LYING CHOICE LIFTS LITTER SIZE
By Simon Wragg
ALLOWING in-pig sows a choice of lying area and leaving feed stalls open between feeding rounds, can significantly increase the number of piglets/litter, a new study has shown.
Research conducted by Jeanne Williams for a BSc in Animal Science at Harper Adams University College found the number of piglets born to sows with a choice of lying area was 1.8 piglets/litter higher.
Studies were conducted in an insulated, environmentally-controlled sow house where groups of between five and eight females were monitored throughout gestation. Food competition tests were carried out to determine the position of each sow in the group hierarchy – allowing comparison between the top and bottom half of each group to be made.
Groups of sows had access to a 11.54sq m (124sq ft) straw-bedded lying area, a 8.15sq m (87sq ft) dunging passage and – depending on regime – a 8.71sq m (93sq ft) feed area. Area/sow was above current recommendation considered sufficient to achieve adequate welfare, she explains.
Her results suggest the total time spent resting was unaffected by increasing the lying area. But sows in the bottom half of the social hierarchy spent a third of the lying time in the feeder, despite a 1C lower mean temperature than the strawed area and the unbedded floor surface, says Miss Williams. Some sows never lay in the bedded lying area.
When feed stalls were closed during the day – as happens on many commercial units – more timid sows lay in both dunging and lying areas.
Overall performance of the PIC Camborough stock was good. But, there was an increase in total piglet numbers when offering sows extra access to feed stalls, she adds.
When free access was permitted the difference top ranking sows produced 13.95 piglets per litter and bottom ones 13.47 piglets per litter. When access was restricted, performance fell to 12.53 piglets per litter and 11.28 piglets per litter in top and bottom ranking sows, respectively.
As a result, Miss Williams study suggests while having space is important, offering sows a choice of space was of greater importance. *
In-pig sows given more choice of lying area, either in dunging, straw or feed area, have higher numbers of piglets/litter.
• Choice of space important.
• Increased litter numbers.
• Leave feeder doors open.