Help me under stand pelvic measurements

[chicken farmer]

I just started doing AI on my small herd. I had a heifer ready to breed this morning. When I got in her, her pelvic opening felt small to me, and the pelvic shelf wasn't smooth it had two knots on it. I ended up not inseminating her.
If I understand it right, you measure the vertical opening and the horizontal opening and multiply them together to reach the pelvic score. The general consensus is you want at pelvic score of at least 160. 13cm x 13 cm seems tiny to me. Am I thinking of this correct.

The heifer was born April 30, 2015.

 

[True Grit Farms]

I'd cull her myself. The only heifer I've had die calving is one I could barley get my hand in. Since then I cull all the tight ones and haven't had any calving problems in the 5+ years. Don't know nothing about measuring but I can sure feel a tight one.

 

[chicken farmer]

My plan is to cull her.
There was plenty of room vertical just the horizontal was tight. My hand fit just not much room side to side, but 13 cm isn't very big. I was just thinking after reading about pelvic measurements that she would probably be fine to breed.
I'm new to AI, so she is only the second heifer I've tried to breed. The cows I've done there seems to be a ton of room in there.

 

[Son of Butch]

My first thought was, brand new to A.I. probably trained only on cows, so not familiar heifers and overly cautious
by not inseminating her (assuming the semen was already thawed.) Use it as a learning experience.
Have a vet measure her and learn whether you were right or not for future reference.

 

[TCRanch]

A 13 x 13/169 measurement should be able to calve an appx 80 lb calf unassisted. This is assuming she's measured at/around 11 months & bred not before 15 months. Depends on the bull. We use heifer bulls with smaller birthweights; one throws an average 68 lbs, his calves are pretty stocky & the other closer to 74 lbs but his calves are long & thin with narrow heads.

 

[dun]

A rough guesstimate of minimum acceptable size is opening your hand and spreading you fingers. If the fingers hitting the sides or top and bottom, that is usually adequate. That depends on your hand size though.

 

[inyati13]

I just started doing AI on my small herd. I had a heifer ready to breed this morning. When I got in her, her pelvic opening felt small to me, and the pelvic shelf wasn't smooth it had two knots on it. I ended up not inseminating her.
If I understand it right, you measure the vertical opening and the horizontal opening and multiply them together to reach the pelvic score. The general consensus is you want at pelvic score of at least 160. 13cm x 13 cm seems tiny to me. Am I thinking of this correct.

The heifer was born April 30, 2015.

I have all my heifers pelvic scored. At the same time the vet does a reproductive tract score on a scale of 1 to 5.

The pelvic measure is as you describe. Two linear measurements in centimeters. They are multipled to arrive at a product in square centimeters. A yearling heifer is preferred to be at least 160 square centimeters.

In selecting heifers to be retained, I prefer at least 175 square centimeters because my average birth weight is 88 pounds.

The reproductive score is qualitative. The vet palpates the reproductive tract. Check size of ovaries and whether they have a corpus luteum to indicate they have cycled. I prefer a 4 on that. I want heifers with good anatomical reproductive system.