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2002

Department of Animal Science: Faculty Publications

Heritability

Articles 1 - 5 of 5

Full-Text Articles in Life Sciences

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

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

Department of Animal Science: Faculty Publications

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


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

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

Department of Animal Science: Faculty Publications

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


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

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

Department of Animal Science: Faculty Publications

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


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

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

Department of Animal Science: Faculty Publications

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


Comparison Of Models For Estimation Of Genetic Parameters For Mature Weight Of Hereford Cattle, J. M. Rumph, R. M. Koch, K. E. Gregory, L. V. Cundiff, L. Dale Van Vleck Feb 2002

Comparison Of Models For Estimation Of Genetic Parameters For Mature Weight Of Hereford Cattle, J. M. Rumph, R. M. Koch, K. E. Gregory, L. V. Cundiff, L. Dale Van Vleck

Department of Animal Science: Faculty Publications

Genetic parameters of mature weight are needed for effective selection and genetic evaluation. Data for estimating these parameters were collected from 1963 to 1985 and consisted of 32,018 mature weight records of 4,175 Hereford cows that were in one control and three selection lines that had been selected for weaning weight, for yearling weight, or for an index combining yearling weight and muscle score for 22 yr. Several models and subsets of the data were considered. The mature weight records consisted of a maximum of three seasonal weights taken each year, at brand clipping (February and March), before breeding (May …