Sire calving ease increases through selection and breeding

How many problem births can I expect when I use a Belgian Blue with a sire calving ease breeding value of 125? And how does this compare to a Holstein with a breeding value of 104? These are questions that are regularly asked in actual practice. Mathijs van Pelt of the Animal Evaluation Unit of Coöperatie CRV explains it here. ‘The sire calving ease breeding value for Belgian Blue bulls and Holstein bulls cannot be compared one-on-one,’ says Van Pelt. ‘For example, the sire calving ease breeding value of Belgian Blue bulls is expressed in relation to the average of the Blue population, while the sire calving ease breeding value of Holstein bulls is expressed in relation to the average of the Holstein population.’ Belgian Blue bulls used for cross-breeding are selected on the basis of births within the pure Blue breed. The calving data collected from Blue breeders is used to calculate breeding values for various factors, such as gestation period, birth weight and sire calving ease. The bulls with favourable indexes are designated as ‘suitable for cross-breeding’. To make selection for livestock farmers easier, CRV classifies these bulls as ‘average’, ‘smooth’ and ‘very smooth’.

Tables 1 and 2 display the percentage problem births that on average can be expected when a bull with a certain sire calving ease breeding value is used. There is another difference here. ‘Blue bulls are used on heifers and older cows and the selection here is also based on sire calving ease. In case of Holstein bulls we are primarily interested in sire calving ease for use on yearlings to reduce calving problems when they calf the first time,’ Van Pelt explains. The percentage problem births when Belgian Blue bulls are used on heifers or older Holstein cows on average is approximately 9 percent. Table 1 shows that this matches a sire calving ease index of 120 for Belgian Blue bulls. By comparison: a Holstein bull with a sire calving ease breeding value of 100 produces approximately 5.6 problem births when used on yearlings and 4.2 percent when used on heifers or older cows. The sire calving ease breeding values are based on the use of conventional sperm and therefore provide an average for heifer and bull calves. When (female) SiryX sperm is used, the risk of problem births can be significantly reduced. Male SiryX sperm from a number of Belgian Blue bulls is also available. When this sperm is used, there is a greater risk of difficult births, however.

Aside from sire calving ease breeding values, the Coöperatie CRV also calculates breeding values for daughter calving ease. ‘This breeding value indicates how many normal or smooth calvings can be expected among the bull’s heifers,’ says Van Pelt. ‘This breeding value therefore provides insight into the calving ease of a bull’s daughters, while the sire calving ease breeding value provides insight into the ease with which a bull’s calves are born,’ is how he explains the difference. Table 3 demonstrates the relationship between the daughter calving ease breeding value and the percentage problem calvings among heifers and multiple calving daughters of a bull.

Statistics prove that selection and breeding based on sire calving ease and daughter calving ease is effective. ‘The genetic predisposition for these characteristics has risen by an average of three points over a period of ten years. This clearly translates into fewer birthing problems,’ Van Pelt indicates. ‘In 2011 almost 10 percent of heifers had problem births. By last year this had dropped to approximately 5 percent.’ The sire calving ease and daughter calving ease breeding values are important building blocks for the birth index. This index also incorporates the breeding values for sire calf viability at birth and for daughter calf viability at birth. Furthermore, starting with the production of this month’s index, the breeding value for calf vitality also forms part of the birth index. ‘Selecting on this index therefore leads to fewer calving problems, fewer stillborn calves and fewer animal deaths in the first year of life,’ Van Pelt explains. ‘Because the birth index is also incorporated into the NVI – the total merit index used in the Netherlands and Flanders – further progress is expected in terms of sire calving ease over the coming years,’ he concludes.

Bulls with favourable breeding values for sire calving ease can easily be selected from the CRV catalogue. Go to the catalogue and select the breed

1. Scroll all the way down to the bottom of the menu on the left
2. Click on ‘Add breeding value filter’
3. Select sire calving ease
4. Use your mouse to shift the small ball to the left to establish the lower limit for sire calving ease.

The catalogue now displays all bulls that meet your minimum requirement. This way you can easily select bulls for the yearlings, for example. The selected bulls are displayed in NVI sequence. In the same way you can select bulls on the daughter calving ease breeding value for Holstein, Fleckvie, MRIJ and other Dutch dual-purpose breeds. Go to: https://shop.crv4all.com/en