Changes

* Autumn born lambs do not reach puberty until 10-12 moths of age.  

* Autumn born lambs do not reach puberty until 10-12 moths of age.  

* This is because, seasonal cues (long days of spring/summer) delay reproductive cyclicity.

* This is because, seasonal cues (long days of spring/summer) delay reproductive cyclicity.

* Thus, [[Reproductive_Behaviour_-_Oestrus_Behaviour_- Anatomy & Physiology|oestrus]] in both spring and autumn born lambs is synchronised.

* Thus, [[Oestrus Behaviour - Anatomy & Physiology|oestrus]] in both spring and autumn born lambs is synchronised.

* This maximizes the chance that all ewes become pregnant in the fall and give birth in the spring when nutritional and environmental conditions are favourable.

* This maximizes the chance that all ewes become pregnant in the fall and give birth in the spring when nutritional and environmental conditions are favourable.

* An adequate degree of nutrition ('fatness') is required before photoperiod can exert an effect.

* An adequate degree of nutrition ('fatness') is required before photoperiod can exert an effect.

* Onset of puberty occurs in January-February in the Northern Hemisphere, where there is increasing day length.

* Onset of puberty occurs in January-February in the Northern Hemisphere, where there is increasing day length.

* Queens born in February-March do not reach puberty until the following spring.

* Queens born in February-March do not reach puberty until the following spring.

* Queens born in summer/autumn generally display their first [[Reproductive_Behaviour_-_Oestrus_Behaviour_- Anatomy & Physiology|oestrus]] the following January.

* Queens born in summer/autumn generally display their first [[Oestrus Behaviour - Anatomy & Physiology|oestrus]] the following January.

* Before this can have effect, there must be adequate nutrition and growth.

* Before this can have effect, there must be adequate nutrition and growth.