Contact us
 |
[email protected] |
 |
3275638434 |
 |
 |
| Paper Publishing WeChat |
Useful Links
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License
Article
Effect of Delayed Insemination on Holstein Cows’ Reproductive Performance
Author(s)
Charlotte Gaillard, Jakob Sehested and Mogens Vestergaard
Full-Text PDF
XML 1558 Views
DOI:10.17265/2161-6256/2016.01.007
Affiliation(s)
Department of Animal Science, Aarhus University, DK-8830 Tjele, Denmark
ABSTRACT
Holstein cows’ fertility
has decreased in the last decade, creating a need for new management methods to improve
the reproductive performance which in this case was
defined by pregnancy rates and number of artificial
inseminations (AI) per pregnancy. Previous studies showed that deliberately delaying
rebreeding until after peak lactation can improve
reproductive performance compared with the traditional
rebreeding in early lactation. The objective was to compare the reproductive
performance of cows in consecutive lactations of different lengths. The reproductive performance (pregnancy rate and
number of insemination to pregnancy) of 62 Holstein cows involved in a 16
months extended lactation trial was recorded and compared with the reproductive
performance of the previous and following 10 months lactation of the same cows. It was hypothesized that a late rebreeding (at eight months, 16 months
lactation) will improve the reproductive performance compared with an early
rebreeding (at two
months, 10 months lactation) in the previous lactation, and it will have no
negative effect on the reproductive performance in the following lactation with
an early rebreeding. The results showed that the pregnancy rates were similar
for the 16 months lactation and the previous and following 10 months
lactations, while the number of AI to pregnancy was increased in the 10 months
lactation, following by the 16 months
lactation. The use of the double AI technique did not improve pregnancy rates
compared with a single AI per estrus, and induced confusion, as how to report the
herd reproductive performance. To conclude, the reproductive performance was
similar between the heifers, primiparous and multiparous cows, and between 10 months
and 16 months lactations.
KEYWORDS
Extended lactation, pregnancy rate, double insemination.
Cite this paper
References