Animal Sciences Commons^™

Genetic And Phenotypic Parameters For Dietary Selection Of Mountain Big Sagebrush (Artemisia Tridentata Nutt. Ssp. Vaseyana [Rydb] Beetle) In Rambouillet Sheep, G. D. Snowder, J. W. Walker, K. L. Launchbaugh, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

The heritability of diet selection for mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana [Rydb] Beetle) by grazing sheep was estimated from fecal samples collected from 549 Rambouillet ewes. Fecal samples were collected in September and October during 1996 and 1997 from free-grazing ewes on intermountain sagebrush-bunchgrass rangelands at the U.S. Sheep Experiment Station in Idaho. The total number of fecal samples was 1,949. Fecal samples were evaluated for composition of big sagebrush by near-infrared spectroscopy. Percentage of sagebrush in the diet was less in September than in October (21.6 vs 31.7%, respectively). Single-trait and bivariate derivative-free REML analyses …

Managing N Inputs And The Effect On N Losses Following Excretion In Open-Dirt Feedlots In Nebraska, Galen Erickson, Terry Klopfenstein

Department of Animal Science: Faculty Publications

Feedlot nutrition will play an important role in meeting environmental challenges of beef cattle feedlots. Nutritionists are continually refining protein requirements and recently adopted a new, metabolizable protein (MP) system to more efficiently use N and allow more accurate diet formulation. Protein requirements vary by animal age and weight during the finishing period. Our hypothesis was that formulating diets with the MP system would decrease N inputs leading to decreased excretion and losses. Comparing industry average diets (13.5% CP) to phase-fed diets formulated to not exceed MP requirements decreased N inputs by 10 to 20% for calves and yearlings without …

Estimating Forage Protein Degradation In The Rumen, Terry J. Klopfenstein, R. A. Mass, K. W. Creighton, H. H. Patterson

Department of Animal Science: Faculty Publications

Forage proteins are degraded rapidly by rumen microorganisms and therefore supply relatively small quantities of undegraded intake protein (UIP). Growing cattle with high metabolizable protein requirements and lactating beef and dairy cows respond to UIP supplementation when fed high-forage diets, even though degradable intake protein (DIP) is adequate. This observation suggests that an accurate estimate of forage UIP is needed to establish optimal supplementation conditions. Microbial protein must be quantitated in duodenal or in situ residue samples to accurately measure forage UIP. Purines commonly are used as a microbial protein marker. Recent reports suggested that the original purine procedure generates …

Switching Feedlot Dietary Fiber Level For Cattle Fed In Winter, T. L. Mader, M. S. Davis, J. M. Dahlquist, A. M. Parkhurst

Department of Animal Science: Faculty Publications

Four feeding regimens were evaluated in two different outside facilities [tree windbreak provided (SP) vs no wind protection provided (NP)] over two winter seasons. Feeding regimens were 1) 7.5% (DM basis) alfalfa hay (AH) diet (Low- Low); 2) 15% (DM basis) AH diet switched to a 7.5% (DM basis) AH diet under cold stress conditions (High-Low); 3) 7.5% (DM basis) AH diet switched to a 15% (DM basis) AH diet under cold stress conditions (Low-High); and 4) 15% (DM basis) AH diet (High-High). For feeding regimens High-Low and Low- High, cold stress was determined by use of a model, based …

Candidate Gene Analysis For Loci Affecting Litter Size And Ovulation Rate In Swine, R. C. Linville, Daniel Pomp, R. K. Johnson, M. F. Rothschild

Department of Animal Science: Faculty Publications

A candidate gene approach was used to determine whether specific loci explain responses in ovulation rate (OR) and number of fully formed (FF), live (NBA), stillborn, and mummified pigs at birth observed in two lines selected for ovulation rate and litter size compared with a randomly selected control line. Line IOL was selected for an index of OR and embryonic survival for eight generations, followed by eight generations of two-stage selection for OR and litter size. Line C was selected at random for 16 generations. Line COL, derived from line C at Generation 8, underwent eight generations of two-stage selection. …

Locomotor Activity, Core Body Temperature, And Circadian Rhythms In Mice Selected For High Or Low Heat Loss, M. R. Mousel, Walter W. Stroup, Merlyn K. Nielsen

Department of Animal Science: Faculty Publications

Daily locomotor activity, core body temperature, and their circadian rhythms were measured in lines of mice selected for high (MH) or low (ML) heat loss and unselected controls (MC). Lines were created by selecting for 16 generations in each of three replicates. Collection of locomotor activity and core temperature data spanned Generations 20 and 21 for a total of 352 mice. Physical activity and core body temperature data were accumulated using implanted transmitters and continuous automated collection. Measurement for each animal was for 3 d. Activity was recorded for each half hour and then averaged for the day; temperature was …

Conjugated Linoleic Acid (Cla), Body Fat, And Apoptosis, Jess L. Miner, C. Cederberg, Merlyn K. Nielsen, Xiaoli Chen, Clifton Baile

Department of Animal Science: Faculty Publications

Objective: The objective of the study was to determine if consumption of conjugated linoleic acid (CLA) by mice could induce apoptosis in adipose tissue. Other objectives were to determine the influence of feeding mice CLA for ≤2 weeks on body fat, energy expenditure, and feed intake.

Research Methods and Procedures: A mixture of CLA isomers (predominantly c9,t11 and t10,c12) was included in the AIN-93G diet at 0, 1, and 2%, and fed to mice for 12 days (Trial 1), or was included at 2% and fed to mice for 0, 5, and 14 days (Trial 2). Feed intake …

Use Of Intra-Uterine Insemination Of Pigs: Pros, Cons & Economics, Donald G. Levis, Scott Burroughs, Sara Williams

Department of Animal Science: Faculty Publications

Reproductive performance is a major concern for pork producers because the financial stability of a pork enterprise that produces piglets is substantially influenced by fecundity index (FI) for number of piglets born alive (FI = farrowing rate x litter size born alive). It is well known that farrowing rate and litter size are affected by numerous factors. A new reproductive technique that pork producers are hearing and reading about is intra-uterine insemination. Intra-uterine insemination is the process of placing spermatozoa directly into the uterine body instead of the cervix as traditionally done. The uterine body is located between the cervix …

Effect Of Animal Grouping On Feeding Behavior And Intake Of Dairy Cattle, R. J. Grant, J. L. Albright

Department of Animal Science: Faculty Publications

Although data are scarce, it is clear that grouping strategy can have a significant impact on the feeding behavior and feed intake of dairy cattle. Feed intake is controlled by ruminoreticular fill and physiological mechanisms, but grouping is a component of the cow’s feeding environment that can modulate intake as a result of its impact on cow comfort, competition for feed and other resources, and herd health. Social dominance and competition for feed impact feeding behavior and proper grouping strategy will minimize the negative impact of excessive competition on intake and enhance beneficial effects of group feeding such as social …

Maximal Replacement Of Forage And Concentrate With A New Wet Corn Milling Product For Lactating Dairy Cows, K. Buddugari, R. J. Grant

Department of Animal Science: Faculty Publications

Three experiments were conducted to determine the maximal amount of concentrate and forage that could be replaced with a new wet corn milling product. The corn milling product contained 23.1% crude protein, 9.9% ruminally undegradable protein, 13.7% acid detergent fiber, 40.3% neutral detergent fiber, and 2.6% ether extract (% of dry matter; DM). In experiment 1, 16 Holstein cows were assigned to one of four diets in a replicated 4 × 4 Latin square design with 28-d periods. The four diets contained 54.3% forage (alfalfa:corn silages, 1:1 DM basis) with the wet corn milling product replacing 0, 50, 75, or …

Atresia Revisited: Two Basic Patterns Of Atresia Of Bovine Antral Follicles, H. F. Irving-Rodgers, I. L. Van Wezel, M. L. Mussard, J. E. Kinder, R. J. Rodgers

Department of Animal Science: Faculty Publications

Our observations of bovine follicles indicated that the original histological classifications of atresia were inaccurate. A detailed histological, ultrastructural and immunohistochemical study of antral follicles from bovine ovaries collected from an abattoir and from animals whose large follicles had been monitored by ultrasonography was conducted to investigate this further. Nidogen and CD68 were immunolocalized to observe the follicular basal lamina and macrophages, respectively. In randomly collected ovaries, approximately one quarter of all antral follicles were undergoing antral atresia, as designated in this study. Antral atresia was characterized by early destruction of the layers of the membrana granulosa closest to the …

Genetic Variation In Two Conserved Local Romanian Pig Breeds Using Type 1 Dna Markers, Daniel C. Ciobanu, Andrew E. Lu, Alexandru Nagy, Richard Wales, Max F. Rothschild, Graham S. Plastow

Department of Animal Science: Faculty Publications

Analysis of the genetic variation of an endangered population is an important component for the success of conservation. Animals from two local Romanian pig breeds, the Mangalitsa and Bazna, were analyzed for variation at a number of genetic loci using PCR-based DNA tests. Polymorphism was assessed at loci which 1) are known to cause phenotypic variation, 2) are potentially involved in trait differences or 3) are putative candidate genes. The traits considered are disease resistance, growth, coat color, meat quality and prolificacy. Even though the populations are small and the markers are limited to specific genes, we found significant differences …

Nutritional Methods To Decrease N Losses From Open-Dirt Feedlots In Nebraska, Galen Erickson, Terry Klopfenstein

Department of Animal Science: Faculty Publications

Nitrogen losses from cattle feedlots are a concern due to loss of valuable N and enrichment of the atmospheric N pool. Nutritional methods to decrease losses would have economic and environmental benefit. One method to decrease N losses is by increasing carbon on the pen surface. From a management perspective, feeding a diet that will increase carbon may be the most cost effective. Therefore, three experiments evaluated feeding corn bran (less digestible than corn) at either 0, 15, or 30% of the diet. The 15 and 30% bran diets increase organic matter (carbon) excretion by approximately 0.5 and 1.0 kg/steer/d, …

Expression And Action Of Neurotropin-3 And Nerve Growth Factor In Embryonic And Early Postnatal Rat Testis Development, Andrea S. Cupp, Grace H. Kim, Michael K. Skinner

Department of Animal Science: Faculty Publications

The current study examines the expression and potential actions of neurotropin-3 (NT3), nerve growth factor (NGF), and their receptors during morphological sex determination (seminiferous cord formation) and perinatal rat testis development. The expression of neurotropins and their receptors was analyzed with immunohistochemistry. Cellular localization of neurotropin ligand and receptor proteins changed during embryonic testis development. Neurotropin-3 was localized to Sertoli cells at Embryonic Day 14 (E14), was present in gonocytes at Postnatal Day 0 (P0), and after birth became localized to the interstitium and Sertoli cells (P3–P5). The expression of trk C (the high affinity receptor for NT3) was localized …

Effects Of Genetic Type And Protein Levels On Growth Of Swine, O.W. Robison, L. L. Christian, R. Goodwin, R. K. Johnson, J. W. Mabry, R. K. Miller, M. D. Tokach

Department of Animal Science: Faculty Publications

A total of 1,588 pigs representing six genetic lines were included in this study. These lines were selected to represent a wide range of biological types for appetite, rate and composition of gain, and meat quality traits. Each line was fed four different diets differing in lysine content. Barrows and gilts were used in the experiment, and pigs were randomly assigned to come off test at one of three weights (113.6, 131.8, or 150 kg). Rates of increase in weight, backfat thickness, and longissimus muscle area were essentially linear. Genetic type and diet influenced (P < .05) rates of change in weight, backfat thickness, and longissimus muscle area and 10th rib fat depth, carcass longissimus muscle area, and dressing percentage. Genetic type × diet interactions were significant for weight change and 10th rib fat. As off-test-weight class increased fat and longissimus muscle area increased in linear fashion. In general, interactions associated with diet resulted from feeding the diet lowest in lysine. There was little evidence of genetic type × diet interactions. If those interactions that tested significant are real, they are a result of extremes in both genetic type (high fatness) and lysine level (low). Slaughtering pigs at heavier weights results in no change in rate of gain over the feeding period and linear increases in longissimus muscle area and backfat thickness.

Parameter Estimates For Greasy Fleece Weight Of Rambouillet Sheep At Different Ages, J. W. Lee, D. F. Waldron, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Variance components for greasy fleece weight in Rambouillet sheep were estimated. Greasy fleece weight was modeled either as repeated measurements on the same trait or as different traits at different ages. The original data were separated according to the age of the ewe at shearing into three classes; 1 yr, 2 and 3 yr, and older than 3 yr. An animal model was used to obtain estimates of genetic parameters with a REML algorithm. Total numbers of animals in pedigrees for the different age classes were 696, 729, and 573, respectively, and 822 for the repeated measures model across ages. …

Swine Nutrition Guide, Duane E. Reese, Robert C. Thaler, Michael C. Brumm, Austin J. Lewis, Phillip S. Miller, George W. Libal

Department of Animal Science: Faculty Publications

This publication is a revision of the previous swine nutrition publication prepared by the University of Nebraska and South Dakota State University. The focus of the publication continues to be on nutrient recommendations for swine. Specific factors (nutritional, environmental and managerial) that affect nutrient recommendations (Figure 1) have been considered and discussed. We believe that the identification and description of the factors in Figure 1 provide the framework for the nutrient recommendations presented in Tables 11 to 16. Industry advisors representing various facets of the pork industry were recruited to review and challenge the concepts incorporated in this publication. Also, …

Bias In Genetic Evaluations By Records Of Cows Treated With Bovine Somatotropin, S. Tsuruta, Jeffrey F. Keown, L. Dale Van Vleck, I. Misztal

Department of Animal Science: Faculty Publications

Records from Dairy Records Management Systems in Raleigh were used to estimate effects of bovine somatotropin (bST) treatment and to predict breeding values for milk production traits. The data comprised 5245 test-day records of bST-treated cows and 126,223 test-day records of untreated cows in first lactation for milk, fat, and protein yields. Fixed effects of bST treatment were estimated from test-day animal models with herd-test-date as another fixed factor. Percentage increases due to bST treatment ranged from 7 to 8% for test-day milk, fat, and protein yields. Random regression coefficients for additive genetic and permanent environmental effects were included in …

Estimation Of Genetic Variance In Corn From F1 Performance With And Without Pedigree Relationships Among Inbred Lines, C. M. Bromley, L. Dale Van Vleck, B. E. Johnson, O. S. Smith

Department of Animal Science: Faculty Publications

Estimates of genetic variance are needed for ranking of inbred lines for selection and for prediction of response to selection. The objectives of this study were to determine whether including relationships among inbred lines affects estimates of genetic variance and whether random association among inbred lines mated together affects estimates. Genetic variance was estimated with different models with restricted maximum likelihood for eight traits from matings of inbred lines from two heterotic groups (Iowa Stiff Stalk Synthetic, SSS, and unrelated to SSS, NSSS) of corn (Zea mays L.). For each comparison relationships among one or both of the inbred …

Parameter Estimates For Direct And Maternal Genetic Effects On Yearling, Eighteen-Month, And Slaughter Weights Of Korean Native Cattle, J. W. Lee, S. B. Choi, Y. H. Jung, Jeffrey F. Keown, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Data collected by the National Livestock Research Institute of the Rural Development Administration of Korea were used to estimate genetic parameters for yearling (YWT, n = 5,848), 18-mo (W18, n = 4,585), and slaughter (SWT, n = 2,279) weights for Korean Native cattle. Nine animal models were used to obtain REML estimates of genetic parameters: DP- 2 included genetic, uncorrelated dam, and residual random effects; DQ-2 included genetic, sire × region × year-season interaction, and residual random effects; DPQ- 2 was based on DQ-2 but included both interaction and dam effects; DMP-2 was based on DP-2 but with dam effect …

Comparison Of Plasma Fsh Concentration In Boars And Gilts From Lines Selected For Ovulation Rate And Embryonal Survival, And Litter Size And Estimation Of (Co)Variance Components For Fsh And Ovulation Rate, R. K. Johnson, J. J. Ford

Department of Animal Science: Faculty Publications

The objective of this research was to determine whether plasma concentration of FSH was genetically correlated with ovulation rate and thus was a useful trait for indirect selection. Blood samples were collected from 619 animals from five lines of pigs. Line I was selected for increased index of ovulation rate and embryonal survival, and Line C was its randomly selected control. Pigs sampled from Lines I and C were from generations 12 and 13. Pigs from three additional lines that were derived from eighth-generation pigs of Lines I and C also were used. These lines were Line C2, a randomly …

Parameter Estimates For Genetic Effects On Carcass Traits Of Korean Native Cattle, J. W. Lee, S. B. Choi, J. S. Kim, Jeffrey F. Keown, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Data (n = 1,746) collected from 1985 through 1995 on Korean Native Cattle by the National Livestock Research Institute of Korea were used to estimate genetic parameters for marbling score, dressing percentage, and longissimus muscle area, with backfat thickness, slaughter age, or slaughter weight as covariates. Estimates were obtained with REML. Model 1 included animal genetic and residual random effects. Model 2 was extended to include an uncorrelated random effect of the dam. Model 3 was based on Model 1 but also included sire × region × year-season interaction effects. Model 4 combined Models 2 and 3. All models included …

Genetic Correlations For Daily Gain Between Ram And Ewe Lambs Fed In Feedlot Conditions And Ram Lambs Fed In Pinpointer Units, L. Dale Van Vleck, Kreg A. Leymaster, Thomas G. Jenkins

Department of Animal Science: Faculty Publications

When performance is recorded in automated facilities that measure feed intake of individual lambs that are penned in a group, such as Pinpointer units, a legitimate question is the degree to which daily gain is genetically correlated with daily gain achieved under feedlot conditions. Lambs were from a composite population (½Columbia, ¼ Suffolk, and ¼ Hampshire germplasm) and of the F₂ or more advanced generations. Data were daily gains of 1,101 rams (PR) fed in Pinpointer units (11 to 17 wk of age) and 2,021 rams (FR) and 3,513 ewes (FE) fed under feedlot conditions (9- or 10-wk period …

Prediction Of Crude Fat Content Of Longissimus Muscle Of Beef Using The Ratio Of Fat Area Calculated From Computer Image Analysis: Comparison Of Regression Equations For Prediction Using Different Input Devices At Different Stations, K. Kuchida, S. Kono, K. Konishi, L. Dale Van Vleck, M. Suzuki, S. Miyoshi

Department of Animal Science: Faculty Publications

Crude fat content of longissimus (ribeye) muscle of beef cattle was predicted from a ratio of fat area (RFA) to area of ribeye muscle calculated from computer image analysis (CIA). Cross sections of 64 ribeyes taken from the 6–7th rib from cattle at experiment station A and cross sections of 94 ribeyes taken from the 6–7th rib from cattle at Experiment Station B were used in this study. Slices (1 to 1.5 cm in thickness) of just the Longissimus dorsi were homogenized and sampled for chemical estimation of crude fat content using petroleum ether. Crude fat content as determined from …

Genetic Parameters Among Weight, Prolificacy, And Wool Traits Of Columbia, Polypay, Rambouillet, And Targhee Sheep, C. M. Bromley, G. D. Snowder, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Genetic parameters for Columbia, Polypay, Rambouillet, and Targhee sheep were estimated using REML with animal models for prolificacy, weight, and wool traits. All bivariate analyses included a covariance between additive genetic effects for the two traits plus appropriate additional covariances. Number of observations by breed ranged from 5,140 to 7,095 for prolificacy traits, from 7,750 to 9,530 for weight traits, and from 4,603 to 34,746 for wool traits. Heritability estimates ranged from .03 to .11 for prolificacy traits (litter size at birth and litter size at weaning), from .09 to .26 for weight traits (birth weight and average daily gain), …

Role Of Transforming Growth Factor-Α And The Epidermal Growth Factor Receptor In Embryonic Rat Testis Development, Elena Levine, Andrea S. Cupp, Linda Miyashiro, Michael K. Skinner

Department of Animal Science: Faculty Publications

Embryonic testis development requires the morphogenesis of cords and growth of all cell populations to allow organ formation. It is anticipated that coordination of the growth and differentiation of various cell types involves locally produced growth factors. The current study was an investigation of the hypothesis that transforming growth factor- α (TGF-α) is involved in regulating embryonic testis growth. TGF-α has previously been shown to function in the postnatal testis. TGF-α and other members of the epidermal growth factor (EGF) family act through the epidermal growth factor receptor (EGFR) to stimulate cell proliferation and tissue morphogenesis. To understand the potential …

Rapid Communication: Porcine Vitamin D-25-Hydroxylase Maps To Chromosome 5, Daniel C. Ciobanu, R. K. Raven, M. F. Rothschild, N. H. Bell

Department of Animal Science: Faculty Publications

Locus Name. Vitamin D-25-hydroxylase.

Species. Sus scrofa.

Locus Symbol. CYP25.

Source of Primers. PCR primers were designed from the published sequence for porcine vitamin D-25-hydroxylase (CYP25) cDNA (GenBank accession no. Y16417). The position of the forward and reverse primers corresponds to 506 to 530 bp and 830 to 854 bp, respectively, of the cDNA. The primer pair amplified a 348-bp fragment of the cDNA and an 862-bp fragment from the pig genomic DNA. The 862-bp fragment (Gen- Bank accession no. AF284378) was subcloned into a pNoTA vector and identity was confirmed by sequencing. Genomic sequences from 1 to 74, …

Genetic Improvement Of The Horse, T. Arnason, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Table of Contents:

Breeding Goals
• General formulation of breeding objectives
• Racing horses
• Riding horses
• Other horse breeds
Genetic Evaluations
• Genetic Background and basic theory
• BLUP – the current standard method for obtaining EBV
• BLUP with the animal model – an effective tool for genetic evaluation of stallions and mares
• Applications of BLUP for genetic improvement of horses
• Use of non-additive genetic effects in horse breeding
Selection – Genetic Response
• Factors determining genetic progress
• Observed genetic progress in several horse populations
• Effects of selection on genetic variation and long-term …

Effect Of Dietary Concentration Of Metabolizable Lysine On Finishing Cattle Performance, M. J. Klemesrud, Terry J. Klopfenstein, Rick Stock, Austin Lewis, D. W. Herold

Department of Animal Science: Faculty Publications

A finishing trial and a metabolism trial were conducted to determine the effect of supplemental metabolizable Lys level on finishing calf performance and to estimate the metabolizable Lys requirement of finishing calves. The finishing trial included 60 individually fed crossbred beef steer calves (237 kg; SD = 20 kg) supplemented with either incremental amounts of rumen-protected Lys and Met, or Met alone. Addition of Lys and Met improved gains and efficiencies (quadratic; P < .02) during the first 56 d. There was no response to supplemental Met alone, suggesting that supplemental Lys rather than Met was responsible for the improvement in performance. Using nonlinear analyses to compare gain relative to supplemental Lys intake, maximum gain was determined to be 2.10 kg/ d, or .27 kg/d above the zero Lys control, at a supplemental Lys intake of 2.56 g/d. Steers supplemented with 3 and 4 g of Lys had a weight advantage over the control steers of 16 kg at 56 d and 32 kg at the end of the 161- d trial. However, there were no statistical responses to Lys or Met during any periods after 56 d. During a separate metabolism trial, four steers fed the control finishing diet were slaughtered, and abomasal contents were collected for amino acid analyses. The predicted (Level 1 NRC, 1996) metabolizable protein flow to the abomasum for the control diet was 715 g/d, and the predicted Lys flow was 37.9 g/d. A supplemental Lys intake of 2.56 g/d would increase the Lys flow to 40.5 g/d. Feedlot diets low in ruminal escape protein may be deficient in metabolizable Lys, especially early in the feeding period. The metabolizable Lys requirement of steer calves gaining 2.10 kg/d is estimated to be 40.5 g/d.

Role Of Neurotropins In Rat Embryonic Testis Morphogenesis (Cord Formation), Elena Levine, Andrea S. Cupp, Michael K. Skinner

Department of Animal Science: Faculty Publications

The process of seminiferous cord formation is the first morphological event that differentiates a testis from an ovary and indicates male sex determination. Cord formation occurs by embryonic Day 14 (Day 0 5 plug date; E14) in the rat. A series of experiments were conducted to determine if neurotropins and their receptors are important for the process of rat embryonic cord formation. The expression of low affinity neurotropin receptor (p75/LNGFR) was determined by immunohistochemistry on sections of both testis and ovary from E13 through birth (Day 0, P0) with an antibody to p75/LNGFR. The staining for p75/ LNGFR was present …