The 2017 calving has begun, only 249 more cows to go! A jersey cross calf was born a few days before it was expected. At Greystone Farm we use Artificial Insemination (AI) for three cycles. If the cow is still not pregnant after the three rounds of AI then we put her in a field with an Aberdeen Angus beef bull for ‘natural service’. The bulls are known as ‘sweeper bulls’ as they sweep up the cows that aren’t pregnant.
At this time of year lots of semen reps contact us in the hope that we will buy some bull semen from them. The bull semen arrives on the farm in long straws which are frozen and stored in a box of liquid nitrogen. When we are ready to use the straws they are taken out and defrosted before being placed inside the cow.
There is a great science in deciding which bull semen to purchase. The semen reps supply lots of information about each bull, based on the progeny he has produced. The traits listed include; calving ease, gestation length, udder formation, milk yield etc…
We aim to start the round of AI on May 5th, with the expectation that after an average nine months and one week, the cows will calve on February 10th. Different breed and types of bulls and cows have different length gestation periods. This knowledge can help to produce a tight calving pattern, which means maximum milk production can be linked to the time of excellent grass growth.
If we think the cow is pregnant, because she hasn’t shown any signs of re-cycling, we ask the vet to do a pregnancy check after 35 days. The vet wears special googles with a small screen. He inserts a probe inside the cow which transmits a picture to the googles. The vet is able to say if the cow is still pregnant and how many days. If the cow is no longer pregnant then we know to put her with the bull. If she is pregnant then we have an accurate due date, which is important for business planning.
This year we are expecting to calve 250 cows over the next three months, with many due in the last two weeks of February. Busy…..