A retrospective study was undertaken on 6 piggeries in north Australia
and South Vietnam to define the reproductive performance of sows in t
he tropics. Reproductive performance was analysed in respect to age of
first mating, time of the year, breed and management practices. There
was a significant effect of the time of the year at mating on farrowi
ng rate. Highest farrowing rates were achieved when sows were mated du
ring the cool time of the year in the Australian piggeries and during
the dry-hot period as opposed to the wet-hot period in Vietnamese pigg
eries. The number of matings per oestrus and interval between matings
influenced both farrowing rate and number of piglets born although an
increased litter size at birth was accompanied by an increase in still
births and mummified foetuses.