On the programme farms, bulls were put in with the spring-calving herds across a variety of dates from May through to late June.
With the 12-week mark now approaching for the earlier bulling dates, some farms are now looking to pull bulls out and over the next few weeks, most bulls should be coming away from the herds.
One of the biggest problems with a spread-out calving pattern is that the batches of cattle become very uneven.
When we look at the Mackays’ 2019 spring- and summer-calving herds combined, it reveals some interesting results.
Firstly, as can be seen in Figure 1, the daily liveweight gain of the calves is fairly consistent across the weeks of calving, with a slight drop-off in some of the later weeks due to the cows not starting to milk until the grass quality had started to decline.
This demonstrates that in general the daily liveweight gain of calves is fairly even across the calving season. This is good from a general individual animal point of view.
However, when we start to look at it on a herd basis, we begin to encounter problems. As previously mentioned, the dataset in use is for both the Mackays’ spring and summer herds.
As would be expected, they were weaned on different days. Indeed, the spring calves were weaned across several days so to account for this, we have used the liveweight gain data and corrected weaning weights across the herd to one single day to allow for comparison. This is shown in Figure 2.
This tells a very different story. Again, as can be expected, later-born calves do not weigh as heavy as earlier-born calves. In this example, the average calf born in the first week of calving is 165kg heavier than a calf born in the last week of calving. When it comes to health treatments at weaning, these two animals are very different and require different treatment.
However, if we look at a calf born in week one and a calf born in week eight, there is a difference of 66kg. This is a much smaller difference and there are no problems in housing these two animals together.
The other point on long drawn-out calvings is workload. The Duguids started the project with calvings in every month of the year barring two. In 2019, this was reduced to three months of spring calving and three months of autumn calving.
This not only rationalises workload, it also leads to a reduction in calf losses as more attention is paid to a group of cows calving. Once it gets down to one or two in a paddock, they receive less attention as other jobs mount up.
The final point on tightening the calving pattern for our herds is that as they are all store sellers. They are able to present even batches of cattle for sale, with very few stragglers to deal with, meaning better prices are paid for the calves sold, translating into better gross margins.
Thoughts are also turning to this year’s sheep breeding season.
It is a good idea to assess ram needs for 2020. Giving tups an MOT now is much better than finding that they are not fit to work once they are out with the ewes and there is still plenty of time to go to the market to source more for the flock.
Checks should include:
During the breeding season a tup can lose up to 15% of his bodyweight. Ideally, pre-breeding he should be in good condition at a condition score of between 3.5 and 4. If he is not, concentrates can be added to the diet in the runup to the breeding season if grass quality has started to drop.