Genetic relationship of age at first calving with conformation traits and calving interval in Hanwoo cows
This study was performed to investigate genetic relationship of age at first calving (AFC) with body development and reproduction capacity in female Hanwoo. The data sets of 52,299 reproduction records of 19,566 heads calved from 2011 to 20...
Main Authors: | , , |
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Format: | Article |
Language: | English |
Published: |
Korean Society of Animal Sciences and Technology
2021-07-01
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Series: | Journal of Animal Science and Technology |
Subjects: | |
Online Access: | http://www.ejast.org/archive/view_article?pid=jast-63-4-740 |
Summary: | This study was performed to investigate genetic relationship of age at first
calving (AFC) with body development and reproduction capacity in female Hanwoo.
The data sets of 52,299 reproduction records of 19,566 heads calved from 2011 to
2019 and conformation records of 19565 heads born from 1997 to 2017 were
analyzed by separating them based on age at first calving. In the analysis,
conformation traits included the body condition score (BCS), height (HT), body
width (BW), hip bone length (HL), hip bone width (HW), and final score (FS). The
heritability and genetic correlation of AFC with conformation traits and calving
interval (CI) were analyzed. The heritability for AFC was 0.716, 0.087, and
0.097 for the before and after 24 months and combined data, respectively. The
genetic correlation of AFC before 24 months with BCS was −0.778,
−0.600 with BW, and 0.442 with HT. The genetic correlation of AFC after
24 months with HT was −0.826, −0.706 with BW, −0.623 with
HL, −0.456 with HW, and −0.675 with FS. When the first calving age
of young heifers approached 24 months, BCS and BW decreased, and HT increased.
When first calving is delayed to after 24 months, the conformation traits become
smaller, which indicates that conformation to some extent affects the delay in
AFC. The genetic correlation between CI and AFC was −0.116, 0.307, and
0.250 for the before and after 24 month of AFC and combined data, respectively.
When first calving date approached 24 months, CI was reduced. The obtained
results suggest that it is important that first calving occurs at an appropriate
age. Additional research is needed to perform proper genetic evaluation of first
calving age in Hanwoo cattle in Korea. |
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ISSN: | 2672-0191 2055-0391 |