Using artificial insemination in suckler herds provides herd owners with an opportunity to avail of different bulls, different breeds and access to some of the best genetics in the country. Observing cows in heat and the additional handling makes AI compatible in autumn calving herds as cattle are housed.

It is less common in spring calving herds as cows are at grass. Handling cows on a daily basis and heat detection increases the workload and in order to facilitate this, cows must be close to the farmyard during the breeding season.

Nevertheless, AI can still play a role in spring-calving herds. In herds with smaller numbers of breeding cows, it can be hard to justify a stock bull, especially if there are home-bred breeding heifers present. Inseminating cows at grass does require excellent management, but it is possible if well planned out.

If using AI, it will focus herd owners on the value of compact calving as a prolonged breeding period in small herds is neither time nor cost efficient.

Teaser bull

Good heat detection is essential to getting the cows back in calf. March calving cows will be coming back into heat from early to mid May, provided they calved in good condition and had no problems at calving. The breeding period coincides with a period when field work starts to increase and cows may only be checked once a day.

Using a teaser bull or a strong autumn weanling can help to identify cows coming into heat. Tail painting will show the mounting activity of the teaser bull, or other cows, to reinforce which cows are on standing heat. Other heat detection aids can be used, but obviously increase the cost.

Mixing older cows with young cows and heifers can also help to increase heat activity in breeding animals.

Synchronisation

Use of hormones can help to regulate when cows and heifers come into heat. Some programmes involve a single injection with estrumate and observing heats two to five days later. Other programmes involve use of hormone-releasing devices, such as CIDRs and AI at set times.

Handling

The important thing about inseminating cows at grass is to avoid stressing the cow. Cows should always be moved slowly and calmly. Where grazing ground surrounds the yard, offering cows 0.5kg to 1kg of meal daily during the breeding season will get cows used to handling. Ideally, the meal should be fed in a trough in handling pens so that cows are used to coming into the yard.

The next most important thing to remember is not to inseminate too soon. The am:pm rule, whereby a cow in heat in the morning should be inseminated in the evening, can be followed if there is at least 10 to 12 hours between observed heat and insemination.