Regional Ileitis in Pigs

Twenty-seven weaned pigs with a wasting appearance were investigated. From a morphological point of view the pigs were divided into three groups. In the group of pigs with macro-scopical signs of regional ileitis, affected tissue showed substantial epithelial proliferation, and electron microscopic studies revealed the presence of microorganisms within the cytoplasm of the epithelial cells. There was a loss of, or only faint, enzymatic activity of alkaline phosphatase in the mucosal epithelium. In another group of five pigs there was no, or only slight, light microscopical signs of regional ileitis but presence of intracellular microorganisms. The enzymatic activity of the ileal epithelium was low. Low enzymatic activity of the ileal epithelium was observed in a third group of wasting pigs, which had no histological or electron microscopical signs of regional ileitis.     

Regional Ileitis in Pigs Isolation of Campylobacter from Affected Ileal Mucosa

In the last few years special interest has been focused on enteric diseases localized to the lower alimentary tract, especially the ileum of weaned pigs. An increasing frequency of disorders of unknown aetiology described as regional ileitis (Emsbo 1951), necrotic enteritis (Jubb & Kennedy 1970), and intestinal adenomatosis (Rowland et al. 1973) has been reported. The changes include thickening of the ileal mucosa with hypertrophy of the muscular wall. The normal structure of villi is replaced by a proliferation of crypt cells. Necrosis of the mucosa and granulation-tissue proliferation in the submucosa occur in later stages. Regional ileitis in man (Crohn et al. 1932) which is described as a chronic enteric disease with granulomatous inflammatory changes localized to segments of the ileum is also attracting increasing attention in medical research (Liljefors 1972). The lesions are also found in the colon, and the presence of a transmissible agent involved in the aetiology of Crohn's disease has been discussed on the basis of animal experiments (Cave et al. 1973). The disease in pigs is accompanied by haematological changes, including decreased concentration of total serum protein, albumin, alkaline phosphatase, and zinc (Martinsson et al. 1974, 1976).     

Fine Structure of Spermatogonia and Spermatocytes in the Rlue Fox (Alopex Lagopus)

The ultrastructural features, characterizing the different types of spermatogonia and spermatocytes in the blue fox, have been studied within and near the reproductive season, and also in the summer and autumn. Two distinct types of spermatogonia — A and Β — are described. The A-spermatogonia often have a prominent nucleolus and numerous cytoplasmic organelles including characteristic whorls of AER. Large vacuoles containing electron dense particles are sometimes observed. In the B-spermatogonia the chromatin forms condensed areas of varying size, and the nucleolus is usually absent. The number of cytoplasmic organelles is generally small. Ultrastructural characteristics are further used to distinguish between the different stages in the prophase of the primary spermatocytes. In leptotene the nucleus contains a thread-like chromatin with electron dense peripheral areas. Towards the end of the stage the mitochondria display dilated cristae, and aggregations of a granular material can be observed in the intermitochondrial matrix. Zytogene is characterized by the appearance of syniaptinemal complexes in the nucleus, and of the chromatoid body and piles of annulate lamellae in the juxtanuclear cytoplasm. In pachytene the chromosomes become apparent as aggregations of condensed chromatin associated with the synaptinemal complexes. The Golgi complex is more prominent than in the previous stages, and the number of the other cytoplasmic organelles is increasing. In the last stages of the prophase (diplotene and diakenesis) the chromosomes become still more electron dense, the nucleolus appears as a very prominent structure, and there is a marked vesiculation of the cytoplasm. The secondary spermatocytes have a characteristic nucleus with a somewhat irregular outline and larger peripheral areas of condensed chromatin. In the cytoplasm a double Golgi complex is frequently observed. In the summer and autumn spermatocytes in zygotene seem to represent the most advanced form of spermatogenic cells.     

Hematological and Biochemical Analyses of Blood and Serum in Pigs with Regional Ileitis with Special Reference to the Pathogenesis

Biochemical and hematological analyses of blood and serum were performed in pigs with regional ileitis and in wasting pigs with a negative necropsy. In sera from pigs with regional ileitis the levels of total protein, albumin, transferrin, alkaline phosphatase and zinc were significantly decreased compared with normal pigs of the same age. The number of white blood cells, and the concentration of Cortisol and α1-antitrypsin were significantly increased. In wasting pigs with early signs of regional ileitis or with a negative necropsy the same blood changes were observed but to a less degree. It was concluded that a wasting syndrome after weaning may precede regional ileitis. Concerning the etiology of regional ileitis the significance of malabsorption and wasting syndrome in combination with invasion of intestinal intercellular microorganisms is discussed.     

The Effect of Prolonged Supplementation of Dietary Zinc on Weight Gain,Tissue Storage of Zinc and some Serum Variables in Fattening Pigs

The effect of prolonged administration of dietary zinc in fattening pigs from 50 to 95 kg body weight was studied. No effect on daily weight gain was recorded. The concentration of zinc in different tissues did not increase. A slight increase of serum zinc was noted, but no other changes of the serum variables tested could be demonstrated. It was concluded that the amounts of zinc which are recommended for treatment of pigs with wasting syndrome do not introduce any significant accumulation of zinc in organs or tissues.