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Posted: Mon Jan 18, 2010 11:21 am
by Louisa Gidney
On our shiny colour wall chart from DCS, it gives estimated calving dates assuming a 263 day gestation period. I was surprised at this, as I always assumed 280 days was the norm for cattle. Does anyone know why DCS have used the 263 day figure for Dexters?
Posted: Mon Jan 18, 2010 4:58 pm
by Broomcroft
I work on 280 days and have never had one less than that. Aberdeen Angus are supposed to be one of the shortest aren't they, and in a test I have seen based on a lot of cattle they came out at 272 days, whereas continentals were around 289 days. I use 280 to give me the earliest possible realistic date for calving (excluding premature obviously, which we've only had once, and born dead).
Edited By Broomcroft on 1263830568
Posted: Mon Jan 18, 2010 7:28 pm
by Mark Bowles
The table i have been using for the last 6 years or so is 284 days. I have found this to be about right, at a guess i should imagine about 20% drop on the due day, very few come a week before or a week late. I am talking around 100 calvings where i have the service date. Obviously to use the 263 days then i would have been well adrift.
Anyone else have any amount of records?
Posted: Mon Jan 18, 2010 8:24 pm
by Saffy
I only have a few Dexters but being lucky enough to see most of them served I have had due dates and have carried on using the same expected gestation times as I did with my milkers. I think they are a few days earlier on average - maybe 4/5 but not 20!
Stephanie
Posted: Mon Jan 18, 2010 9:24 pm
by GEE TEE
I Think if you count the days you will find it is 283 days and not 263 days as quoted under the heading of the gestation table,misprint/operator error?
Posted: Tue Jan 19, 2010 5:27 am
by wagra dexters
Of live calvings for which I know the exact dates, ie AI joinings:-
Days 283 to 288 = 35
Day 282 = 14
281 = 13
280 = 17
279 = 15
278 = 9
277 = 13
276 = 12
275 = 21
274 = 11
273 = 8
272 = 8
271 = 3
270 = 2
269 = 2
268 = 2
>none
265 = 1
>none
262 = 1
We did also have a healthy calf born that was supposedly 241 days but that cow was in calf when we bought her so even though it was by AI I didn't do it so can't guarantee it.
Sires have a lot more influence over gestation length than do the dams.
Margaret
Posted: Tue Jan 19, 2010 5:41 am
by wagra dexters
PS. All calvings less than 272 days are either Wm Hedgehog 3rd or his sons.
Bookhams Robert, Shootlands Ben MacDhui, Trillium Chabotte, and Bindalee Celtic Chieftain, plus the above, make up the 272 days. TC & BCC are Canadian Wm breeding.
Knotting and Saltaire descendants tend to come into the later calvings, also other red lines. They are all the bigger calves, not necessarily any stronger or healthier.
Margaret
Posted: Tue Jan 19, 2010 11:06 am
by Louisa Gidney
Thanks everyone. It seems as though GeeTee's suggestion of a typo for 283 days is most plausible but I'm surprised this was not picked up at proof reading before printing.
Posted: Tue Jan 19, 2010 11:08 am
by Broomcroft
There's going to be a lot of people calling their vets this year because of late calving :D
Posted: Tue Jan 19, 2010 3:09 pm
by marion
Hi Margaret, That's interesting, because I have had lots and lots of my Dexters born at 274-275 days, and a few sooner than that. If I remember correctly the longest gestation was 287..heifer from an older cow, but most just don't go as long as the tables say they should.
There is of course, a lot of Woodmagic breeding behind our Cdn. cows 
..marion
Posted: Thu Jan 21, 2010 10:35 am
by Broomcroft
This is not exactly scientific to say the least, but we are just calving about 45 cows, 75% to an Angus and 25% to a Dexter, and the first born was to a cow that is 75% Woodmagic (by the AA), and the third was by her daughter. Both really nice calves. Looking at my record, she always seem to calve before most others.
Edited By Broomcroft on 1264066789