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Department of Animal Science: Faculty Publications

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Full-Text Articles in Animal Sciences

Effect Of Source Of Pig, Housing System, And Receiving Diet On Performance Of Purchased Feeder Pigs, M. C. Brumm, E. R. Peo, Jr., S. R. Lowry, A. Hogg Jan 1982

Effect Of Source Of Pig, Housing System, And Receiving Diet On Performance Of Purchased Feeder Pigs, M. C. Brumm, E. R. Peo, Jr., S. R. Lowry, A. Hogg

Department of Animal Science: Faculty Publications

An experiment was conducted to determine the effect of source of pig, housing system and receiving diet on performance of purchased feeder pigs. Pigs purchased from distant auction markets (DM) gained slower for the first 13 d post-arrival (P<.01, trials 1 and 2) than pigs of similar size purchased from local, one-owner sources (LS).

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Testosterone Feedback On Fsh Secretion In Male Sheep, M. J. D'Occhio, B. D. Schanbacher, J. E. Kinder Jan 1982

Testosterone Feedback On Fsh Secretion In Male Sheep, M. J. D'Occhio, B. D. Schanbacher, J. E. Kinder

Department of Animal Science: Faculty Publications

Testosterone-filled Silastic capsules were implanted into mature rams at the time of castration (wethers). After 6 weeks, a tonic pattern of FSH secretion was observed in rams, wethers and wethers implanted with testosterone. Castration caused serum concentrations of FSH to increase 4-5-fold. Relatively low serum concentrations of testosterone (25-50% of intact ram values) did not significantly affect FSH secretion in wethers, but wethers exposed to concentrations of testosterone equivalent to those of intact rams had serum concentrations of FSH similar to those of intact rams. We suggest that testosterone feedback can account for the gross differences in FSH observed between …

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Oxidation Rates Of Major Fatty Acids In Fasting Neonatal Pigs, R. D. Boyd, R. A. Britton, H. Knoche, B. D. Moser, E. R. Peo Jr., R. K. Johnson Jan 1982

Oxidation Rates Of Major Fatty Acids In Fasting Neonatal Pigs, R. D. Boyd, R. A. Britton, H. Knoche, B. D. Moser, E. R. Peo Jr., R. K. Johnson

Department of Animal Science: Faculty Publications

Thirty-two pigs were used to compare the oxidation rates of uniformly labeled (U-14C) palmitic (16:0), stearic (18:0), oleic (18:1) and linoleic (18:2) acids in fasting neonatal pigs. The pigs were allowed to nurse the sow for 24 to 48 h following birth. Subsequently, they were removed, an indwelling catheter was surgically placed in the external iliac vein and the pigs were fasted for 12 h to attain a postabsorptive state. The 14C fatty acids were administered as a single infusion (10 / μCi) via the catheter, and recovery of the label as expired 14CO2 was determined at …

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Influence Of Energy Intake During Lactation On The Interval From Weaning To First Estrus In Sows, D. E. Reese, B. D. Moser, E. R. Peo, Jr., A. J. Lewis, Dwayne R. Zimmerman, J. E. Kinder, W. W. Stroup, Win Butler Jan 1982

Influence Of Energy Intake During Lactation On The Interval From Weaning To First Estrus In Sows, D. E. Reese, B. D. Moser, E. R. Peo, Jr., A. J. Lewis, Dwayne R. Zimmerman, J. E. Kinder, W. W. Stroup, Win Butler

Department of Animal Science: Faculty Publications

A total of 191 crossbred sows were used to determine the effect of energy intake during one lactation on (1) sow and pig performance and (2) the percentage of sows in estrus by 7, 14, 21 and 70 d post-weaning. Sows received 8 (Lo) or 16 (Hi) Meal of metabolizable energy (ME)/d (Exp. 1 and 2) and 8 (Lo), 12 (Md) or 16 (Hi) Meal of ME/d (Exp. 3) during a 28-d lactation period. All sows were fed an equal amount of crude protein, vitamins and minerals that met or exceeded the recommendations of the National Research Council.

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Influence Of Energy Intake During Lactation On Subsequent Gestation, Lactation And Postweaning Performance Of Sows, D. E. Reese, B. D. Moser, E. R. Peo, Jr., A. J. Lewis, Dwayne R. Zimmerman, J. E. Kinder, W. W. Stroup, Win Butler Jan 1982

Influence Of Energy Intake During Lactation On Subsequent Gestation, Lactation And Postweaning Performance Of Sows, D. E. Reese, B. D. Moser, E. R. Peo, Jr., A. J. Lewis, Dwayne R. Zimmerman, J. E. Kinder, W. W. Stroup, Win Butler

Department of Animal Science: Faculty Publications

Forty-four second parity crossbred sows were used to determine (1) the effect of energy intake during their first lactation (Lac 1) on subsequent reproductive performance from re-breeding to farrowing and (2) the effect of energy intake during two successive lactations on performance during the second lactation (Lac 2) and post-weaning periods. Sows received 8 (Lo) or 16 (Hi) Meal of metabolizable energy (ME)/d during Lac 1 and 5.4 Mcal of ME/d during the subsequent gestation.

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Selection For Lean Growth In Swine, Erik R. Cleveland, P. J. Cunningham, E. R. Peo, Jr. Jan 1982

Selection For Lean Growth In Swine, Erik R. Cleveland, P. J. Cunningham, E. R. Peo, Jr.

Department of Animal Science: Faculty Publications

Growth rate (ADG) and back fat (BF) data were collected during five generations of selection in two lines of Gene Pool pigs (14-breed synthetic): select (S) and control (C). C were randomly selected, while mass selection was practiced in the S line with an index (I), I = 100 + 286.6 (ADG) - 39.4 (BF). S and C pigs were fed a 14% protein, corn-soybean meal diet from 42 d of age until they reached 79.4 kg.

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Individual And Maternal Additive And Heterotic Effects On 205-Day Weight In Beef Cattle, M. D. Macneil, C. A. Dinkel, L. Dale Van Vleck Jan 1982

Individual And Maternal Additive And Heterotic Effects On 205-Day Weight In Beef Cattle, M. D. Macneil, C. A. Dinkel, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Weaning weight records on 47,652 calves in 371 contemporary groups were obtained from the South Dakota Beef Cattle Improvement Association and used to estimate breed individual and maternal additive effects and heterotic effects on 205-d weight. A mixed model was used. Individual additive effects were -22.6 ± 1.3 kg for Red Angus, -19.0 ± 1.1 for Hereford, -12.2 ± .9 for Angus, -11.5 ± 3.1 for Polled Hereford, -10.1 ± 2.2 for Shorthorn, -7.5 ± 4.9 for Tarentaise, 5.3 ± 1.6 for Gelbvieh, 9.5 ± 1.8 for Limousin, 11.4 ± 3.1 for Chianina, 12.4-± 1.2 for Charolais, 14.6 ± 1.2 …

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Selection With Restriction In Cattle, E. Niebel, L. Dale Van Vleck Jan 1982

Selection With Restriction In Cattle, E. Niebel, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Application of new and accurate methods of estimating breeding values and systematic selection based on performance characters have increased the complexity of animal breeding. Negative correlations between the most important characters may be involved, especially in the selection of dairy and beef cattle. This problem demands efficient selection models to maximize genetic improvement of some economic traits and simultaneously to restrict other antagonistic traits to a certain genetic change. We have established a general theory of selection indexes with constraints to impose fixed and proportional restrictions when several selection indexes containing different information sources are applied. A detailed description of …

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Comparison Of First Lactations And All Lactations Of Dams To Predict Sons’ Milk Evaluations, P. A. Murphy, R. W. Everett, L. Dale Van Vleck Jan 1982

Comparison Of First Lactations And All Lactations Of Dams To Predict Sons’ Milk Evaluations, P. A. Murphy, R. W. Everett, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Multiple regression of genetic evaluations of about 170 Holstein bulls on sire, dam, and maternal grandsire genetic evaluations indicated that the partial regression coefficient for the sire is similar to the theoretical regression coefficient (.45 vs..50), that the regression coefficient for the dam is much smaller than the theoretical regression coefficient when all records of the dam including her first are included in her evaluation (.12 vs..35), although about as expected when only first records of the cow and her herdmates are used (.33 vs..35), and that the regression for the maternal grandsire is larger than expected when his proof …

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Monte Carlo Study Of Genetic Groups In Sire Evaluation, T. R. Famula, L. Dale Van Vleck Jan 1982

Monte Carlo Study Of Genetic Groups In Sire Evaluation, T. R. Famula, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Fixed genetic groups have been defined arbitrarily in linear models for sire evaluation. This simulation examined genetic groups under several selection strategies. Sires with highest estimated transmitting abilities were selected to have sons and additional female progeny. The process of evaluation and selection of sires and dams was continued for four generations. Final estimates of transmitting ability were compared to actual transmitting ability for several sire evaluation models on 300 simulated data sets. Genetic groups defined by generation increased the accuracy of estimating sire transmitting abilities over ignoring genetic groups when selected dams and sires of young bulls were mated. …

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Components Of Variance Of Dairymen's Workability Traits Among Holstein Cows, K. Agyemang, E. Clapp, L. Dale Van Vleck Jan 1982

Components Of Variance Of Dairymen's Workability Traits Among Holstein Cows, K. Agyemang, E. Clapp, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Dairymen of an artificial insemination cooperative subjectively evaluated 5,601 of their cows in first lactation sired by 187 young Holstein bulls for temperament, milking speed, udder, leg and foot problems, and milk production. Exclusive categories were defined for each characteristic. Individual categories were separate traits, and components of variance and covariance were estimated for herd-year of measurement, sire of cow, and residual effects. Variance from sire of cow was less than 3% of the total for all traits so that heritabilities within herd-year were less than .12 for every trait. Variances and covariances were used in a multiple trait sire …

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Relationships Among Sires In Estimating Genetic Variance, L. Dale Van Vleck, G. F. S. Hudson Jan 1982

Relationships Among Sires In Estimating Genetic Variance, L. Dale Van Vleck, G. F. S. Hudson

Department of Animal Science: Faculty Publications

A method to account for relationships among sires in estimating covariance among paternal half-sibs and heritability is described. The reduction in sum of squares from fitting sire effects after eliminating all other effects in the model is divided by the sum of products of elements of the matrix of coefficients after absorption and elements of the matrix of relationships among sires rather than by the trace of the matrix of coefficients. The method requires computation of relationships that for many sires may be difficult.

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Theoretical Weights For Regression Of A Son's Genetic Evaluation On His Sire's And His Dam's Genetic Evaluations, L. Dale Van Vleck Jan 1982

Theoretical Weights For Regression Of A Son's Genetic Evaluation On His Sire's And His Dam's Genetic Evaluations, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Theoretical weights for prediction of a son's genetic evaluation from genetic evaluations of his sire and dam are derived. Weights for sire and dam are equal and depend on number of daughters of the son when the bull evaluation is from his daughters alone and cow evaluation is from her records alone. Mixed model procedures which incorporate records of other relatives change theoretical weights. When records of daughters of both the son and his sire are used in evaluations of both, theoretical weights for the sire to predict the son's evaluation are about .50 for many combinations of daughter numbers …

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Effect Of Tallow And Choline Chloride Addition To The Diet Of Sows On Milk Composition, Milk Yield And Preweaning Pig Performance, R. D. Boyd, B. D. Moser, E. R. Peo Jr., A. R. Lewis, R. K. Johnson Jan 1982

Effect Of Tallow And Choline Chloride Addition To The Diet Of Sows On Milk Composition, Milk Yield And Preweaning Pig Performance, R. D. Boyd, B. D. Moser, E. R. Peo Jr., A. R. Lewis, R. K. Johnson

Department of Animal Science: Faculty Publications

Four trials were conducted with a total of 188 crossbred sows to determine the effect of feeding diets supplemented with tallow (0 or 8%) and choline chloride (220 or 770 mg/kg diet) prior to parturition and during lactation on preweaning pig performance. On d 100 of gestation, sows were allotted to four factorially arranged dietary treatments: 0% tallow-220 mg/kg choline chloride, 0% tallow-770 mg/kg choline chloride, 8% tallow-220 mg/kg choline chloride, 8% tallow-770 mg/kg choline chloride. Diets without tallow were fed at the rate of 1.82 kg/d with an additional .18 kg/d of cornstarch, whereas sows receiving diets supplemented with …

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Crossbreeding In Swine: Experimental Results, Rodger K. Johnson Jul 1981

Crossbreeding In Swine: Experimental Results, Rodger K. Johnson

Department of Animal Science: Faculty Publications

A review of recent swine crossbreeding experiments is presented and integrated with earlier work. Variation among experiments in observed heterosis for specific crosses was large for reproduction and sow productivity traits. However, standard errors of estimates were also large. It seems likely that heterosis, expressed in absolute values or in percentage units, is different for specific crosses. It is unclear whether these differences are large enough to warrant the use of unique parameter values for comparisons of alternate mating systems. In addition to average heterosis values, average direct and maternal genetic effects are given.

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Effect Of Maternal Dietary Energy Source On Glucose Homeostasis, Liver Glycogen And Carcass Lipid In The Neonatal Pig, R. D. Boyd, B. D. Moser, A. J. Lewis, E. R. Peo Jr., R. K. Johnson, R. D. Nimmo May 1981

Effect Of Maternal Dietary Energy Source On Glucose Homeostasis, Liver Glycogen And Carcass Lipid In The Neonatal Pig, R. D. Boyd, B. D. Moser, A. J. Lewis, E. R. Peo Jr., R. K. Johnson, R. D. Nimmo

Department of Animal Science: Faculty Publications

Two experiments were conducted to determine the effects of supplementary dietary energy (carbohydrate versus fat) fed to sows during late gestation on energy storage and glucose homeostasis in neonatal pigs. In the first experiment, 28 crossbred sows received one of two dietary treatments that were initiated on day 100 of gestation. The control group was fed daily 1.82 kg of a corn-soybean meal-based diet plus an additional .18 kg of cornstarch. Their counterparts were fed 1.82 kg of a cornsoybean meal diet containing 8% bleachable fancy tallow. The effect of maternal dietary energy source during late gestation on glucose homeostasis …

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Genetic And Phenotypic Relationships Between Pubertal And Growth Characteristics Of Gilts, L. K. Hutchens, R. L. Hintz, R. K. Johnson Apr 1981

Genetic And Phenotypic Relationships Between Pubertal And Growth Characteristics Of Gilts, L. K. Hutchens, R. L. Hintz, R. K. Johnson

Department of Animal Science: Faculty Publications

Data on 737 crossbred and purebred gilts were used to obtain heritability estimates for age at puberty (AGEPUB) and weight at puberty (WTPUB) and their genetic and phenotypic correlations with birth weight (BW), weaning weight (WW), postweaning daily gain (ADG), adjusted age at 90.7 kg (AGE) and adjusted backfat at 90.7 kg (BF). The heritability estimates for AGEPUB were low to moderate (.19 and .40, based upon paternal and maternal half-sib estimates, respectively.) The genetic (rg) and phenotypic (rp) correlations between AGEPUB and BW (rg = -.07; rp = -.09), WW (rg = -.25; rp = …

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Relationship Between Production And Stayability In Holstein Cattle, G. F. S. Hudson, L. Dale Van Vleck Jan 1981

Relationship Between Production And Stayability In Holstein Cattle, G. F. S. Hudson, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Records from 97,555 first daughters of 1,487 Holstein sires in artificial insemination were used to estimate components of variance and covariance of first lactation milk and fat production and stayability to 36, 48, 60, 72, and 84 mo of age. Henderson's Method 3 was used with a model including fixed herd-year- season and genetic group effects and random sire within group and residual effects. Heritabilities for milk and fat production and 36-, 48-, 60-, 72-, and 84-mo stayability were .31, .30, .02, .04, .05, .05, and .05. Genetic and phenotypic correlations between milk production and stayability ranged from .47 to …

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Sire Evaluation By Only Extended Partial Milk And Fat Records, T. R. Famula, L. Dale Van Vleck Jan 1981

Sire Evaluation By Only Extended Partial Milk And Fat Records, T. R. Famula, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

The standard of comparison for dairy production records is the 305-day lactation, and much research has been directed to estimating 305-day milk and fat records from incomplete or in-progress records. This study was to determine the effect of several methods of extending incomplete records on sire evaluation. Complete 305-day milk and fat records of first lactations of 73,724 daughters of 1,362 artificial insemination Holstein sires processed at the New York Dairy Records Processing Laboratory were used to compute sire proofs for yield of milk and fat. Partial records of two lengths (60 to 80 days and 130 to 160 days) …

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Effect Of Level Of Dietary Calcium-Phosphorus During Growth And Gestation On Calcium-Phosphorus Balance And Reproductive Performance Of First-Litter Sows, R. D. Nimmo, E. R. Peo, Jr., J. D. Crenshaw, B. D. Moser, A. J. Lewis Jan 1981

Effect Of Level Of Dietary Calcium-Phosphorus During Growth And Gestation On Calcium-Phosphorus Balance And Reproductive Performance Of First-Litter Sows, R. D. Nimmo, E. R. Peo, Jr., J. D. Crenshaw, B. D. Moser, A. J. Lewis

Department of Animal Science: Faculty Publications

Twenty-four bred gilts were used in a Ca-P metabolism trial. Twelve gilts were fed gestation treatment A (13 g Ca, 10 g/day), while the other 12 were fed gestation treatment B (19.5 g Ca, 15 g P/day). One-half of the gilts in each treatment group were fed .65% Ca, .50% P from 7 to 94 kg, and half were fed .975% Ca, .75% P for the same period. Treatment B gilts excreted more (P<.005) fecal and urinary P. Twenty-four first litter sows fed the same treatment diets during growth and gestation and given .75% Ca, .50% P during lactation were used in a Ca and P balance trial conducted from day 38 to 42 of lactation.

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Influence Of Age, Sex, And Calcium And Phosphorus Levels On The Mechanical Properties Of Various Bones In Swine, T. D. Crenshaw, E. R. Peo, Jr., A. J. Lewis, B. D. Moser, D. Olson Jan 1981

Influence Of Age, Sex, And Calcium And Phosphorus Levels On The Mechanical Properties Of Various Bones In Swine, T. D. Crenshaw, E. R. Peo, Jr., A. J. Lewis, B. D. Moser, D. Olson

Department of Animal Science: Faculty Publications

Seventy-two 4-week-old pigs were randomly assigned by sex (gilts, barrows, boars) to two dietary treatments and four age periods for determinations of the effects of age, sex and Ca and P levels on the mechanical properties of various bones in swine.

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Comparisons Of Mating Systems With Duroc, Hampshire And Yorkshire Breeds Of Swine For Efficiency Of Swine Production, E. R. Wilson, R. K. Johnson Jan 1981

Comparisons Of Mating Systems With Duroc, Hampshire And Yorkshire Breeds Of Swine For Efficiency Of Swine Production, E. R. Wilson, R. K. Johnson

Department of Animal Science: Faculty Publications

Estimates of direct and maternal genetic and heterosis effects for purebreds and crosses among the Duroc, Hampshire and Yorkshire breeds were made from data on 1,243 litters from the Oklahoma crossbreeding experiment. The estimates were used to simulate the production efficiency of 21 mating systems. Each mating system was defined to include purebred, crossbred and commercial matings needed to maintain 10,000 farrowings. Linear programming was used to maximize the number of Yorkshire equivalent pigs foreach system. An index of economic weights for days to 100 kg, feed efficiency and probe backfat (traits expressed as a deviation from Yorkshire) was calculated …

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Comparison Of Three-Breed And Backcross Swine For Litter Productivity And Postweaning Performance , E. R. Wilson, R. K. Johnson Jan 1981

Comparison Of Three-Breed And Backcross Swine For Litter Productivity And Postweaning Performance , E. R. Wilson, R. K. Johnson

Department of Animal Science: Faculty Publications

Duroc, Hampshire and Yorkshire boars were mated with crossbred gilts of Duroc-Hampshire, Duroc-Yorkshire and Hampshire-Yorkshire breeding to produce 133 three-breed and 259 backcross litters that were farrowed during four seasons beginning in the fall of 1975. Threebreed cross litters were .31 ± .27, .57 ± .24 and .50 ± .24 pigs larger than backcross litters at birth, 21 and 42 days, respectively, and .6 ± .34, 2.3 ± 1.2 and 5.4 ± 2.4 kg heavier at these ages. The differences in average pig weight and survival percentage were small. Three-breed cross litters gained faster (.024 ± .007 kg/day) and were …

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Bone Strength As A Trait For Assesing Mineralization In Swine: A Critical Review Of Techniques Involved, T. D. Crenshaw, E. R. Peo, Jr., A. J. Lewis, B. D. Moser Jan 1981

Bone Strength As A Trait For Assesing Mineralization In Swine: A Critical Review Of Techniques Involved, T. D. Crenshaw, E. R. Peo, Jr., A. J. Lewis, B. D. Moser

Department of Animal Science: Faculty Publications

Lack of standardized test procedures has resulted in considerable variation in reported values for bone strength. Such variation can be attributed in part to the type of instruments used to determine physical properties of bone, procedures used to prepare the bones for testing and equations used to calculate strength. If bone strength is to be used as a major criterion of response in mineral nutrition research, standardization of procedures for measuring and reporting bone strength is essential. Traits that describe the mechanical properties of bone as determined in the commonly used flexure test in which force is applied perpendicularly to …

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Effect Of Level Of Dietary Calcium-Phosphorus During Growth And Gestation On Performance, Blood And Bone Parameters Of Swine, R. D. Nimmo, E. R. Peo, Jr., B. D. Moser, A. J. Lewis Jan 1981

Effect Of Level Of Dietary Calcium-Phosphorus During Growth And Gestation On Performance, Blood And Bone Parameters Of Swine, R. D. Nimmo, E. R. Peo, Jr., B. D. Moser, A. J. Lewis

Department of Animal Science: Faculty Publications

One-hundred and ninety-two crossbred weanling gilts (7.25 kg) were assigned to one of two treatments - (A) .65% Ca, .50% P or (B) .975% Ca, .75% P - and fed to an average weight of 92.8 kilograms. Average daily gain (.65 and .67 kg, respectively) and feed/gain were not affected by dietary treatment, but average daily feed intake was lower (P<.05) for gilts on treatment A (1.87 vs 1.95 kg).

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Measures Of Racetrack Performance With Regard To Breeding Evaluation Of Trotters, M. J. Ojala, L. Dale Van Vleck Jan 1981

Measures Of Racetrack Performance With Regard To Breeding Evaluation Of Trotters, M. J. Ojala, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Trotting records on the Finnish Horse were divided into two subsets: the total data set, with 13,000 race records on 554 horses by 206 sires, and the summary data set, with 1,378 records summarized annually for each horse. The purpose of the study was to determine whether these data could be utilized in a simple, yet useful way for the assessment of breeding value. A total of 24 measures of performance based on time at finish, money won and rank at finish were studied in the summary data set. The total data set included four traits compiled from records made …

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Components Of Variance For Milk And Fat Yields In Dairy Goats, M. U. Iloeje, L. Dale Van Vleck, G. R. Wiggans Jan 1981

Components Of Variance For Milk And Fat Yields In Dairy Goats, M. U. Iloeje, L. Dale Van Vleck, G. R. Wiggans

Department of Animal Science: Faculty Publications

Age-season adjusted records from five breeds of dairy goats on Dairy Herd Improvement test from 1965 to 1976 were used to estimate components of variance for milk yield, fat yield, and fat percentage. The data were 6,452 Alpine, 1,730 LaMancha, 6,897 Nubian, 2,759 Saanen, and 4,007 Toggenberg lactation records. Components of variance were estimated by Henderson's Method 1 with a four-way model that included random effects of herd, year-season, sire, and doe. Herd effects accounted for 22 to 31% of the total variation in milk and fat yields and 15 to 25% of the variation in fat percentage. These effects …

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Inheritance Of Teat Number And Its Relationship To Maternal Traits In Swine, R. A. Pumfrey, R. K. Johnson, P. J. Cunningham, Dwane R. Zimmerman Jun 1980

Inheritance Of Teat Number And Its Relationship To Maternal Traits In Swine, R. A. Pumfrey, R. K. Johnson, P. J. Cunningham, Dwane R. Zimmerman

Department of Animal Science: Faculty Publications

The relationship of teat number to seven measures of female reproduction was evaluated in the University of Nebraska Gene Pool population. Teat number was recorded for 7,513 pigs, ovulation rate for 2,794. gilts and litter size and weight at birth and weaning (42 days) for 789 gilts. Paternal half-sib and full-sib analyses were used to estimate heritabilities for each trait and to estimate the genetic and phenotypic correlations of teat number with the measures of reproduction. The direct response to selection for ovulation rate and the correlated response in teat number were also evaluated from the regressions of line differences …

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The Relationships Between Plasma Progesterone And Lh And The Numbers Of Corpora Lutea And Embryos In Purebred And Crossbred Gilts, R. P. Wettemann, R. K. Johnson, I. T. Omtvedt Jun 1980

The Relationships Between Plasma Progesterone And Lh And The Numbers Of Corpora Lutea And Embryos In Purebred And Crossbred Gilts, R. P. Wettemann, R. K. Johnson, I. T. Omtvedt

Department of Animal Science: Faculty Publications

Relationships between plasma progesterone and luteinizing hormone (LH) and the numbers of corpora lutea and embryos were determined in 133 8-month-old purebred Duroc, Hampshire and Yorkshire gilts and two-breed crosses among the three breeds. The numbers of corpora lutea and normal embryos were determined at slaughteronday 30.8 ± .2 of pregnancy, and progesterone and LH were quantified in plasma obtained the previous day. Progesterone concentrations in plasma were influenced by sire (P<.10), breed of dam (P<.05) and breed of sire x breed of dam (P<.05). Hampshire gilts had higher concentrations of progesterone in plasma than did Durocs (P<.05) and Yorkshires (P<.01). None of the effects in the model was significant for LH. Plasma progesterone and LH had heritability estimates of .48 ± .41 and .29 ± .40, respectively. Most genetic and phenotypic correlations of plasma progesterone and LH with other traits were small. These data indicate that progesterone concentrations in plasma at 30 days of pregnancy are not a satisfactory predictor of the numbers of corpora lutea and embryos. The differences in plasma progesterone between breeds illustrate the need to consider the breed of gilts when selecting animals for the study of luteal function or physiological factors that may influence progesterone concentrations in plasma.

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Genetic And Economic Implications Of Fetal Effects On The Dam, L. Dale Van Vleck, L. P. Johnson Jan 1980

Genetic And Economic Implications Of Fetal Effects On The Dam, L. Dale Van Vleck, L. P. Johnson

Department of Animal Science: Faculty Publications

The genetic model for fetal effect on production of the dam is described, and studies on genetic and economic implications are reviewed. The effect on production from the sire of the cow has 1.58 to 3.02 times as much economic value as the effect from the sire of the fetus. The use of mate records in evaluating a sire in addition to daughter records could increase economic gain from selection by 1 to 2% depending on the variation from sire of fetus. Mate records alone do not appear valuable for sire selection. About 1% of the variation in milk yield …

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