Explanation

The period from kidding/lambing to the next oestrus is technically called the postpartum anoestrus period, but in livestock management contexts, the interval from parturition (kidding/lambing) to conception or service is often referred to as the service interval. However, strictly speaking, the time to the *next oestrus* is the postpartum anoestrus duration. Let's re-evaluate. The question asks for the period from kidding/lambing to next oestrus. This is the 'postpartum anoestrus' or 'breeding interval' depending on definition. 'Service interval' usually implies parturition to service/conception. 'Calving interval' is parturition to parturition. In many MCQs for animal husbandry, 'Service interval' is used loosely for the time from kidding to breeding readiness/oestrus. Given the options, B is the standard answer in this context.