Calving Ease (Co)Variance Components for a Sire-Maternal Grandsire Threshold Model
نویسندگان
چکیده
منابع مشابه
Calving ease (Co)variance components for a sire-maternal grandsire threshold model.
Variance components for a sire-maternal grandsire (MGS) threshold model were estimated from subsets of the US calving ease (CE) database, which includes over 10 million calving records with CE scored 1 (no problem) to 5 (extreme difficulty). Selected records included sire and MGS among the 2601 most frequently appearing bulls. The data were further restricted by requiring at least 20 records in...
متن کاملImplementation of a sire-maternal grandsire model for evaluation of calving ease in the United States.
The objective of this study was to add a maternal grandsire (MGS) effect to the existing sire model for national calving ease genetic evaluations. The Animal Improvement Programs Laboratory (AIPL) of USDA assumed responsibility for conducting the national genetic evaluation for calving ease and maintaining the associated database in 1999. Existing evaluations used a sire threshold model. Adding...
متن کاملGenetic parameters of calving ease using sire-maternal grandsire model in Korean Holsteins
OBJECTIVE Calving ease (CE) is a complex reproductive trait of economic importance in dairy cattle. This study was aimed to investigate the genetic merits of CE for Holsteins in Korea. METHODS A total of 297,614 field records of CE, from 2000 to 2015, from first parity Holstein heifers were recorded initially. After necessary data pruning such as age at first calving (18 to 42 mo), gestation ...
متن کاملStillbirth (co)variance components for a sire-maternal grandsire threshold model and development of a calving ability index for sire selection.
(Co)variance components for stillbirth in US Holsteins were estimated under a sire-maternal grandsire threshold model using subsets of data from the national calving ease database, which includes over 6 million calving records with associated stillbirth scores. Stillbirth was coded as a binomial trait indicating whether the calf was alive 48 h postpartum. Records were selected for calves whose ...
متن کاملGenetic evaluation of stillbirth in United States Holsteins using a sire-maternal grandsire threshold model.
A sire-maternal grandsire threshold model was used for genetic evaluation of stillbirth in US Holsteins. Calving ease and stillbirth records for herds reporting at least 10 dead calves were extracted from the Animal Improvement Programs Laboratory database. About half of the 14 million calving ease records in the database had a known livability score, mostly from herds processed by Dairy Record...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Dairy Science
سال: 2003
ISSN: 0022-0302
DOI: 10.3168/jds.s0022-0302(03)73771-0