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1998

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Articles 181 - 210 of 422

Full-Text Articles in Animal Sciences

A Study On The Zooplanktonic Fauna Of The Dam Lakeskunduzlar And Çatören (Kırka-Eskişehir), Ahmet Altindağ, Şakir Özkurt Jan 1998

A Study On The Zooplanktonic Fauna Of The Dam Lakeskunduzlar And Çatören (Kırka-Eskişehir), Ahmet Altindağ, Şakir Özkurt

Turkish Journal of Zoology

In the present study, the zooplanktonic fauna of the Kunduzlar and Çatören dam lakes (Kirka basin-Eskişehir) was investigated during August 1994-June 1995. Eight species of Rotifera, five species of Cladocera and two species of Copepoda were identified in both dam lakes. In addition, the mean zooplankton abundance (ind. m -3 ) and physical and chemical parameters of dam lakes were given.

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Calving Difficulty And Calf Response To Stress, Todd Cappel, Andrea Bueno, Edd Clemens Jan 1998

Calving Difficulty And Calf Response To Stress, Todd Cappel, Andrea Bueno, Edd Clemens

Nebraska Beef Cattle Reports

Calving difficulty altered the stress-related capabilities of the calf, placing the newborn in a compromised situation. Calves derived by severe mechanical pull or cesarean section exhibited depressed short-term defensive capabilities, lower cortisol and elevated neutrophil values, necessary for fighting infectious organisms. Of equal concern: when compared to calves born with little or no parturition difficulty, the stressed calves failed to develop effective adaptive mechanisms, having lower thyroid activity and lymphocyte values of principle importance for long-term survival. Neither the heifer’s mothering ability nor her disposition tended to influence her calf’s stress indicators.

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Effects Of Luteinizing Hormone Releasing Hormone Antagonist On The Bovine Corpus Luteum, Debra T. Clopton, Jorge Quintal, Freddie Kojima, Karol Fike, Jim Kinder Jan 1998

Effects Of Luteinizing Hormone Releasing Hormone Antagonist On The Bovine Corpus Luteum, Debra T. Clopton, Jorge Quintal, Freddie Kojima, Karol Fike, Jim Kinder

Nebraska Beef Cattle Reports

The size and function of the corpus luteum were examined after administration of luteinizing hormone releasing hormone antagonist. Luteinizing hormone releasing hormone antagonist was administered to three animal groups starting: 1) 2 days before the preovulatory luteinizing hormone surge inducing ovulation; 2) at initiation of the preovulatory surge; and 3) 2 days after the preovulatory surge. Although size and function of the corpus luteum were suppressed in all treated groups, the greatest developmental suppression occurred when luteinizing hormone release was blocked 2 days before the preovulatory surge of LH inducing ovulation. Therefore, optimal pregnancy rates in cattle may depend on …

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Observations On Acidosis Through Continual Feed Intake And Ruminal Ph Monitoring, Rob Cooper, Terry J. Klopfenstein, Rick Stock, Cal Parrott Jan 1998

Observations On Acidosis Through Continual Feed Intake And Ruminal Ph Monitoring, Rob Cooper, Terry J. Klopfenstein, Rick Stock, Cal Parrott

Nebraska Beef Cattle Reports

A system of continual data acquisition of feed intake and ruminal pH has been developed for studying subacute acidosis in finishing steers. Feed intake is monitored with feedbunks which are suspended from weigh cells. Ruminal pH is monitored with submersible pH electrodes suspended in the rumen. Numerous anecdotal observations of subacute acidosis have been made throughout the feeding periods of several steers, providing information unlikely to be recognized during a planned trial. Therefore, this model for studying subacute acidosis offers many unique opportunities for enhancing our understanding of the interactions between feed intake and acidosis.

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Effects Of Feed Intake Variation On Acidosis And Performance Of Finishing Steers, Rob Cooper, Terry J. Klopfenstein, Rick Stock, Cal Parrott, Dan Herold Jan 1998

Effects Of Feed Intake Variation On Acidosis And Performance Of Finishing Steers, Rob Cooper, Terry J. Klopfenstein, Rick Stock, Cal Parrott, Dan Herold

Nebraska Beef Cattle Reports

Four metabolism and two finishing trials were conducted to determine the effects of imposed feed intake variation on acidosis and performance of finishing steers. In metabolism trials, intake variation of 3 lb DM/day increased acidosis of limit-fed steers as measured by ruminal pH. However, when steers were fed at ad libitum levels of intake, intake variation of up to 4 lb DM/day did not increase acidosis. In finishing trials, imposed intake variation of 4 lb DM/day neither decreased daily gain nor feed efficiency of steers fed at ad libitum levels of intake.

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Effect Of Winter Gain On Summer Rate Of Gain And Finishing Performance Of Yearling Steers, Dale Downs, Galen E. Erickson, Don C. Adams, Terry J. Klopfenstein Jan 1998

Effect Of Winter Gain On Summer Rate Of Gain And Finishing Performance Of Yearling Steers, Dale Downs, Galen E. Erickson, Don C. Adams, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

The effect of winter rate of gain on subsequent grazing and finishing performance was evaluated using 80 medium- framed steers. During the winter period, steers were fed to achieve gains of approximately .7 (low gain; 40 head) or 1.7 lb/day (high gain; 40 head). Warm-season Sandhills range was grazed by 20 low-gain and 20 high-gain steers, while the other 40 grazed bromegrass pasture from May to September. Both low- and high-gain cattle grazing brome pasture gained slower than those grazing sandhills range. During summer grazing, low-gain cattle gained faster than high-gain cattle, but compensated for only 19.9% (sandhills) and 18.7% …

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Evaluation Of 1996 Nrc For Protein And Phosphorus Requirements Of Finishing Cattle, Galen E. Erickson, Todd Milton, Terry J. Klopfenstein Jan 1998

Evaluation Of 1996 Nrc For Protein And Phosphorus Requirements Of Finishing Cattle, Galen E. Erickson, Todd Milton, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

Two trials were conducted to evaluate the 1996 Beef NRC computer model for protein and phosphorus requirements of feedlot cattle. The control ration was formulated for the same levels of crude protein (13.5%) and phosphorus (0.35%) in both trials; however, supplemental protein was from urea in Trial 1 and urea, feather meal and blood meal in Trial 2. The balanced ration was formulated utilizing the 1996 NRC. The balanced ration was changed to effectively meet the changing requirements for DIP, UIP and P. In Trial 1, gains and efficiencies were similar between treatments; however, DMI was lower with cattle fed …

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Nutrient Balance Of Nitrogen, Organic Matter, Phosphorus And Sulfur In The Feedlot, Galen E. Erickson, Terry J. Klopfenstein, Daniel T. Walters, Gary Lesoing Jan 1998

Nutrient Balance Of Nitrogen, Organic Matter, Phosphorus And Sulfur In The Feedlot, Galen E. Erickson, Terry J. Klopfenstein, Daniel T. Walters, Gary Lesoing

Nebraska Beef Cattle Reports

Ninety-six crossbred yearling steers (656 lb) were assigned to either control (CON) or balanced (BAL) treatments. Steers were fed for 135 days in 12 waste-management pens with runoff collection basins. Control diet consisted of a DRC, 7.5 % roughage finisher formulated for 13.5 % protein and 0.35 % phosphorus. Balanced diet was formulated using the 1996 NRC model to meet the animal’s protein (11.5%) and phosphorus (0.22%) requirements. Gains were unaffected and feed efficiency tended to improve by feeding the BAL diet. Nitrogen and P excretion were lower with BAL steers compared with CON steers. Consequently, the manure’s N:P ratio …

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Phosphorus Requirement Of Finishing Yearlings, Galen E. Erickson, Mark Klemesrud, Todd Milton, Terry J. Klopfenstein Jan 1998

Phosphorus Requirement Of Finishing Yearlings, Galen E. Erickson, Mark Klemesrud, Todd Milton, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

Sixty yearling crossbred steers (849 lb) were fed individually either 0.35 or 0.70 % of DM as Ca and 0.14, 0.19, 0.24, 0.29 or 0.34 % P. Ash content was determined on bones from the lower front legs and one rib from each carcass was used to determine breaking strength. Performance and bone characteristics were not affected by dietary P concentration or P intake. Steers fed the 0.70 % Ca diets had lower gains and poorer efficiencies when compared to those fed 0.35 % Ca. These results indicate the requirement for finishing yearlings is 0.14 % P or less and …

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A Novel Estrous Synchronization Program For Beef Cattle Using Melengestrol Acetate, Karol Fike, Michael Wehrman, Brad Lindsey, Ellen G. M. Bergfeld, Eric Melvin, Jorge Quintal, Eraldo Zanella, Freddie Kojima, James Kinder Jan 1998

A Novel Estrous Synchronization Program For Beef Cattle Using Melengestrol Acetate, Karol Fike, Michael Wehrman, Brad Lindsey, Ellen G. M. Bergfeld, Eric Melvin, Jorge Quintal, Eraldo Zanella, Freddie Kojima, James Kinder

Nebraska Beef Cattle Reports

Estrous synchronization rate and conception and pregnancy rates to AI were evaluated following three estrous synchronization protocols for beef cattle. During 1995 and 1996, heifers and cows (n = 379) received either: 1) melengestrol acetate (MGA) for 18 days plus an injection of progesterone and estradiol in oil 7 days before end of treatment; 2) MGA for 17 days; or 3) two injections of PGF2&#;&#;&#;10 days apart. The greatest pregnancy rates (number conceived/number treated) among both anestrous and estrual females were achieved following treatment with MGA and an injection of progesterone and estradiol.

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Solvent-Extracted Germ Meal, Corn Bran And Steep Liquor Blends For Finishing Steers, Daniel Herold, Mark Klemesrud, Terry J. Klopfenstein, Todd Milton, Rick Stock Jan 1998

Solvent-Extracted Germ Meal, Corn Bran And Steep Liquor Blends For Finishing Steers, Daniel Herold, Mark Klemesrud, Terry J. Klopfenstein, Todd Milton, Rick Stock

Nebraska Beef Cattle Reports

Three trials evaluated solvent-extracted germ meal for finishing ruminants. Dry corn bran and steep liquor/ distillers solubles were fed in combination with solvent-extracted germ meal to evaluate interactions of byproduct blends. Byproducts enhanced intake and gain relative to dry-rolled corn diets. Adding tallow to byproduct diets increased efficiency. Feeding solvent-extracted germ meal with steep liquor heightened performance, but the benefit diminished when steep liquor level reached 30% of dry matter. Including solvent-extracted germ meal with wet corn gluten feed influenced neither daily gain nor intake. Results show solvent-extracted germ meal, either alone or blended with steep liquor/distillers solubles and dry …

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Induction Of Estrus In Anestrous Suckled Beef Cows, Karol Fike, Michael Day, Keith Inskeep, James E. Kinder, Paul Lewis, Robert Short, Harold Hafs Jan 1998

Induction Of Estrus In Anestrous Suckled Beef Cows, Karol Fike, Michael Day, Keith Inskeep, James E. Kinder, Paul Lewis, Robert Short, Harold Hafs

Nebraska Beef Cattle Reports

Suckled anestrous beef cows (n=362) received either: 1) an intravaginal implant containing progesterone for 7 days plus a 1 mg injection of estradiol benzoate 24 to 30 hours after implant removal; 2) an intravaginal implant containing progesterone for 7 days; 3) a sham implant for 7 days plus a 1 mg injection of estradiol benzoate 24 to 30 hours after implant removal; or 4) a sham implant for 7 days. Treatment with progesterone resulted in resumption of luteal function in suckled anestrous beef cows with most cows developing corpora lutea with a typical lifespan, whereas treatment with estradiol benzoate enhanced …

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Prolonged Elevated Concentrations Of Estradiol Do Not Affect Conception Rates In Beef Cattle, Karol Fike, Michael Wehrman, Ellen G. M. Bergfeld, Freddie Kojima, James E. Kinder Jan 1998

Prolonged Elevated Concentrations Of Estradiol Do Not Affect Conception Rates In Beef Cattle, Karol Fike, Michael Wehrman, Ellen G. M. Bergfeld, Freddie Kojima, James E. Kinder

Nebraska Beef Cattle Reports

Following treatments causing either prolonged elevated concentrations of estradiol associated with development of persistent follicles or inhibited elevated concentrations of estradiol and development of persistent follicles, conception rates were compared. Beef females received either four norgestomet implants for 9 days (day 0 = treatment initiation; n=59) or one norgestomet implant for 7 days and three additional norgestomet implants for 2 days (n=60). All implants were removed on day 9 followed by estrous detection and AI for 7 days. Treatment and day interacted to affect estradiol concentrations from day 0 to day 9 with elevated estradiol in females treated with one …

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Dietary Calcium And Phosphorous: Relationship To Beef Tenderness And Carcass Maturity, Dana Hanson, Galen E. Erickson, Chris R. Calkins, Terry J. Klopfenstein, Todd Milton, Mark Klemesrud Jan 1998

Dietary Calcium And Phosphorous: Relationship To Beef Tenderness And Carcass Maturity, Dana Hanson, Galen E. Erickson, Chris R. Calkins, Terry J. Klopfenstein, Todd Milton, Mark Klemesrud

Nebraska Beef Cattle Reports

The effect of dietary mineral status as related to carcass maturity or meat tenderness was studied. Finishing yearling steers were individually fed varying levels of calcium and phosphorous. Neither mineral was significantly related to overall carcass maturity scores or meat tenderness. When fed at the levels in this trial, it appears there are no adverse effects of dietary calcium and phosphorous on carcass or meat characteristics.

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Dried Poultry Waste As A Protein Supplement For Cows Grazing Winter Forages, D. J. Jordon, Terry J. Klopfenstein, Don C. Adams, Jackie Johnson, Mark Klemesrud, James A. Gosey Jan 1998

Dried Poultry Waste As A Protein Supplement For Cows Grazing Winter Forages, D. J. Jordon, Terry J. Klopfenstein, Don C. Adams, Jackie Johnson, Mark Klemesrud, James A. Gosey

Nebraska Beef Cattle Reports

Two trials conducted in 1996-1997 evaluated dried poultry waste relative to soybean meal for cows grazing winter forages. In Trial 1, cows grazing native Sandhills winter range received: 1) no supplement; 2) urea; 3) 22% dried poultry waste+urea; 4) soybean meal; 5) 22% dried poultry waste+soybean meal; or 6) 44% dried poultry waste. Cows receiving supplements gained more weight (P<.001) and maintained greater body condition (P<.001) than unsupplemented cows. Cows receiving urea gained less (P<.10) than cows receiving more natural protein, although body condition remained similar. In Trial 2, cows grazing cornstalks received supplements containing either soybean meal or dried poultry waste; however, gains were not different.

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Evaluation Of Feather Meal For Calves Grazing Cornstalks, D. J. Jordon, Terry J. Klopfenstein, Mark Klemesrud Jan 1998

Evaluation Of Feather Meal For Calves Grazing Cornstalks, D. J. Jordon, Terry J. Klopfenstein, Mark Klemesrud

Nebraska Beef Cattle Reports

Three years of cornstalk grazing trials were conducted from 1995-97 to determine the feeding value of a sunflower, feather and blood meal supplement compared to a traditional soybean meal supplement. Analysis revealed no year x treatment interaction in years 1 and 2, so data were pooled. Gains of calves receiving soybean meal (0.97 lb/day) were not significantly different from those consuming sunflower/ feather meal (0.83 lb/day). In year 3, protein sources were evaluated for undegradable intake protein before formulation. Gains were similar between soybean meal (0.19 lb/day) and sunflower/feather meal (0.16 lb/day). A supplement containing sunflower/ feather meal is an …

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Feather Meal As A Source Of Sulfur Amino Acids For Growing Steers, Mark Klemesrud, Terry J. Klopfenstein Jan 1998

Feather Meal As A Source Of Sulfur Amino Acids For Growing Steers, Mark Klemesrud, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

One-hundred twenty individually fed steer calves were used to evaluate feather meal as a source of sulfur amino acids. Treatment proteins included a urea control and meat and bone meal (6.4% of dietary DM) plus 0, 1, or 2% feather meal with incremental levels of rumen protected methionine. Adding feather meal to meat and bone meal resulted in a linear increase in gain. Likewise, rumen-protected methionine also improved gain. These results indicate feather meal can provide a portion of the sulfur amino acids lacking in meat and bone meal. However, additional methionine may further improve performance.

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Spring Versus Summer Calving For The Nebraska Sandhills: Production Characteristics, Greg Lardy, Terry J. Klopfenstein, Don C. Adams, Dick Clark, Jackie Johnson, Andy Applegarth Jan 1998

Spring Versus Summer Calving For The Nebraska Sandhills: Production Characteristics, Greg Lardy, Terry J. Klopfenstein, Don C. Adams, Dick Clark, Jackie Johnson, Andy Applegarth

Nebraska Beef Cattle Reports

Effects of summer calving versus traditional spring calving were investigated over three years. Calving dates were: 1) March to April (beginning March 18) for spring calving and 2) mid-June to mid-August (beginning June 18) for summer calving. Spring-born calves were weaned in October, while summer-born calves were weaned in November or January. Summer calving cows were bred either on native range or subirrigated meadow. Birth weights were higher for summer-born calves, although weaning weights were lower. Pregnancy rates for spring-calving cows bred on native range were similar to summer-calving cows bred on subirrigated meadow or native range. Summer calving reduced …

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Use Of The Nrc Model For Evaluating Nutrient Balances Of Grazing Beef Cattle, Greg Lardy, Don C. Adams, Terry J. Klopfenstein, Dennis R. Brink Jan 1998

Use Of The Nrc Model For Evaluating Nutrient Balances Of Grazing Beef Cattle, Greg Lardy, Don C. Adams, Terry J. Klopfenstein, Dennis R. Brink

Nebraska Beef Cattle Reports

Research conducted at the Gudmundsen Sandhills Laboratory evaluated the National Research Council Beef Cattle Nutrient Requirements Model. Equations describing seasonal variability in CP, IVOMD, escape protein and degradable intake protein of native Sandhills range and subirrigated meadow were developed. Estimates of TDN and protein degradability for feedstuffs commonly used by Nebraska cow-calf producers are given. The NRC Model generally predicted nutrient balances in agreement with research trials. Microbial efficiency is lower for less-digestible forages. The NRC model is useful for evaluating grazed diets when accurate estimates of protein degradability, digestibility and intake are available.

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Escape Protein Supplementation And Weaning Effects On Calves Grazing Meadow Regrowth, Greg Lardy, Don C. Adams, Terry J. Klopfenstein, June Ueckert, Richard T. Clark Jan 1998

Escape Protein Supplementation And Weaning Effects On Calves Grazing Meadow Regrowth, Greg Lardy, Don C. Adams, Terry J. Klopfenstein, June Ueckert, Richard T. Clark

Nebraska Beef Cattle Reports

Forty spring-born calves grazing subirrigated meadow regrowth were assigned to two weaning and two supplementation treatments in the fall of 1995 and 1996. Weaning treatments were: 1) weaning September 1; or 2) nursing during the trial. Supplementation treatments were 1) no supplemental undegraded intake protein (escape protein); or 2) supplemental undegraded intake protein. No treatment interactions were detected indicating weaning and supplementation affects were independent. Nursing calves had higher weight gains (2.1 versus 1.3 lb/day) and lower forage intakes (5.2 versus 6.5 lb/day) than weaned calves. Supplemental undegraded intake protein increased weight gains of calves (1.94 versus 1.45 lb/day). We …

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Use Of The Nrc Model For Predicting Nutrient Balances Of Finishing Cattle, Greg Lardy, Rob Mccoy, Drew Shain, Todd Milton, Dennis R. Brink, Terry J. Klopfenstein Jan 1998

Use Of The Nrc Model For Predicting Nutrient Balances Of Finishing Cattle, Greg Lardy, Rob Mccoy, Drew Shain, Todd Milton, Dennis R. Brink, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

Trials conducted at the University of Nebraska’s Research Feedlot were used to validate the NRC Beef Cattle Nutrient Requirements Model. Guidelines were developed for nutrient values for feedstuffs commonly fed in Nebraska feedlots. Generally, the NRC model predicted DIP and MP balances which were in agreement with performance data. The NRC Model generally under-predicted feed intake. The NRC model correctly predicted DIP deficiencies in dry-rolled corn diets which did not contain supplemental degradable protein. The effective NDF level of wet corn gluten feed appears to be higher than that of dry-rolled corn. The NRC model is a useful tool for …

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Extended Grazing And Byproduct Diets In Beef Growing Finishing Systems, Ramiro Lucena, Terry J. Klopfenstein, Mark Klemesrud, Rob Cooper Jan 1998

Extended Grazing And Byproduct Diets In Beef Growing Finishing Systems, Ramiro Lucena, Terry J. Klopfenstein, Mark Klemesrud, Rob Cooper

Nebraska Beef Cattle Reports

Two experiments evaluated methods of reducing costs of finished beef. The first experiment, used lambs as a model for cattle. A dry rolled corn diet served as a control and two byproduct diets: 1) corn gluten feed; or 2) gluten feed plus wheat midds, were supplemented with three levels of tallow. Byproduct diets gave feed efficiencies nearly equal to corn and efficiencies increased with tallow supplementation. In the second experiment, 128 steers were used in grazing systems including smooth brome, warm-season grasses, oats and cornstalks and finished on corn or byproduct diets. High forage gains reduced costs and slaughter breakevens.

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Lipid Sources In Finishing Diets For Yearling Steers, Ivan G. Rush, Burt Weichenthal, Brad Van Pelt Jan 1998

Lipid Sources In Finishing Diets For Yearling Steers, Ivan G. Rush, Burt Weichenthal, Brad Van Pelt

Nebraska Beef Cattle Reports

Adding Synergy2 to a corn-based finishing diet to provide 1.12% lipid did not significantly increase steer performance in this trial or in pooled results between this trial and one reported in 1995. However, numerical increases were observed in daily gain and feed dry matter intake for Synergy when compared to control values. Pooled results for additions of pork fat (white grease) to provide 1.12 or 2.24% lipid were intermediate to those for the control and Synergy treatments. Any performance benefit attributed to Synergy may be as much from its effect on dry matter intake as it is from nutrient …

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Metabolism And Digestibility Of Corn Bran And Corn Steep Liquor/Distillers Solubles, Tony Scott, Terry J. Klopfenstein, Rick Stock, Rob Cooper Jan 1998

Metabolism And Digestibility Of Corn Bran And Corn Steep Liquor/Distillers Solubles, Tony Scott, Terry J. Klopfenstein, Rick Stock, Rob Cooper

Nebraska Beef Cattle Reports

Six ruminally cannulated steers and six intact steers were used in a 6x6 Latin square design to determine the effect of corn bran and/or corn steep liquor/distillers solubles on ruminal metabolism and digestibility. Steers fed corn steep liquor/distiller’s solubles had lower average daily pH. Corn bran helped maintain a higher average pH. Corn steep liquor/distillers solubles fed alone altered the fermentation pattern of steers. There was a tendency for corn bran to reduce digestibility and for corn steep liquor/distillers solubles to improve digestibility.

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Summer And Fall Forage Grazing Combinations: Five-Year Summary, Drew Shain, Terry J. Klopfenstein, D. J. Jordon, Rick Stock Jan 1998

Summer And Fall Forage Grazing Combinations: Five-Year Summary, Drew Shain, Terry J. Klopfenstein, D. J. Jordon, Rick Stock

Nebraska Beef Cattle Reports

A five-year study using British-breed crossbred cattle included slaughter breakeven analysis and evaluated the effect of grazing alternative summer and fall forages on beef production systems. Grazed summer and fall forage combinations included continuous brome and combinations of brome, warm-season grasses, alfalfa, sudangrass, red clover, native Sandhills range, turnips, rye and cornstalks. The most consistent improvement in summer grazing gain and most desirable slaughter breakeven costs were observed in cattle grazing brome and warm-season grasses or brome and Sandhills range. A reduction in slaughter breakeven cost by grazing fall forages was observed in years with adequate moisture for forage growth. …

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Ruminal Degradation Of Rubisco By Beef Cattle Grazing Switchgrass And Big Bluestem, Dan Vaughn, Walter H. Schacht, Lowell E. Moser, Robert Graybosch, Terry J. Klopfenstein Jan 1998

Ruminal Degradation Of Rubisco By Beef Cattle Grazing Switchgrass And Big Bluestem, Dan Vaughn, Walter H. Schacht, Lowell E. Moser, Robert Graybosch, Terry J. Klopfenstein

Nebraska Beef Cattle Reports

This two-year study was conducted on monocultures of switchgrass and big bluestem to: (1) determine the concentration of the protein ribulose-1,5- bisphosphate carboxylase (Rubisco), found only in the bundle sheath cells of warm-season grasses, in omasal, masticate and fecal samples of grazing cattle; and (2) estimate rumen-escape Rubisco via bundle sheath cells. A quantifying enzyme-linked immunosorbent assay, along with estimates of rumen and lower tract digestibilities, indicated as much as 11% of Rubisco in big bluestem and 13% in switchgrass escaped rumen degradation and was absorbed in the lower tract. Realizing these amounts of escape Rubisco represent a significant level …

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An Enzyme-Microbial Feed Product For Finishing Steers, Burt Weichenthal, Ivan G. Rush, Brad Van Pelt Jan 1998

An Enzyme-Microbial Feed Product For Finishing Steers, Burt Weichenthal, Ivan G. Rush, Brad Van Pelt

Nebraska Beef Cattle Reports

Feeding MSE (multiple stabilized enzymes in an enzyme-microbial feed product) at the rate of 2 lb of product per ton of diet dry matter in two trials with finishing yearling steers, increased daily gain by an average of 6.9% over feeding Rumensin-Tylan at 29 g and 10 g per ton, respectively. Feed-to-gain ratio was improved by an average of 5.6% with MSE in the same comparison. Carcass measurements were similar, except for slight increases in hot carcass weight and dressing percent for cattle fed MSE. Percentages of liver abscesses were low and similar for both treatments.

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Comparison Of Sire Breed Solutions For Growth Traits Adjusted By Mean Expected Progeny Differences To A 1993 Base, K. L. Barkhouse, L. Dale Van Vleck, Larry V. Cundiff, D. S. Buchmann, D. M. Marshall Jan 1998

Comparison Of Sire Breed Solutions For Growth Traits Adjusted By Mean Expected Progeny Differences To A 1993 Base, K. L. Barkhouse, L. Dale Van Vleck, Larry V. Cundiff, D. S. Buchmann, D. M. Marshall

Department of Animal Science: Faculty Publications

Records on growth traits were obtained from five Midwestern agricultural experiment stations as part of a beef cattle crossbreeding project (NC-196). Records on birth weight (BWT, n =3,490), weaning weight (WWT, n = 3,237), and yearling weight (YWT, n = 1,372) were analyzed within locations and pooled across locations to obtain estimates of breed of sire differences. Solutions for breed of sire differences were adjusted to the common base year of 1993. Then, factors to use with within-breed expected progeny differences (EPD) to obtain a crossbreed EPD were calculated. These factors were compared with factors obtained from similar analyses of …

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Intraspecific Heterochrony And Life History Evolution: Decoupling Somatic And Sexual Development In A Facultatively Paedomorphic Salamander, Travis J. Ryan, Raymond D. Semlitsch Jan 1998

Intraspecific Heterochrony And Life History Evolution: Decoupling Somatic And Sexual Development In A Facultatively Paedomorphic Salamander, Travis J. Ryan, Raymond D. Semlitsch

Scholarship and Professional Work - LAS

Morphological features such as size and shape are the most common focus in studies of heterochronic change. Frequently, these easily observed and measured features are treated as a major target of selection, potentially ignoring traits more closely related to fitness. We question the primacy of morphological data in studies of heterochrony, and instead suggest that principal sources of fitness, such as life history characteristics, are not only the chief targets of selection, but changes in them may necessitate changes in other (subordinate) elements of the organism. We use an experimental approach to investigate the timing of metamorphosis and maturation in …

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Effects Of Inbreeding And Heterozygosity On Preweaning Traits In A Closed Population Of Herefords Under Selection, L. Dale Van Vleck, M. D. Macneil Jan 1998

Effects Of Inbreeding And Heterozygosity On Preweaning Traits In A Closed Population Of Herefords Under Selection, L. Dale Van Vleck, M. D. Macneil

Department of Animal Science: Faculty Publications

Records of five inbred lines at the Livestock and Range Research Laboratory were used to evaluate effects of inbreeding and heterozygosity on preweaning traits. Members of each line were descendants of a single founder Hereford bull. A total of 8,065 records of birth weight and 7,380 records of preweaning daily gain and weaning weight were analyzed by derivative-free REML using a model that included fixed effects of sex, combination of year and month of birth and parity of dam, with covariates for direct and maternal genetic fractions of inheritance from the genetic groups, inbreeding, and heterozygosity fractions. Heterozygosity fractions were …

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