Most spring-calving herds are now in week four of the breeding season. At this stage most cows should have had a cycle, and if cows are calved 30 days and still haven’t shown a heat, you should organise to have them looked at via scanning or a vet examination. Good scanning operators will pick up pregnancies from 28 to 30 days. Scanning cows served over 30 days will give you peace of mind that everything is going as planned. With a target conception rate of 60% that means that in a 30-cow herd, you should have 16 to 18 cows in-calf at this stage. If conception rate is lower than 60% and there are a lot of repeats, alarm bells should ring and you need to find the problem. If a mature bull has been running with a group of replacement heifers, he could be taken out and replaced with a young bull, as the level of repeats in this group should be low. Replacement heifers should not be bred for longer than nine weeks. If she hasn’t gone in-calf after three cycles, you have to ask yourself if she’s worth keeping.