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Animal Sciences

Series

1996

Selection

Articles 1 - 4 of 4

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Prediction Of Breeding Values For Tenderness Of Market Animals From Measurements On Bulls, K. L. Barkhouse, L. Dale Van Vleck, Larry V. Cundiff, M. Koohamaraie, D. D. Lunstra, J. D. Crouse Jul 1996

Prediction Of Breeding Values For Tenderness Of Market Animals From Measurements On Bulls, K. L. Barkhouse, L. Dale Van Vleck, Larry V. Cundiff, M. Koohamaraie, D. D. Lunstra, J. D. Crouse

Department of Animal Science: Faculty Publications

Data were tenderness measures on steaks from 237 bulls (Group II) slaughtered after producing freezable semen and on 1,431 related steers and heifers (market animals, Group I ) from Angus, Hereford, Pinzgauer, Brahman, and Sahiwal crosses from the Germ Plasm Evaluation project at the U.S. Meat Animal Research Center. Tenderness was assessed through Warner-Bratzler Shear Force (SF), taste panel tenderness (TPT), marbling score (MS), and myofibrillar fragmentation index (MFI). For all traits, as fraction Bos indicus inheritance increased, implied tenderness decreased. Heritability estimates were generally not significantly different from zero. Genetic correlations generally indicated favorable associations among the traits. The …


Effect Of Selection For Size Of Testes In Boars On Semen And Testis Traits, Ying-Tsorn Huang, Rodger K. Johnson Mar 1996

Effect Of Selection For Size Of Testes In Boars On Semen And Testis Traits, Ying-Tsorn Huang, Rodger K. Johnson

Department of Animal Science: Faculty Publications

The objective of this study was to evaluate the effects of selection for increased size of testes on semen and testis characteristics. Boars from a line selected for increased size of testes at 150 d of age (TS, n = 25) and a randomly selected control line (C, n = 18) were used. Semen was collected three times per week for 3 wk (TRT1) then daily for 3 wk (TRT2) beginning when boar age averaged 276 d. It was followed by a 4-wk period of one collection per week and then the TRT1-TRT2 sequence was repeated. After 64 collections, boars …


Embryonal Survival To 6 Days In Mice Selected On Different Criteria For Litter Size, E. L. De A. Ribeiro, M. A. J. Van Engelen, Merlyn K. Nielsen Jan 1996

Embryonal Survival To 6 Days In Mice Selected On Different Criteria For Litter Size, E. L. De A. Ribeiro, M. A. J. Van Engelen, Merlyn K. Nielsen

Department of Animal Science: Faculty Publications

Embryonal survival was compared in mice resulting from four criteria of selection: LS = selection on number born; IX = selection on an index of ovulation rate and ova success; UT = selection on number born to unilaterally ovariectomized females; and LC = unselected control. Selection occurred for 21 generations with three replicates of the four criteria; thereafter, relaxed selection was practiced. The evaluation was performed using mice of two replicates at Generation 35 and one replicate at Generation 36. Data on a total of 289 female mice were recorded. Females, at an average age of 9 wk, were mated …


Effect Of Variance Of Interaction Effects Of Sire And Herd On Selection For Milk And Fat Yield, G. Dimov, Jeffrey F. Keown, L. Dale Van Vleck, H. D. Norman Jan 1996

Effect Of Variance Of Interaction Effects Of Sire And Herd On Selection For Milk And Fat Yield, G. Dimov, Jeffrey F. Keown, L. Dale Van Vleck, H. D. Norman

Department of Animal Science: Faculty Publications

The animal model for genetic evaluations of dairy cattle by the USDA currently includes a term for interaction effects of sire and herd. The relative magnitude of the variance of that effect was established in the 1960s as 14% of the total variance, but recent research has shown that the proportion is 2% or less. This report compared EBV using either the 14% or the actual estimate from 20 samples of records from herds in California, New York, and Pennsylvania. From 6 to 22% of bulls or cows selected for milk and fat yields based on evaluation with 14% of …