Advancing the breeding season and increasing production in early lambing flocks

Date published: 17 August 2022

One of the main benefits of sponging and PMSG is that it gives a tight lambing with most ewes lambing over 4-5 days which could suit part time farmers. Sponging sheep will advance the normal breeding season by around 6 weeks.

A typical programme for synchronising ewes is suggested below in Table 1.

Table 1. Synchronisation programme for early lambing ewes

Improving the performance of sponging

To obtain the best results with sponging it is important to have the ewes weaned at least 6 weeks in advance and in body score of around 3.5. Have plenty of mature rams available, ideally 3 rams per 20 ewes. Ram lambs are generally not recommended. Order the sponges well in advance and store the PMSG in a fridge according to manufacturer’s instructions. PMSG is administered into the muscle immediately after the sponge removal, the amount given per ewe will depend on breed of sheep and month of the year. Consult your veterinary surgeon for specific advice and read the instructions clearly.

Melatonin implant

This is a hormone administered at the base of the ear around 35 days prior to ram introduction to the flock. It works by releasing a small amount of melatonin similar to what the ewe produces naturally as daylight hours decrease. It therefore has the ability to make the ewes come into season earlier in the year and produce a lambing percentage similar to a March lambing flock.

Table 2. Melatonin implant programme

Summary

Lamb prices this spring have been encouraging, but it is still very important for early lambing flocks to produce at least 1.65 lambs per ewe. Either sheep sponging /PMSG or Melatonin implants are useful programmes to bring forward the lambing season for early lambing flocks, make lambing more compact and achieve their targets to improve output and profit. Consult your veterinary surgeon about which programme is most suitable for your flock and follow their advice.