Farm Table says:
This 35-minute webinar hosted in 2015 looks at risks relating to lamb survival using results from lamb autopsies.
Improving lamb survival is important to the industry and actions can be taken to improve lamb survival. Gordon touches on the main tasks to assist with lamb survival.
In more than 100 years, lamb survival rates have not changed – at least 10% singles and 30% twins dies.
Survival = lambs scanned less lambs weaned.
Gordon notes that the “Core” lamb losses that have been difficult to reduce our 10% for single lambs and 20% for twin lambs. Greater these percentages are what Gordon refers to as “More”. Getting back to the core should be the aim for farmers.
The “Core” problem risks include:
- Long birth times
- Gestational growth restriction
- Poor colostrum quality/milk yield.
These lead to low oxygen during gestation and during birth.
Whereas, the causes for “More” includes:
- Inadequate maternal nutrition (too many heavy single lambs and too many small twin lambs)
- Impaired teat function.
These are within our control.
Other causes are abortions, inclement weather, and predation.
Gordon estimated that only 30% of ewes are pregnancy scanned, therefore very little will be known about lamb survival rates by these farmers that don’t scan.
The most common findings from lamb autopsies are:
- Dystocia and birth injury (48%)
- Starvation and mismothering (25%)
- Abortion and prematurity (10%)
- Predation (7%)
The risk of suffering a brain injury increase with slow birth times, light lambs and cold or hot weather.
Recommendations are given to improve lamb survival are:
- Improved ewe condition
- Pasture availability (no significant improvement above 1,400 kg DM/ha)
- Supplementary feeding to increase colostrum before and after lambing (lupins, barley, lucerne hay, maize)
- Mob size
- Paddock shelter