Watch: A breeding update from Newford
With calving now complete, the breeding season at Newford Farm commenced on Monday, April 21. Michael Fagan brings us up to date with the latest happenings from the demonstration farm, where 100% AI will be used over a 10-week breeding season.
To monitor pre-breeding activity, all cows were tail painted during the first week of April and all detected heats were recorded. Activity was good, somewhat helped by the fact that the majority of the cows were in the ideal body condition score for breeding (BCS of 2.5).
During the breeding season, cows in the Newford herd will be ran as two groups (~39 cows per group), accompanied by a teaser bull to aid in heat detection. These vasectomised bulls have been fitted with MooCall heat detection collars, as well as a chin ball harness, and were purchased at a cost of €1,075.
To save on labour, once a day AI will be used and cows will be inseminated at midday each day. If a cow is inseminated at 12 noon and she is still displaying standing heat again that evening, the cow will be inseminated again the next day.
For insights on Newford’s breeding season, watch the below video:
Replacement heifers
The 31 replacement heifers at Newford were bred using an 8-day synchronisation programme, with mating taking place on April 18th. These heifers are Angus and Aubrac first crosses from the dairy herd and have the following average breeding values:
- Replacement Index of €173
- Carcass weight of 3.26kg
- Carcass conformation of 0.28 (PTA)
- Beef calving interval of -4.22 days
- Age of finish of -2.89 days
Sire selection
When selecting sires for the 2025 season, Newford Farm focused on the Terminal Index, calving difficulty, conformation and the cost of the AI straw.
Key sire criteria included:
- 5 Star on the Terminal Index
- Calving difficulty of 7% or less for the main mature herd
- >2 of a conformation score for the cow herd
- Sires selected for heifers had a calving difficulty of 5.2% or less (reliability of +70%) at >1.9 score for conformation
- The AI straw cost less than €30
From this, the sires in table 1 below were selected:
Table 1: AI sires to be used on Newford over the 2025 breeding season
| Code | Sire name | Breed | Terminal Index (€) | Calving difficulty (%) | Reliability (%) | Carcass weight (kg) | Age of finish | Conformation | Cost of straw (€) |
|---|---|---|---|---|---|---|---|---|---|
| AI sires for the main herd | |||||||||
| LM9379 | Shannon Stan | LM | 184 | 2.50 | 58 | 33.7 | -2.8 | 2.60 | 12 |
| LM8727 | Magister | LM | 179 | 3.40 | 58 | 33.6 | -3.2 | 3.20 | 20 |
| LM9577 | Drumline S1185 | LM | 178 | 4.70 | 61 | 36.9 | 0.3 | 2.70 | 12 |
| CH1123 | Remus | CH | 174 | 4.60 | 48 | 52.7 | -4.7 | 2.00 | 26 |
| CH8742 | Kinnard Ronaldo | CH | 174 | 4.10 | 55 | 45.4 | -0.8 | 2.50 | 30 |
| AI sires for replacement heifers | |||||||||
| AU1170 | Deerpark Nevin | AU | 158 | 5.2 | 64 | 24.5 | -11 | 2.2 | 10 |
| LM7599 | Moebius | LM | 157 | 3.2 | 80 | 35.1 | -2.4 | 2.2 | 25 |