Australian Livestock Scanning Services Group

The results and recommendations from 23 years of on-property R&D with commercial sheep and cattle producers. We specialise in precision scanning for pregnancy, twinning, and ageing of foetus in sheep and cattle and in helping to raise lamb survival and cow fertility in stud and commercial breeding enterprises.

mob: 0428 667 567, email: fowler.doug@bigpond.com


16. Get more lambs – select the most fertile ewes

Culling ewes which have failed on two occasions to rear a lamb will increase net reproduction rate in the current flock. Scanning can play a pivotal role in implementing this strategy.
1. Determine failure to join
Scan the ewes with ultrasound and identify the empty ewes with a permanent mark. These ewes should then be joined with the maidens next year in order to give them the maximum chance of becoming pregnant. Ewes that fail twice should be sold or run as wethers because their lifetime reproductive performance will be lower (see below).
2. Determine failure to rear (lambed & lost)
Conduct a post lambing udder check as soon as possible after lambing ceases. The "dry" ewes will have been identified at scanning and the ewes that are not lactating at the post lambing udder check will be those that have lambed and lost their lambs. Ewes that have lambed and lost should be excluded from the breeding nucleus of the operation as soon as is practical because their lifetime reproductive performance will be lower (see below).
3. Select the fertile ewes
The lifetime, reproductive performance of ewes that have failed to join or joined and failed to rear, are shown below. By the time a ewe has been given two opportunities to join and lamb, she will have indicated her likely lifetime performance. You can then use the following guidelines to determine whether a ewe in any year remains in the breeding nucleus, is sold or is run as a wether.

Early reproductive performance as an Indicator of the rest of lifetime performance

  1. 1. Dry once at their first two joinings, performance for the rest of their lives will be:
    Pregnancy rate (65%); Twinning rate (145%); Lamb survival Rate (75%); Lamb weaning rate (82%)
  2. 2. Pregnant but fail to wean twice, performance for the rest of their lives will be:
    Pregnancy rate (72%); Twinning rate (145%); Lamb survival Rate (64%); Lamb weaning rate (67%)
  3. 3. Pregnant but fail to wean once, performance for the rest of their lives will be:
    Pregnancy rate (79%); Twinning rate (146%); Lamb survival Rate (75%); Lamb weaning rate (86%)
  4. 4. Pregnant twice and weaned twice, performance for the rest of their lives will be:
    Pregnancy rate (81%); Twinning rate (149%); Lamb survival Rate (78%); Lamb weaning rate. (94%)