How does postpartum anoestrus affect fertility?

The stimulus of suckling, sometimes linked to a poor body condition, lowers the frequency of LHLuteinising hormone: responsible for the final maturation of the follicle and ovulation. pulses. Therefore, only 25% to 30% of suckling cows ovulate their first post-partumPeriod between parturition and the return to cyclicity (and therefore appearance of heat). dominant follicleSmall secretory or excretory cavity. Ovarian follicles grow until ovulation or female gamete emission.. That translates into large proportion of beef cattle in anoestrusState characterised by the absence of cyclicity and therefore the absence of heat. It is frequently observed after parturition for a longer or shorter period depending on the breed and physiological status. at the time of breeding.

In a dairy cow that is thin at calvingGiving birth to a calf., ovulationExpulsion of an ovum from the ovary in female animals. of the first dominant follicleSmall secretory or excretory cavity. Ovarian follicles grow until ovulation or female gamete emission. will only occur in 20% of cases due to low energy availability.

A significant energy deficit in the weeks following calvingGiving birth to a calf. delays the first ovulationExpulsion of an ovum from the ovary in female animals..

AnoestrusState characterised by the absence of cyclicity and therefore the absence of heat. It is frequently observed after parturition for a longer or shorter period depending on the breed and physiological status. can occur more commonly when cows are tethered or kept in dark stalls.

Late embryo mortality or pyometraInfection of the uterus lining (metritis) characterised by the accumulation of pus in its lumen. can lead to the retention of a corpus luteumOrganelle formed after ovulation of a dominant follicle. Its thick wall is formed from progesterone-secreting cells. It is the sign of the cyclical activity being maintained in the event of pregnancy. that then prevents normal cyclicityCharacterizes what is cyclical: returns to regular intervals and is repeated in a cycle. Return to cyclicity is highly important in the post-partum phase..

An ultrasound examination determines whether the cyst is follicular or luteal. Many specialists do not consider luteal cysts a pathological state, but in most cases simply CL structures with large cavities (common in most CLs in the early stage of the oestrous cycle).  

Common before first ovulationExpulsion of an ovum from the ovary in female animals. postpartum and happens in roughly in 50% of the cows. The hypothalamusThe part of the brain that lies below the thalamus, forming the major portion of the ventral region of the diencephalon and controls autonomic nervous activities and part of the hormonal system. simply does not respond to increasing levels of oestrogen near the time of ovulationExpulsion of an ovum from the ovary in female animals.. After first ovulationExpulsion of an ovum from the ovary in female animals. and the priming of progesteroneSteroid hormone secreted by the corpus luteum of the ovary which has the property of making the endometrium suitable for implantation, maintenance and development of the fertilized egg. (Progesterone also results in multiple activities for the endometrium, myometrium, cervix, vagina and udder.). It inhibits GnRH secretion by feedback action on the pituitary., the hypothalamusThe part of the brain that lies below the thalamus, forming the major portion of the ventral region of the diencephalon and controls autonomic nervous activities and part of the hormonal system. tends to cause oestrusAlso known as heat, is the physiological and behavioral phenomena which precedes and accompanies ovulation in female mammals. behaviour near ovulationExpulsion of an ovum from the ovary in female animals..

The herdsmen should allocate at least 2 to 3 observational periods in the day lasting at least 30 minutes each.

There is a negative relationship between the level of milk production and the time in which cows show behavioural oestrusAlso known as heat, is the physiological and behavioral phenomena which precedes and accompanies ovulation in female mammals.. High yielding cows may only exhibit oestrusAlso known as heat, is the physiological and behavioral phenomena which precedes and accompanies ovulation in female mammals. for less than 5 hours. 

Hard or slippery flooring limits the physical activity and in particular the incidence of mounting behaviour.