Most farms try to achieve a condensed calving period, with the majority of the herd calving within a 4-week period and the whole herd within 8-weeks.

How compact your calving pattern is will determine or have an impact on:

• Number of days in milk (lactation days) and therefore production
• Number of replacements bred and the rate of genetic gain within a herd
• Number of empties that affects your ability to cull within the herd
• Management practices regarding both labour requirements and feed management
• Your overall profitability of your farm

Your calving pattern of your herd is dependent on 2 main factors:

Submission Rate

Reported as a percentage of the whole herd that is put up to be bred within a set period. The industry target is to have more than 90% within 21 days. The submission rate will depend on:

• Accurate heat detection
• The number of animals cycling

There are some reproductive interventions that we can use to increase the submission rate of your herd and improve your overall calving pattern. Eg Why wait for PG programmes and treating non-cycling cows, heifer synchrony programs etc.

Conception Rate

This is the percentage of animals put up for AI which will hold to that service (get pregnant). The conception rates will depend on:

• Cow fertility - this depends on the animal's health and nutritional status. Ways to improve this is to ensure your cows mineral levels are adequate, early aggressive treatments with metrichecking, good body condition score and nutrition levels, etc
• Accuracy of heat detection. This is very important and one of the main reasons for low conception rates
• Bull/AI fertility

If you are wanting to condense the calving of your herd we would recommend talking to your KeyVet to discuss where the biggest gains can be made. Usually, this will involve having a good look into your whole reproductive performance over previous years. Small incremental gains made here can drastically improve the profitability of your farm, so it is well worth delving into to create a solid plan for this mating period and going forward!