Spontaneous and experimental myofibrillar hypoplasia and its relation to splayleg in newborn pigs

Abstract

The relation of myofibrillar hypoplasia to clinical splayleg was studied. A strain of Belgian Landrace sows was selected for this study because they produced pigs which had no myofibrillar hypoplasia. Myofibrillar hypoplasia could nevertheless by induced experimentally in these animals by dexamethasone treatment of the sows during late pregnancy. The lesion was observed without clinical signs and was compared to the myofibrillar hypoplasia in clinical cases of splayleg. The differences between these 2 groups may account for the appearance of clinical signs. These differences included the maturity of the myofibrils and the degree of autophagolysosomal glycogen breakdown.

Detection of atypical porcine pestivirus in Brazil in the central nervous system of suckling piglets with congenital tremor

“…The syndrome was first described 50 years ago (Thurley, Gilbert, & Done, 1967); yet, the pathophysiology and cause(s) of SL are ill-defined. Several factors and pathogens have been investigated and hypothesized as potential causes including large litters, low-birthweight (Cunha, 1972), Large White and Landrace breeds, shortened pregnancy (Papatsiros, 2012), Fusarium (Miller, Hacking, Harrison, & Gross, 1973), immature skeletal muscle (Bergmann, 1976;Ducatelle, Maenhout, Coussement, & Hoorens, 1986), cholinergic system defects and/or late maturation of motor nerves (le Hong, Kolb, M€ uller, & Vallentin, 1990), choline deficiency and specific genes (Maak, Jaesert, Neumann, & von Lengerken, 2003;Maak, Jaesert, Neumann, Yerle, & von Lengerken, 2001;Stigler, Distl, Kruff, & Kr€ ausslich, 1991). However, no definitive conclusions have been drawn.…”

Porcine congenital splayleg is characterised by muscle fibre atrophy associated with relative rise in MAFbx and fall in P311expression

“…Pregnant sows treated with glucocorticoids [ 8 ], and experimentally fed Fusarium (F-2) toxin (zearalenone) contaminated grain [ 9 ] showed higher incidence of PCS. However, histological changes in glucocorticoid induced or mycotoxin-induced PCS are distinct from naturally occurring PCS [ 10 ]. The role of dietary choline appears unimportant in the prevention of PCS [ 11 , 12 ].…”

“…A range of pathological lesions has been described for PCS, the most common feature being the presence of myofibrillar hypoplasia, often interpreted as an immaturity of the muscle [ 1 , 10 ]. Myofibrillar hypoplasia ranges from a slight reduction of myofibrillar content to severe myofibrillar deficiency, with vacuolation, focal degeneration and necrosis.…”

Incidence of splayleg pigs in Nebraska litter size selection lines1

“…Using Cushing's syndrome in humans as a model, in which glucocorticoids are in excess, induced glucocorticoid myopathy in rats resulted in myofibrillar hypoplasia, degeneration, and a SL phenotype. Ducatelle et al (1986) supported this hypothesis by inducing myofibrillar hypoplasia with dexamethasone treatment in sows during late pregnancy. Svendsen et al (1991) was able to compare SL blood serum concentrations of specific compounds to levels in normal pigs.…”