Planning your breeding programme for 2012
Article by Dr. Dan Ryan published in the Farming Independent August 31, 2011
It is now that 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 or to remove stock bulls from the middle of July to the end 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 in excess cow numbers for quota available. The number of replacement heifers 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 cessation.
Body condition score
It is now critical that cows are gaining body condition and that they achieve the ideal body condition score of 3 by the time they are dried off at seven months of pregnancy. This is not the case in at least 70% 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 pertaining to poor body condition score, relate to 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. They need to gain weight. The target for the maiden heifers needs to be .75 kilograms 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 on 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 and the group size averaged 30 heifers each year. 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 between 75% and 90% for the 13 week breeding period. In the extreme type Holstein cow, the pregnancy rates are significantly lower than that encountered of the British Friesian Cross Holstein cow or the Jersey Cross Holstein 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 pertain 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 in the year system.
Farmers are identifying their empty cows earlier this year after finishing the breeding programme. 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. Once again because of the demands of quota management in a Superlevy year, farmers plan to remove these cows from the milk production system. These cows will not be carried over to a breeding programme next Spring or milked through the Winter as in former years. Cull cow values will very much depend on the genetic structure of the cow with very little return on the Jersey Cross bred cow.