Reproductive performance of gilts and sows in ordinary piggeries was investigated with special reference to litter size, piglets weaned per litter, the cause of preweaning mortality and the incidence of diarrhea. Biochemical properties of Escherichia coli isolated from piglets with diarrhea were also determined. The results obtained are summarised as follows:
1. Of the 2,226 gilts and sows farrowed, average number of piglets born alived and weaned piglets per litter were 8.9 and 7.1, respectively, indicating that both gilts and sows lost more than 20% of all their piglets prior to weaning.
2. The causes of preweaning mortality in order of prevalence were diarrhea (39.3%), pneulnonia (20.0%), crushing (13.8%), starvation (11.0%) and born weak (10.3%).
3. Incidence of 3 diarrheal syndromes of piglets, i.e. 1 week diarrhea, 3 week diarrhea and post-weaning diarrhea were 18.4%, 66.1% and 15.5%, respectively, showing that most farms were suffering from so called ‘white scours’in piglets 14∼28 days old.
4. Biochemical properties of 268 cultures of E. coli isolated from diarrheal piglets were tested and compared with those of standard strains of porcine origin. All those properties of isolates were matched to standard E.coli teated while variable results were obtained with haemolytic capabilities of cultures tested.
5. Of 147 isolates 16 cultures (10.9%) were identified as colicin producers.
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