Evaluation of the optimum protein requirements for Vietnamese pigs

The studies reported in this thesis were carried out in Central Vietnam where pig production plays an important role and pig farmers face a general dietary protein shortage for their animals. The objectives of the work presented were (1) to investigate the crude protein (CP) supply to local Mong Cai (MC) pigs as well as lean type pigs (including crossbreds); (2) to derive CP requirements under high temperature conditions in the tropics; (3) to determine optimal lysine content in the diet of lactating Mong Cai (MC) sows and their piglets; (4) to evaluate the effects of floor types and dietary CP content on performance of sows and piglets. An interview based study of smallholders farmers showed that poor nutritive value of the diets for fattening pigs and sows is observed in three agro–ecological zones (Upland, Lowland and Coastal) in Central Vietnam. Pig on smallholder farms can produce more lean meat if they feed their pigs a higher dietary CP level. The optimum dietary CP level for the different breeds of pigs investigated (MC; F1, Large White Mong Cai and F2, (Landrace Mong Cai) Large White) were found to be 13 % for MC, 15 % for F1 and 16 % for F2 pigs. High dietary CP levels (>19 % CP) for MC, F1 and F2 negatively affected growth performance. The optimum dietary CP content for lean type pigs kept under the hot humid tropical climate of Central Vietnam to ascertain the maximum growth performance and carcass characters in Large White (LW) and Landrace (LD) pigs must be more than 16 % CP. The other study indicated that increasing dietary lysine level from 0.7 to 1.2 % reduced the sows weight loss during lactation. No effect was found on the number of piglets born nor piglet survival at 7 days. The number of piglets weaned was improved by lysine levels of over 1.02 %. Using raised wooden floors resulted in a higher number of piglets and litter weight at weaning compared to piglets on ground clay and concrete floor. In conclusion, the current work indicates that improving protein quantity and quality in traditional diets for Vietnamese pigs kept by smallholder farmers can significantly improve productivity of MC, F1 and F2 pigs, and as such improve the income of farmers.