Breed differences in ewe lamb management
Breed differences in ewe lamb management
Replacement ewes normally join flocks at 18 months of age with the intention of producing their first litter at 24 months. The cost of a replacement ewe at joining the flock at approximately 18 months of age is equivalent to 25% of the value of her lifetime lamb carcass output. Joining replacements as ewe lambs to lamb down at 12 months old will increase the lifetime output of the ewe and in turn reduce the replacement costs of the flock. Weight at joining is the main factor that will determine the success of joining ewe lambs to the ram as weight at joining increases the probability of rearing at least one lamb per ewe joined. The effect of weight of ewe lambs at joining on the probability of rearing at least one ewe lamb varies by breed. To have a 0.9 probability (90% chance) of rearing at least one lamb Belclare, Suffolk x Belclare and ≥75% Suffolk ewe lambs would need to be 48.5, 51.2 and 60.0 kg at joining respectively. The mature weight of Belclare and Suffolk ewes is 77 and 83 kg, respectively, thus Belclare, Suffolk x Belclare and ≥75% Suffolk ewes lambs would need to be 63%, 64% and 72% of mature body when joining at 9 months of age to have a 90% probability of rearing at least one lamb when lambing at 1 year of age. When using this matrix, genotypes of low prolificacy need to be heavier at joining as the loss of a lamb has a greater impact in small litters.
Replacement ewes normally join flocks at 18 months of age with the intention of producing their first litter at 24 months. The cost of a replacement ewe at joining the flock at approximately 18 months of age is equivalent to 25% of the value of her lifetime lamb carcass output. Joining replacements as ewe lambs to lamb down at 12 months old will increase the lifetime output of the ewe and in turn reduce the replacement costs of the flock. Weight at joining is the main factor that will determine the success of joining ewe lambs to the ram as weight at joining increases the probability of rearing at least one lamb per ewe joined. The effect of weight of ewe lambs at joining on the probability of rearing at least one ewe lamb varies by breed. To have a 0.9 probability (90% chance) of rearing at least one lamb Belclare, Suffolk x Belclare and ≥75% Suffolk ewe lambs would need to be 48.5, 51.2 and 60.0 kg at joining respectively. The mature weight of Belclare and Suffolk ewes is 77 and 83 kg, respectively, thus Belclare, Suffolk x Belclare and ≥75% Suffolk ewes lambs would need to be 63%, 64% and 72% of mature body when joining at 9 months of age to have a 90% probability of rearing at least one lamb when lambing at 1 year of age. When using this matrix, genotypes of low prolificacy need to be heavier at joining as the loss of a lamb has a greater impact in small litters.
SheepNet : SHaring Expertise and Experience towards sheep Productivity through NETworking (2 of 2)
Ongoing | 2016-2019
- Main funding source
- Horizon 2020 (EU Research and Innovation Programme)
- Geographical location
- France