Effect of crop type on calf size and traits

Fodder beet vs kale wintering of pregnant cows – resulting impacts on calf stature (size) and bone density.



Key person
DairyNZ (collaboration with Massey University)

Project objectives

  • Investigate whether the diet cows are wintered on affects calf liveweight and stature at birth and if so, what the differences in bone mineralisation or density are.

Project description

Previous research has demonstrated that kale and fodder beet diets differ in many nutrients, particularly phosphorus and nitrogen (crude protein). Over recent years it had been suggested that fodder beet feeding may be contributing to increased risk of humeral fractures in rising 2-year old replacements. Since both phosphorus and nitrogen are associated with bone development in utero, this project aimed to understand whether the diet cows were wintered on affected calf liveweight and stature at birth and if so, what the differences in bone mineralisation or density are, if any.

During spring 2018 and 2019 all replacement heifer calves were weighed on arrival into the calf shed and had their wither height, girth and length measured. These liveweight and stature measures continued until the animals completed their first lactation. In spring 2019 a pilot study was undertaken with bull bobbies to assess bone structure and density. 

Project outcomes/learnings

Liveweight and stature:

  • In both years, calves born to dams wintered on FB were 9% lighter at birth and shorter in wither height and length from shoulder to tail than those born to dams wintered on kale.

Bone structure:

  • Differences were observed in some of the bone parameters that were measured in the pilot study, the significance of which requires further investigation.

During spring 2020 the bone measurements were repeated in the newborn calves and a cohort will be reared to post puberty and bone health reassessed. The project will also look to investigate non-invasive options for measuring bone density. 

Stay up to date with our Newsletters, weekly notes, Field Day notices and other updates.

{{errors.first('rs-aede-5128-d84d', 'rs-aede-a25a-dba3')}}
{{errors.first('rs-aede-5128-ce4a', 'rs-aede-a25a-dba3')}}

Message Sent.