Determined efforts being made to stop late calving
Published 30/08/2011 | 05:00
Now is the time of year to assess the performance of your spring breeding programme. This is the first year that I have seen a determined effort to stop AI and remove the stock bull from the second half of July. This will automatically reduce the number of cows calving in May and June next year.
The primary reason for the determined effort to stop late calving of cows is quota management. Most dairy farmers have far too many cows for the quota available. The number of replacement heifers also far exceeds that required. Farmers now realise that the superlevy will be an issue for the forthcoming years and that there will be restrictions on the volumes of milk supplied to our creameries post-quota.
It is now critical that cows are gaining body condition and that they achieve the ideal body condition score of three by the time they are dried off at seven months of pregnancy. This is not the case in at least 70pc of the cows observed on my farm visits. Failure to address body condition score targets now will have a detrimental effect on reproductive performance in your herd next year. Further investigation into poor body condition scores reveals issues such as severe infestation with liver and stomach fluke, IBR and overstocking with poor dry matter intakes.
Do not forget the replacement stock on your farm. Both weanling heifers and in-calf heifers need to gain weight. The target for the maiden heifers needs to be 0.75kg per day. A weighing scale is the best investment for the farm to keep an eye on weights. This can be routinely carried out on a monthly basis at the time of either dosing or moving maiden heifers to new pastures.
On a recent visit to a client in Co Limerick, I remarked to the dairy farmer that he had excellent in-calf heifers. He informed me that this was the first year he placed emphasis on target weights for the heifers from time of birth. He weighed the heifers on a monthly basis and those heifers not achieving target weight were grouped separately and fed supplementing concentrates to achieve desired target. Based on the pregnancy scan of these heifers, all the heifers were in-calf which was the first year that this was achieved in the past eight years. The principal reason that the heifers were not in-calf was that they failed to come out of puberty because of environmental stressors.
Currently, pregnancy rates range from 75-90pc for the 13-week breeding period. In the extreme Holstein cow, pregnancy rates are significantly lower than that encountered in the British Friesian-cross or Jersey-cross cow. This difference is mainly attributed to poor management of the Holstein cow on grass based systems. There are also other environmental factors associated with low pregnancy rates observed. The most significant ones relate to liver and stomach fluke infestations and IBR. It's critical in the current dairy management practice to have a picture of the health status in your herd. This can be carried out routinely by milk sampling at three regular periods during the year.
Farmers are identifying their empty cows earlier this year after finishing the breeding programme on schedule. Scanning is an excellent tool to complete this procedure and can be accurately used from 25 days after removing the stock bull or finishing AI.