نتایج جستجو برای: holsteins

تعداد نتایج: 728  

Journal: :Journal of animal science 1991
L D Van Vleck K E Gregory S E Echternkamp

A genetic correlation near unity between ovulation rate in heifers and later twinning frequency led to consideration of using measures of ovulation rate in heifers for each estrous cycle, beginning at puberty, to increase accuracy of selection for twinning rate. An initial evaluation with a multiple trait animal model for predicting breeding values included six genetic groups: 1) selected Scand...

Journal: : 2021

Die Einflüsse von Habitatparametern und das Vorkommen anderer Arten auf die Haselmaus sowie Aktivitätsphasen dieser Art wurden mit Kamerafallen Lockmittel in isolierten Straßenrandhabitaten im Westen Schleswig-Holsteins Osten Hamburgs untersucht. gemittelte Anzahl Nächten bis zum ers- ten Nachweis betrug 5,88 (± 4,55) Individuen oft nur einmal gesichtet. Ein Muster drei nächtlichen Aktivitätssc...

Journal: :Proceedings of the National Academy of Sciences 2016

Journal: :Journal of dairy science 2000
L B Hansen

The annual genetic trend for milk yield of Holsteins in the United States has accelerated with time and had means of 37 kg during the 1960s, 79 kg during the 1970s, 102 kg during the 1980s, and 116 kg from 1990 to 1996. Selection programs of the dairy cattle breeding firms in the United States have become more selective and effective with time, and selection goals continue to place major emphas...

Journal: :Journal of dairy science 1994
M M Schutz P M Vanraden G R Wiggans

Lactation means of somatic cell scores from sample days were used to estimate the components of variation for additive genetic, permanent environmental, and herd-sire interaction effects. Data included records of 4314 Ayrshire, 7845 Brown Swiss, 18,115 Guernsey, 1,135,752 Holstein, 67,862 Jersey, and 787 Milking Shorthorn cows from across the US. Records were preadjusted for length of lactation...

Journal: :Journal of dairy science 1999
C P Van Tassell G R Wiggans H D Norman

Heritabilities for milk, fat, and protein yields were estimated from first lactation data used for USDA-Dairy Herd Improvement Association (DHIA) genetic evaluations. Contemporary group assignments and standard deviations within herd-year were determined with the procedure used for national evaluations. Pedigree data were included for animals born since 1970; yield data were included for cows b...

1997
M. M. Schutz

Predicted transmitting abilities (PTA) for somatic cell scores (SCS) have been calculated and released to the US dairy industry since 1994. Phenotypically, SCS appear to be decreasing on a population basis, but genetic trends are small. Genetic trends among bulls sampled by artificialinsemination (AI) organizations also are small. Correlations of sire PTA for SCS and PTA for yield traits were n...

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