top of page

A Genetic Approach to Improved Fertility


Improve fertility of your herd by including SCR in your customised plan. World Wide Sires is proud to lead the industry in providing elite genetics and semen fertility. WWS recognizes the importance of creating pregnancies in allowing our customers to realise the value of the genetics, so we make every effort to maximize the fertility of each dose of semen sold. Sire Conception Rate (SCR) is the only measure of male fertility that is published by a third party (not an individual AI organisation) and that uses data from all the USA Dairy Records Processing Centres. The Council on Dairy Cattle Breeding (CDCB) is the organization that publishes the official dairy cattle evaluations for all traits, including SCR, in the USA. For this reason, WWS supports the use of SCR when selecting bulls for high semen fertility. SCR is an indicator of the semen fertility of bulls used for Artificial Insemination (AI) based upon conception rate of service sires. SCR takes into consideration the inbreeding percentage of the bull being used (service sire) as well as the percent inbreeding of the offspring resulting from the mating. In addition to reported fertility from usage of the bull’s semen, the age of the bull, the AI organization collecting the semen, and the year the semen was used are also accounted for. Variables relating to the females being bred are removed in order to find the most accurate measure of the bull’s ability to create a pregnancy. In financial terms, SCR brings real value and increases herd profitability. Each point of SCR equates to a 1% increase in conception rate, so a bull with +2.0 SCR would have a 2% higher conception rate than the average of the population. There are many tools for ranking the semen fertility of bulls. However, as the only measure of male fertility that utilises data from all of the USA Dairy Records Processing Centres and is published by a third party, WWS supports the use of SCR when selecting bulls for high semen fertility. References: Dechow, Chad. Hoard’s Dairyman. How much can we pay for high-end bulls? February, 2016. Improve fertility of your herd by including DPR in your customised genetic plan. Daughter Pregnancy Rate (DPR) measures the cow’s ability to begin cycling, show estrus, conceive, and maintain pregnancy. DPR is highly correlated with Productive Life (PL). A DPR of 1.0 equates to a 1% increase in pregnancy rate during a given 21 day estrus cycle. Every 1.0 PTA increase in DPR indicates 4 fewer days open. For example, daughters of a bull with 3.4 DPR will get in calf 13.6 days quicker on average than a bull with a DPR of 0. Take this real life example from a grazing herd in South Africa. It’s clear to see that the high DPR sires, do indeed, create daughters that become pregnant more quickly than the daughters of low DPR sires.


Lactation - Holstein Friesian grazing herd in South Africa

No. Cows

Average parent average DPR

Average days open

Top 25% for top DPR

85

1.7

92

Top 25% for bottom DPR

85

-1.0

113

Difference

21

2nd Lactation Holsteins in Grazing Herd in South Africa



0 comments

Comments


bottom of page