Open Access. Powered by Scholars. Published by Universities.®

Animal Sciences Commons™

Open Access. Powered by Scholars. Published by Universities.®

Department of Animal Science: Faculty Publications

Articles 661 - 690 of 1242

Full-Text Articles in Animal Sciences

Influence Of Glyphosate-Tolerant (Event Nk603) And Corn Rootworm Protected (Event Mon863) Corn Silage And Grain On Feed Consumption And Milk Production In Holstein Cattle, R. J. Grant, K. C. Fanning Jan 2003

Influence Of Glyphosate-Tolerant (Event Nk603) And Corn Rootworm Protected (Event Mon863) Corn Silage And Grain On Feed Consumption And Milk Production In Holstein Cattle, R. J. Grant, K. C. Fanning

Department of Animal Science: Faculty Publications

Two studies were conducted to evaluate the effect of a glyphosate-tolerant (event nk603) and a corn rootworm protected (event MON863) corn hybrid on feed intake and milk production compared with the nontransgenic hybrid and two reference hybrids. In Experiment 1, 16 multiparous Holstein cows were assigned to one of four treatments in replicated 4 × 4 Latin squares with 28- d periods. Diets contained 40% (dry matter [DM] basis) of either 1) glyphosate-tolerant corn silage (GT), 2) nontransgenic control corn silage, or 3) two nontransgenic reference hybrids which are commercially available. Each diet also contained 23% corn grain from the …

Go to article

Heritability Of Intramammary Infections At First Parturition And Relationships With 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. Hargrove, Jeffrey F. Keown Jan 2003

Heritability Of Intramammary Infections At First Parturition And Relationships With 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. Hargrove, Jeffrey F. Keown

Department of Animal Science: Faculty Publications

The objective of this study was to determine the relationships among daughter intramammary infections at first parturition and sire transmitting abilities for somatic cell score, udder type traits, productive life, and protein yield. Quarter milk samples from 958 daughters (in eight Pennsylvania herds and one Nebraska herd) of 182 Holstein sires were collected within a few days of first calving and cultured to determine intramammary infection status. A total of 446 cows had intramammary infections in 835 quarters at first parturition. Incidence of intramammary infections at first parturition and the proportion of quarters infected per cow were regressed on age …

Go to article

Effect Of Chronic Treatment With The Gonadotrophin-Releasing Hormone Agonist Azagly-Nafarelin On Basal Concentrations Of Lh In Prepubertal Bulls, H. Jiménez-Severiano, M. J. D'Occhio, D. D. Lunstra, M. L. Mussard, J. W. Koch, L. R. Ehnis, W. J. Enright, J. E. Kinder Jan 2003

Effect Of Chronic Treatment With The Gonadotrophin-Releasing Hormone Agonist Azagly-Nafarelin On Basal Concentrations Of Lh In Prepubertal Bulls, H. Jiménez-Severiano, M. J. D'Occhio, D. D. Lunstra, M. L. Mussard, J. W. Koch, L. R. Ehnis, W. J. Enright, J. E. Kinder

Department of Animal Science: Faculty Publications

Administration of GnRH agonist for an extended period inhibits pulsatile LH release but enhances testicular function of bulls. The mechanism whereby long-term administration of GnRH agonist enhances testosterone concentration in the blood of bulls has not been determined. The aim of this study was to determine whether chronic treatment with the GnRH agonist, azagly-nafarelin, increases blood concentrations of LH and FSH in prepubertal bulls. Two different doses of the GnRH agonist were administered via Alzet mini-osmotic pumps for 28 days. Blood samples were collected at 20 min intervals for 24 h at days 2, 13 and 25 of treatment. Agonist-treated …

Go to article

The Effect Of Corn Silage Particle Size And Cottonseed Hulls On Cows In Early Lactation, P. J. Kononoff, A. J. Heinrichs Jan 2003

The Effect Of Corn Silage Particle Size And Cottonseed Hulls On Cows In Early Lactation, P. J. Kononoff, A. J. Heinrichs

Department of Animal Science: Faculty Publications

The objective of this study was to evaluate the effects of reducing forage particle length (FPL) and the inclusion of cottonseed hulls (CSH) on intake, digestibility, chewing activity, and milk production of cows in early lactation. Sixteen multiparous cows averaging 17 ± 3 d in milk and 677 ± 58 kg BW were assigned to one of four 4 × 4 Latin squares. One square contained ruminally cannulated cows to evaluate effects of treatment on rumen fermentation and function. During each of the 23-d periods, cows were offered one of four total mixed rations that differed in particle length (long …

Go to article

The Effect Of Corn Silage Particle Size On Eating Behavior, Chewing Activities, And Rumen Fermentation In Lactating Dairy Cows, P. J. Kononoff, A. J. Heinrichs, H. A. Lehman Jan 2003

The Effect Of Corn Silage Particle Size On Eating Behavior, Chewing Activities, And Rumen Fermentation In Lactating Dairy Cows, P. J. Kononoff, A. J. Heinrichs, H. A. Lehman

Department of Animal Science: Faculty Publications

The objective of this experiment was to evaluate effects of reducing corn silage particle size on eating behavior, chewing activity, and rumen fermentation in lactating dairy cows. Four cannulated, multiparous cows averaging 110 ± 4 d in milk and weighing 675 ± 70 kg were randomly assigned to a 4 × 4 Latin square. During each of four 14-d periods, animals were offered one of four diets that were chemically similar but varied in corn silage particle size: short (SH), mostly short (MSH), mostly long (MLG), and long (LG), with a geometric mean particle length of 7.4, 7.8, 8.3, and …

Go to article

Effects Of Final Implant Type And Supplementation Of Melengestrol Acetate® On Finishing Feedlot Heifer Performance, Carcass Characteristics, And Feeding Economics1, C. N. Macken, C. T. Milton, T. J. Klopfenstein, B, D, Dicke, D. E. Mcclellan Jan 2003

Effects Of Final Implant Type And Supplementation Of Melengestrol Acetate® On Finishing Feedlot Heifer Performance, Carcass Characteristics, And Feeding Economics1, C. N. Macken, C. T. Milton, T. J. Klopfenstein, B, D, Dicke, D. E. Mcclellan

Department of Animal Science: Faculty Publications

Three finishing experiments were conducted in commercial feedlots to determine effects of implant programs on finishing heifer performance, carcass characteristics, and economics. A total of 3,307 heifers were used in the three experiments. Overall, four treatment comparisons were tested within the three separate experiments. Treatment groups included the following: 1) heifers implanted with Synovex® Plus (Fort Dodge Animal Health; Fort Dodge, IA) but not fed melengestrol acetate (MGA®; Pharmacia and Upjohn Company; Kalamazoo, MI) , 2) heifers implanted with Synovex® Plus and fed MGA®, 3) heifer implanted with Revalor®-H (Intervet Inc.; Millsboro, DE) and fed MGA®, and 4) …

Go to article

The Ability Of The N-Alkane Technique To Estimate Intake And Diet Choice Of Sheep, R. M. Lewis, A. M. Magadlela, N. S. Jessop, G. C. Emmans Jan 2003

The Ability Of The N-Alkane Technique To Estimate Intake And Diet Choice Of Sheep, R. M. Lewis, A. M. Magadlela, N. S. Jessop, G. C. Emmans

Department of Animal Science: Faculty Publications

This study assessed the efficacy of the n-alkane technique to estimate intake and diet composition in animals given single foods or a choice of two. In thefirst experiment intakes of pelleted ryegrassand lucerne, given eitheralone or as a choice, were measured in lambshoused indoors in individual pens. Each of the three feeding treatments was given to 12 lambs at two degrees of maturity (0.30 and 0·45 of estimated mature sizes). The 12 lambs were constituted as three replicates of the two sexes of each of two breeds. The measured intakes werecompared with those estimated using the n-alkanes C31 andC33, found …

Go to article

Chemotactic Role Of Neurotropin 3 In The Embryonic Testis That Facilitates Male Sex Determination, Andrea S. Cupp, Mehmet Uzumcu, Michael F. Skinner Jan 2003

Chemotactic Role Of Neurotropin 3 In The Embryonic Testis That Facilitates Male Sex Determination, Andrea S. Cupp, Mehmet Uzumcu, Michael F. Skinner

Department of Animal Science: Faculty Publications

The first morphological event after initiation of male sex determination is seminiferous cord formation in the embryonic testis. Cord formation requires migration of pre-peritubular myoid cells from the adjacent mesonephros. The embryonic Sertoli cells are the first testicular cells to differentiate and have been shown to express neurotropin-3 (NT3), which can act on highaffinity trkC receptors expressed on migrating mesonephros cells. NT3 expression is elevated in the embryonic testis during the time of seminiferous cord formation. A trkC receptor tyrophostin inhibitor, AG879, was found to inhibit seminiferous cord formation and mesonephros cell migration. Beads containing NT3 were found to directly …

Go to article

Supplementation To Meet Metabolizable Protein Requirements Of Primiparous Beef Heifers: Ii. Pregnancy And Economics, H. H. Patterson, Don C. Adams, Terry J. Klopfenstein, R. T. Clark, B. Teichert Jan 2003

Supplementation To Meet Metabolizable Protein Requirements Of Primiparous Beef Heifers: Ii. Pregnancy And Economics, H. H. Patterson, Don C. Adams, Terry J. Klopfenstein, R. T. Clark, B. Teichert

Department of Animal Science: Faculty Publications

Metabolizable protein (MP) requirements of spring calving heifers increase over the winter due to advancing gestation. The MP content of grazed winter forage is low, which may result in an MP deficiency. The objective was to compare the response of supplementing pregnant yearling heifers to meet MP requirements versus conventional CP supplementation. In 1997–98 and in 1998–99, pregnant, March-calving heifers (2,120 animals; 358 kg) at two locations of a commercial ranch in the Nebraska Sandhills, were used following breeding through calving as 2-yr-olds (cows). Heifers were randomly allotted to one of two supplementation treatments (about 265 heifers/treatment) each year at …

Go to article

Supplementation To Meet Metabolizable Protein Requirements Of Primiparous Beef Heifers: I. Performance, Forage Intake, And Nutrient Balance, H. H. Patterson, Terry J. Klopfenstein, Don C. Adams, Jacqueline Musgrave Jan 2003

Supplementation To Meet Metabolizable Protein Requirements Of Primiparous Beef Heifers: I. Performance, Forage Intake, And Nutrient Balance, H. H. Patterson, Terry J. Klopfenstein, Don C. Adams, Jacqueline Musgrave

Department of Animal Science: Faculty Publications

Three experiments were conducted to evaluate the response of supplementing primiparous heifers based on the metabolizable protein (MP) system during pregnancy and lactation. In Exp. 1, 12 pregnant, March-calving heifers (432 ± 10 kg) grazing Sandhills range were randomly allotted to one of two treatments: supplementation based on either the MP system (MPR) or the CP system (CPR). Supplements were fed to individual heifers from October to February and no hay was offered. Grazed forage organic matter intake (FOMI) was measured in November, January, and February. In Exp. 2, 18 heifers (424 ± 8 kg) were randomly allotted to one …

Go to article

The Effect Of Reducing Alfalfa Haylage Particle Size On Cows In Early Lactation, P. J. Kononoff, A. J. Heinrichs Jan 2003

The Effect Of Reducing Alfalfa Haylage Particle Size On Cows In Early Lactation, P. J. Kononoff, A. J. Heinrichs

Department of Animal Science: Faculty Publications

The objective of this experiment was to evaluate effects of reducing forage particle size on cows in early lactation based on measurements of the Penn State Particle Separator (PSPS). Eight cannulated, multiparous cows averaging 19 ± 4 d in milk and 642 ± 45 kg BW were assigned to one of two 4 × 4 Latin Squares. During each of the 23-d periods, animals were offered one of four diets, which were chemically identical but included alfalfa haylage of different particle size; short (SH), mostly short (MSH), mostly long (MLG), and long (LG). Physically effective neutral detergent fiber (peNDF) was …

Go to article

Modification Of The Penn State Forage And Total Mixed Ration Particle Separator And The Effects Of Moisture Content On Its Measurements, P. J. Kononoff, A. J. Heinrichs, D. R. Buckmaster Jan 2003

Modification Of The Penn State Forage And Total Mixed Ration Particle Separator And The Effects Of Moisture Content On Its Measurements, P. J. Kononoff, A. J. Heinrichs, D. R. Buckmaster

Department of Animal Science: Faculty Publications

The Penn State Particle Separator has led to widespread measurement of forage and total mixed ration (TMR) particle size. However, a large proportion of small particles may pass through both sieves when a TMR is analyzed, and field research has suggested that both shaking frequency and sample dry matter may affect the results. The objectives of this project were to test the effects of an additional sieve with a smaller aperture size, shaking frequency, and sample moisture content on results obtained. A sieve was constructed out of wire with a nominal size aperture of 1.18 mm. Samples of alfalfa haylage, …

Go to article

Estrogen Receptor-Α Populations Change With Age In Commercial Laying Hens, K.K. Hansen, R.J. Kittok, G. Sarath, C.F. Toombs, N. Caceres, M.M. Beck Jan 2003

Estrogen Receptor-Α Populations Change With Age In Commercial Laying Hens, K.K. Hansen, R.J. Kittok, G. Sarath, C.F. Toombs, N. Caceres, M.M. Beck

Department of Animal Science: Faculty Publications

Older hens in production lay larger but fewer eggs than younger birds, and the incidence of soft and broken shells is greater in older hens than younger. These changes are attributable at least in part to changing hormone profiles and diminished ability of the hen to transport calcium at the duodenum. In further exploration of this relationship, a study was conducted with three ages of Hy-Line W-36 birds: prelay pullets (PL; 19 wk, 0% production), peak-production hens (PP; 29 wk, ∼93% production), and late-stage hens (LS; 71 wk, ∼80% production). Hens from the PP and LS groups were palpated for …

Go to article

Interaction Between Bunk Management And Monensin Concentration On Finishing Performance, Feeding Behavior, And Ruminal Metabolism During An Acidosis Challenge With Feedlot Cattle, Galen Erickson, C. T. Milton, K. C. Fanning, R. J. Cooper, R. S. Swingle, J. C. Parrott, G. Vogel, Terry Klopfenstein Jan 2003

Interaction Between Bunk Management And Monensin Concentration On Finishing Performance, Feeding Behavior, And Ruminal Metabolism During An Acidosis Challenge With Feedlot Cattle, Galen Erickson, C. T. Milton, K. C. Fanning, R. J. Cooper, R. S. Swingle, J. C. Parrott, G. Vogel, Terry Klopfenstein

Department of Animal Science: Faculty Publications

Two commercial feedlot experiments and a metabolism study were conducted to evaluate the effects of monensin concentrations and bunk management strategies on performance, feed intake, and ruminal metabolism. In the feedlot experiments, 1,793 and 1,615 steers were used in Exp. 1 and 2, respectively, in 18 pens for each experiment (six pens/treatment). Three treatments were evaluated: 1) ad libitum bunk management with 28.6 mg/kg monensin and clean bunk management strategies with either 2) 28.6 or 3) 36.3 mg/ kg monensin. In both experiments, 54 to 59% of the clean bunk pens were clean at targeted clean time, or 2200, compared …

Go to article

Effect Of Feeding Glyphosate-Tolerant (Roundup-Ready Events Ga21 Or Nk603) Corn Compared With Reference Hybrids On Feedlot Steer Performance And Carcass Characteristics, Galen Erickson, N. D. Robbins, J. J. Simon, L. L. Berger, Terry Klopfenstein, E. P. Stanisiewski, G. F. Hartnell Jan 2003

Effect Of Feeding Glyphosate-Tolerant (Roundup-Ready Events Ga21 Or Nk603) Corn Compared With Reference Hybrids On Feedlot Steer Performance And Carcass Characteristics, Galen Erickson, N. D. Robbins, J. J. Simon, L. L. Berger, Terry Klopfenstein, E. P. Stanisiewski, G. F. Hartnell

Department of Animal Science: Faculty Publications

Three experiments were conducted to compare the feeding value of genetically enhanced corn (Roundup Ready corn events GA21 and nk603) with nontransgenic hybrids. The four treatments included two separate reference hybrids (REF), the near-isogenic control hybrid (CON), and the genetically enhanced corn (RR), resulting in two preplanned comparisons of CON vs. RR and RR vs. the average of REF. In Exp. 1 (RR event GA21), 175 steers (BW = 427 kg) were fed in 25 pens with seven pens per corn hybrid, except CON, which contained four pens due to limited quantities of that hybrid. In Exp. 2 (RR event …

Go to article

Corn Processing Method In Finishing Diets Containing Wet Corn Gluten Feed, T. L. Scott, C. T. Milton, Galen Erickson, Terry Klopfenstein, Rick A. Stock Jan 2003

Corn Processing Method In Finishing Diets Containing Wet Corn Gluten Feed, T. L. Scott, C. T. Milton, Galen Erickson, Terry Klopfenstein, Rick A. Stock

Department of Animal Science: Faculty Publications

Two trials were conducted to determine the effect of corn processing method on performance and carcass traits in steers fed finishing diets containing wet corn gluten feed (WCGF). In Trial 1, 480 steer calves (303 kg initial BW) were fed eight finishing diets: 1) dry-rolled corn (DRC) without; and 2) with 32% (DM basis) WCGF; 3) steam-flaked corn (SFC) without; and 4) with WCGF; 5) a combination of DRC and SFC without WCGF; 6) finely-ground corn (FGC) with WCGF; 7) high-moisture corn (HMC) with WCGF; and 8) whole corn (WC) with WCGF. Feeding WC + WCGF increased (P < 0.10) DMI and decreased gain:feed compared with all other treatments. Feeding DRC + WCGF increased (P < 0.10) DMI and decreased (P < 0.10) gain:feed compared with treatments other than WC + WCGF. Steers on treatments that included WCGF gained similarly, regardless of corn processing method, and at a rate 6% faster (P < 0.10) than steers fed diets that did not include WCGF. Gain:feed did not differ among steers fed SFC, SFC + WCGF, SFC + DRC, and HMC + WCGF. Steers fed SFC or SFC + WCGF were more efficient (P < 0.10) than steers fed DRC or FGC + WCGF. In Trial 2, 288 steer calves (382 kg initial BW) were fed six finishing diets: 1) DRC without; and 2) with 22% (DM basis) WCGF; 3) SFC without; and 4) with WCGF; 5) finely rolled corn (FRC) with WCGF; and 6) HMC corn with WCGF. Steers fed DRC + WCGF or FRC + WCGF consumed more DM (P < 0.10) than steers fed DRC, SFC, or SFC + WCGF. Feed intake did not differ between steers fed SFC + WCGF and HMC + WCGF. All treatment groups receiving WCGF consumed more DM (P < 0.10) feed than steers fed DRC or SFC without WCGF. Steers fed SFC + WCGF gained 8% faster (P < 0.10), and steers fed DRC 9.5% slower (P < 0.10) than steers receiving all other treatments. Daily gains did not differ among other treatment groups. Steers fed SFC or SFC + WCGF gained 10% more (P < 0.10) efficiently than all other treatment groups. Feed efficiency did not differ among steers fed DRC, DRC + WCGF, FRC + WCGF, and HMC + WCGF. Estimates for the NEg of …

Go to article

Breed Comparisons Of Angus, Brahman, Hereford, Pinzgauer, Sahiwal, And Tarentaise For Weight, Weight Adjusted For Condition Score, Height, And Body Condition Score, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck Dec 2002

Breed Comparisons Of Angus, Brahman, Hereford, Pinzgauer, Sahiwal, And Tarentaise For Weight, Weight Adjusted For Condition Score, Height, And Body Condition Score, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Data from topcross cows (n = 468) from six breeds of sire (Angus, Brahman, Hereford, Pinzgauer, Sahiwal, Tarentaise) and two breeds of dam (Angus and Hereford) of Cycle III of the Germplasm Evaluation (GPE) program at the U.S. Meat Animal Research Center (MARC) comprising cow weight (CW, n = 9,012), height (CH, n = 9,010), and condition score (CS, n = 8,991) recorded in four seasons per year from 2 to 6 yr of age were used to estimate breed-group differences. The mixed models included cow age, season of measurement and their interactions, year of birth, pregnancy-lactation code (PL), and …

Go to article

Breed Comparisons Of Angus, Charolais, Hereford, Jersey, Limousin, Simmental, And South Devon For Weight, Weight Adjusted For Body Condition Score, Height, And Body Condition Score Of Cows, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck Dec 2002

Breed Comparisons Of Angus, Charolais, Hereford, Jersey, Limousin, Simmental, And South Devon For Weight, Weight Adjusted For Body Condition Score, Height, And Body Condition Score Of Cows, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Breed means and differences for weight (CW, n = 19,851), height (CH, n = 14,553), and condition scores (CS, n = 19,536) recorded in four seasons per year were evaluated for 881 cows ranging from 2 to 7 yr of age from Cycle I of the Germplasm Evaluation Program at the U.S. Meat Animal Research Center. Cows were straightbred Herefords and Angus and top-crosses from mating of Hereford, Angus, South Devon, Jersey, Simmental, Limousin, and Charolais sires to Hereford and Angus dams. The model included cow age, season of measurement, and their interactions, with year of birth, pregnancy-lactation (PL) code, …

Go to article

Comparisons Of Angus-, Braunvieh-, Chianina-, Hereford-, Gelbvieh-, Maine Anjou-, And Red Poll-Sired Cows For Weight, Weight Adjusted For Body Condition Score, Height, And Body Condition Score, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck Dec 2002

Comparisons Of Angus-, Braunvieh-, Chianina-, Hereford-, Gelbvieh-, Maine Anjou-, And Red Poll-Sired Cows For Weight, Weight Adjusted For Body Condition Score, Height, And Body Condition Score, Jesus Arango, L. V. Cundiff, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Data from Angus, Hereford, and topcross cows (n = 641) from 2- to 8-yr-old daughters of seven breeds of sires included in Cycle II of the Germplasm Evaluation Program at the U.S. Meat Animal Research Center, comprising cow weight (CW, n = 15,698), height (CH, n = 15,676), and condition score (CS, n = 15,667), were used to estimate breed-group differences. Data were recorded in four seasons of each year (1975 to 1982). The mixed model included cow age, season of measurement, and their interactions, year of birth, pregnancy-lactation code (PL), and breed-group as fixed effects for CW and CS. …

Go to article

Estimates Of Genetic Parameters And Genetic Change For Reproduction, Weight, And Wool Characteristics Of Columbia Sheep, Kathryn J. Hanford, L. Dale Van Vleck, G. D. Snowder Dec 2002

Estimates Of Genetic Parameters And Genetic Change For Reproduction, Weight, And Wool Characteristics Of Columbia Sheep, Kathryn J. Hanford, L. Dale Van Vleck, G. D. Snowder

Department of Animal Science: Faculty Publications

Genetic parameters from both single-trait and bivariate analyses for prolificacy, weight and wool traits were estimated using REML with animal models for Columbia sheep from data collected from 1950 to 1998 at the U.S. Sheep Experiment Station (USSES), Dubois, ID. Breeding values from both single-trait and seven-trait analyses calculated using the parameters estimated from the single-trait and bivariate analyses were compared with respect to genetic trends. Number of observations were 31,401 for litter size at birth and litter size at weaning, 24,741 for birth weight, 23,903 for weaning weight, 29,572 for fleece weight and fleece grade, and 2,449 for staple …

Go to article

Genetic Parameters For Weight, Weight Adjusted For Body Condition Score, Height, And Body Condition Score In Beef Cows, Jesus Arango, Larry V. Cundiff, L. Dale Van Vleck Dec 2002

Genetic Parameters For Weight, Weight Adjusted For Body Condition Score, Height, And Body Condition Score In Beef Cows, Jesus Arango, Larry V. Cundiff, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Weight (CW, n = 61,798), weight adjusted for condition score (WA), hip height (CH, n = 56,494), and condition score (CS, n = 61,434) of cows (2 through 8 yr of age) produced by crosses of 22 sire breeds with Angus and Hereford dams in the first four cycles of the Germplasm Evaluation (GPE) Program at the U.S. Meat Animal Research Center were used to estimate genetic parameters with REML. The model included sire breed, dam breed, age in years, season of measurement (1 to 4) and their interactions, and year of birth and pregnancy-lactation code (PL) as fixed effects …

Go to article

Estimates Of Parameters Between Direct And Maternal Genetic Effects For Weaning Weight And Direct Genetic Effects For Carcass Traits In Crossbred Cattle, R. K. Splan, Larry V. Cundiff, M. E. Dikeman, L. Dale Van Vleck Dec 2002

Estimates Of Parameters Between Direct And Maternal Genetic Effects For Weaning Weight And Direct Genetic Effects For Carcass Traits In Crossbred Cattle, R. K. Splan, Larry V. Cundiff, M. E. Dikeman, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Estimates of heritabilities and genetic correlations were obtained for weaning weight records of 23,681 crossbred steers and heifers and carcass records from 4,094 crossbred steers using animal models. Carcass traits included hot carcass weight; retail product percentage; fat percentage; bone percentage; ribeye area; adjusted fat thickness; marbling score, Warner- Bratzler shear force and kidney, pelvic and heart fat percentage. Weaning weight was modeled with fixed effects of age of dam, sex, breed combination, and birth year, with calendar birth day as a covariate and random direct and maternal genetic and maternal permanent environmental effects. The models for carcass traits included …

Go to article

Selection For Maternal Behavior In Mice—Direct And Correlated Responses, Chung-Feng Chiang, Rodger K. Johnson, Merlyn K. Nielsen Dec 2002

Selection For Maternal Behavior In Mice—Direct And Correlated Responses, Chung-Feng Chiang, Rodger K. Johnson, Merlyn K. Nielsen

Department of Animal Science: Faculty Publications

Three generations of divergent selection for a maternal care index (MCI) in mice were practiced in each of three replicates. MCI was recorded for 29–32 dams and litters in each replicate/line subclass. Pups of the top (or bottom) 6– 10 dams in each replicate, depending on number of females in the litters, were selected in high (H) and low (L) MCI lines. At birth, litters with more than 10 pups were standardized to 10 pups whereas litters with no more than 10 pups remained intact. On day 4, 8, 12, and 16 of lactation, time budgets during a 30-min session …

Go to article

Effects Of Urea, Isolated Soybean Protein And Blood Meal On Growing Steers Fed A Corn-Based Diet, W. F. Knaus, Donald H. Beerman, L. O. Tedeschi, M. Czajkowski, D. G. Fox, J. B. Russell Nov 2002

Effects Of Urea, Isolated Soybean Protein And Blood Meal On Growing Steers Fed A Corn-Based Diet, W. F. Knaus, Donald H. Beerman, L. O. Tedeschi, M. Czajkowski, D. G. Fox, J. B. Russell

Department of Animal Science: Faculty Publications

A short term feeding trial was conducted to assess effects of nitrogen (N) supplementation on growing cattle and the ability of the Cornell Net Carbohydrate and Protein System (CNCPS) to predict responses. Four corn-based diets were used: (1) a 30% ruminal N-deficient control diet; (2) a urea supplemented diet; (3) a urea+isolated soy protein (ISP) diet; and (4) a urea + ISP + blood meal (BM) diet. Four Holstein steers (average initial body weight of 251 kg) were randomly assigned in a 4 × 4 Latin Square treatment design. Steers were fed 95% of ad libitum intake on an hourly …

Go to article

Maternal Behavior In Mice Selected For Large Litter Size, Chung-Feng Chiang, Rodger . K. Johnson, Merlyn K. Nielsen Sep 2002

Maternal Behavior In Mice Selected For Large Litter Size, Chung-Feng Chiang, Rodger . K. Johnson, Merlyn K. Nielsen

Department of Animal Science: Faculty Publications

A total of 96 lactating mice and their pups from each of three replications of lines selected 21 generations for increased litter size (LS) followed by 23–25 generations of random selection and contemporary unselected control lines (LC) were characterized for maternal behavior. Sixteen dams and their pups from each replication of LS and LC lines were sampled. Litter sizes at birth for LS versus LC in the first, second, and third replicates were 17.3 versus 13.2, 15.9 versus 13.1, and 12.3 versus 10.6 pups, respectively, with LS dams averaging 2.87 ± .70 pups more. One-half of the litters were standardized …

Go to article

Effect Of Duration Of Performance Test On Variance Component Estimates For Lamb Growth Rate, G. D. Snowder, L. Dale Van Vleck Jul 2002

Effect Of Duration Of Performance Test On Variance Component Estimates For Lamb Growth Rate, G. D. Snowder, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

The objective was to determine the effect of periods of adjustment and duration of performance test on estimating genetic variance parameters for ADG. Variance components were estimated from ADG data collected from 1978 to 1984 on a total of 1,047 Targhee ewe and ram lambs at the U.S. Sheep Experiment Station (Dubois, ID). Across all years, lambs averaged 84 ± 9 d of age and 25 ± 5.4 kg of weight when placed on test. Lambs were provided ad libitum access to a commercial pellet of barley grain and ground alfalfa for 14 wk. Every 2 wk, ADG was recorded. …

Go to article

Animal Diet Modification To Decrease The Potential For Nitrogen And Phosphorus Pollution, Terry J. Klopfenstein, Rosalina Angel, Gary Cromwell, Galen E. Erickson, Danny G. Fox, Carl Parsons, Larry D. Satter, Alan L. Sutton, David H. Baker, Austin Lewis, Deanne Meyer Jul 2002

Animal Diet Modification To Decrease The Potential For Nitrogen And Phosphorus Pollution, Terry J. Klopfenstein, Rosalina Angel, Gary Cromwell, Galen E. Erickson, Danny G. Fox, Carl Parsons, Larry D. Satter, Alan L. Sutton, David H. Baker, Austin Lewis, Deanne Meyer

Department of Animal Science: Faculty Publications

In 1996, the Council for Agricultural Science and Technology (CAST) published a report entitled Integrated Animal Waste Management. One of the recommendations in that report was to “change animal diets to decrease nutrient outputs” (CAST 1996, 1). Since that time, concentration of animal production units has continued, public concern about the environmental effects of animal manure has increased, and the Environmental Protection Agency (EPA) has proposed more restrictive requirements for concentrated animal feeding operations (CAFO regulations).

Progress has been made since 1996 to decrease nutrient outputs by animals through diet modification and nutrition. The current study describes the existing …

Go to article

Heritability And Repeatability Of Sexual Performance Scores Of Rams, G. D. Snowder, J. N. Stellflug, L. Dale Van Vleck May 2002

Heritability And Repeatability Of Sexual Performance Scores Of Rams, G. D. Snowder, J. N. Stellflug, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Sexual performance has been subjectively measured with a libido test during screening of rams before public sale and breeding at the U.S. Sheep Experiment Station from 1990 to 2000. The objective of this study was to determine whether sexual performance was genetically influenced. Sexual performance scores ranged from 1 to 6 with scores increasing from sexually inactive to highly sexually active in the presence of estrous ewes. The overall average score was 3.5 ± 0.02. Records from four breeds (Columbia, n = 807; Polypay, n = 1,668; Rambouillet, n = 1,208; and Targhee, n = 1,002) were combined into one …

Go to article

Testis Developmental Phenotypes In Neurotropin Receptor Trka And Trkc Null Mutations: Role In Formation Of Seminiferous Cords And Germ Cell Survival, Andrea S. Cupp, Lina Tessarollo, Michael K. Skinner May 2002

Testis Developmental Phenotypes In Neurotropin Receptor Trka And Trkc Null Mutations: Role In Formation Of Seminiferous Cords And Germ Cell Survival, Andrea S. Cupp, Lina Tessarollo, Michael K. Skinner

Department of Animal Science: Faculty Publications

The objective of the present study was to determine if the neurotropin receptors trkC and trkA are involved in embryonic testis development. These receptors bind neurotropin 3 and nerve growth factor, respectively. The hypothesis tested was that the absence of trkC or trkA receptors will have detrimental effects on testis development and morphology. The trkA and trkC homozygote knockout (KO) mice generally die either at or shortly after birth. Therefore, heterozygote mice were mated to obtain homozygote gene KO mice at Embryonic Day (E) 13, E14, E17, and E19 of gestation, with E0 being the plug date. Gonads from approximately …

Go to article

Size Of Beef Cows: Early Ideas, New Developments, Jesus Arango, L. Dale Van Vleck Mar 2002

Size Of Beef Cows: Early Ideas, New Developments, Jesus Arango, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Optimum size for beef cattle is debated among researchers, cattle breeders and producers. Cattle vary widely in body size but optimal size depends on the production system. Selection has placed emphasis on growth, favoring leaner and faster growing cattle. This trend has led to an increase immature size of cattle that may not necessarily be advantageous. Many research results have indicated that there is not a direct relationship between size and efficiency in beef production if each biological type of cattle is managed according to its nutrient requirements and management practices within the beef industry in the world, however, a …

Go to article

First Prev Next Last