Breeding programme making steady progress
The third week of the breeding programme for my research project is well under way now.
We have bred 40% of heifers in 15 days. When weather conditions are poor, heifers show little or no expressions of heat, leaving it very difficult for a farmer to determine their status.
Therefore, this figure is very satisfying, given the wet conditions over the last two weeks.
The vasectomised bull and heat patches have been a great aid to heat detection thus far. While observing the heifers, it is noticeable that the vasectomised bull tends to follow heifers a number of days before they stand to be mounted.
The reason for this is the bull detects the chemical odours being released from the heifer. These chemical odours are known as pheromones.
Pheromones induce a reaction from an animal of the same species. In this case the pheromones released are of a sexual nature and induce sexual behaviour from the bull such as mounting and following the female.
(Similar behaviour can be seen when a young lad experiences Mojo’s for the first time.)
Sniffing the genital region is a common action from the bull. A bull can also distinguish between oestrus and non-oestrus urine. The response from the bull is curling of his upper lip and wrinkling of the nose.
This is known as ‘flehmen response’. I can assure you the ‘flehmen response’ isn’t practised in Mojo’s.
It is clear to see why the vasectomised bull has been such an addition to our breeding programme. In most cases he will give us a ‘heads-up’ that a heifer is about to come into heat, allowing us to keep a close eye.
When the heifer eventually comes on heat and a standing mount is observed, they are artificially inseminated (AI) 12 hours post standing mount.
So far, with the exclusion of one, they have all been inseminated at the right time.
The one heifer was brought in a too early. If a heifer is inseminated too early, she generally receives a second insemination within 12 hours to ensure correct insemination.
I had an experience with one heifer where she showed signs of heat five days post AI. This caused confusion as an AI technician will not be able to serve a heifer if she is not on heat.
We opted to check her to be sure. The heifer in question was brought in for handling and the AI technician concluded she wasn’t in heat and didn’t require a second serve. I was relieved to say the least. I am looking forward to determining whether she held her first serve. Her behaviour five days post AI may have been a sign she was going to repeat.
Monday the 18th will be three weeks of breeding finished. Heifers that didn’t hold the first serve will start repeating from then on. There will be repeats but all going to plan, not many. Here’s hoping.