How old should the donor cow be?

The minimum age for embryo collection is a maiden heifer of 11 months; apart from this there are no limits to the age of a donor cow. However, older cows, over 12 years of age, are less predictable in their response to superovulation treatment. Older cows in particular are less likely to produce the average of six viable embryos per collection.

How many times can a cow be used for embryo collection?

Embryo collection may continue for as long as the cow continues to respond to superovulation treatment. This will vary from one individual to another; it is possible for some cows to achieve good results for many collections. Others may need a 'rest' between programmes. A rest may involve allowing the cow to cycle naturally two or three times or returning her in-calf before further embryo collection resumes.

How frequently can collections be done?

Provided all goes well embryos may be collected from a cow approximately every 6 - 8 weeks. This timing allows her to come into heat following a collection and to undergo the programme for the next collection.

Will superovulation treatment affect the cow's future fertility?

No. The cow is examined by a veterinary surgeon a few days after embryo collection and an injection is given to return her to a normal heat cycle. She will show normal fertility when next on heat.

I haven't been able to get my best cow in calf - is there any point in trying to collect embryos?

The answer to this question depends very much on the reason your cow has failed to hold in calf. In many cases the 'problem' does not affect the ability of the cow to yield embryos when flushed. For some owners their only chance of achieving further pregnancies from cows with a poor breeding history is through the use of embryo transfer. We would, however, prefer to reserve the answer to this question until a full history of the cow and any treatment she may have received is available.

When is the best time to start collecting embryos from a donor?

As soon as you know that an increase in the number of calves from a particular animal will increase your profit margins either through increased production and the sale of additional progeny. Maiden heifers can be flushed from 11 months of age provided they are well grown, and cycling normally. Cows can be flushed from 8 weeks calved provided they are clean and cycling, preferably having had two heats.

Do all cows respond to superovulation treatment?

Cows respond to superovulation treatment very much on an individual basis. The first time a cow is programmed, a drug and dose that experience has shown to give the best response for her particular breed, size and age group will be administered. Genus has, at its disposal, a number of different drugs each of which can be varied in dosage. If the initial collection is disappointing, it is normally possible to improve the result in a second or subsequent collection.

Is it better to use maiden heifers or cows as recipients?

Either - it depends on what you have available. Cows older than fourth calvers should be avoided but otherwise to use the lower end of your herd as recipients is usually extremely cost-effective. The most important elements with regard to recipients are accurate heat detection and management - please refer to recipient selection and management notes.

Does the recipient have any influence on the calf?

On its genetic make up - NO. The only influence a recipient has on the calf it is carrying is to nurture it until it is born. If the recipient is in poor condition this will reflect in the calf, but the breed, colour, size, shape and its genes are derived solely from the sire and dam used for embryo collection.