Fertility is not about cow size. Large cows are fertile if fed enough. Practical fertility is predominantly about body condition. We can feed/ manage and/or breed for body condition. Inherent body condition (fat) is determined by relative intake. This is largely about size. Halve cow size and you can double return on investment.
High practical fertility can be achieved with the following:
- Fat genotype
- Calve on green grass
- Wean on green grass
- Cows on cheap rumen supplement during their dry period and the dry period