Effect of dietary lysine supplement on the performance of Mong Cai sows and their piglets

The objective of this study was to determine optimal lysine requirement of lactating Mong Cai sows and their piglets. An experiment was conducted using 30 Mong Cai sows in a factorial randomized design with 5 dietary total lysine levels (0.60, 0.70, 0.85, 1.0 and 1.15%) for one-week pre-partum and 5 dietary total lysine levels (0.60, 0.75, 0.90, 1.05 and 1.2%) for lactation diets. Mong Cai sows were about 1 to 2 years old and had an initial body weight of 120 kg (sd = 2.5) after farrowing. Sows were restrictively fed 1.7 kg feed during gestation and were fed ad libitum during lactation. Diets of sows contained about 12% CP during pregnancy and about 14% CP for the lactation period. DE concentration of the diets ranged between 12.5-13.0 MJ of DE. Water was supplied at up to 8 liters per sow per day in a basin. Studied traits were related to both sows and their progeny. Sows were weighed at 107 days of gestation, after farrowing and at weaning. Sow back-fat depth was measured at 110 days of gestation, after farrowing, at 21 days of lactation and at weaning. Number of piglets born, at 24 h after birth, at 21 days of age and at weaning were recorded. Piglets were weighte at birth, at 21 days and at weaning. Supplying lysine one week pre-partum had no effect on the number of piglets born nor litter weight at birth (p = 0.776 and p = 0.224). A positive effect of increasing dietary lysine level during lactation from 0.60 to 1.20% was observed with regard to less sow weight loss, and increased piglet weight at 21 days and at weaning. The level of lysine that resulted in the lowest sow backfat loss and the highest weaned piglet weight was 1.05%; this may be the optimum level of lysine for the diet of lactating Mong Cai sows. At this lysine level, the number of weaned piglets was also highest