Maintaining herd health – Parasite control should be planned ahead of time to ensure burdens of stomach worm, lungworm or fluke are not present.
- Control of infectious diseases such as BVDv, IBR and Leptospira Hardjo is critical to ensure good AI results.
Suitable handling facilities – Handling facilities are essential as cattle will need to be gathered on several occasions during the programme and for AI. Ideally the crush should be covered, as synchronising a large batch of heifers/cows in heavy rain/snow is not ideal!
Management of Body Condition Scores (BCS) – BCS is an important tool for suckler producers to help them optimise health, welfare and fertility, while minimising calving difficulties and production costs and should be managed on a year-round basis and particularly for calving, mating and weaning. Energy deficiency leading to poor BCS and prolonged anoestrus is by far the most common cause of poor fertility in many herds whereas fatter cows have more difficulty calving, increasing the risk of caesareans or even calf mortality. Therefore forward planning is essential to ensure cows are calved at target BCS to ensure most are cycling prior to synchronisation.
Trace elements – Trace element supplementation such as copper, selenium and iodine, if required should be administered in advance of breeding.
Sexual maturity of replacement heifers – Sexual maturity in heifers is related to weight rather than age; therefore heifers born earlier in the calving season are likely to be heavier at bulling and are genetically more fertile. In order to achieve first calving at 24 months, management practices should ensure that heifers are of adequate size (65% of mature weight) for successful mating at 15 months. Heifers will need to grow at an average live weight gain of 0.85-1.0kg/day from birth to hit target weights for mating¹.
ARTIFICIAL INSEMINATION IN THE BEEF SUCKLER HERD
- Advantages of Artificial Insemination
- Access to quality terminal sires with accurate Estimated Breeding Value (EBV) data allowing selection of specific traits such as easy calving for heifers, terminal characteristics (i.e. growth, carcass) for beef production or maternal characteristics (i.e. milk) for breeding replacements.
- Options for AI
- a) AI to observed heats
- Beef cows that calve in target body condition score (BCS) around 2.5-3 should normally start cycling and show heats within 50-60 days of calving.
- 20-30 min periods of heat detection 2-3 times daily can be an effective way of selecting cows for AI especially in autumn-calving housed cows – early morning and evening are critical times to observe for heats.
- Heat detection aids such as such as ear tag sensors, activity meters/pedometers and tail paint have also been used successfully in beef herds.
- Cows should be inseminated within 12 hours of being seen standing to be mounted.
- b) Synchronised AI
Advantages
- Increasing the percentage of cows calved in the first 21 days of the calving period by having groups of cows/heifers all bred on day 1 of the mating period. Having a more compact calving period has an economic benefit by having batches of uniform, quality calves that are heavier at weaning.
- Synchronising a batch of cows or heifers will give you a reference heat: i.e. observe for returns 18-24 days post service.
- Using breeding protocols in conjunction with fixed time AI will ensure all cows are served. Some protocols are suitable for cycling and non-cycling (anoestrous) cows.
