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Department of Animal Science: Faculty Publications

Articles 931 - 960 of 1242

Full-Text Articles in Animal Sciences

Efficacy Of The Urea Dilution Technique In Estimating Empty Body Composition Of Pigs Weighing 50 Kilograms, L. I. Chiba, A. J. Lewis, E. R. Peo, Jr. Jan 1990

Efficacy Of The Urea Dilution Technique In Estimating Empty Body Composition Of Pigs Weighing 50 Kilograms, L. I. Chiba, A. J. Lewis, E. R. Peo, Jr.

Department of Animal Science: Faculty Publications

The efficacy of the urea dilution technique in estimating the empty body composition of pigs weighing 50 kg was evaluated in three trials using 17 contemporary (Large White x Landrace x Hampshire x Duroc) and 8 Nebraska Gene Pool x contemporary pigs. Blood samples were collected via ear catheter before infusion (-60, -30 and 0 min) and at various times (3 to 90 min) after urea infusion (2.16 mmol/kg live BW), and analyzed for plasma urea. Backfat thickness of live pigs from the contemporary line was measured ultrasonically. Pigs then were killed by euthanasic injection. and total bodies (with gastrointestinal …

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Nutritive Value Of Rubber Seed (Hevea Brasiliensis) Meal: Utilization By Growing Pigs Of Semipurified Diets In Which Rubber Seed Meal Partially Replaced Soybean Meal, G. M. Babatunde, W. G. Pond, E. R. Peo, Jr. Jan 1990

Nutritive Value Of Rubber Seed (Hevea Brasiliensis) Meal: Utilization By Growing Pigs Of Semipurified Diets In Which Rubber Seed Meal Partially Replaced Soybean Meal, G. M. Babatunde, W. G. Pond, E. R. Peo, Jr.

Department of Animal Science: Faculty Publications

Thirty-six four-way cross (Chester White x Landrace x Large White x Yorkshire) growing bmws and gilts were used to investigate the effects of replacing graded levels of protein from soybean meal with equivalent levels of protein from rubber seed meal in 16% CP semipurified diets on the performance characteristics, hematocrit, plasma metabolites and N utilization of pigs.

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Twinning In Cattle: Ii. Genetic And Environmental Effects On Ovulation Rate In Puberal Heifers And Postpartum Cows And The Effects Of Ovulation Rate On Embryonic Survival, S.E. Echternkamp, K. E. Gregory, G. E. Dickerson, Larry V. Cundiff, R. M. Koch, L. Dale Van Vleck Jan 1990

Twinning In Cattle: Ii. Genetic And Environmental Effects On Ovulation Rate In Puberal Heifers And Postpartum Cows And The Effects Of Ovulation Rate On Embryonic Survival, S.E. Echternkamp, K. E. Gregory, G. E. Dickerson, Larry V. Cundiff, R. M. Koch, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

The potential of ovulation rate before 18 to 21 mo of age in puberal heifers as an indirect selection criterion for twinning rate was considered. Heritability (h2) was .07 ± .03 for single observations and .34 ± .18 for the mean of 7.9 estrous cycles per heifer. Estimated repeatability (r) of ovulation rate was ≤h2, indicating negligible permanent environmental effects. Expected h2 for mean ovulation rate (assuming h2 = r = .07 for single observations) for increasing numbers of estrous cycles would be as follows: 4, .23; 6, .31; 8, .38; and 10, .43. …

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Twinning In Cattle: 1. Foundation Animals And Genetic And Environmental Effects On Winning Rate, K. E. Gregory, S. E. Echternkamp, G. E. Dickerson, Larry V. Cundiff, R. M. Koch, L. Dale Van Vleck Jan 1990

Twinning In Cattle: 1. Foundation Animals And Genetic And Environmental Effects On Winning Rate, K. E. Gregory, S. E. Echternkamp, G. E. Dickerson, Larry V. Cundiff, R. M. Koch, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Foundation cows were selected using prior records from one of two sources, private herds or other projects at the Research Center. Comparing twinning rates before and after selection, the repeatability was lower for those from the fist (.08) than for those from the second (.16) source with a combined value of .12. Realized heritability of single-parity twinning rate estimated from selection of parents and response in daughters of foundation females was .06. Paternal half-sib estimate of heritability of twinning rate was .02 ± .07. Estimates of repeatability computed from calving records of females born in the project indicate that permanent …

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Index Selection For Components Of Litter Size In Swine: Response To Five Generations Of Selection, S. M. Neal, R. K. Johnson, R. J. Kittock Oct 1989

Index Selection For Components Of Litter Size In Swine: Response To Five Generations Of Selection, S. M. Neal, R. K. Johnson, R. J. Kittock

Department of Animal Science: Faculty Publications

Selection for an index of ovulation rate (OR) and embryo (fetal) survival rate (ES) to 50 d of gestation (I = 10.6 x OR + 72.6 x ES) was practiced for five generations in a line that was a composite population of the Large White and Landrace breeds of swine. A control line sampled from the same population was selected randomly and mated. Ovulation rate and number of fetuses (FETS) were measured by laparotomy and ES was calculated as FETS/OR. The select line averaged 43 litters by 18 sires and the control line averaged 42 litters by 15 sires per …

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Control Of Luteinizing Hormone In Postpubertal Boars With Large Testes, P. L. Wolfe, M. W. Wolfe, T. T. Stumpf, J. A. Stotts, M. L. Day, R. J. Kittock, R. K. Johnson, J. E. Kinder Oct 1989

Control Of Luteinizing Hormone In Postpubertal Boars With Large Testes, P. L. Wolfe, M. W. Wolfe, T. T. Stumpf, J. A. Stotts, M. L. Day, R. J. Kittock, R. K. Johnson, J. E. Kinder

Department of Animal Science: Faculty Publications

The objective of the present study was to investigate endocrine control of LH in post-pubertal boars with large testes. Eight boars with the highest estimated paired testis weights from a line selected for large testes and nine boars from a line selected at random were used. Blood samples were collected over a 13-h period at weekly intervals for 4 wk. Samples were collected at 12-min intervals for 12 h before and 1 h after exogenous LHRH. Boars were bled when they were intact during the initial week. The second and third blood collections were 7 and 14 d after castration. …

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Estimation Of Genetic Parameters For Milk And Fat Yields Of Dairy Cattle In Spain And The United States, M. J. Carabano, L. Dale Van Vleck, G. R. Wiggans, R. Alenda May 1989

Estimation Of Genetic Parameters For Milk And Fat Yields Of Dairy Cattle In Spain And The United States, M. J. Carabano, L. Dale Van Vleck, G. R. Wiggans, R. Alenda

Department of Animal Science: Faculty Publications

Interaction of genotype with environment was studied with 10,780 Spanish production records (daughters of 210 Holstein-Friesian bulls) and two subsets of United States data (800,821 records with 1170 sires and 762,152 records with 1186 sires). Only 74 bulls had daughter records in both Spanish and United States data. Genetic and phenotypic (co)variances and correlations and heritability for milk and fat yields were estimated both within country and between countries with countries considered as separate traits (joint analysis). (Co)variance components were estimated with a REML procedure. Heritability estimates for milk and fat in the Spanish population (.16 and .14, within country; …

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Variance Heterogeneity In Direct And Maternal Weight Traits By Sex And Percent Purebred For Simmental-Sired Calves, D. J. Garrick, E. J. Pollak, R. L. Quaas, L. Dale Van Vleck Feb 1989

Variance Heterogeneity In Direct And Maternal Weight Traits By Sex And Percent Purebred For Simmental-Sired Calves, D. J. Garrick, E. J. Pollak, R. L. Quaas, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Phenotypic variances for linear and transformed weight traits were partitioned into residual, direct genetic (D) and maternal genetic (M) components using REML techniques with American Simmental Association data from calves born 1969 to 1985. Variance components were estimated separately from subclasses defined by sex (male, female) and percent Simmental (50, >75). The model included fixed effects of contemporary group and age-of-dam (5 yr). Additive relationships among sires and maternal grandsires were included. Results follow for a sire-maternal grandsire model for ≥ 75% Simmental untransformed data based on 143,280 male and 281,805 female weaning weights (WW) representing 4,763 and 7,406 sires, …

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Correlations Among First And Second Lactation Milk Yield And Calving Interval, M. C. Dong, L. Dale Van Vleck Jan 1989

Correlations Among First And Second Lactation Milk Yield And Calving Interval, M. C. Dong, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Estimates of genetic correlations were .17 between first lactation milk yield and concurrent calving interval, .10 between second lactation milk yield and first calving interval, and .82 between first and second milk yields. Corresponding phenotypic correlations were .27, .16, and .58. Heritability estimates were .27 and .25 for first and second lactations and .15 for calving interval. Estimates were averages of two samples of 15 New York State herds averaging 144 Al-sired Holstein cows and 30 sires. Milk yields were 305-d, mature equivalent. Calving interval was days between first and second freshening. First milk records without a second freshening were …

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Muscle Protein Turnover And Tenderness In Broiler Chickens Fed Cimaterol, J. B. Morgan, Steven J. Jones, Chris R. Calkins Jan 1989

Muscle Protein Turnover And Tenderness In Broiler Chickens Fed Cimaterol, J. B. Morgan, Steven J. Jones, Chris R. Calkins

Department of Animal Science: Faculty Publications

To investigate the impact of cimaterol (CIM) on muscle protein turnover, carcass and muscle composition, muscle cathepsin B+L activity and meat tenderness, 21-d-old broiler chickens (n = 88) were assigned to dietary treatments of either 0 or 1 ppm CIM. Fractional synthesis rates (FSR), fractional accretion rates (FAR), proximate composition and collagen content were determined in the breast muscle (BM; pectoralis major) and a group of leg muscles (LM; gastrocnemius and peroneous longus) from groups of six birds per treatment within each of two time periods (age = 38 or 56 d). Whole body composition,' serum hydroxyproline content and BM …

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Anticholesteremic Property Of Lactobacillus Acidophilus Yogurt Fed To Mature Boars, A. D. Danielson, E. R. Peo, Jr., K. M. Shahani, A. J. Lewis, P. J. Whalen, M. A. Amer, Win Butler Jan 1989

Anticholesteremic Property Of Lactobacillus Acidophilus Yogurt Fed To Mature Boars, A. D. Danielson, E. R. Peo, Jr., K. M. Shahani, A. J. Lewis, P. J. Whalen, M. A. Amer, Win Butler

Department of Animal Science: Faculty Publications

Three strains of Lactobacilus acidophilus (LA) were isolated from the feces of mature boars that were not being fed antibiotics from the Nebraska Gene Pool (NGP). All three LA isolates were screened in vitro for anticholesteremic and antimicrobial activities. One strain, LA16, caused the greatest reduction in cholesterol and inhibited both Bacillus subtilis and Escherichia coli the most. ♥

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Adjustment Factors For 120-Day Weaning Weight In Rambouullet Range Lambs, R. M. Lewis, M. Shelton, J. O. Sanders, D. R. Notter, W. R. Pirie, Texas Agricultural Experiment Station Jan 1989

Adjustment Factors For 120-Day Weaning Weight In Rambouullet Range Lambs, R. M. Lewis, M. Shelton, J. O. Sanders, D. R. Notter, W. R. Pirie, Texas Agricultural Experiment Station

Department of Animal Science: Faculty Publications

Additive and multiplicative environmental adjustments for effects of dam age, lamb sex and birth-rearing type on 120-d weight were derived using data from 819 Rambouillet range lambs. The relationship between mean and variance within environmental effect classes was one criterion for evaluating suitability of adjustment methods. Among lamb sexes and birth-rearing types, larger means were associated with greater variability (P < .01). Variances became homogeneous (P > .10) when data were expressed on a logarithmic scale, suggesting that multiplicative adjustments for these effects are needed. Because variances were homogeneous with respect to dam age (P > .50), additive adjustment factors are suggested for this effect. Validation of a …

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Influence Of Energy And Protein Intake During Lactation On Body Composition Of Primiparous Sows, J. H. Brendemuhl, A. J. Lewis, E. R. Peo, Jr. Jan 1989

Influence Of Energy And Protein Intake During Lactation On Body Composition Of Primiparous Sows, J. H. Brendemuhl, A. J. Lewis, E. R. Peo, Jr.

Department of Animal Science: Faculty Publications

The effects of energy and protein intakes by 32 primiparous sows during a 28-d lactation on sow and litter performance and sow body composition and bone properties were examined. Dietary treatments were energy intakes of 8 (LE) and 16 (HE) Mcal of ME/d and protein intakes of 380 (LP) and 760 (HP) g of CP/d in a 2 x 2 factorial arrangement. Sows fed diets that were inadequate in either energy or protein lost more weight than did sows fed the HE-HP diet, but back fat losses were greater when energy intake was deficient than when protein was deficient.

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Estimation Of Genetic Parameters For Production And Reproduction In Finnish Ayrshire Cattle, E. Mantysaari, L. Dale Van Vleck Dec 1988

Estimation Of Genetic Parameters For Production And Reproduction In Finnish Ayrshire Cattle, E. Mantysaari, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Records of AI-sired cows born between 1978 and 1982 were used to form two composite production and reproduction data sets. First (second) consisted of 35,568 (26,443) first lactations of daughters of 270 (237) sires. Traits were FCM, heifer, and first parity nonreturn rates, days between calving and first insemination, and days open, with means 5075 (5280) kg, .62 (.62), .44 (.49), 81 (81) d and 110 (111) d. (Co)variance components were estimated by REML with an expectation maximization algorithm. Sire model included age, month, herd-year effects, and relationships among sires. Records on animals with observations missing on some traits were …

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Prediction Of Progeny Genetic Evaluations From Simultaneous Genetic Evaluations Of The Dam, Sire, And Maternal Grandsire With An Animal Model, L. Dale Van Vleck, C. P. Van Tassell, R. A. Westell Dec 1988

Prediction Of Progeny Genetic Evaluations From Simultaneous Genetic Evaluations Of The Dam, Sire, And Maternal Grandsire With An Animal Model, L. Dale Van Vleck, C. P. Van Tassell, R. A. Westell

Department of Animal Science: Faculty Publications

Simultaneous genetic evaluations for bulls and cows obtained by mixed model procedures with an animal model incorporating all numerator relationships for artificially sired Holstein cows in northeastern United States were compared with separate (Northeast) mixed model evaluations of cows and sires for predicting genetic evaluations of progeny from dam, sire, and maternal grandsire evaluations. Regression coefficients for progeny (322,104 daughters and 837 sons) evaluations on dam, sire, and maternal grandsire evaluations were for daughters: Northeast evaluations; .50, .37, and -.02 compared to theoretical coefficients of .74, .52, and -.13, and simultaneous evaluations; .61, .50, and -.09 compared to theoretical coefficients …

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Genetic Parameters For Production Traits Of Holsteins In California, New York, And Wisconsin, K. M. Wade, L. Dale Van Vleck Nov 1988

Genetic Parameters For Production Traits Of Holsteins In California, New York, And Wisconsin, K. M. Wade, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Heritabilities and genetic correlations were estimated for milk and fat yields and fat percentage from 305-d, mature-equivalent records of registered and grade Holsteins in California, New York, and Wisconsin. Parameter estimates were obtained with daughter on dam regression within herd-year-season and sire of daughter. Data were pairs of first lactation records (38,115 in California, 171,555 in New York, and 136,031 in Wisconsin) from 1975 through 1984. California had higher means for milk (9046 kg) and fat (323 kg) than the other two states (approximately 7840 kg and 289 kg), but heritabilities of .36 and .34 were not greatly different from …

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Correlated Responses Of Carcass And Reproductive Traits To Selection For Rate Of Lean Growth In Swine, E. R. Cleveland, R. K. Johnson, P. J. Cunningham Oct 1988

Correlated Responses Of Carcass And Reproductive Traits To Selection For Rate Of Lean Growth In Swine, E. R. Cleveland, R. K. Johnson, P. J. Cunningham

Department of Animal Science: Faculty Publications

Mass selection for an index of increased post-weaning average daily gain and decreased backfat thickness was practiced for five generations. Litter size and weight for 221 gilt litters, birth weight and nipple number for 2,242 piglets and weaning weight at 42 d of age for 2,111 pigs were recorded. Carcass measurements were taken on 331 pigs. Differences between means of the lines (select control) were regressed on cumulative selection differential of the index. These regression coefficients were negative (P > .10) for total number born, number born alive, number weaned per litter, nipple number and carcass backfat thickness. Coefficients were …

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Comparison Of Methods Of Predicting Breeding Values Of Swine, J. W. Keele, R. K. Johnson, L. D. Young, T. E. Socha Oct 1988

Comparison Of Methods Of Predicting Breeding Values Of Swine, J. W. Keele, R. K. Johnson, L. D. Young, T. E. Socha

Department of Animal Science: Faculty Publications

Best linear unbiased predictions (BLUP) using information from all known relatives; selection index using phenotype, full-sib average and half-sib average; and phenotypic deviation from contemporary group average were compared as methods of predicting breeding values for days to 100 kg and backfat. Swine records (n = 203,869) from five Hampshire, one Duroc and six Yorkshire herds were obtained from the Nebraska SPF Swine Accrediting Agency. Heritability values used to compute BLUP or index were either estimates based on within-breed offspring on parent regression or values recommended by the National Swine Improvement Federation (NSIF) guidelines. Within-breed estimates of heritability ranged from …

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Effect Of Sex Ratio Of The Birth Litter On Subsequent Reproductive Performance Of Gilts, W. R. Lamberson, R. M. Blair, K. A. Rohde Parfet, B. N. Day, R. K. Johnson Oct 1988

Effect Of Sex Ratio Of The Birth Litter On Subsequent Reproductive Performance Of Gilts, W. R. Lamberson, R. M. Blair, K. A. Rohde Parfet, B. N. Day, R. K. Johnson

Department of Animal Science: Faculty Publications

Records on age at puberty from 1,555 gilts and total number of pigs born in litters of 1,187 gilts from the Nebraska gene pool population were used to evaluate the effects of uterine environment on subsequent reproductive performance. Independent variables were line, year, line x year, proportion of males in the birth litter (sex ratio), number born in the birth litter (fraternity size) and sex ratio x fraternity size. Sex ratio, fraternity size and their interaction influenced age at puberty (P < .01) but not number born (P > .2). Partial regression coefficients indicated that age at puberty tended to decrease as sex ratio increased, particularly …

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Estimates Of Genetic And Environmental (Co)Variances For First Lactation Milk Yield, Survival, And Calving Interval, M. C. Dong, L. Dale Van Vleck Aug 1988

Estimates Of Genetic And Environmental (Co)Variances For First Lactation Milk Yield, Survival, And Calving Interval, M. C. Dong, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Variance and covariance components for milk yield, survival to second freshening, and calving interval in first lactation were estimated by REML with the expectation and maximization algorithm for an animal model which included herd-year- season effects. Cows without calving interval but with milk yield were included. Each of the four data sets of 15 herds included about 3000 Holstein cows. Relationships across herds were ignored to enable inversion of the coefficient matrix of mixed model equations. Quadratics and their expectations were accumulated herd by herd. Heritability of milk yield (.32) agrees with reports by same methods. Heritabilities of survival (.11) …

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Heritabilities Of And Genetic Correlations Among Six Health Problems In Holstein Cows, H. K. Lin, P. A. Oltenacu, L. Dale Van Vleck, H. N. Erb, R. D. Smith Aug 1988

Heritabilities Of And Genetic Correlations Among Six Health Problems In Holstein Cows, H. K. Lin, P. A. Oltenacu, L. Dale Van Vleck, H. N. Erb, R. D. Smith

Department of Animal Science: Faculty Publications

Information from 7712 lactations of Holstein dairy cows was collected from 33 commercial herds around Ithaca, NY in the 3 yr from 1981 to 1983. The data were divided into subsets corresponding to lactation 1, lactation 2, and lactation 3 or greater. To estimate heritabilities of dystocia, retained placenta, metritis, ovarian cysts, milk fever, and mastitis, a mixed linear model (herd-year fixed and sire random effects) with 0 or 1 as the observed response was used. Variance components were estimated using Henderson's Method 3. The results show moderate heritabilities (.15 to .40) for dystocia, metritis, milk fever, and mastiffs and …

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Predicting Milk Yield Of Holstein Cows From 306 To 395 Days In Milk, T. L. Stanton, R. W. Blake, M. A. Tomaszewski, P. F. Dahm, L. Dale Van Vleck, K. E. Olson, R. E. Goodwill, K. R. Butcher Jul 1988

Predicting Milk Yield Of Holstein Cows From 306 To 395 Days In Milk, T. L. Stanton, R. W. Blake, M. A. Tomaszewski, P. F. Dahm, L. Dale Van Vleck, K. E. Olson, R. E. Goodwill, K. R. Butcher

Department of Animal Science: Faculty Publications

Prediction equations were determined to estimate daily milk yield from 306 to 395 d in milk for forecasting herd milk sales from Holstein cows in lactation > 305 d. Data were test day milk weights for 65,322 primiparous and 119,220 pluriparous lactations of > 305 d from the Southern US. A forecast model was developed using same lactation 305 d milk yield (in classes of 500 kg increments) that gave similar predicted daily yields as models utilizing last sample milk weight information. This model has the advantage of early forecasting of later milk using projected 305-d yields. Reduced forecast models ignoring days …

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Potential Of Cytoplasmic Effects For Selection In Dairy Cattle, K. O'Neill, L. Dale Van Vleck Jul 1988

Potential Of Cytoplasmic Effects For Selection In Dairy Cattle, K. O'Neill, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Maternal cytoplasmic inheritance may cause an upward bias in heritability estimates from daughter on dam regression. Inaccurate evaluations of bulls or dams of future sires would result if such estimates were used in genetic evaluation. Expected genetic selection differential for bulls would be overestimated, but genetic gain would be little affected by incorrect heritability estimates. Genetic evaluations of dams of sires would be less accurate when incorrect heritability estimates are used, but actual selection differentials would be only slightly less than optimum. If cytoplasmic effects were ignored during selection, less genetic improvement would seem to be the result. However, expected …

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Effect Of Relationships On Estimation Of Variance Components With An Animal Model And Restricted Maximum Likelihood, M. C. Dong, L. Dale Van Vleck, G. R. Wiggans Jul 1988

Effect Of Relationships On Estimation Of Variance Components With An Animal Model And Restricted Maximum Likelihood, M. C. Dong, L. Dale Van Vleck, G. R. Wiggans

Department of Animal Science: Faculty Publications

Milk, fat, and protein yields in first lactation of two samples of 12 herds consisting of 4020 and 4024 Holstein cows in New York were used to estimate genetic and phenotypic covariances with an animal model by REML. Relationships were calculated within herd in three ways to provide inverses of relationship matrices. Full relationships consisted of tracing relationships to parents (base animals) of animals with milk and fat records between 1970 and 1980. Full relationships less base animals consisted of tracing relationships only one generation back from when protein records became available in 1981. Sire-only relationships were compiled using only …

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Genetic (Co)Variances For Milk And Fat Yield In California, New York, And Wisconsin For An Animal Model By Restricted Maximum Likelihood, L. Dale Van Vleck, M. C. Dong, G. R. Wiggans Jun 1988

Genetic (Co)Variances For Milk And Fat Yield In California, New York, And Wisconsin For An Animal Model By Restricted Maximum Likelihood, L. Dale Van Vleck, M. C. Dong, G. R. Wiggans

Department of Animal Science: Faculty Publications

Two samples of data from approximately 4000 Holstein cows were analyzed by REML with a multivariate (milk and fat yields) animal model for first lactations started in 1970 through 1977 and in 1978 through 1985 and also for first lactation records started in low, middle, and high production herds in 1978 through 1985 separately for California, New York, and Wisconsin herds. Heritability estimates for milk yield (similar for fat yield) ignoring category of herd production were .29 for 1978 and later and .34 for 1977 and earlier. Estimates for low, middle, and high production herds were .23, .29, and .36. …

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Genetic (Co)Variances For Milk, Fat, And Protein Yield In Holsteins Using An Animal Model, L. Dale Van Vleck, M. C. Dong Jun 1988

Genetic (Co)Variances For Milk, Fat, And Protein Yield In Holsteins Using An Animal Model, L. Dale Van Vleck, M. C. Dong

Department of Animal Science: Faculty Publications

First lactation milk, fat, and protein yields for first lactations of 8044 Holstein cows in New York from 24 herds were used to estimate genetic and phenotypic covariances with an animal model by restricted maximum likelihood. Numerator relationships within herd, including those from sires, were utilized, although relationships across herds were ignored. Each analysis was terminated after 300 rounds of iteration. Average milk production (twice daily milking, 305-d lactation, mature equivalent) was 8630 kg. Estimates were obtained for each individual herd and groups of 3, 6, and 12 herds. Average estimates from separate analyses of the 24 herds were nearly …

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Book Review: Veterinary Genetics By F W Nicholas, L. Dale Van Vleck Jun 1988

Book Review: Veterinary Genetics By F W Nicholas, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

This book, by a well-respected senior lecturer in animal genetics, contains everything a veterinarian is likely to need to know about genetics, and more. The coverage is comprehensive, with emphasis on the interplay of biology and the environment with genetics. Important areas of population and quantitative genetics are treated as non-mathematically as possible, with more complete development available in extensive appendixes.

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Comparison Of Heritability And Variation For Milk Yield Of Registered And Non-Registered Holstein Cows, L. Dale Van Vleck, J. C. Schneider, C. P. Van Tassell Mar 1988

Comparison Of Heritability And Variation For Milk Yield Of Registered And Non-Registered Holstein Cows, L. Dale Van Vleck, J. C. Schneider, C. P. Van Tassell

Department of Animal Science: Faculty Publications

First lactation milk records of AI Holstein cows in the northeastern United States were analyzed for among and within-sire variation separately by year of freshening, class of herd production, and registry status of registered or nonregistered with a model that included effects of herd-seasons, sires of sampling daughters, and sires of daughters of proven sires. Heritability from the paternal half-sib correlation among records of daughters of sampling sires was similar for registered and nonregistered cows. Differences in heritability in different years and class of herd production were similar to those found in previous analyses that ignored registry status. Residual variances …

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Animal Model Evaluation Of Ayrshire Milk Yield With All Lactations, Herd-Sire Interaction, And Groups Based On Unknown Parents, G. R. Wiggans, I. Misztal, L. Dale Van Vleck Jan 1988

Animal Model Evaluation Of Ayrshire Milk Yield With All Lactations, Herd-Sire Interaction, And Groups Based On Unknown Parents, G. R. Wiggans, I. Misztal, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

An animal model was applied to predict genetic merit for Ayrshire milk yield. The model included fixed herdyear- season (32,287) and random herdsire interaction (32,159), permanent environment, animal, and residual effects. Animals evaluated included 119,541 cows with 301,799 records, 5762 sires, and 11,893 dams without records. Genetic groups (36) were defined for unknown parents and parents not contributing ties or records. Groups were defined by sex of parent and by birth year and sex of animal with unknown parent. Evaluations included combinations of these group effects derived from tracing each path in pedigree back to an unknown parent group. Iteration …

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Relationships Among Calcium-Dependent Protease, Cathepsins B And H, Meat Tenderness And The Response Of Muscle To Aging, Chris R. Calkins, S. C. Seideman Jan 1988

Relationships Among Calcium-Dependent Protease, Cathepsins B And H, Meat Tenderness And The Response Of Muscle To Aging, Chris R. Calkins, S. C. Seideman

Department of Animal Science: Faculty Publications

This study was conducted to compare the relative importance of Ca-dependent protease (CDP) and cathepsins B and H to meat tenderness and changes in tenderness in response to postmortem cooler aging. Charolais bulls (n = 8) and steers (n = 7) were slaughtered at 15 mo of age, and total activities of CDP-I (a protease with neutral pH optimum that requires micromolar amounts of Ca for activity) and cathepsins B and H (lysosomal proteases with acidic pH optima) were determined within 1 h. Shear-force values were obtained after 1, 3, 6, 9 and 14 d of aging. Data were pooled …

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