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Full-Text Articles in Life Sciences

Relationship Of Molecular Breeding Value For Beef Tenderness With Heifer Traits Through Weaning Of Their First Calf, Robert A. Cushman, Gary L. Bennett, Richard G. Tait, Anthony K. Mcneel, Eduardo Casas, Timothy P.L. Smith, Harvey C. Freetly Oct 2021

Relationship Of Molecular Breeding Value For Beef Tenderness With Heifer Traits Through Weaning Of Their First Calf, Robert A. Cushman, Gary L. Bennett, Richard G. Tait, Anthony K. Mcneel, Eduardo Casas, Timothy P.L. Smith, Harvey C. Freetly

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Polymorphisms in μ-calpain (CAPN1) that beneficially associate with beef tenderness are reported to antagonistically associate with calving day in beef heifers and post-partum interval to estrus in beef cows. We, therefore, hypothesized that a molecular breeding value for slice shear force, calculated based on CAPN1 and calpastatin (CAST) genotypes, would demonstrate an antagonistic relationship between genomically predicted slice shear force and ordinal calving date in replacement beef heifers. A secondary objective of this study was to evaluate the association of a polymorphism in diacylglycerol O-acyltransferase (DGAT1) with reproductive traits in beef heifers. One hundred eighty-seven MARC III heifers (¼ Angus, …


Using Genomics To Measure Phenomics: Repeatability Of Bull Prolificacy In Multiple-Bull Pastures, Gary L. Bennett, John W. Keele, Larry A. Kuehn, Warren M. Snelling, Robert A. Cushman, Tara G. Mcdaneld, Aaron M. Dickey, Darrell Light Jul 2021

Using Genomics To Measure Phenomics: Repeatability Of Bull Prolificacy In Multiple-Bull Pastures, Gary L. Bennett, John W. Keele, Larry A. Kuehn, Warren M. Snelling, Robert A. Cushman, Tara G. Mcdaneld, Aaron M. Dickey, Darrell Light

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Phenotypes are necessary for genomic evaluations and management. Sometimes genomics can be used to measure phenotypes when other methods are difficult or expensive. Prolificacy of bulls used in multiple-bull pastures for commercial beef production is an example. A retrospective study of 79 bulls aged 2 and older used 141 times in 4–5 pastures across 4 years was used to estimate repeatability from variance components. Traits available before each season’s use were tested for predictive ability. Sires were matched to calves using individual genotypes and evaluating exclusions. A lower-cost method of measuring prolificacy was simulated for five pastures using the bulls’ …


Changes In Whole Blood Parameters In Beef Heifers May Contribute To Delayed Pubertal Attainment, Jessica A. Keane Apr 2021

Changes In Whole Blood Parameters In Beef Heifers May Contribute To Delayed Pubertal Attainment, Jessica A. Keane

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

Pubertal development in beef heifers is a transient period that has many contributing factors. Previously in our lab, progesterone (P4) concentrations collected from heifers at weaning (Oct) to breeding (May) were used to identify four distinct pubertal groups: Typical, Early, Start-Stop, and Non-Cycling. There is limited research on heifers and the impacts of whole blood cell populations, particularly WBCs, during pubertal development; however, girls with differing puberty onset displayed altered concentrations of hematocrit, white blood cells (WBC), and hemoglobin concentrations. Thus, our hypothesis was that heifer pubertal groups with delayed or precocious puberty may have increased white blood cells or …


Observations On The Distribution And Status Of Selected Nebraska Mammals, Zachary P. Roehrs, Russell A. Benedict, Thomas E. Labedz, Hugh H. Genoways Feb 2021

Observations On The Distribution And Status Of Selected Nebraska Mammals, Zachary P. Roehrs, Russell A. Benedict, Thomas E. Labedz, Hugh H. Genoways

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Information on the distribution and current status of 25 species or subspecies of mammals occurring in Nebraska are presented. The species covered include one shrew, an armadillo, eight bats, 10 rodents (including two subspecies of one species), three carnivores, and one artiodactyl. Distributional information reported includes the first state record for one species (Sorex nanus) and new county records for 18 species. In Nebraska, we know that mammals are shifting their geographic ranges with some extending populations into the state, whereas others are expanding their geographic ranges within the state. The current status of six additional mammalian taxa …


Comparison Of Performance Of F1 Romanov Crossbred Ewes With Wool And Hair Breeds During Spring Lambing Under Intensive And Extensive Production Systems, Brad A. Freking, Thomas W. Murphy Jan 2021

Comparison Of Performance Of F1 Romanov Crossbred Ewes With Wool And Hair Breeds During Spring Lambing Under Intensive And Extensive Production Systems, Brad A. Freking, Thomas W. Murphy

Roman L. Hruska U.S. Meat Animal Research Center: Reports

The objective was to evaluate wool (Dorset and Rambouillet) and hair (Dorper, Katahdin, and White Dorper) breeds for their ability to complement Romanov germplasm in two distinct production systems by estimating direct sire and grandsire effects on lamb growth, survival, and ewe productivity traits. Rams of the five breeds (n = 75) were mated to Romanov ewes (n = 459) over a 3-yr period to produce five types of crossbred lambs (n = 2,739). Sire breed (P > 0.06) did not impact body weight or survival traits of the first-generation crossbred (F1) lambs. The productivity of retained crossbred ewes (n = …


Der Kormoran Phalacrocorax Carbo In Der Mongolei, Michael Stubbe, Lucie Marie Baltz, Davaa Lchagvasuren, Lukas Kratzsch, Lara-Sophie Dey, Annegret Stubbe Jan 2021

Der Kormoran Phalacrocorax Carbo In Der Mongolei, Michael Stubbe, Lucie Marie Baltz, Davaa Lchagvasuren, Lukas Kratzsch, Lara-Sophie Dey, Annegret Stubbe

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

The Great Cormorant Phalacrocorax carbo is a wide spread breeding species in Mongolia with a progressive population trend. Observations of the Mongolian-German Biological Expeditions were analyzed and summarized with data from literature. About 1,500 young birds were ringed in 2016 and 2017. One important recovery was coming from the wintering area Mai Po Marshes Nature Reserve of Hong Kong. It is unclear if all Mongolian Cormorants are flying at the same route to their wintering region in South China. The main feeding fishes in Mongolia belong to endemic species of the genus Oreoleuciscus (Cyprinidae). Measurements of 113 eggs from Tolbo- …


Mist-Netting Of Forest-Dwelling Bats In The Lazovsky State Nature Reserve, Russian Far East, Kerstin Birlenbach Jan 2021

Mist-Netting Of Forest-Dwelling Bats In The Lazovsky State Nature Reserve, Russian Far East, Kerstin Birlenbach

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Many bat species depend on a high value of healthy and undisturbed forests with a high ratio of roost sites in old tree stands. This investigation focused on the diversity, distribution and reproduction status of bats within the area of Lazovsky State Nature Reserve. The importance of an area for bats can be measured by the ratio of reproduction. The most important and sensitive time in a bats yearly circle is the time of hibernation in winter and the reproduction time of females. From the beginning of July to the end of August 2007, in total 139 bats of eight …


Review: Perspective On High-Performing Dairy Cows And Herds, J. H. Britt, R. A. Cushman, C. D. Dechow, H. Dobson, P. Humblot, M. F. Hutjens, G. A. Jones, F. M. Mitloehner, P. L. Ruegg, I. M. Sheldon, J. S. Stevenson Jan 2021

Review: Perspective On High-Performing Dairy Cows And Herds, J. H. Britt, R. A. Cushman, C. D. Dechow, H. Dobson, P. Humblot, M. F. Hutjens, G. A. Jones, F. M. Mitloehner, P. L. Ruegg, I. M. Sheldon, J. S. Stevenson

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Milk and dairy products provide highly sustainable concentrations of essential amino acids and other required nutrients for humans; however, amount of milk currently produced per dairy cow globally is inadequate to meet future needs. Higher performing dairy cows and herds produce more milk with less environmental impact per kg than lower performing cows and herds. In 2018, 15.4% of the world's dairy cows produced 45.4% of the world's dairy cow milk, reflecting the global contribution of high-performing cows and herds. In high-performing herds, genomic evaluations are utilized for multiple trait selection, welfare is monitored by remote sensing, rations are formulated …


Surgical Sterilization Impacts On Behavior Of Coyote Pairs, Tyler Leary, Jeffrey T. Schultz, Julie K. Young Jan 2021

Surgical Sterilization Impacts On Behavior Of Coyote Pairs, Tyler Leary, Jeffrey T. Schultz, Julie K. Young

USDA Wildlife Services: Staff Publications

Coyotes (Canis latrans) involved in depredation of livestock, an act frequently resulting in human-wildlife conflict, often do so out of necessity for provisioning pups. Surgical sterilization methods such as vasectomy that preserve gonadal hormones have been successful in reducing depredation by free-ranging coyotes while allowing individuals to maintain territoriality and mate fidelity. However, use of these methods remain costly and ineffective for wide-scale use. Given the alternative proposal of using chemical sterilization techniques, we investigated whether the use of hormone-altering sterilization methods impacted behavior of captive coyote pairs (i.e., male-female pair bonds). Our objective was to evaluate behavior …


Measuring Adrenal And Reproductive Hormones In Hair From Southern Beaufort Sea Polar Bears (Ursus Maritimus), Marilize Van Der Walt, Lorin A. Neuman-Lee, Patricia A. Terletzky, Todd C. Atwood, Eric M. Gese, Susannah S. French Jan 2021

Measuring Adrenal And Reproductive Hormones In Hair From Southern Beaufort Sea Polar Bears (Ursus Maritimus), Marilize Van Der Walt, Lorin A. Neuman-Lee, Patricia A. Terletzky, Todd C. Atwood, Eric M. Gese, Susannah S. French

USDA Wildlife Services: Staff Publications

Polar bears (Ursus maritimus) use sea ice to access marine mammal prey. In Alaska’s Southern Beaufort Sea, the declining availability of sea ice habitat in summer and fall has reduced opportunities for polar bears to routinely hunt on the ice for seals, their primary prey. This reduced access to prey may result in physiological stress with subsequent potential consequences to reproductive function (physiological changes that accompany reproduction), which can be measured via reproductive hormones. Hormone concentrations in hair can be used as a minimally invasive alternative to serum concentrations, which must come from animal captures. Hair samples also …


Reproductive Trade-Offs In The Colorado Checkered Whiptail Lizard (Aspidoscelis Neotesselatus): An Examination Of The Relationship Between Clutch And Follicle Size, Hannah E. Caracalas, S. S. French, S. B. Hudson, B. M. Kluever, A. C. Webb, D. Eifler, A. J. Lehmicke, Lise M. Aubry Jan 2021

Reproductive Trade-Offs In The Colorado Checkered Whiptail Lizard (Aspidoscelis Neotesselatus): An Examination Of The Relationship Between Clutch And Follicle Size, Hannah E. Caracalas, S. S. French, S. B. Hudson, B. M. Kluever, A. C. Webb, D. Eifler, A. J. Lehmicke, Lise M. Aubry

USDA Wildlife Services: Staff Publications

Life history theory predicts that there should be an inverse relationship between offspring size and number, because individuals cannot simultaneously maximize both when resources are limited. Although extensively studied in avian species, the occurrence and determinants of reproductive tradeoffs in oviparous reptiles are far less understood, particularly in parthenogenetic species. We studied this trade-off in the Colorado Checkered Whiptail, Aspidoscelis neotesselatus, a female-only parthenogenetic lizard. Using data previously collected in 2018 and 2019, we tested for clutch and egg size trade-offs and determined whether this relationship could be influenced by female size and aspects of physiological condition. Physiological condition …