Yes, I have twins quite regularly. Yes, occasionally, they are twisted up and need assistance. But, sometimes singles are backwards and need assistance. Nephew checked one cow and got a really strange look on his face as he was feeling around. He had twins that were criss-crossed! One calf had it's head coming forward and one calf was over the top of it from left to right. He stuffed both back in & pulled them out one at a time.
My cows have plenty of milk, so raising 2 isn't a problem. I have NEVER seen any relation to twinning out of a twin. Although, I will admit I had a set of twin heifers - sold one and kept one. She was 16 years old and had her first set of twins in the fall while we were at state fair. She raised both through the winter on hay - but didn't breed back, so we shipped her (at 17 years old). But, both heifers were kept as replacements. Was that what you would call increasing twinning?? (twin having twins).
Sorry I haven't been active on here. Life has been super busy here on the farm. Finished calving first week in March. Had to get 4 Lots (2 c/c pairs & 2 heifers) ready for sale pictures and videos for end of March, then fought mud rest of April, 4 days at sale, home 1.5 days to get farm running smooth, gone 9 days Kauai (poor me!!!) - then 8 days to get 5 head ready for our first show! Well worth our effort! Had 48 Simmental cattle there - won Reserve Grand Cow/Calf, Res Grand Bull (with a Jan bull calf!), and won Res. Grand Heifer. 3 different farms took the Grand title - all with purchased animals! We did VERY well.
Now we are working on selling some heifer calves, bred yearlings and a few bull calves. We already have 5 bull calves sold (orders before we started calving). Nephew has been promoting them on FB. Has 1 heifer committed for and several requests for pictures and videos after seeing our prices - which scares "tire kickers away".