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Articles 691 - 720 of 1242
Full-Text Articles in Animal Sciences
Comparison Of Models For Estimation Of Genetic Parameters For Mature Weight Of Hereford Cattle, J. M. Rumph, R. M. Koch, K. E. Gregory, L. V. Cundiff, L. Dale Van Vleck
Comparison Of Models For Estimation Of Genetic Parameters For Mature Weight Of Hereford Cattle, J. M. Rumph, R. M. Koch, K. E. Gregory, L. V. Cundiff, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Genetic parameters of mature weight are needed for effective selection and genetic evaluation. Data for estimating these parameters were collected from 1963 to 1985 and consisted of 32,018 mature weight records of 4,175 Hereford cows that were in one control and three selection lines that had been selected for weaning weight, for yearling weight, or for an index combining yearling weight and muscle score for 22 yr. Several models and subsets of the data were considered. The mature weight records consisted of a maximum of three seasonal weights taken each year, at brand clipping (February and March), before breeding (May …
C. Pieramati, M. Fioretti, A. Rosati
C. Pieramati, M. Fioretti, A. Rosati
Department of Animal Science: Faculty Publications
Effects of inbreeding of animal and dam on estimates of genetic parameters and predictions of breeding values for five productive and reproductive traits of Piedmontese cattle were studied. Traits were (a) age at first insemination, (b) age at first calving, (c) 120-day weight, (d) yearling weight of males, and (e) yearling weight of females. Data for animals born from 1970 to 1995 were used. Inbreeding coefficients were computed using pedigree records back to 1900. A sire model was used for estimating genetic parameters and predicting breeding values. Two models were used for each trait. Model 1 included fixed effects of …
Estimation Of Genetic Parameters For Milk, Fat, Protein And Mozzarella Cheese Production For The Italian River Buffalo Bubalus Bubalis Population, A. Rosati, L. Dale Van Vleck
Estimation Of Genetic Parameters For Milk, Fat, Protein And Mozzarella Cheese Production For The Italian River Buffalo Bubalus Bubalis Population, A. Rosati, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
The objective of this work was to estimate genetic parameters for the Italian population of river buffaloes. Lactation records (10,663) for milk, fat, protein and mozzarella cheese production of river buffalo cows were analyzed by fitting a multiple trait animal model using restricted maximum likelihood. The number of cows with records was 3873 with 6842 animals in the relationship matrix. mozzarella cheese production per lactation was computed by considering milk yield, and fat and protein percentages. The average lactational yields of milk, fat, protein and calculated mozzarella (kg) and fat and protein percentages were 2286.8±492.1, 196.9±45.6, 104.7±21.7, 589.1±125.4, 8.59±0.85 and …
Genetic Parameters And Responses Of Linear Type, Yield Traits, And Somatic Cell Scores To Divergent Selection For Predicted Transmitting Ability For Type In Holsteins, B. J. Degroot, Jeffrey F. Keown, L. Dale Van Vleck, Erin L. Marotz
Genetic Parameters And Responses Of Linear Type, Yield Traits, And Somatic Cell Scores To Divergent Selection For Predicted Transmitting Ability For Type In Holsteins, B. J. Degroot, Jeffrey F. Keown, L. Dale Van Vleck, Erin L. Marotz
Department of Animal Science: Faculty Publications
The objective was to examine the direct and correlated responses of linear type, yield traits, and somatic cell scores (SCS) to divergent selection for predicted transmitting ability for type (PTAT) in Holsteins, while maintaining selection for yield traits across lines. For four generations, one-half of the University of Nebraska research Holstein herd was bred to Holstein sires with PTAT -1.50 and the other half to sires with PTAT - 1.25, with nearly equal predicted transmitting abilities for yield traits for both groups. Estimates of genetic and residual correlations and heritabilities were obtained from REML estimates of (co)variance components. Model for …
Methods And Compositions To Enhance Tenderness And Value Of Meat, Chris R. Calkins, Jesus Pablo Velazco De La Garcia, Nancy Coromoto Jerez-Timaure
Methods And Compositions To Enhance Tenderness And Value Of Meat, Chris R. Calkins, Jesus Pablo Velazco De La Garcia, Nancy Coromoto Jerez-Timaure
Department of Animal Science: Faculty Publications
A method of enhancing the tenderness of meat for animal or human consumption by treatment of pre-rigor muscle with the compositions of the invention. It has been found that other quality meat traits can also be enhanced with the method of the invention.
Rapid Communication: Mapping Of The Beta Tropomyosin (Tpm2) Gene To Pig Chromosome 1, J. Sherwood, Daniel C. Gill, M. F. Rothschild
Rapid Communication: Mapping Of The Beta Tropomyosin (Tpm2) Gene To Pig Chromosome 1, J. Sherwood, Daniel C. Gill, M. F. Rothschild
Department of Animal Science: Faculty Publications
Locus. Pig Tropomyosin beta (TPM2) gene.
Genus and Species. Sus Scrofa.
Source and Description of Primers. Primers were derived by using well-conserved regions of published human and mouse sequence (GenBank accession nos. AF209746 and NM_009416). The primers were used to amplify a 1.4-kp fragment of the porcine TPM2 gene covering exons 3 through 8. The porcine cDNA sequence (GenBank accession no. AF420022) showed 95% exonic identity (325 bp) at the nucleotide level to the human skeletal muscle beta tropomyosin (GenBank accession no. X06825). Additionally, pig specific primers were designed to amplify a 246-bp piece that spans exons 3 to …
Uncoupling Proteins And Energy Expenditure In Mice Divergently Selected For Heat Loss, T. G. Mcdaneld, Merlyn K. Nielsen, Jess Miner
Uncoupling Proteins And Energy Expenditure In Mice Divergently Selected For Heat Loss, T. G. Mcdaneld, Merlyn K. Nielsen, Jess Miner
Department of Animal Science: Faculty Publications
The objective of this study was to determine whether variation in energy expenditure created by selection on heat loss is mediated by uncoupling protein-1 (UCP1) in brown adipose tissue. Divergent selection for heat loss developed lines of mice with high (MH) and low (ML) maintenance energy expenditure. Concentration of UCP1 mRNA in brown adipose tissue (BAT) was 93% greater in ML than in MH mice (P < 0.02). Two new lines of mice, KH and KL, were bred by backcrossing a UCP1 knockout gene into the MH and ML lines, respectively; KH and KL with both knockout (−/−) and wild type (+/+) UCP1 genotypes were generated. At 13 wk of age, KH mice exhibited greater heat loss (166 kcal∙kg0.75∙d−1) than KL mice (126.4 kcal∙ kg0.75∙d−1) regardless of the UCP1 knockout (P < 0.0001). Concentration of UCP2 mRNA in BAT was 74% greater in UCP1 knockout mice (−/−) than in wild type (+/+; P = 0.0001). We conclude that response to selection for increased energy expenditure was not mediated by increased expression or function of UCP1.
Effect Of Corn Processing On Starch Digestion And Bacterial Crude Protein Flow In Finishing Cattle, R. J. Cooper, C. T. Milton, Terry J. Klopfenstein, T. L. Scott, C. B. Wilson, R. A. Mass
Effect Of Corn Processing On Starch Digestion And Bacterial Crude Protein Flow In Finishing Cattle, R. J. Cooper, C. T. Milton, Terry J. Klopfenstein, T. L. Scott, C. B. Wilson, R. A. Mass
Department of Animal Science: Faculty Publications
Six ruminally and duodenally cannulated yearling steers (523 kg) were used in a replicated 3 × 3 Latin square design experiment to study the effects of corn processing on nutrient digestion, bacterial CP production, and ruminal fermentation. Dietary treatments consisted of 90% concentrate diets that were based on dry-rolled (DRC), high-moisture (HMC), or steam-flaked (SFC) corn. Each diet contained 2.0% urea (DM basis) as the sole source of supplemental nitrogen. Each period lasted 17 d, with d 1 through 14 for diet adaptation and d 15 through 17 for fecal, duodenal, and ruminal sampling. Dry matter and OM intakes were …
Fiber-Type Composition Of Muscles Of The Beef Chuck And Round, K. S. Kirchofer, Chris R. Calkins, B. L. Gwartney
Fiber-Type Composition Of Muscles Of The Beef Chuck And Round, K. S. Kirchofer, Chris R. Calkins, B. L. Gwartney
Department of Animal Science: Faculty Publications
Thirty-eight muscles of the beef chuck and round were histochemically stained to characterize fiber-type composition in order to facilitate optimal muscle use in value-added products. Select-grade chucks and rounds (n = 4 each) were chosen to represent two carcass weight classes (250 to 295 kg and 363 to 410 kg) and two yield grades (1 and 3). Muscles were sectioned and stained with a procedure that included a succinate dehydrogenase and an adenosine triphosphatase staining technique. Number and diameter of β-red, α-red, and α-white muscle fibers were used to determine muscle fiber percentage, muscle fiber area, and percent area in …
Composition And Morphology Of The Follicular Basal Lamina During Atresia Of Bovine Antral Follicles, H. F. Irving-Rodgers, M. L. Mussard, J. E. Kinder, R. J. Rodgers
Composition And Morphology Of The Follicular Basal Lamina During Atresia Of Bovine Antral Follicles, H. F. Irving-Rodgers, M. L. Mussard, J. E. Kinder, R. J. Rodgers
Department of Animal Science: Faculty Publications
The fate of the follicular basal lamina during atresia was investigated using bovine follicles, in which different follicle phenotypes have been observed. These phenotypes include: healthy follicles with rounded basal granulosa cells with an aligned basal lamina or follicles with columnar basal granulosa cells with a basal lamina of many loops (loopy), and atretic follicles in which either the antral granulosa cells (antral atresia) or the basal cells (basal atresia) die first. Loopy lamina and basal atresia occur only in small antral follicles < 5 mm in diameter. Follicles were collected from cattle of unknown reproductive history and processed for immunohistochemistry and electron microscopy, and from animals in which follicle growth had been monitored by daily measurements of follicle diameter by ultrasonography. Electron microscopic observations of dominant follicles during the growth phase, plateau and regression showed that the basal lamina was still visible and intact upon atresia. These follicles had a conventional aligned basal lamina, which they retained, except for some degree of folding, as they progressed into antral atresia. In small follicles (2–5 mm in diameter), the basal cell shape (rounded or columnar) and appearance of the basal lamina (aligned or of many loops) did not appear to be related to the type of atresia. On atresia the follicular basal laminae retained immunoreactive laminin α1 and β2, type IV collagen a1 and nidogen. Laminin α2, which may come from the theca, was present in the follicular basal lamina of only 22% of healthy follicles, but was expressed very commonly in 71% of the atretic follicles. Laminin α2 expression was found in both phenotypes of healthy follicles, antral and basal atretic follicles, and follicles with aligned or loopy basal laminae. It is concluded that the basal lamina is not degraded upon atresia, but does undergo a variety of other changes.
Rapid Communication: Mapping Of The Ca2+ Atpase Of Fast Twitch 1 Skeletal Muscle Sarcoplasmic Reticulum (Atp2a1) Gene To Porcine Chromosome 3, Daniel C. Ciobanu, Y. Ciobanu, M. F. Rothschild
Rapid Communication: Mapping Of The Ca2+ Atpase Of Fast Twitch 1 Skeletal Muscle Sarcoplasmic Reticulum (Atp2a1) Gene To Porcine Chromosome 3, Daniel C. Ciobanu, Y. Ciobanu, M. F. Rothschild
Department of Animal Science: Faculty Publications
Locus Name. Ca2+ ATPase of fast twitch 1 skeletal muscle sarcoplasmic reticulum.
Species. Sus scrofa.
Locus Symbol. ATP2A1.
Source of Primers. Two sets of PCR primers were designed based on human ATP2A1 sequences (Gen- Bank accession numbers U96773 and U96777) available in the GenBank database. Using pig genomic DNA as a template we used set A primers to amplify approximately 1,100 bp spanning exon 1 to exon 2 and set B primers to amplify 1,200 bp gene segment covering some of exon 8 through part of exon 9. These sequences were deposited in GenBank, accession number AY027797-AY027799.
Utilization Of Distillers Grains Form The Fermentation Of Sorghum Or Corn In Diets For Finishing Beef And Lactating Dairy Cattle, S. Al-Suwaiegh, K. Fanning, R. J. Grant, C. T. Milton, Terry J. Klopfenstein
Utilization Of Distillers Grains Form The Fermentation Of Sorghum Or Corn In Diets For Finishing Beef And Lactating Dairy Cattle, S. Al-Suwaiegh, K. Fanning, R. J. Grant, C. T. Milton, Terry J. Klopfenstein
Department of Animal Science: Faculty Publications
Beef finishing and dairy lactation experiments were conducted to evaluate the nutritional value of distillers grains (DG) from sorghum or corn fermentation, in both wet (35.4% DM) and dry (92.2% DM) form (dairy trial only). In the finishing experiment, 60 yearling steers were used in a completely randomized design with three diets that were fed for 127 d: 1) control diet with 86% (DM basis) dry-rolled corn and no DG; 2) 30% of ration DM as wet corn DG in place of dry-rolled corn; and 3) 30% of ration DM as wet sorghum DG in place of dry-rolled corn. All …
Effect Of Corn Processing On Degradable Intake Protein Requirement Of Finishing Cattle, R. J. Cooper, C. Milton, Terry Klopfenstein, D. J. Jordon
Effect Of Corn Processing On Degradable Intake Protein Requirement Of Finishing Cattle, R. J. Cooper, C. Milton, Terry Klopfenstein, D. J. Jordon
Department of Animal Science: Faculty Publications
Three finishing trials were conducted to determine effect of corn processing on degradable intake protein requirement (DIP) of feedlot cattle. In Trial 1, 252 steers were fed 90% concentrate, high moisture corn-based diets that contained 0, 0.4, 0.8, or 1.2% urea (DM basis) to provide dietary DIP values of 7.0, 8.2, 9.3, and 10.5% of DM, respectively. Nonlinear analysis predicted maximal feed efficiency at 10.2% dietary DIP (95% confidence interval was 9.9 to 13.3%). In Trial 2, 264 steers were fed 90% concentrate, steam-flaked corn-based diets that contained 0, 0.4, 0.8, 1.2, 1.6, or 2.0% urea (DM basis) to provide …
Dried Poultry Waste For Cows Grazing Low-Quality Winter Forage, D. J. Jordon, Terry J. Klopfenstein, Don C. Adams
Dried Poultry Waste For Cows Grazing Low-Quality Winter Forage, D. J. Jordon, Terry J. Klopfenstein, Don C. Adams
Department of Animal Science: Faculty Publications
Two trials conducted in 1996–97 measured BW and body condition score changes of cows fed different sources of degradable intake protein, including dried poultry waste and soybean meal, while grazing low-quality winter forages. In Trial 1, 60 spring calving cows (5 yr; 555 kg) were used in an individual supplementation trial. Cows were gathered three times a week, sorted into individual pens, and fed their respective supplement. Cows grazed dormant native Sandhills winter range (common pasture) and were assigned to one of six supplemental treatments: 1) no supplement, 2) urea, 3) 22% dried poultry waste + urea, 4) soybean meal, …
Relationships Among Severity And Duration Of Clinical Mastitis And Sire Transmitting Abilities For Somatic Cell Score, Udder Type Traits, Productive Life, And Protein Yield, D. L. Nash, G. W. Rogers, J. B. Cooper, G. L. Gargrove, Jeffrey F. Keown
Relationships Among Severity And Duration Of Clinical Mastitis And Sire Transmitting Abilities For Somatic Cell Score, Udder Type Traits, Productive Life, And Protein Yield, D. L. Nash, G. W. Rogers, J. B. Cooper, G. L. Gargrove, Jeffrey F. Keown
Department of Animal Science: Faculty Publications
The objective of this study was to determine the relationships among severity and duration of clinical mastitis during first and second lactation and sire transmitting abilities for somatic cell score, udder type traits, productive life, and protein yield. Recording of clinical episodes began at first parturition for 1704 Holstein cows (in six Pennsylvania herds and one Nebraska herd) and continued into second lactation for 1055 of these cows. A total of 456 cows (sired by 168 bulls) had at least one clinical episode during first lactation, and 230 cows (sired by 100 bulls) had at least one clinical episode during …
Technical Note—A Comparison Of Methods Used To Measure Eating And Ruminating Activity In Confined Dairy Cattle, P. J. Kononoff, H. A. Lehman, A. J. Heinrichs
Technical Note—A Comparison Of Methods Used To Measure Eating And Ruminating Activity In Confined Dairy Cattle, P. J. Kononoff, H. A. Lehman, A. J. Heinrichs
Department of Animal Science: Faculty Publications
Detailed knowledge of chewing and rumination activities is critical to fully understand the dietary factors affecting normal rumen function. An automatic system for the digital recording of the jaw movements in free-ranging grazing cattle has been described, but its ability to measure chewing activity of cattle housed in confinement and fed total mixed rations has not yet been evaluated. The eating and ruminating behaviors of eight lactating dairy cows were recorded simultaneously by a wireless automatic system and by 5-min interval observation over 24-h periods. Results indicated that both methods agreed on identification of eating and ruminating bouts. Mean differences …
Memorial Khem Shahani, Robert W. Hutkins, Burt Maxcy, Steve Taylor
Memorial Khem Shahani, Robert W. Hutkins, Burt Maxcy, Steve Taylor
Department of Animal Science: Faculty Publications
Khem Shahani, Professor Emeritus at the University of Nebraska, died recently in Sicily while on a speaking tour and visiting family. Professor Shahani had a long, illustrious career in dairy microbiology and was one of the world's leading researchers in the area of probiotic bacteria. This is a field that, in the past few years, has seen remarkable growth and interest in the scientific comm.unity. Khem was one of only a few scientists who early on worked toward establishing a scientific basis for the role that probiotics play in nutrition and health. His outstanding record of research, teaching, and service …
Application Of Fuzzy-Neural Network In Classification Of Soils Using Ground-Penetrating Radar Imagery, Lameck O. Odhiambo, Robert S. Freeland, Ronald E. Yoder, J. Wesley Hines
Application Of Fuzzy-Neural Network In Classification Of Soils Using Ground-Penetrating Radar Imagery, Lameck O. Odhiambo, Robert S. Freeland, Ronald E. Yoder, J. Wesley Hines
Department of Animal Science: Faculty Publications
Errors associated with visual inspection and interpretation of radargrams often inhibits the intensive surveying of widespread areas using ground-penetrating radar (GPR). To automate the interpretive process, this paper presents an application of a fuzzy-neural network (F-NN) classifier for unsupervised clustering and classification of soil profile using GPR imagery. The classifier clusters and classifies soil profiles strips along a traverse based on common pattern similarities that can relate to physical features of the soil (e.g., number of horizons; depth, texture and structure of the horizons; and relative arrangement of the horizons, etc). This paper illustrates this classification procedure by its application …
Rapid Communication: Physical And Linkage Mapping Of The Porcine Calcitonin (Calc) Gene, J. E. Neil, S. E. Zhang, J. M. Helm, Daniel C. Ciobanu, M. F. Rothschild
Rapid Communication: Physical And Linkage Mapping Of The Porcine Calcitonin (Calc) Gene, J. E. Neil, S. E. Zhang, J. M. Helm, Daniel C. Ciobanu, M. F. Rothschild
Department of Animal Science: Faculty Publications
Genus and Species. Sus scrofa.
Locus. Porcine calcitonin (CALC) gene.
Source and Description of Primers. Primers, CCA1F and CCA1R, were designed from canine calcitonin sequence (GenBank Accession no. AJ271090) to amplify genomic porcine DNA. Using sequence obtained from the amplified PCR product, additional pig-specific primers (CIPBF, CIPBR, CIPCF, CIPCR) were designed.
Primer Sequences. CCA1F: 5′-CAC TTT GGA TTG GCC GCG C-3′; CCA1R: 5′-ACC AGG GCA GCC AGC AGG A-3′; CIPBF: 5′-AAC TTC CCA CTC TGC ACA CT-3′; CIPBR: 5′-AGA CCA AAC TTC AGC AGG AT- 3′; CIPCF: 5′-TTC TCC TTC CTC TGC TTC TG-3′; CIPCR: 5′-GCA AAC CCA ATA …
Effects Of Manipulating Protein And Phosphorus Nutrition Of Feedlot Cattle On Nutrient Management And The Environment, Terry J. Klopfenstein, Galen E. Erickson
Effects Of Manipulating Protein And Phosphorus Nutrition Of Feedlot Cattle On Nutrient Management And The Environment, Terry J. Klopfenstein, Galen E. Erickson
Department of Animal Science: Faculty Publications
Feedlot nutrition will play a role in meeting challenges such as nutrient management. Nitrogen and phosphorus are two nutrients that are currently studied in this context. One nutritional method is formulating diets not to exceed requirements for nitrogen and phosphorus. Requirements are different for calves and yearlings. The requirements also change during the finishing period. Phosphorus requirements have not been extensively studied for feedlot cattle between 270 and 600 kg. Therefore, P requirements studies were conducted to determine the P requirement of calves (265 kg) and yearlings (385 kg). The requirement was not detected with P levels as low as …
Phosphorus Requirement Of Finishing Feedlot Calves, Galen Erickson, Terry Klopfenstein, C. T. Milton, Dennis Brink, M. W. Orth, K. M. Whittet
Phosphorus Requirement Of Finishing Feedlot Calves, Galen Erickson, Terry Klopfenstein, C. T. Milton, Dennis Brink, M. W. Orth, K. M. Whittet
Department of Animal Science: Faculty Publications
Dietary P supplied to feedlot cattle is important because an inadequate supply will compromise performance, whereas excess P may harm the environment. However, P requirements of feedlot cattle are not well documented. Therefore, 45 steer calves (265.2 ±16.6 kg) were individually fed to determine the P required for gain and bone integrity over a 204-d finishing period. The basal diet consisted of 33.5% high-moisture corn, 30% brewers grits, 20% corn bran, 7.5% cottonseed hulls, 3% tallow, and 6% supplement. Treatments consisted of 0.16 (no supplemental inorganic P), 0.22, 0.28, 0.34, and 0.40% P (DM basis). Supplemental P was provided by …
The Role Of Nutrition In Reducing Nutrient Output From Ruminants, L. D. Satter, Terry J. Klopfenstein, Galen E. Erickson
The Role Of Nutrition In Reducing Nutrient Output From Ruminants, L. D. Satter, Terry J. Klopfenstein, Galen E. Erickson
Department of Animal Science: Faculty Publications
Much of the effort expended on nutrient management has focused on the post-excretion product. It is important to keep in mind that management of the diet can have important impacts on quantitative and qualitative aspects of the excreted nutrients. Surveys of nutritionists and extension specialists show that dairy producers are advised to feed 0.45 to 0.50% phosphorus (P) (DM basis) in their lactating cow diets. This is 20% in excess of NRC (2001) requirements. Feeding to requirement would reduce P excretion by 25 to 30% and would reduce solubility and potential for runoff of the P that is applied to …
Direct And Correlated Responses To Two-Stage Selection For Ovulation Rate And Number Of Fully Formed Pigs At Birth In Swine, A. Ruiz-Flores, R. K. Johnson
Direct And Correlated Responses To Two-Stage Selection For Ovulation Rate And Number Of Fully Formed Pigs At Birth In Swine, A. Ruiz-Flores, R. K. Johnson
Department of Animal Science: Faculty Publications
Our objectives were to estimate responses and genetic parameters for ovulation rate, number of fully formed pigs at birth, and other production traits following two-stage selection for increased ovulation rate and number of fully formed pigs. Eight generations of selection were practiced in each of two lines. One selection line was derived from a line that previously selected eight generations for an index to increase ovulation rate and embryonic survival (the IOL pigs). The other selection line was derived from the unselected control line of the index selection experiment (the COL pigs). The control line (C) was continued with random …
Predictors Of Marker-Informativeness For An Outbred F2 Design, J. L. Rocha, Daniel Pomp, L. Dale Van Vleck, Merlyn K. Nielsen
Predictors Of Marker-Informativeness For An Outbred F2 Design, J. L. Rocha, Daniel Pomp, L. Dale Van Vleck, Merlyn K. Nielsen
Department of Animal Science: Faculty Publications
Generalization of the polymorphism information content (PIC) index to represent marker informativeness (MI) for a three-generation F2 design requires that two additional sources of non-informativeness be added to the PIC formula: the probability of matings between like-heterozygous F1 individuals, of which one is non-informative; and that of matings between like-heterozygous F1 individuals, which are both fully informative but where line of origin of the same alleles is reciprocal. Given the dense marker-maps currently available for some species, this F22 informativeness parameter constitutes the natural criterion for marker selection in F2 designs, and two computer …
Increased Plasma Follicle-Stimulating Hormone Concentrations In Prepubertal Gilts From Lines Selected For Increased Number Of Corpora Lutea, J. J. Ford, D. R. Zimmerman, T. H. Wise, K. A. Leymaster, R. K. Christenson
Increased Plasma Follicle-Stimulating Hormone Concentrations In Prepubertal Gilts From Lines Selected For Increased Number Of Corpora Lutea, J. J. Ford, D. R. Zimmerman, T. H. Wise, K. A. Leymaster, R. K. Christenson
Department of Animal Science: Faculty Publications
Plasma follicle-stimulating hormone (FSH) was evaluated in gilts from two studies in which ovulation rate was increased through direct selection for number of corpora lutea (CL) to determine whether selection for ovulation rate affected FSH secretion during prepubertal development. In the first study, 76 control and 110 selected gilts of University of Nebraska gene pool lines were bled twice during prepubertal development. Plasma FSH concentrations were greater (P < 0.05) at 53 (13.5%) and 75 (21.3%) d of age in selected than in control gilts. In the second study, 254 control gilts, 261 gilts from a line selected for ovulation rate, and 256 gilts from a line selected for uterine capacity were bled at three prepubertal ages. Plasma FSH was greater (P < 0.05), relative to controls, on d 34 (> 24%), 55 (> 13%), and 85 (> 10%) in White Composite gilts selected for either increased ovulation rate or for greater uterine capacity. Unilateral ovariectomy and hysterectomy were performed at …
Usefulness Of Subjective Ovine Milk Scores: I. Associations With Range Ewe Characteristics And Lamb Production, G. D. Snowder, A.D. Knight, L. Dale Van Vleck, C. M. Bromley, T. R. Kellom
Usefulness Of Subjective Ovine Milk Scores: I. Associations With Range Ewe Characteristics And Lamb Production, G. D. Snowder, A.D. Knight, L. Dale Van Vleck, C. M. Bromley, T. R. Kellom
Department of Animal Science: Faculty Publications
Range ewes are commonly evaluated for milking ability by producers to determine the ewe’s ability to rear lamb(s). The U.S. Sheep Experiment Station has subjectively scored (low, average, high) a ewe’s milking ability within 24 h of lambing for many years. The relationship of subjective milk scores with lamb production was investigated using lambing records of Columbia (n = 1,731), Polypay (n = 1,129), Rambouillet (n = 1,704), and Targhee (n = 1,638) ewes. The incidence of high milk scores increased from less than 10% at first parity to 29 to 40% at second and greater parities. At maturity, Columbia …
Usefulness Of Subjective Ovine Milk Scores: Ii. Genetic Parameter Estimates, G. D. Snowder, L. Dale Van Vleck, A. D. Knight, T. R. Kellom, C. M. Bromley
Usefulness Of Subjective Ovine Milk Scores: Ii. Genetic Parameter Estimates, G. D. Snowder, L. Dale Van Vleck, A. D. Knight, T. R. Kellom, C. M. Bromley
Department of Animal Science: Faculty Publications
Genetic parameters for a subjective milk score given to ewes within 24 h of parturition were estimated to determine the usefulness of milk score as a selection trait to improve milk production, which influences total litter weight weaned. Heritability of milk score and the genetic correlation of milk score with litter weight weaned were estimated by REML separately for four sheep breeds, Rambouillet (n = 1,731), Targhee (n = 1,638), Columbia (n = 1,731), and Polypay (n = 1,129). Litter weight weaned was the total weight of lambs weaned at approximately 120 d of age under a western range production …
Comparison Of Conventional And Two-Stage Reversible Flow, Static-Bed Biodenitrification Reactors, Bryan L. Woodbury, Mohamed F. Dahab
Comparison Of Conventional And Two-Stage Reversible Flow, Static-Bed Biodenitrification Reactors, Bryan L. Woodbury, Mohamed F. Dahab
Department of Animal Science: Faculty Publications
This paper compares the operation of a traditional single-stage system with a two-stage, reversible flow biodenitrification system for removing nitrates from drinking water. The purpose of this study was to investigate the ability of these two-stage systems to remove nitrate and residual organics from treated water as compared to single-stage units. In the reversible flow system, the second-stage (i.e. follow) reactor is operated in series with the first-stage (i.e. lead) reactor. After a given period of operation, the flow regime is reversed so that the follow reactor becomes the lead one and vice versa. The active solids remaining in the …
Identification Of Quantitative Trait Loci Affecting Reproduction In Pigs, J. P. Cassady, R. K. Johnson, Daniel Pomp, G. A. Rohrer, L. Dale Van Vleck, E. K. Spiegel, K. M. Gilson
Identification Of Quantitative Trait Loci Affecting Reproduction In Pigs, J. P. Cassady, R. K. Johnson, Daniel Pomp, G. A. Rohrer, L. Dale Van Vleck, E. K. Spiegel, K. M. Gilson
Department of Animal Science: Faculty Publications
The objective of this research was to identify chromosomal regions harboring QTL affecting reproduction in pigs. A three-generation resource population was developed by crossing low-indexing pigs from a randomly selected control line (C) with high-indexing pigs of a line selected for increased index of ovulation rate and embryonic survival (I). Differences between Lines I and C at Generation 10 were 6.7 ova and 3.3 fetuses at 50 d of gestation and 3.1 fully formed and 1.6 live pigs at birth. Phenotypic data were collected on F2 females, born in three replicates, for ovulation rate (n = 423), age at …
Genetic Correlations For Litter Weight Weaned With Growth, Prolificacy, And Wool Traits In Columbia, Polypay, Rambouillet, And Targhee Sheep, L. Dale Van Vleck, C. M. Bromley, G. D. Snowder
Genetic Correlations For Litter Weight Weaned With Growth, Prolificacy, And Wool Traits In Columbia, Polypay, Rambouillet, And Targhee Sheep, L. Dale Van Vleck, C. M. Bromley, G. D. Snowder
Department of Animal Science: Faculty Publications
Total litter weight weaned at 120 d postpartum per ewe lambing is often believed to be a measure of range ewe productivity. Genetic correlations for litter weight weaned at 120 d with prolificacy, growth, and wool traits for Columbia, Polypay, Rambouillet, and Targhee sheep were estimated using REML with animal models. Observations per breed ranged from 5,140 to 7,083 for litter weight weaned, from 5,140 to 7,095 for prolificacy traits, from 7,750 to 9,530 for growth traits, and from 4,603 to 18,443 for wool traits. Heritability estimates for litter weight weaned were low and ranged from 0.02 to 0.11. Fraction …