Development of a system of artificial rearing for piglets surplus to the sow's rearing capacity and evaluation of its repercussions
This work describes, by means of evidence from the literature, the problem of pre-weaning piglet mortality and shows that the major cause of loss is malnutrition. It is proposed that by housing the piglets from soon after birth in a near optimal environment and providing adequate nutrition then a high proportion of losses could be reduced. From evidence presented in the literature, the requirements of the piglet for nutrition, protection against infection and environmental factors were determined. A 2 stage system of artificial rearing was developed to meet these requirements. In Stage 1, the piglets were individually housed from 6 hours of age in pens with a heated floored lying area, a mesh floored mucking area and a feeding bowl protected by a mechanical gate. Automated feeding equipment delivered hourly to each piglet a measured amount of liquid diet based upon cow colostrum and whole milk powder; after each feed the entire system was cleansed. At 3 kg liveweight, the pigs were housed in Stage 2 in tiered cages in pens of 5 and fed on commercially available dry diets based upon milk pellets until 8 kg liveweight when a gradual change to cereal based pellets followed. At 12 kg liveweight, the pigs were transferred to the normal farm accommodation. The successful preliminary trials led to the development of more accurate and reliable liquid feeding equipment, which was used in controlled experiments to determine which combination of dietary components and environmental temperatures best suited the system. Improved Stage 2 cages were developed which incorporated heated floors and these were compared with the tiered cages. The components found suitable were combined into a system and these were tested under controlled conditions to determine if piglet mortality could be reduced in the sow herd. The successful results were evaluated and a system suitable for commercial application described.