Gestation

[OH Breeder]

I have been around cattle for years and I don't want to sound stupid. BUT....I ll ask anyways. Do you think certain breeds of cattle have shorter gestation? I always thought some did. Do you think certain bulls have shorter gestation?
The reason I am asking is I have a clubbier bred heifer. SHe is bred to angus bull for first time calving. She is not due for 2 weeks but she looks like she will go early. I know heifers can calve early but do you think the breed and the bull contribute to that?
Be nice.

 

[AndersenClubCalves]

Oh them first time heifers can be really tricky in my experience I've seen them get a tight bag and run around bawling for weeks before they decide to lay down and acually do somthing about. But have alson heard on the angus cows usually calve ten days earlier and charolais cows about ten days later. Now for the other breeds i dont have a clue.

 

[vcsf]

There are absolutely differences between breeds and between bulls within a breed for average gestation length.  I believe justintime has talked a few times about his two full Irish import Shorthorn bulls Highfield Irish Mist and IDS Duke of Dublin and how Mist was almost two weeks shorter in average gestation than Duke.

The following is taken from an old ABS breeding chart which says the figures come from research papers or the breed association.

BREED                              Average Days Gestation
Ayrshire                                          278
Brown Swiss                                    291
Guernsey                                        284
Hostein                                            279
Jersey                                              280
Angus                                              279
Brahman                                          291
Chianina                                          287
Charolais                                          287
Gelbvieh                                          287
Hereford                                          286
Limousin                                          286
Maine-Anjou                                    288
Polled Hereford                              286
Santa Gertrudis                              289
Simmental                                        288
Shorthorn                                        281
Tarentaise                                      286

 

[OH Breeder]

Great info vcsf.

 

[kfacres]

I was going to suggest the old ABS breeding chart- before VCSF beat me to it...  The ironic thing is all are based off of the SHorthorn (milking or beef) at 280 days-- what we consider a normal cow's gestation length.. and this board is LOADED with shorthorn people!

With my own cow herd and sheep flock- I have found that certain lines do carry gestation different.  These shortend gestation animals typically fall into what we call Low birthweight and calving ease.  It is the most noticable with our dairy- as we have many breeds and their crosses.. and use a variety of bulls-- with the other two operations, the genetics are pretty well identical- but differences are still noted.

 

[leanbeef]

I was going to site the research, but thanks for posting actual information! That suggests about a 2 week variance in the AVERAGE for each breed, and obviously there is at least that much variance within a breed as well. I'm pretty meticulous about our AI breeding dates, due dates and calving dates, and what I've noticed is almost every cow will calve within 10 days on either side of her due date, which gives you a 21 day window. The distribution would follow a bell curve, with most being closer to the due date and a very few extreme outliers for whatever reason. Personally, I've seen more come earlier than 10 days early than I have later than 10 days late, but either of those are potential problems in my book. The really early calves I've had are small and sometimes weak, and usually in extremely hot weather. Twins will usually be 6-10 days early as well. The 10-day-past-due-date is usually a big bull calf, but not always! They'll come when it's time, I reckon...

Speaking of that...don't try to induce a cow. There are drugs that will induce labor, but they don't help the cervix to dilate, and that's a problem. That means C-section.

 

[Okotoks]

The new 2012  Sire summary for the Australian Shorthorn Association just came out and it includes gestation length. Two of the top 3 bulls are American ones. Interesting that CE , BW and gestation length does not always correlate. 

http://www.shorthorn.com.au/assets/files/Breedplan/SSATEK_GROUP-2012-Jan-pubsires-top-GL.pdf

Full sire summary links

http://www.shorthorn.com.au/

or animal search link

http://abri.une.edu.au/online/cgi-bin/i4.dll?1=313021&2=2431&3=56&5=2B3C2B3C3A

 

[kfacres]

in a plain ole pasture and herd sire mating system.. without markers, how is gestation length measured and recorded?

 

[Okotoks]

in a plain ole pasture and herd sire mating system.. without markers, how is gestation length measured and recorded?

Like with anything you need the data so unless it's an onbserved breeding or an AI date it can't be inputted. The Australian Shorthorn Association had the Durham Project so they had a dozen years of AI breeding on the bulls used in the project. As well the USA bulls would all be AI matings so the accuracy would be higher on them and of course any other bulls used AI.

 

[kfacres]

I don't recall the ASA ever having a spot on the reg application to record date of breeding...

 

[Okotoks]

I don't recall the ASA ever having a spot on the reg application to record date of breeding...

the ASA doesn't have a gestation EPD either

 

[leanbeef]

The Simmental association's registration application USED TO ask for breeding dates, but it was optional information...not required for registry. I'm disappointed that we've stopped asking for that information. I guess there were too many other areas to focus on once upon a time when we needed to make some changes! We just published our first docility EPDs...maybe eventually we'll start thinking gestation will be something to think about again.