Oliver O’Hara November/December Update 2025

Animal Health

The weanlings have been vaccinated against respiratory disease to help prevent pneumonia over winter and given an injectable dose with Ivomec super. This treated them for adult liver fluke, stomach worms, lung worms and lice. While rumen fluke is an issue on the farm, it doesn’t typically affect the cattle on the out farm.

The lying and feeding space was calculated for the weanlings on the home farm. One shed is straw bedded and measured 61.55m2. Weanlings on straw bedding require 3m2 of lying space meaning that there is sufficient lying space for 20 weanlings if the feed area is kept well bedded. With ration feeding they require 0.5m of feeding space as some of the heifers are over 400kg and 4.5m was available, allowing for 9 weanlings with 10 feed spaces available. As the feed space is the most limiting factor, only 9 weanlings are recommended to be housed there. As Oliver had 5 weanlings there, they have more than enough feed and lying space over winter.

Figure 1: Weanlings housed in loose shed have more than enough feeding and lying space

The slatted shed contains 18.9m2 of lying space per pen. Housed on this, weanlings require 1.7m2 of lying space. This means that each pen can hold 11 weanlings. They also need approximately 0.45m of feeding space when fed ration and the width of each pen is 4.72m, meaning that 10 weanlings can be fed at the same time on one side. Oliver has the option to feed on both sides and as such 11 weanlings is the maximum recommended capacity per pen for optimum performance.

Figure 2: The slatted shed can accommodate 11 weanlings per pen

Animal Nutrition

Oliver has taken 1 silage sample from his first cut, as shown in the Figure below. It tested at 74.3% DMD with 14.35% crude protein and 19.1% dry matter. It was well preserved with a pH of 4 and had low ammonia levels of 4.01%. The ash content was high at 10.36% and the NDF was moderate at 46.4%. The ME was good at 10.72 MJ/kg.

Figure 3: Silage sample results from 1^st cut

It was being fed to the weanlings and the dry cows. To balance the diet for the weanlings, they would need to be fed 3kg of a 14% crude protein ration to gain over 1kg per day (for show cattle and stock for sale in spring).

For weanlings that are going back to grass next spring with a target winter weight gain of 0.6kg/day, they would only need 0.5kg of a 16% crude protein ration.

While the silage sample is excellent quality for the weanlings, it is too high for the dry cows that are already in good body condition. Oliver can move them onto a lower DMD silage of 65% in the lead up to calving, but continue to give them pre-calving minerals daily.

Performance

Oliver and Shane had one heifer entered in the Winter Fair in Carrick on Shannon where she was sold. She was born in April 2025 from a Belgian Blue cross cow and sired by the Limousin stock bull. She weighed 301kg on 29^th October and had gained 1.28 kg/day since birth.

The cows and calves were weighed on the farm for SCEP on 29^th October. 18 calves were born on the farm from 1^st January to 30^th June 2025. The ICBF weaning performance report shows that the bull calves averaged 313kg at 200 days and gained 1.34 kg/day from birth. The heifers averaged 291kg at the same age and gained 1.24 kg/day from birth. They are excellent weights and well ahead of the target weights of 300kg and 250kg respectively.

The weaning efficiency (calf weight as a percentage of cow live weight) was also very good at 44%, ahead of the target 42%.

Figure 4: April born heifer #578 (left) weighed 318kg and December 2024 born heifer #566 (right) weighed 417kg on 27^th October