Animal Sciences Commons^™

Genetic Parameter Estimates And Breed Effects For Calving Difficulty And Birth Weight In A Multi-Breed Population, Cashley Ahlberg

Department of Animal Science: Dissertations, Theses, and Student Research

There are multiple breeds of beef cattle available to utilize in breeding systems to maximize production and economics. Calving difficulty (dystocia) is a significant cost to beef production and is more prevalent in first-calf heifers. The objectives of this study were to estimate genetic parameters and breed differences for calving difficulty and birth weight as a first step towards the development of across-breed adjustment factors for calving difficulty.

Two models were employed to analyze birth weight (BWT) and calving difficulty (CD) recorded on 4,579 first parity females from the Germplasm Evaluation program at the U.S. Meat Animal Research Center (USMARC). …

Glucose Significantly Enhances Enterotoxigenic Escherichia Coli Adherence To Intestinal Epithelial Cells Through Its Effects On Heat-Labile Enterotoxin Production, Prageeth Wijemanne, Rodney A. Moxley

School of Veterinary and Biomedical Sciences: Faculty Publications

The present study tested whether exposure of enterotoxigenic Escherichia coli (ETEC) to glucose at different concentrations in the media results in increased bacterial adherence to host cells through increased heat-labile enterotoxin (LT) production, thereby suggesting the effects are physiological. Porcine-origin ETEC strains grown in Casamino acid yeast extract medium containing different concentrations of glucose were washed and inoculated onto IPEC-J2 porcine intestinal epithelial cells to test for effects on adherence and host cell cAMP concentrations. Consistent with previous studies, all LT+ strains had higher ETEC adherence to IPEC-J2 cells than did LT2 strains. Adherence of the LT2 but not the …

Nebraska Bqa: Antibiotic Use Guidelines, Rob Eirich

Nebraska Beef Quality Assurance Program

Cattlemen have demonstrated a commitment to animal health through vaccination programs developed carefully in cooperation with their veterinarian. When animals must be treated with an antibiotic after disease diagnosis, producers need to follow important antibiotic use guidelines established through the National Beef Quality Assurance (BQA) program.

Nebraska Bqa: Effective Cattle Handling, Rob Eirich

Nebraska Beef Quality Assurance Program

Cattlemen know the importance of proper cattle handling and its effect on animal health and performance. Beef Quality Assurance has been implementing effective cattle handling (low-stress) into educational programs since its establishment in the 1980s.

Handling Cattle Through High Heat Humidity Indexes, Rob Eirich

Nebraska Beef Quality Assurance Program

As cattlemen enter the summer months, they need to understand and deal with heat and humidity. Consider incorporating the following practices into management plans to help reduce additional stress.

Nebraska Bqa: Handling Compromised Animals, Rob Eirich

Nebraska Beef Quality Assurance Program

Cattle producers have long recognized the need of proper husbandry and stewardship for the animals entrusted into their care. Best livestock production practices, based on research and sound science, help ensure the well-being, animal health and productivity of cattle.

Calf Branding/Processing Time And Beef Quality Assurance, Rob Eirich

Nebraska Beef Quality Assurance Program

It is spring and that means branding time across cattle country. As producers are finishing calving season and preparing for branding/processing, it is important to review Beef Quality Assurance (BQA) guidelines. Let's take a minute to look at the key BQA principles:

Audits And Assessments In Beef Cattle Production, Rob Eirich

Nebraska Beef Quality Assurance Program

Assessments and audits are becoming a part of doing business in beef cattle production, as we are seeing beef processors implementing third-party audits. Since beginning as the Nebraska Director of Beef Quality Assurance (BQA) in July, I have been studying and gathering information on the National Cattlemen's Beef Association (NCBA) Assessment Guides and third-party audits in the beef industry.

Nebraska Beef Quality Assurance: Focused On The Safety, Wholesomeness And Quality Of Beef

Nebraska Beef Quality Assurance Program

Across the nation, beef producers face the challenge of making a living from the land, while producing safe, wholesome beef. Beef that will provide a great eating experience each and every time for American and International consumers.

Effects Of Dietary Change On Viral-Bacterial Interactions In The Rumen Of Cattle, Christopher L. Anderson, Melissa L. Jolly, Adam L. Shreck Shreck, Galen E. Erickson, Terry J. Klopfenstein, Samodha C. Fernando

Nebraska Beef Cattle Reports

This ongoing study investigates the impact of diet and bacteriophage activity on the structuring of rumen microbial community composition and diversity. Fistulated cattle were acclimated to a given diet for 21 days before samples were collected and subsequently enriched for viral particles with tangential flow filtration. Taxonomic identification, abundance, and functional attributes were assigned to both bacterial and viral communities. Principle coordinate analysis of the bacterial communities revealed significant clustering based on diet. While diet drives the structuring of rumen bacterial communities, bacteriophages may maintain high, constant bacterial diversity.

Vein Steak Differences In Strip Loins Of Heifers Due To Mutation Of The Myostatin Gene, Michelle E. Semler, Chris R. Calkins, Galen E. Erickson Erickson

Nebraska Beef Cattle Reports

Strip loins from heifers with variations of the myostatin gene; 19 homozygous dominant (Angus), 20 heterozygous dominant (Angus x Piedmontese), and 20 homozygous recessive (Piedmontese) were studied. Strip loins were cut into 1-inch thick steaks and total number of steaks and number of steaks with Gluteusmedius (often called vein steaks) were recorded. Strip loins from heterozygous dominant heifershad a greater number of non-vein steaks and decreased percentage of vein steaks compared to homozygous dominant and homozygous recessive samples. Differences in percentage of vein steaks were inconsistent and showed no meaningful pattern.

Energy Value Of De-Oiled Modified Distillers Grains Plus Solubles In A Forage-Based Diet, Meredith L. Bremer, Andrea K. Watson, Dirk B. Burken Burken, James C. Macdonald, Galen E. Erickson

Nebraska Beef Cattle Reports

Sixty individually fed steers were used to determine the effects of feeding de-oiled modified distillers grains plus solubles (MDGS) on steer performance in an 84-day forage-based growing study. De-oiled MDGS did not significantly alter performance when compared to normal MDGS if fed at the same concentration in growing diets. Inclusion of either de-oiled or normal MDGS at 40% of the diet resulted in improved ending BW, DMI, ADG, and F:G as compared to inclusion of 20% MDGS in the diet.

Transitioning Cattle From Ramp® To A Finishing Diet On Feedlot Performance And Feed Intake Variance, Cody J. Schneider, Brandon L. Nuttelman, Dirk B. Burken Burken, Terry J. Klopfenstein, Galen E. Erickson

Nebraska Beef Cattle Reports

Individually fed cattle were adapted to high grain diets with a traditional grain adaptation program or one of two RAMP^® adaptation programs. RAMP programs adapted cattle to a finishing diet gradually over 28 days in four steps or directly without an adaptation. Feed intake variance among d was greater for traditionally adapted cattle compared to either RAMP program, but DMI was not different during the adaptation period. Over the 138-day period, feedlot performance and carcass traits were not affected by adaptation treatment. Cattle fed RAMP for 10 days can be transitioned to a finishing ration containing 47.5% Sweet Bran …

Using Enspira™ To Improve Fiber Digestion, Jana L. Harding, Galen E. Erickson, James C. Macdonald Donald

Nebraska Beef Cattle Reports

Two experiments evaluated the effectof treating various feedstuffs with an enzyme(Enspira) on digestibility. Twelve feeds commonly fed to beef cattle were treated with four levels of the enzyme(0, 0.25, 0.50, or 0.75 lb of enzyme per ton of DM). Enzyme treatment increased in vitro DMD of high moisture corn (HMC), wet distillers grains plus solubles (WDGS), corn bran, and husks. There was a quadratic increasein gas production for corn leaves, as well as a linear increase in gas production for corn bran treated with increasing levels of Enspira. Treating feeds with the commercial enzyme Enspiraimproved in vitro digestibility of feeds …

Nutrient And Tenderness Differences Of Beef From Heifers Due To Mutation Of The Myostatin Genehypothesized, Michelle E. Semler, Chris R. Calkins, Galen E. Erickson Erickson

Nebraska Beef Cattle Reports

Strip loins and eye of rounds were obtained from heifers genotyped with variations of the myostatin gene; 19 homozygous dominant (Angus), 20 heterozygous dominant (Angus x Piedmontese), and 20 homozygous recessive (Piedmontese). Steaks were aged for 14 days, cooked fresh (never frozen), and nutrient steaks were frozen three days postmortem. Meat from homozygous recessive heifers was equal in tenderness to homozygous dominant and heterozygous dominant heifers. Fat content of meat from homozygous recessive heifers decreased while moisture and protein increased compared to homozygous dominant and heterozygous dominant. Calorie content decreased with increasing copies of the recessive gene. Thus, meat from …

Effect Of Feeding De-Oiled Wet Distillers Grains Plus Solubles On Beef Oxidation And Tenderness, Katherine I. Domenech, Kim A. Varnold, Michelle E. Semler, Michael D. Chao, Tommi F. Jones, Galen E. Erickson, Chris R. Calkins

Nebraska Beef Cattle Reports

Cattle fed a de-oiled wet distiller’s grains plus solubles (WDGS) diet were compared to cattle fed corn or traditional (full-fat) WDGS diets to determine effects on discoloration, oxidation, and tenderness of beef aged for seven and 21 days. At seven days of aging, dietary treatment had no effect on discoloration. At 21 days of aging, beef from cattle fed de-oiled WDGS had less oxidation than the corn control and several of the full-fat WDGS treatments. Although tenderness increased with aging and retail display, dietary treatment had no effect on tenderness. These findings suggest that these dietary treatments, followed by a …

Effects Of Feeding Distillers Grains In A Yearling Beef System On Meat Quality, Kelby M. Sudbeck, Kimberly A. Varnold, James C. Macdonald Donald, Chris R. Calkins, Galen E. Erickson

Nebraska Beef Cattle Reports

Distillers grains use while wintering on cornstalks during summer grazing and during the finishing period was evaluated to determine the effects of lifetime exposure to distillers grains on meat characteristics. Finishing diets with distillers grains increased discoloration in steaks following six days of retail display for steaks aged seven days, and after four days of retail display for steaks aged 21 days. Supplementation during summer grazing increased discoloration when cattle were not finished using distillers grains. There were no differences in oxidative rancidity among dietary treatments. Supplementing with distillers grains prior to finishing was not additive in impacting the color …

Differences In Fecal Bacterial Community Composition Between Beef Steers Which Are High-Shedders And Low-Shedders Of Shiga Toxin-Producing Escherichia Coli (Stec), Nirosh D. Aluthge, Yoshitha A. Wanniarachchi, Brandon L. Nuttelman Nuttelman, Cody J. Schneider, Terry J. Klopfenstein, Galen E. Erickson, Samodha C. Fernando

Nebraska Beef Cattle Reports

The community composition of the fecal microbiota was compared between beef steers which were high-shedders and low-shedders of Shiga toxin-producing Escherichia coli. Based on Shannon and Chao 1 diversity indices, the high-shedders had a more diverse fecal bacterial community than the low-shedding steers. Members of the genus Prevotella were observed as being more abundant in the low-shedders compared to the high-shedders, while Succinivibrio were more abundant in the high-shedders. Isolation of specific bacteria which are significantly more abundant in low-shedders may pave the way to developing direct-fed microbials which are effective in reducing STEC shedding among high-shedding beef steers.

Follicular Vascular Endothelial Growth Factor A Expression Before And After The Lh Surge, Renee M. Mcfee, Robin A. Artac, Adam F. Summers, William E. Pohlmeier, Vanessa M. Brauer, Scott G. Kurz, Robert A. Cushman, Jennifer R. Wood, Andrea S. Cupp

Nebraska Beef Cattle Reports

Granulosa cell expression of VEGFAisoforms in dominant bovine follicles was evaluated. Collection of granulosa cells via follicle aspiration revealed altered expression of the proangiogenic VEGFA_164 isoform but not the antiangiogenic VEGFA_164B isoform prior to and after the LH surge. Expression of VEGFA_164 declines as both the LH surge and ovulation approaches. In addition, VEGFA_164 and VEGFA_164B expression prior to the LH surge was positively correlated with FSHR and CYP19A1 expression, suggesting that VEGFA expression may be regulated by FSH. These data indicate differential expression of VEGFA isoforms may be an important feature of bovine dominant follicle development.

Androgen Excess In Beef Cows Results In Altered Theca Cell Gene Expression And Fertilityand, Adam F. Summers, William E. Pohlmeier, Vanessa M. Brauer Brauer, Kevin M. Sargent, Renee M. Mcfee, Scott G. Kurz, Robert A. Cushman, Jennifer R. Wood, Andrea S. Cupp

Nebraska Beef Cattle Reports

Within the University of Nebraska–Lincoln physiology herd, two sub-populations of cows with different concentrations of androstenedione have been identified. Androstenedione is a precursor for estradiol production, and androstenedione concentration is increased 24.5-fold in the high androstenedione cows. Our objective was to determine the cause of increased androstenedione production in high androstenedione cows and the effects on theca cell and oocyte gene expression. High androstenedione cows had increased steroidogenic enzyme abundance in theca cells and altered oocyte mRNA abundance. Increased androgen production in high androstenedione cows is associated with altered gene expression and/or mRNA stability during oocyte growth and maturation, which …

Effect Of Pubertal Status And Number Of Estrous Cycles Prior To The Breeding Season On Pregnancy Rate In Beef Heifers, Rebecca A. Vraspir, Adam F. Summers, Andrew J. Roberts Roberts, Rick N. Funston

Nebraska Beef Cattle Reports

Three experiments were conducted to evaluate whether pubertal status and number of estrous cycles prior to breeding influences pregnancy rate in beef heifers. Pubertal heifers were heavier and older at the start of breeding and had greater AI and overall pregnancy rate than non-pubertal heifers. Second season pregnancy rate was greater for heifers reaching puberty prior to first breeding and for heifers having ≥ 2 estrouscycles prior to breeding compared with non-pubertal heifers. Pregnancy rate was greater for heifers achieving puberty prior to breeding; however, earlier onset of puberty did not significantly improve first pregnancy rates.

Economics Of Distillers Grains Supplementation In A Forage System With Spayed Heifers, Kari L. Gillespie, Terry J. Klopfenstein, James C. Macdonald Donald, Brandon L. Nuttelman, Cody J. Schneider, Galen Erickson, J. D. Volesky

Nebraska Beef Cattle Reports

In a two-year study, spayed heifer calves were backgrounded on cornstalks with 2 lb or 5 lb wet distillers grains with solubles supplemented daily. During the summer, heifers grazed native range and received no summer supplementation or were supplemented with modified distillers grains with solubles at 0.6% BW daily. Heifers were finished on a common regimen, and an economic scenario was applied to each phase of production and overall. Supplementing more in winter increased profit, but summer supplementation did not impact overall profitability. Numerically, heifers not supplemented during the summer were more profitable than supplemented heifers.

Distillers Grains Supplementation In A Forage System With Spayed Heifers, Kari L. Gillespie, Terry J. Klopfenstein, James C. Macdonald Donald, Brandon L. Nuttelman, Cody J. Schneider, Jerry D. Volesky, Galen Erickson

Nebraska Beef Cattle Reports

Spayed heifers were developed into yearlings by grazing corn residue and bromegrass, followed by native range, and were finished on a common diet. Treatments were 2 lb or 5 lb of wet distillers grains with solubles (WDGS; DM basis) supplement on corn residue daily, and modified distillers grains with solubles (MDGS) fed at 0.6% BW daily or no MDGS during summer grazing. Feeding 5 lb increased winter ADG by 0.68 lb (year 1) or 0.40 lb (year 2) compared to 2 lb, and increased HCW after finishing. Summer supplementation increased summer ADG by 0.50 lb (year 1) or 0. 44 …

Effects Of Calf Age At Weaning On Cow And Calf Performance And Efficiency In A Drylot/Confinement Production System, Jason M. Warner, Karla H. Jenkins, Rick J. Rasby, Matt K. Luebbe, Galen E. Erickson, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

An ongoing study evaluated the effectsof calf age at weaning on cow and calf performance and reproduction in a confinement production system. Early-weaning improved cow BW at normal weaning. Pregnancy rates were not impacted by calf age at weaning. Dry matter intake was not different between early-weaned cows and calves compared with normal-weaned pairs. Feed requirements and energy utilization were equal between early- and normal-weaned pairs when fed a distillers grains and crop residue based diet.

Impact Of Supplemental Protein Source On Pregnant Beef Heifers, Adam F. Summers, T. L. Meyer, Michael F. Kirby Kirby, Jim R. Teichert, Rick N. Funston

Nebraska Beef Cattle Reports

Crossbred, AI-pregnant heifers were fed in a Calan Broadbent individual feeding system for 110 days beginning at approximately day 142 of gestation. Heifers were offered ad libitum grass hay and no supplement, hay plus distillers based supplement, or hay plus dried corn gluten based supplement. Supplements were isocaloric, isonitrogenous, and equal in lipid content but differed in rumen undegradable protein. Protein supplementation increased DMI and ADG in pregnant heifers; however, calf birth BW and subsequent pregnancy rates were similar.

Preconception Distillers Grains Supplementation Improves Mature Beef Cow Return To Estrous, Adam F. Summers, Daniel M. Larson, Andrea S. Cupp Cupp

Nebraska Beef Cattle Reports

For three years, cows and first-calf heifers were supplemented two levels of RUP prior to breeding to determine the effect of RUP on reproductive efficiency and performance. Cows resumed estrous after being supplemented 30 days with distillers grains, but pregnancy rate was not different. First-calf heifer performance and reproductive efficiency was similar regardless of protein supplement offered. Protein supplements offered in this study did not impact cow BW, milk production, or progeny performance. More cows supplemented with distillers grains prior to the breeding season resumedluteal activity prior to breeding; however, pregnancy rates were similar.

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

Nebraska Beef Cattle Reports

A finishing experiment evaluatedsubstitution of corn silage and modified distillers grains with solubles (MDGS) in place of corn. The treatment arrangementwas a 2 X 2 + 1 factorial with 15 or 45% corn silage and 20 or 40% MDGS plus a control containing 5% cornstalks and 40% MDGS. There were interactions between corn silage and MDGS for carcass adjusted performance. As corn silage inclusion was increased in the diet, F:G increased when fed with 20% MDGS, however there was no difference when fed with 40% MDGS.

Effects Of A Terminal Sorting System With Zilpaterol Hydrochloride On Feedlot Steers, F. Henry Hilscher, Dirk B. Burken, Brandon L. Nuttelman Nuttelman, Galen E. Erickson, Kathy Hanford, Kyle J. Vander Pol, John P. Hutcheson

Nebraska Beef Cattle Reports

Crossbred yearling steers were utilized to evaluate the effects of Zilpaterol hydrochloride (Zilmax^®) and terminal sorting 50 days prior to harvest on feedlot performance and carcass characteristics. Four treatments were used: an unsorted group not fed Zilmax (–CON), an unsorted group fed Zilmax, sorting by weight into two market groups and fed Zilmax, or sorting by weight into four market groups and fed Zilmax (4-Sort). Carcass weight was increased in cattle fed Zilmax by 33 lb and was further increased by 9 lb by 4-SORT. Yield grade and marbling score were lower for all cattle fed Zilmax compared …

Transitioning Cattle From Ramp® To A Finishing Diet On Feed Intake And Ruminal Ph, Cody J. Schneider, Adam L. Shreck, Terry J. Klopfenstein Klopfenstein, Galen E. Erickson

Nebraska Beef Cattle Reports

A metabolism trial was conducted where steers were adapted to high grain diets using a traditional approach or one of two RAMP^® adaptation programs. RAMP programs adapted cattle to a finishing diet either gradually over 28 days in four steps or switched to a finishing ration without steps. Feed intake and ruminal pH were monitored continuously throughout the trial. Cattle on the 4-STEP treatment spent more time eating compared to other treatments but total feed consumption was similar among treatments. Ruminal pH was greater for cattle on RAMP adaptation programs when compared to traditional grain adaptation. Cattle fed RAMP …

Alkaline Treated Wheat Straw Or Corn Stover Fed To Growing Calves, Adam L. Shreck, Brandon L. Nuttelman, Cody J. Schneider Schneider, Dirk B. Burken, Casey N. Macken, William A. Griffin, Galen E. Erickson, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

Four hundred sixty steer calves were fed CaO treated (5% of DM) or untreated wheat straw and corn stover with wet distillers grains plus solubles (WDGS) during a 69-day growing study. An interaction between crop residue and alkaline treatment was observed for ending BW and ADG. The relative response in ADG and ending BW due to alkaline treatment was greater for wheat straw compared to corn stover. Steers fed wheat straw diets had greater DMI and improved F:G compared to corn stover diets. Alkaline treatment increased DMI and improved F:G, although the F:G response was small. Growing calves on untreated …