Changes

==Introduction==

==Introduction==

Unlike polyoestrus animals such as the cow or sow which can reproduce all year round some species such as the Mare, Ewe, Goat, Rabbit, Hampster and Doe have an '''Anoestrus''' phase to their reproductive cycling. This means that for part of the year they are not experiencing oesrous cyclicity and so are not reproductively active. such animals can be lond or short day polyoestrus breeders. seasonality of reproduction is due to the effect of light levels on the brain. Reproductive seasonality maximises the chance of offspring survival by timing parturition to coinside with spring when nutritional and climate conditions are optimum for lactation and for growth of the offspring.

Unlike polyoestrus animals such as the cow or sow which can reproduce all year round some species such as the Mare, Ewe, Goat, Rabbit, Hampster and Doe have an '''Anoestrus''' phase to their reproductive cycling. This means that for part of the year they are not experiencing oesrous cyclicity and so are not reproductively active. such animals can be lond or short day polyoestrus breeders. seasonality of reproduction is due to the effect of light levels on the brain. Reproductive seasonality maximises the chance of offspring survival by timing parturition to coinside with spring when nutritional and climate conditions are optimum for lactation and for growth of the offspring. It is important to be able to distinguish between seasonal anoestrus and pathological infertility.

==science of seasonality==

==science of seasonality==

==short day breeeders==

==short day breeeders==

==Manipulation of Seasonal breeders==

==Manipulation of Seasonal breeders==

=photoperiod=

photoperiod, nutrition, temperature.