CAMELS’ REPRODUCTIVE AND PHYSIOLOGICAL PERFORMANCE TRAITS AS AFFECTED BY ENVIRONMENTAL CONDITIONS

Abstract

The male camel is described as a seasonal breeder with a marked peak in sexual activity (the rut) during the breeding season and it is generally thought that the male is sexually quiescent for the remainder of the year, but it is capable of mating and fertilizing an estrous female at any time of the year. Similarly, the she-camel, although it shows strong tendency to be regarded as a seasonal breeder, pregnancy can occur at any season of the year as a polyestrus animal. However, in all cases, sexual activity of the females coincides with that of the males and both respond to the same environmental conditions. Globally, the breeding season of the camels begins at different dates beginning of September and ends at different dates until June in the different parts of the Northern World and from June to September in the Southern parts of the World, which are the mildest periods of the year, but with decreasing and / or increasing daylight, while the non-breeding season is in summer hot months. The severe hot  conditions (which are strongly related to the length increase of the photoperiod) under which the camel lives directly without any shelter in summer disturb the physiological functions that affect deleteriously the sexual activity and all the related traits of the camels' polyoestrous nature. However, although photoperiodic variations have a strong influence, yet there is some evidence suggesting that the suprachiasmatic nucleus (SCN) may be sensitive to changes in ambient temperature, with some cells being more responsive to cold and others more responsive to heat. Furthermore, the molecular mechanisms that regulate rhythmicity, such as the cyclic changes in the expression of clock proteins, can be altered by temperature changes. Further studies on the importance of SCN in reproductive functions of the camel, are needed.