How this can be achieved, and at the same time reduce the carbon footprint of NI lamb, is the key focus of farmer-funded research currently being undertaken on NI farms.

The research programme, which is jointly funded by the Department of Agriculture and Rural Development (DARD) and AgriSearch, and co-ordinated by the Agri-Food and Biosciences Institute (AFBI), Hillsborough, is being undertaken on five commercial lowland farms around NI, as well as Hillsborough.

The project’s aim is to develop breeding strategies which are economically sustainable, reduce labour input, improve welfare, and lower greenhouse gas (GHG) emissions.

Ewe fertility is the key driver of production efficiency and profitability so the main focus of the project has been to develop more productive and easily managed ewes for the lowland sector, examining a range of maternal breed crosses for their fertility, lambing ease and mothering ability.

To achieve this, a three-breed rotational breeding policy was employed on each of the six flocks, using Lleyn or Belclare, Highlander and Texel rams to produce superior female replacements.

Ram selection is another key factor affecting flock performance so the crossbred ewes were mated to a range of terminal sire-breed rams to investigate their lambing ease, growth performance and carcase characteristics.

The majority of ewes lambed down for the first time at two years old and results from the first phase of the ewe trial (one and two crop ewes) are outlined in Table 1. The ewes were 59kg on average at mating and are expected to reach a mature weight of approximately 65kg; 10kg to 20kg lighter than more traditional lowland ewe types like the Mule or Suffolk X Cheviot.

||PIC2||

Within the three-breed rotation, Highlander X ewes recorded the highest weaning rates of all the ewe breeds studied. Ewe efficiency, in terms of the weight of lamb weaned per kilogramme of ewe body weight, is a good indicator of flock performance and has been linked with a lower carbon footprint. All of the ewes achieved efficiencies of 0.80-0.90, that is, their weaned lamb output was equivalent to 80% to 90% of their body weight.

The Highlander X ewes again excelled on this front due to their superior weaning rate.

Ram effects on lamb performance and carcase quality are outlined in Table 2. Using Primera rams was found to reduce the incidence of lambing difficulties by about one third compared with using either Suffolk or Texel rams, although there was some loss of carcase conformation as a result. Being an earlier maturing breed, the carcases of Primera-sired lambs also tended to be slightly fatter at a 20kg carcase weight.

The study is continuing for a further two years to investigate lamb output from the older three and four crop ewes, and to assess the longevity of these ewe breeds. Further information on the study to date can be obtained by visiting the AFBI and AgriSearch stands at SheepNI 2013, Ballymena market on Monday 1 July.