of the corn bran, HMC, corn residue, and corn silage were not different between the treatments. Rate of digestion of the corn residue and corn silage was lower for the enzyme treatment compared to the control. Averageruminal pH was not significantly different between the two treatments. Correspondingly, there was no difference in VFA profile. There were no differences in DM, OM, NDF, ADF, or hemicellulose digestibilities between the control and enzyme treatment.

Effects Of Replacing Corn With A Pelleted Treated Corn Stover And Distillers Grains On Performance Of Finishing Cattle, Jana L. Harding, Curtis J. Bittner, Dirk B. Burken Burken, Galen E. Erickson, James C. Macdonald

Nebraska Beef Cattle Reports

A finishing study evaluated the effectsof replacing 10, 20, or 30% corn (DM basis) with pelleted treated corn stover and distillers grains in a diet containing either 20 or 40% modified distillers grains plus solubles (MDGS) on finishing cattle performance. Steers consuming 10, 20, or 30% of the pelleted feed with 40% MDGS had equal or similar performance to the control diet with 40% MDGS. Cattle consuming 10% pelleted feed with 20% MDGS had similar efficiencies as the control diet; however, feeding the pellet at 20 or 30% of the diet DM with 20% MDGS decreased feed efficiency.

Effect Of Corn Residue Removal On Subsequent Crop Yields, Mary E. Drewnoski, L. Aaron Stalker, James C. Macdonald Donald, Galen E. Erickson, Kathy J. Hanford, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

Two studies were conducted to evaluate the effects of corn residue harvest on subsequent crop yields. In a long-term study (16 years), cattle grazing corn residue in the spring (February to the middle of April) or the fall (November through January) slightly improved subsequent soybean yields and had no effect on corn yields in an irrigated field maintained in an annual corn-soybean rotation at Mead, Neb. In a five-year study, fall grazing (December through January) or baling of corn residue had no effect on subsequent corn grain yields in a field maintained in continuous corn production at Brule, Neb. These …

Effect Of Feeding Distillers Grains In Different Phases Of Production On The Fatty Acid Profile And Oxidation Of Frozen, Cooked Beef Links, Brandy D. Cleveland, Amy L. Redfield, James C. Macdonald Donald, Tommi F. Jones, Gary A. Sullivan

Nebraska Beef Cattle Reports

Lipid oxidation of cooked ground beef links made from cattle fed different diets and with different concentrations of added natural antioxidants was compared to evaluate product shelf life. Fatty acid composition was analyzed on raw lean, composite, and fat portions from each shoulder clod. Samples without antioxidants were the most oxidized, with no differences between other antioxidant concentrations throughout frozen storage. An increase in polyunsaturated fatty acids was found in beef when finished on modified distillers grains but did not result in increased oxidation. Therefore, the addition of natural antioxidants was effective at reducing oxidative rancidity regardless of animal diet.

A Basic Mechanism Of Beef Tenderization: Feeding Wet Distillers Grains Plus Solubles Contributes To Sarcoplasmic Reticulum Membrane Instability, Michael D. Chao, Katherine I. Domenech, Chris R. Calkins Calkins

Nebraska Beef Cattle Reports

Feeding wet distillers grains plus solubles (WDGS) could increase polyunsaturated fatty acid (PUFA) concentration in the sarcoplasmic reticulum (SR) membrane, thereby altering membrane integrity, resulting in more rapid post-rigor calcium leakage, greater enzyme activity and improved tenderness. Steers were finished on either 0% WDGS or 50% WDGS. Steaks from steers fed WDGS were more tender and had greater free calcium concentrations. Feeding WDGS also increased proportions of PUFA in SR membrane and altered SR lipid and phospholipid profiles. These findings suggest that feeding increased concentrations of WDGS in the finishing diet can possibly increase meat tenderness through the proposed mechanism.

Feeding Elevated Levels Of Corn Silage And Mdgs In Finishing Diets, Dirk B. Burken, Brandon L. Nuttelman, Curtis J. Bittner Bittner, Terry J. Klopfenstein, Galen E. Erickson

Nebraska Beef Cattle Reports

A finishing experiment evaluated substitution of corn silage and modified distillers grains with solubles (MDGS) in place of corn. The experimental arrangementwas a 2 X 2 + 1 factorial with diets containing 15 or 45% corn silage and 20 or 40% MDGS as well as a control containing 5% cornstalks and 40% MDGS. There were no interactions between corn silage and MDGS inclusion for carcass adjusted performance. As corn silage inclusion increased in the diet, there was a modest reduction in ADG and an increase in F:G. When MDGS inclusion was increased, ADG and F:G were improved. Cattle fed 40% …

The Effects Of Corn Price, Shrink, And Harvest Moisture On Corn Silage Economics, Dirk B. Burken, Terry J. Klopfenstein, Galen E. Erickson Erickson

Nebraska Beef Cattle Reports

Economic assumptions were applied to corn production to set corn silage prices for breakeven corn production, whether harvested for corn grain or corn silage. Price levels were used for the calculation of returns per finished steer as corn silage inclusion increased in finishing diets containing distillers grains. As corn price increased, the economics of feeding elevated concentrations of corn silage became more favorable. The economic importance of shrink and harvest moisture content were assessed. As corn price increases and the inclusion of corn silage increases, corn silage management decisions have greater economic importance.