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Kay O'Sullivan April Update

Plan your breeding season now

Plan your breeding season now

  • What bulls should you use to breed replacements?
  • Can you use terminal sires on poorer cows?
  • Select easy calving bulls for heifers <8% heifer calving difficulty with over 80% reliability
Take faecal egg samples from cattle that weren’t dosed over winter

Take faecal egg samples from cattle that weren’t dosed over winter

  • Treat if necessary based on FEC results
  • Watch withdrawal periods for finishing cattle
  • Take another FEC sample after dosing to check if product worked effectively
Develop a nutrient management plan for your farm

Develop a nutrient management plan for your farm

  • Base this on your most recent set of soil samples
  • Correct soil pH first by spreading lime
  • Use organic manures on low P and K index fields


There are 19 cows calved this spring and 4/5 remaining up until the end of May. One is also due in July.  No major issues arose at calving.

One twin was rejected by its mother and she is being bucket fed with milk replacer along with the calf whose dam died.

Kay will start breeding on 20th June and finish on 25th August (~10 weeks). She has a number of AI bulls selected for use on her cows this year which include ZHF, ESH, KYA, AA5310, AA4633, AA4632 and AA4089. 

The herd replacement index for the cows is €86, which is 3 stars on the Eurostar index. To reach an average of 5 stars across breed this would have to be over €115 according to the March 2022 evaluation and over €125 to be 5 stars within the AA breed. For Kay to achieve this she will have to use bulls that are over €150 on the replacement index and keep these replacement heifers. From the AI straws that she has available to her this year, ZHF and AA4632 meet this criteria and these should be used on her best cows in the herd.

The best cows in the herd can be selected using the weaning performance report by looking at the calves with the highest 200 day weight (target >250kg) and by looking at the weaning efficiency of the cows (target >42%). The suckler cow report can also be used to determine the slaughter performance of the progeny of the cows in the herd.

ESH, KYA and AA4633 are negative for carcass weight and should only be used on the biggest cows in the herd so as not to end up with very small and/or narrow cows in the future. ZHF and AA4089 are the best bulls on the terminal index from Kay's selection, with eurostar values of €93 and €82 respectively. ZHF has a carcass weight of 12kg and carcass conformation of 0.91. AA4089 has a carcass weight of 8kg and carcass conformation of 0.72. 

Animal Health

As Kay is an organic farmer it is compulsory for her to have an animal health plan. She cannot routinely dose animals for worms and fluke, but instead uses methods like rotational grazing, mixed grazing of cattle and sheep and other methods to reduce the potential worm burden. To assess the effectiveness of these methods, she faecal samples stock on the farm. If these samples show a rise in the worm count above 150 eggs per gram for cattle and 250 eggs per gram in sheep she discusses with her vet what treatment is required. Medicines can only be used on the farm if she can show a requirement and the vet can sign-off the appropriate treatment on the organic certification record book.

Faecal egg samples were taken from the weanlings in January and they came back clear for coccidia, rumen fluke, liver fluke, lung worms, tape worms and stomach worms. They were sampled again in early April and the results came back at 150 eggs per gram of strongyles (stomach worms).

This level indicated a need to treat the cattle and after consultation with her vet, Kay dosed them on 9th April. She used an ivermectin product which was administered by injection and covers lung worms, stomach worms and lice. The typical withdrawal period of this product is 28 days but because Kay is an organic farmer she is legally obliged to double this (56 days). However the meat processor further requires the withdrawal period to be tripled to 84 days.

As a result of the extended withdrawal period, the 6 heifers that are due to be finished in mid-May were not treated as the withdrawal period would affect their slaughter date.

A faecal egg count reduction test (FECRT) will be carried out on the farm to ensure that the dosing product worked. To do this, Kay will take a further FEC sample from the same treated cattle 14-16 days after dosing to see if the egg burden has reduced. If the burden has reduced by over 95% (i.e. less than 7 eggs per gram) it would indicate that there is no anthelminthic resistance to the ivermectin ingredient (macrocyclic lactone family) on Kay’s farm.

Soil Fertility

Soil samples were taken on the farm and the results have been used to develop a nutrient management plan for the farm. Overall the soil pH is good with only 7% of the farm with a pH of less than 6.2. These fields will receive lime at a rate of 2t/acre this year to correct it.

The phosphorus indexes are very low on the farm with 82% in index 1, 8% in index 2 and only 10% in index 3. This will be difficult to correct in Kay’s farming system as she is not allowed to purchase standard chemical phosphorus and the Physlag 27 that she is permitted to buy is very expensive. She typically has enough dung produced over the winter to cover 90% of the farm which is spread in September. Kay has decided to spread the dung in July instead to reduce any risk of nutrient loss, and will particularly focus on fields that have been cut for silage/hay and fields that are in a higher index 1 to try and build them up. She is allowed to import certain organic manures if they are approved by the organic certification body, but with importing dung there is a risk of disease such as coccidiosis. Cattle slurry and dairy sludge are hard to source but they are a good option if the opportunity arises.

The potassium levels on the farm are quite good with 49% of the farm in index 3 or higher and 51% in index 2. Again, Kay is unable to spread typical K compounds and Patent Kali which she is permitted to spread is very expensive. Therefore these fields can also be prioritised for dung or possible future imports of organic manure.