کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8501673 1553844 2018 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Phenotypic and genetic relationships between age at first calving, its component traits, and survival of heifers up to second calving
ترجمه فارسی عنوان
روابط فنوتیپی و ژنتیکی بین سن در ابتدای زایش، صفات جزء آن و بقا تلیسه ها تا زایمان دوم
کلمات کلیدی
سن اول زایمان، بقای، طول عمر، سن در تلقیح اولیه،
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم دامی و جانورشناسی
چکیده انگلیسی
The aim of this study was to answer the question whether models for genetic evaluations of longevity should include a correction for age at first calving (AFC). For this purpose, phenotypic and genetic relationships between AFC, its component traits age at first insemination (AFI) and interval from first to last insemination (FLI), and survival of different periods of the first lactation (S1: 0 to 49 d, S2: 50 to 249 d, S3: 250 d to second calving) were investigated. Data of 721,919 German Holstein heifers, being inseminated for the first time during the years from 2003 to 2012, were used for the analyses. Phenotypic correlations of AFI, FLI, and AFC to S1 to S3 were negative. Mean estimated heritabilities were 0.239 (AFI), 0.007 (FLI), and 0.103 (AFC) and 0.023 (S1), 0.016 (S2), and 0.028 (S3) on the observed scale. The genetic correlation between AFI and FLI was close to zero. Genetic correlations between AFI and the survival traits were −0.08 (S1), −0.02 (S2), and −0.10 (S3); those between FLI and the survival traits were −0.14 (S1), −0.20 (S2), and −0.44 (S3); and those between AFC and the survival traits were −0.09 (S1), −0.06 (S2), and −0.20 (S3). Some of these genetic correlations were different from zero, which suggests that correcting for AFC in genetic evaluations for longevity in dairy cows might remove functional genetic variance and should be reconsidered.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Dairy Science - Volume 101, Issue 1, January 2018, Pages 425-432
نویسندگان
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