Below, you will find tips for farmers when using AI in suckler herds.
According to Alan Dillon, Teagasc beef specialist, docility needs to be one of the main selection criteria for suckler herds from a health and safety point of view and an efficiency target.
He said time is scarce on farms now, and “stock that are hard to handle, being wild and aggressive have no place on-farm”.
When choosing an AI sire, he explained, the first thought to cross a farmer’s mind: is what purpose will the progeny be used for potentially?
Breeding replacement heifers
If any females are to be bred as replacement heifers in the suckler herd, then a farmer should utilise a maternal sire with high sub-indices for milk and docility.
A number of bulls, particularly those with more terminal characteristics, have a negative figure for milk.
“These are not suitable for breeding replacement heifers. Aim for a figure over +5kg for milk to ensure the progeny will have adequate milk to rear a calf.”
He said that while carcass characteristics are the most important traits for terminal bulls, they are also imperative for bulls to breed replacement heifers.
“Remember, the cow is 50% of the calf’s genetics. It is not uncommon for some traditional breeds with very easy calving characteristics to have negative carcass weight figures, again this needs to be checked, and unsuitable bulls avoided.”
He advised farmers to target a bull with a minimum carcass figure of +10kg for breeding replacement heifers to ensure their progeny have the genetics to grow and perform.
The Teagasc beef specialist stressed that farmers should avoid excessive carcass conformation when breeding replacements. “Excessive muscle in the hindquarters can lead to more difficult calvings, which may influence fertility on subsequent breeding seasons.”
Using AI in suckler herds – Terminal figures
According to Dillon, when selecting bulls for terminal figures, the main focus is on calving difficulty, carcass weight and carcass conformation.
“There are several bulls available with high carcass weight and relatively low calving difficulty figures.”
He said these are the bulls farmers should focus on as opposed to those with very high levels of expected calving difficulty. He warned that the latter can lead to higher vet costs and possibly have a negative effect on future fertility.
Table 1. Example bulls for terminal and replacement characteristics
He highlighted the advantages of AI as follows:
- Firstly, the potential to access top genetics across all breeds (replacement & terminal);
- More cost-effective for smaller herds;
- Higher reliability if you select a team of sires;
- Also, it reduces the safety risk of having a stock bull.
Heat detection aids
- Firstly, simple detection aids such as scratch cards/pads/tail paint;
- Electronic heat detectors that use teaser bull to transmit a signal from a neck collar to a tag in a cow’s ear by text message;
- Synchronisation programmes to trigger the onset of heat and use fixed time AI;
- Lastly, restricted suckling from 30 days post-calving;
- Purpose – replacement or terminal.