pelvic measurements

[buckaroo_bif]

Can anyone tell me the correct formula to figure pelvic area into calving ease?
If you have a pelvic area that measures 15cm by 15 cm on a yearling heifer you take 15x15=225 divided by ? what?
or am i not even close to knowing what i am talking about?
thanks

 

[Bama]

http://muextension.missouri.edu/explore ... g02017.htm

Table 1
Using pelvic measurements to estimate deliverable calf size (birth weight)

Time of measurement Heifer age Heifer weight Pelvic area Pelvic area per birth weight ratio Estimated calf birth weight
Before breeding 12-13 months 600 pounds 140 cm2 2.1 67 pounds
160 cm2 2.1 76 pounds
180 cm2 2.1 86 pounds
Pregnancy exam 18-19 months 800 pounds 180 cm2 2.7 67 pounds
200 cm2 2.7 74 pounds
220 cm2 2.7 82 pounds

Pelvic measurements can be obtained at the time of pregnancy exam, but a factor of 2.7 should be used to estimate calf birth weight of 18- to 19-month-old 800-pound heifers. Tables 1 and 2 provide estimates of the deliverable calf size a heifer can accommodate at first calving based on pelvic area at given weights and ages. Scientists at the University of Nebraska suggest that these ratios appear to be good indicators of dystocia and report an accuracy of nearly 80 percent.

 

[buckaroo_bif]

Thanks Bama!
So if I have a 12 month old heifer with a pelvic area of 200 cm (or whatever number) I divide that by 2.1?
correct?
which

 

[Bama]

Yep a 12 mont old 600 pounder you would use a factor of 2.1. Click on the link at the top and you will get all the measurements for differant ages and weights.