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Articles 1 - 21 of 21
Full-Text Articles in Life Sciences
Estimation Of Genetic Parameters For Production And Reproduction In Finnish Ayrshire Cattle, E. Mantysaari, L. Dale Van Vleck
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 …
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
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 …
Genetic Parameters For Production Traits Of Holsteins In California, New York, And Wisconsin, K. M. Wade, L. Dale Van Vleck
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 …
Comparison Of Methods Of Predicting Breeding Values Of Swine, J. W. Keele, R. K. Johnson, L. D. Young, T. E. Socha
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 …
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
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 …
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
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 …
Estimates Of Genetic And Environmental (Co)Variances For First Lactation Milk Yield, Survival, And Calving Interval, M. C. Dong, L. Dale Van Vleck
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) …
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
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 …
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
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 …
Potential Of Cytoplasmic Effects For Selection In Dairy Cattle, K. O'Neill, L. Dale Van Vleck
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 …
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
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 …
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
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. …
Genetic (Co)Variances For Milk, Fat, And Protein Yield In Holsteins Using An Animal Model, L. Dale Van Vleck, M. C. Dong
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 …
Book Review: Veterinary Genetics By F W Nicholas, L. Dale Van Vleck
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.
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
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 …
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
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 …
Genetic Groups In An Animal Model, R. A. Westell, R. L. Quaas, L. Dale Van Vleck
Genetic Groups In An Animal Model, R. A. Westell, R. L. Quaas, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Rules are presented for assigning coefficients to the genetic group portion(s) of the mixed model equations after transformation to solve directly for total genetic value (group plus animal solutions) simultaneously for sires and cows using an animal model. Inclusion of all known relationships seems to reduce the need for groups to account for genetic selection and genetic trend. Migration of animals into a population, however, results in a need for grouping to account for genetic merit of the migrants. Selection of parents on which records are not available also creates a need for grouping. Group solutions represent the average genetic …
Relationships Among Calcium-Dependent Protease, Cathepsins B And H, Meat Tenderness And The Response Of Muscle To Aging, Chris R. Calkins, S. C. Seideman
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 …
Relationship Between Herd Management Practices In The Midwest On Milk And Fat Yield, Jeffrey F. Keown
Relationship Between Herd Management Practices In The Midwest On Milk And Fat Yield, Jeffrey F. Keown
Department of Animal Science: Faculty Publications
A dairy management survey was conducted in fall 1985 and spring 1986 in the nine-state area served by the Midstates Dairy Records Processing Center in Ames, IA. The questionnaire, consisting of 57 questions with 254 possible choices, was used to survey dairy producers on DHI testing in Arkansas, Illinois, Iowa, Kansas, Missouri, Nebraska, North Dakota, Oklahoma, and South Dakota. The questions covered housing pactices, milking equipment and practices, feeding regimens, calf rearing and feeding, feed additives, various management categories, and artificial insemination usage. The survey responses were merged with the 1985 year end rolling herd production averages from the processing …
Escape Protein Supplementation Of Yearling Steers Grazing Smooth Brome Pastures, S. J. Anderson, Terry J. Klopfenstein, V. Wilkerson
Escape Protein Supplementation Of Yearling Steers Grazing Smooth Brome Pastures, S. J. Anderson, Terry J. Klopfenstein, V. Wilkerson
Department of Animal Science: Faculty Publications
Two grazing trials utilizing individually supplemented yearling steers were conducted to study the effect of supplemental escape protein on steer performance during the active growth periods, spring and fall, of smooth brome (Bromus inermis). Graded levels (0, .11, .23 and .34 kg x head-1 x d-1) of an equal-protein-basis mixture of bloodmeal and corn gluten meal were offered daily, replacing corn starch, which was used as the negative control. All steers received 582 g supplemental dry matter per day. Supplementation with escape protein improved daily performance in both spring (P<.01) and fall (P<.02). Analysis of pooled data from both trials indicated a linear (P<.01) and quadratic (P<.05) increase in steer performance with increasing level of escape protein in the diet. Analysis of grass samples collected throughout and composited over each trial demonstrated that grass protein was highly degraded in the rumen. Using a modified dacron bag technique, 12-h degradability was found to be 80 to 90% of the potentially digestible protein fraction. Rates of protein degradability were 14 and 11.7%/h. Assuming 5%/h rate of passage, escape protein was calculated to be 9.2 and 13.1% of total protein. As a result of the significant growth response observed above that of the energy-supplemented controls and the high ruminat protein degradabilities of the grass observed in the laboratory, it was concluded that growing ruminants grazing actively growing smooth brome pastures were deficient in metabolizable protein.
Relative Economic Values Assigned To Milk, Fat Test, And Type In Pricing Of Bull Semen, J. S. Wilder, L. Dale Van Vleck
Relative Economic Values Assigned To Milk, Fat Test, And Type In Pricing Of Bull Semen, J. S. Wilder, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Data on 324 Holstein bulls from the July 1983 USDA Sire Summary and Holstein Association type evaluations were analyzed using multiple regression to determine which traits or combination of traits in a sire evaluation are most important in determining the price of a straw of semen. Over all bull studs, type was a major economic influence in determining price of semen. When bulls with outlier prices ($100 or more) were excluded, relative economic values over all buII studs were 4.31:2.63:1 for milk, type, and fat test. For three bull studs with more than 35 bulls with evaluations for milk, type, …