Genetic association between arthritis in piglets and reproduction

Apart from ill-thrift, arthritis in suckling piglets contributes to losses and increased labour and use of antibiotics. The aim of this study was to analyse genetic disposition for developing arthritis or not.

During two and a half year, all pigs at the research station at Lövsta, Swedish University of Agricultural Sciences, with 110 sows were studied, i.e. 6,787 liveborn piglets, boars (1 Duroc, D; 42 Hampshire, H; 11 Landrace, L; 47 Yorkshire, Y) and, sows (207 Y, 12 Y x L). Each pig had an identity and an individual record. The occurrence of arthritis was registered from birth to 5 weeks.

In total 415 of the piglets were diagnosed with arthritis (6.1%), where of 86% took place during the first 3 weeks of life.

Y-sows;523 litters, 305 with no arthritis (58%, 11.3±3.5), 125 with one piglet with arthritis (24%, 12.7±2.9), 93 with more than one piglet with arthritis (17%, 14.6±2.9).

Y x L-sows; 27 litters; 16 with no arthritis (59%, 14.3±3.3), 6 with one piglet with arthritis (22%, 14.3±1.6), 5 with more than one piglet with arthritis (19%, 15±2.9).

In Y-sows a significantly (P < 0.001) larger litter size was seen in litters with more than one arthritis.

D-boars; 23 litters, 13 with no arthritis (57%, 12.5±3.6), 9 with one piglet with arthritis 39%, (12.7±3.1), 1 with more than one piglet with arthritis (4%, 17.0±0.0).

H-boars; 192 litters, 110 with no arthritis (57%, 11.8±3.4), 44 with one piglet with arthritis (23%, 12.7±2.9), 38 with more than one piglet with arthritis (20%, 15.3±3.2).

L-boars; 51 litters, 26 with no arthritis (51%, 10.6±4.2), 16 with one piglet with arthritis (31%, 13.5±2.3), 9 with more than one piglet with arthritis (18%, 14.8±2.6).

Y-boars; 284 litters, 175 with no arthritis (62%, 11.3±3.5), 63 with one piglet with arthritis (22%, 12.7±3.2), 46 with more than one piglet with arthritis (16%, 13.9±2.5).

In H-, L- and Y-boars a significantly (P < 0.01) larger litter size was seen in litters with more than one arthritis.

There was a higher incidence of arthritis in litters with more than 12 piglets. Although the total milk production of sows tends to increase with litter size the amount of milk per piglet tends to decrease, and it is likely that increased aggressions between piglets increase the risk for skin lesions - especially during the first few days of life.

Still, there were large litters without arthritis. The estimates of genetic correlation to sow and boar found in this study imply that good conformation/locomotion traits could be combined litter size. Leg conformation and locomotion traits are heritable, so it ought to be possible to improve these traits by selection.

Disclosure of Interest: None Declared.