Smart tags to help lamb survival

New research is looking to technological advances to help producers lift lamb survival through genetic selection.

The CSIRO-led collaboration with the University of New England, supported by Meat and Livestock Australia, is using SmartTag technology to measure ewe and lamb behaviour during and immediately after birth.

The results will help improve field-based measures for assessing lamb vigour.

Studies have shown that lamb vigour - shown by behaviours such as the time it takes a newborn lamb to stand and suckle, or bleat - is a heritable trait, but these traits are difficult to measure in a commercial setting.

Instead, lamb vigour scores are usually assessed during tagging and measurement of the lamb within the first 12-18 hours of life. These are based on a combination of subjective assessments of the degree of struggling and vocalisation, and the rate of the lamb's return back to the ewe.

CSIRO research scientists Drewe Ferguson, Ali Small and Phil Valencia are working with UNE's Geoff Hinch and his PhD student Christine Morton on the lamb vigour research project.

It seeks to identify which of the behaviours that make up the current lamb vigour scores are the most important, and whether they can be more objectively measured.

"This is really stage one - the proof of concept stage - of what we hope will be a larger project," Mr Ferguson said.

"We're looking specifically at the duration of labour and the time it takes the newborn lamb to bleat.

"The ewes are fitted with SmartTags that contain sensors that record each ewe's movements and both the ewe's and lamb's vocalisations.

"Our goal is to develop simple prediction algorithms that can read the information from the SmartTag and predict the time of birth based on changes in movements and vocalisations.

"If successful, we would be keen to develop the technology platform further so that, ultimately, it could be applied in larger-scale genetic improvement schemes," Mr Ferguson said.

The research at CSIRO's FD McMaster Research Laboratory at Armidale in NSW is based on five artificially inseminated ewe cohorts selected from the research station flock.

"We selected both maiden ewes and multiparous ewes (who have given birth at least twice) that were either single or twin-bearing to give biological variation in their behaviours at the time of birth, as well as variation in lamb behaviour," Mr Ferguson said.

"We used sires from the Sheep CRC Information Nucleus Flock that had divergent estimated breeding values for specific vigour traits that relate to neonatal behaviour. For example, some sires' progeny were very quick to bleat and stand; other sires had lower EBVs for those traits."

The ewes lambed in a shed during September and October 2012, and each birth was monitored by video and by a team of technical support personnel who were present around the clock.

Measures relating to the chosen EBVs, such as rectal temperature, bleat response to restraint and time to return to the ewe, were taken from each lamb at specific time points during the first day of life.

Researchers are aligning the video data of specific behaviours with what was recorded on the SmartTags to generate the preliminary prediction algorithms.

Regardless of any advances in measuring and selecting for lamb vigour, Mr Ferguson and Ms Small agreed producers should use genetic selection in conjunction with best practice ewe management.

"Genetic improvement is one avenue for improving lamb survival, but you still need to look after ewe body condition, nutrition, shelter provision, predator control, and so on," Mr Ferguson said.