October 23, 2009

Janssen Animal Health has introduced Maprelin, a pig hormone that stimulates oestrus in gilts and sows, shortens weaning to oestrus interval and can improve reproductive performance throughout the breeding herd.

 

Maprelin, which contains a new synthetic molecule, Peforelin, is the first gonadotropin releasing hormone (GnRH) that specifically induces follicle stimulating hormone (FSH) to be registered for pigs.

 

Follicle development starts at weaning or at the end of a Regumate treatment period. Ovulation rate depends on the total number of follicles that are capable of reacting to the shift in the release of luteinising hormone (LH)/FSH that takes place, known as recruitment, and the number of follicles that have sufficient LH receptors when FSH levels start to drop, known as selection.

 

Both these factors can be influenced by a large dose of FSH at the right time. A single, low volume dose of Maprelin induces the release of the animal's own FSH, which stimulates more follicles to grow and develop LH receptors, inducing high ovulation rate. This natural method differs from other GnRHs in that they mainly trigger the release of LH, and only to a small extent FSH.

 

Large follicles release oestrogens, which are responsible for the external signs of heat in breeding females - standing reflex, swollen vulva and restlessness.

 

At this stage GnRH leads to a surge of LH from the pituitary gland and this induces ovulation. For optimal results viable sperm should be present at the time of ovulation.

 

The ovulated follicles now form corpora lutea. These produce progesterone, which is vital for maintaining pregnancy.

 

The shorter service and farrowing periods achieved by synchronising the cycle of gilts and sows, and through inducing oestrus and ovulation, bring many benefits including:

    

    -    Reduced variation in gestation period helps with more efficient fostering management.

             

Maprelin is the second stage of Janssen Animal Health's pig production programme, Syncoris, which helps to improve profitability by maximising reproductive performance.