Open Access. Powered by Scholars. Published by Universities.®
- Institution
- Publication Year
- Publication
- Publication Type
Articles 61 - 87 of 87
Full-Text Articles in Life Sciences
Genetic Parameters Among Weight, Prolificacy, And Wool Traits Of Columbia, Polypay, Rambouillet, And Targhee Sheep, C. M. Bromley, G. D. Snowder, L. Dale Van Vleck
Genetic Parameters Among Weight, Prolificacy, And Wool Traits Of Columbia, Polypay, Rambouillet, And Targhee Sheep, C. M. Bromley, G. D. Snowder, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Genetic parameters for Columbia, Polypay, Rambouillet, and Targhee sheep were estimated using REML with animal models for prolificacy, weight, and wool traits. All bivariate analyses included a covariance between additive genetic effects for the two traits plus appropriate additional covariances. Number of observations by breed ranged from 5,140 to 7,095 for prolificacy traits, from 7,750 to 9,530 for weight traits, and from 4,603 to 34,746 for wool traits. Heritability estimates ranged from .03 to .11 for prolificacy traits (litter size at birth and litter size at weaning), from .09 to .26 for weight traits (birth weight and average daily gain), …
Genotypic Expression At Different Ages: I. Prolificacy Traits Of Sheep, H. Okut, C. M. Bromley, L. Dale Van Vleck, G. D. Snowder
Genotypic Expression At Different Ages: I. Prolificacy Traits Of Sheep, H. Okut, C. M. Bromley, L. Dale Van Vleck, G. D. Snowder
Department of Animal Science: Faculty Publications
Genetic parameters for prolificacy traits for Columbia (COLU), Polypay (POLY), Rambouillet (RAMB), and Targhee (TARG) breeds of sheep were estimated with REML using animal models. Traits were number of live births (LAB), litter size at birth (LSB) and weaning (LSW), and litter weight weaned (LWW). Numbers of observations ranged from 5,140 to 7,095 for prolificacy traits and from 5,101 to 8,973 for litter weight weaned for the four breeds. For single-trait analyses, ewes were classified as young (1 yr old), middle-aged (2 and 3 yr old), or older (> 3 yr old). After single-trait analyses, three-trait analyses were done for …
Genetic Parameters For Growth Traits For A Composite Terminal Sire Breed Of Sheep, E. Mousa, L. Dale Van Vleck, K. E. Leymaster
Genetic Parameters For Growth Traits For A Composite Terminal Sire Breed Of Sheep, E. Mousa, L. Dale Van Vleck, K. E. Leymaster
Department of Animal Science: Faculty Publications
Records of 9,055 lambs from a composite population originating from crossing Columbia rams to Hampshire ´ Suffolk ewes at the U.S. Meat Animal Research Center were used to estimate genetic parameters among growth traits. Traits analyzed were weights at birth (BWT), weaning (7 wk, WWT), 19 mo (W19), and 31 mo (W31) and postweaning ADG from 9 to 18 or 19 wk of age. The ADG was also divided into daily gain of males (DGM) and daily gain of females (DGF). These two traits were analyzed with W19 and with W31 in three-trait analyses. (Co)variance components were estimated with REML …
Heritability Estimation Of Milk Production Of Cows Of Different Origin And Breed In Karacabey State Farm, İsmet Doğan, Okan Ertuğrul
Heritability Estimation Of Milk Production Of Cows Of Different Origin And Breed In Karacabey State Farm, İsmet Doğan, Okan Ertuğrul
Turkish Journal of Veterinary & Animal Sciences
The objective of this study was to estimate heritability (h^2), a useful criterion, in the improvement studies which would be conducted to improve milk productivity in the Karacabey State Farm. A total of 760 cows, of which milk yield records were used in the study in different lactation period, consisted of 111 American Browns , 142 American Holsteins , 87 German Browns , 130 Swiss Browns , 83 Holland Holsteins and 207 Karacabey Browns. Milk yields were corrected according to the 2x305ME standardisation procedure. Furthermore, coefficients of relationship were calculated separately for Brown and Holstein cows using the pedigree cards …
Estimation Of Heritability Of Milk Yield Through Analysis Of Variance In A Repeated Measures Design In Holsteins, İsmet Doğan, Mahi̇ye Özçeli̇k, Nurhan Doğan
Estimation Of Heritability Of Milk Yield Through Analysis Of Variance In A Repeated Measures Design In Holsteins, İsmet Doğan, Mahi̇ye Özçeli̇k, Nurhan Doğan
Turkish Journal of Veterinary & Animal Sciences
In this study, data relating to the milk yield of a Holstein herd on Bala State Farm was analysed for the period 1985-92. The aim of this study was to estimate the heritability of the milk yield using two-factor experiments with repeated measures on one factor. The heritability of the milk yield was estimated to be 0.36.
Genetic Parameters For Sex-Specific Traits In Beef Cattle, R. K. Splan, Larry V. Cundiff, L. Dale Van Vleck
Genetic Parameters For Sex-Specific Traits In Beef Cattle, R. K. Splan, Larry V. Cundiff, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Data from 3,593 beef heifers and 4,079 of their steer paternal half-sibs were used to estimate genetic parameters of and among female growth and reproductive traits and male carcass traits. Estimates of heritability for adjusted 205-d weight, adjusted 365-d weight, age at puberty, calving rate, and calving difficulty measured on females were .16, .38, .47, .19, and .18, respectively; estimates for calving rate and calving difficulty were expressed on a normal scale. Estimates of heritability for hot carcass weight; retail product percentage; fat percentage; bone percentage; rib eye area; kidney, pelvic, and heart fat percentage; adjusted fat thickness; marbling score; …
Sex Effects On Breed Of Sire Differences For Birth, Weaning, And Yearling Weights, L. Dale Van Vleck, Larry V. Cundiff
Sex Effects On Breed Of Sire Differences For Birth, Weaning, And Yearling Weights, L. Dale Van Vleck, Larry V. Cundiff
Department of Animal Science: Faculty Publications
Weights of males and females can be considered to be correlated traits with different averages and variances. This study attempted to determine whether defining traits as expressed in males or in females would change estimates of breed of sire differences needed to calculate across-breed factors for adjustment of within-breed EPD to across-breed EPD. Records from the US Meat Animal Research Center of progeny of Hereford, Angus, and MARC III composite dams mated to 12 sire breeds that had been used to calculate breed of sire adjustments in 1996 were used. Breeds of sire were Hereford, Angus, Shorthorn, Brahman, Simmental, Limousin, …
Bayesian Analysis Of Twinning And Ovulation Rates Using A Multiple-Trait Threshold Model And Gibbs Sampling, C. P. Van Tassell, L. Dale Van Vleck, K. E. Gregory
Bayesian Analysis Of Twinning And Ovulation Rates Using A Multiple-Trait Threshold Model And Gibbs Sampling, C. P. Van Tassell, L. Dale Van Vleck, K. E. Gregory
Department of Animal Science: Faculty Publications
The Multiple-Trait Gibbs Sampler for Animal Models programs were extended to allow analysis of ordered categorical data using a Bayesian threshold model. The algorithm is based on data augmentation, where a value on the unobserved underlying normally distributed variable (liability) is generated in each round of iteration for each categorical observation. The programs allow analysis of several continuous and ordered categorical traits. Categorical traits can have any number of response levels. Models can be different for each trait. The programs were used to analyze twinning and ovulation rates from a herd of cattle selected for twinning rate at the U.S. …
Estimates Of Genetic And Phenotypic Parameters For Birth Weight In Brown And Simmentalcalves Raised At Altindere State Farm, Ali Kaygisiz
Estimates Of Genetic And Phenotypic Parameters For Birth Weight In Brown And Simmentalcalves Raised At Altindere State Farm, Ali Kaygisiz
Turkish Journal of Veterinary & Animal Sciences
The purpose of this study is to estimate genetic and phenotypic parameters for birth weight in Brown and Simmental calves raised at Altindere State Farm in Van. The least squares means of birth weight for Brown and Simmental calves were 40.13±0.41 and 40.04±0.27 kg, respectively. The effect of year and sex on birth weight were highly significant (P
Direct And Maternal Genetic Covariances By Age Of Dam For Weaning Weight, L. Dale Van Vleck, K. E. Gregory, G. L. Bennett
Direct And Maternal Genetic Covariances By Age Of Dam For Weaning Weight, L. Dale Van Vleck, K. E. Gregory, G. L. Bennett
Department of Animal Science: Faculty Publications
Weaning weights of calves of dams at ages in years of 2, 3, and older were modeled to be three separate traits. Fixed effects were sex of calfyear of birth combinations for nine pure breeds and sex of calf-year of birth-generation for three composite populations. Random effects fitted for each trait were correlated direct and maternal genetic, maternal permanent environmental, and temporary environmental. Direct and maternal effects were correlated across traits. A multiple-trait, derivative-free REML algorithm was used to estimate the 30 (co)variance components. Number of animals per breed group ranged from 1,244 to 4,326. For the three traits for …
Estimates Of Heritabilities And Genetic And Environmental Correlations For Left- And Right-Side Uterine Capacity And Ovulation Rate In Mice, Merlyn K. Nielsen, Y. L. Kochera Kirby, A. C. Clutter
Estimates Of Heritabilities And Genetic And Environmental Correlations For Left- And Right-Side Uterine Capacity And Ovulation Rate In Mice, Merlyn K. Nielsen, Y. L. Kochera Kirby, A. C. Clutter
Department of Animal Science: Faculty Publications
Heritabilities for and genetic and environmental correlations between uterine capacity, ovulation rate, and body mass (BM) were estimated in mice. Uterine capacity was defined as the number of fetuses (LUC or RUC for left or right side) in one uterine horn for unilaterally ovariectomized females. Ovulation rate (corpora lutea, LCL or RCL for left or right ovary) was measured on the remaining single ovary in these same females. Data on 1,931 mice from four selection populations were used. Left ovulation rate and LUC were measured on 958 animals, and RCL and RUC of another 972 animals were recorded. Genetic and …
Estimates Of Genetic Parameters For 320-Day Pelvic Measurements Of Males And Females And Calving Ease Of 2-Year-Old Females, L. A. Kriese, L. Dale Van Vleck, K. E. Gregory, K. G. Boldman, Larry V. Cundiff, R. M. Koch
Estimates Of Genetic Parameters For 320-Day Pelvic Measurements Of Males And Females And Calving Ease Of 2-Year-Old Females, L. A. Kriese, L. Dale Van Vleck, K. E. Gregory, K. G. Boldman, Larry V. Cundiff, R. M. Koch
Department of Animal Science: Faculty Publications
Records from 12 breed groups collected from 1983 to 1991, included in the Germ Plasm Utilization project at the U.S. Meat Animal Research Center, were analyzed separately by breed group and combined to estimate heritabilities and genetic correlations for 320-d male and female pelvic width, height, and area, and for 320-d male pelvic and female 2-yr-old calving ease. Calving ease was analyzed as a trait of the dam using 1) actual and 2) binary scale calving ease scores with a covariate of calf birth weight. A bivariate animal model and derivative-free REML incorporating sparse matrix techniques were used. When breed …
Heritability And Repeatability For Milk Production Traits Of Japanese Holsteins From An Animal Model, Mitsuyoshi Suzuki, L. Dale Van Vleck
Heritability And Repeatability For Milk Production Traits Of Japanese Holsteins From An Animal Model, Mitsuyoshi Suzuki, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Records of the first three lactations of cows were obtained from the file of the Dairy Herd Testing Association in Hokkaido. The data were divided into 10 files containing approximately 24,000 cows each. The derivative-free REML method was used to estimate variances with a repeatability model. The model contained herd-year, calving month, and the linear and quadratic effects of age at calving as fixed effects; additive genetic, permanent environmental, and temporary environmental effects were the random effects. Estimates from the 10 data files were pooled into a simple arithmetic mean. Empirical standard errors were. calculated from the samples. Average estimates …
Estimates Of Genetic Parameters For Direct And Maternal Effects On Embryonic Survival In Swine, Luis T. Gama, Keith G. Boldman, Rodger K. Johnson
Estimates Of Genetic Parameters For Direct And Maternal Effects On Embryonic Survival In Swine, Luis T. Gama, Keith G. Boldman, Rodger K. Johnson
Department of Animal Science: Faculty Publications
Survival of 16,838 potential embryos was determined by counting corpora lutea and fetuses at 50 d of gestation for 1,081 litters by 225 sires. These data, coded as 1 or 0 depending on whether an ovulation was represented by a fetus, were used to estimate direct and maternal additive genetic variances and their covariance for embryonic survival. Data were from fist-parity gilts of a Large White-Landrace composite population subdivided into two lines, one selected for an index of ovulation rate and embryonic survival for seven generations and a contemporary control line. Variance components were obtained by ANOVA and expectations of …
Comparison Of Methods Of Estimating Variance Components In Pigs, J. W. Keele, T. E. Long, R. K. Johnson
Comparison Of Methods Of Estimating Variance Components In Pigs, J. W. Keele, T. E. Long, R. K. Johnson
Department of Animal Science: Faculty Publications
Components of variance due to average effects of genes (σ g2), environmental effects common to littermates (σ c2), and environmental effects peculiar to individual pigs (σ e2 )were estimated (ˆ) by the Pseudo Expectation Approach (PE). Data were litter size (LS), backfat (BF; centimeter) and ADG (kilograms/day) collected from the Nebraska Gene Pool swine population between 1967 and 1986. Mean square errors (MSE) for ĥ2 and ĉ2 (ôg2 and ôc2 divided by phenotypic variance) by PE and nested ANOVA and h2 estimated by offspring on parent regression (REGOP) …
Heritability Estimates Of Transformations Of Normally Distributed Records, A. L. Destefano, L. Dale Van Vleck
Heritability Estimates Of Transformations Of Normally Distributed Records, A. L. Destefano, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Milk yields were simulated for identical twin and parent-progeny pairs to determine effect of transformations on genetic variance. Use of identical twin pairs excludes variability due to Mendelian sampling and contribution by the other parent present in parent-progeny records. Phenotypic variances of 616,800; 1,439,200, and 2,261,600 and means from 2267 to 13,603 by increments of 2267 were used for linear scale records. Phenotypic variances of .0100O, .01875, and .02750 and means equal to the natural logarithm of the means for linear scale were used for log scale records. Heritability varied from .05 to .95 by increments of .lo. For each …
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
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. …
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
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 …
Factors Influencing Best Annual Racing Time In Finnish Horses, M. Ojala, L. Dale Van Vleck, R. L. Quaas
Factors Influencing Best Annual Racing Time In Finnish Horses, M. Ojala, L. Dale Van Vleck, R. L. Quaas
Department of Animal Science: Faculty Publications
The fixed effects of year of race, season of race, sex, method of start, annual number of starts, length of race and racetrack were evaluated on best annual racing time in Finnish Horses. Data included 1,378 records for 554 horses by 206 sires. Five models were assumed within the age groups from 3 to 6 yr. The annual number of starts, method of start and season of race effects were interrelated. An increase in number of starts was associated with considerable improvement in a horse's best annual racing time. Records should not, however, be adjusted for effect of annual number …
Lambing Performance Of Morlam And Dorset Ewes Under Accelerated Lambing Systems, L. C. Iniguez, R. L. Quaas, L. Dale Van Vleck
Lambing Performance Of Morlam And Dorset Ewes Under Accelerated Lambing Systems, L. C. Iniguez, R. L. Quaas, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Two accelerated lambing systems, Morlam using Morlam sheep (USDA, Beltsville 1966 to 1975) and Carnal using Dorset ewes (Cornell 1978 to 1981), were evaluated for first lambing ages, interlambing intervals and conception probabilities. Morlam ewes were continuously exposed to rams over the year, while Carnal Dorset ewes were exposed every other month. Morlam lambs were mated as early as 367 d of age and Carnal Dorset lambs as early as 340 d. Early lambing was associated with higher rates of perinatal mortality (P>.05) and smaller litter size (P<.O1). Lambing years among Morlam ewes and season of birth of Carnal Dorset ewes influenced (P<.01) their first lambing ages. Lambing intervals averaged 293 and 303 d among Morlam and Carnal Dorset ewes, respectively. Age at first lambing and season in which the previous lambing occurred with influential factors (P<.01) on lambing intervals of Morlam ewes; longer intervals resulted when ewe lambs were mated at early ages (<12 mo), and when the previous lambing occurred in winter. Estimates of conditional probabilities of conception by month given the occurrence of estrus, reflected seasonal changes in both systems. The overall probability of conception for the Morlain system (P=.16) was relatively higher than that for the Carnal Dorset system (P=.14); numbers of lambings per ewe per yr were 1.28 and 1.21, respectively. Estimates of heritability for age at first lambing, lambing interval and conception probability were. 31, .06 and .30, respectively.
Genetic Parameter Estimates For Reproductive Traits Of Male And Female Littermate Swine, R. O. Bates, D. S. Buchanan, R. K. Johnson, R. P. Wetteman, R. W. Fent, L. K. Hutchens
Genetic Parameter Estimates For Reproductive Traits Of Male And Female Littermate Swine, R. O. Bates, D. S. Buchanan, R. K. Johnson, R. P. Wetteman, R. W. Fent, L. K. Hutchens
Department of Animal Science: Faculty Publications
Reproductive traits of purebred and crossbred pigs produced in a four-breed diallel mating system using the Duroc, Landrace, Spotted and Yorkshire breeds were collected for five consecutive farrowing seasons (two farrowing seasons/year) beginning in fall 1976. Paternal half-sib heritabilities and genetic correlations for testicular traits (120 boars from 36 sires), serum testosterone (TE) and luteinizing hormone (LH) concentrations before and after treatment with gonadotropin releasing hormone (GnRH; 131 boars from 37 sires) and breeding performance traits (151 boars from 38 sires) were estimated. Heritability estimates were generally small to moderate except for sperm/gram testis (SGT), LH concentrations before (LH0) and …
Preweaning Survival In Swine: Heritability Of Direct And Maternal Effects, William R. Lamberson, R. K. Johnson
Preweaning Survival In Swine: Heritability Of Direct And Maternal Effects, William R. Lamberson, R. K. Johnson
Department of Animal Science: Faculty Publications
The heritabilities of direct and maternal effects on litter survival to weaning (LS) were estimated from records of 1,243 litters of pigs from the Nebraska Gene Pool population born from 1968 to 1981. Heritabilities were estimated by: (1) weighted least-squares regressions of average survival for litters of sons on average survival for litters of their sire, (2) nested analysis of variance with LS fitted to a model including year-line and sire of litter, (3) weighted least-squares regression of average survival for the litter of daughters on the survival of the litter of their dam and (4) nested analysis of variance …
Genetic And Phenotypic Parameters Estimated From Nebraska Speci Fic-Pathogen-Free Swine Field Records, P. J. David, R. K. Johnson, T. E. Socha
Genetic And Phenotypic Parameters Estimated From Nebraska Speci Fic-Pathogen-Free Swine Field Records, P. J. David, R. K. Johnson, T. E. Socha
Department of Animal Science: Faculty Publications
Records collected during 1971 through 1979 from 101,606 hogs raised in 18 Nebraska Specific Pathogen Free herds were analyzed. Traits considered were backfat at 100 kg (BF), weight at 140 d of age (WT) and, in some analyses, number of live pigs/litter at birth (NBA). The phenotypic correlation of BF and WT, averaged across herds, was -.07. The correlations between BF and NBA and between WT and NBA were .04 and -.05, respectively. Average phenotypic standard deviations for BF, WT and NBA were 2.6 mm, 8.8 kg and 2.0 pigs. Estimates of the heritability of BF and WT were lower …
Measures Of Racetrack Performance With Regard To Breeding Evaluation Of Trotters, M. J. Ojala, L. Dale Van Vleck
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 …
Inheritance Of Teat Number And Its Relationship To Maternal Traits In Swine, R. A. Pumfrey, R. K. Johnson, P. J. Cunningham, Dwane R. Zimmerman
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 …
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
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.
Estimation Of Heritabilities For Weight, Height And Front Cannon Bone Circumference Of Thoroughbreds, R. L. Hintz, H. F. Hintz, L. Dale Van Vleck
Estimation Of Heritabilities For Weight, Height And Front Cannon Bone Circumference Of Thoroughbreds, R. L. Hintz, H. F. Hintz, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
A total of 19,833 records on 1,992 Thoroughbred foals out of 813 dams and by 365 sires was used to estimate heritability of weight, height at withers, and front cannon bone circumference. Measurement ages ranged from 0 to 174 days. Records were adjusted for the fixed effects of age of dam, sex of foal, and month and year of birth of the foal. Body weight, height at withers and front cannon bone circumference tended to be rather lowly heritable during the first few months but were moderately to strongly heritable by 1 year of age.