Hoang Nghia Duyet et al., 2010. Livest. Res. Rural Dev., 22 (3): 59

The effects on the reproductive performance of Mong Cai (MC) and Yorkshire (Y) sows of three levels of foliage in the diets in gestation and lactation were evaluated. Dietary treatments 0L, 50L and 100L corresponded to replacement of 0, 50 and 100%, respectively, of the soybean meal in gestation and lactation diets by a foliage mixture consisting of equal parts of water spinach, cassava leaves and sweet potato leaves on a dry matter (DM) basis.

 DM and nutrient intakes were not affected by treatment in gestation. Litter size at birth was not influenced by dietary treatment, but mean piglet live weight and total litter live weight (LW) at birth were significantly lower (P<0.05) in treatment 100L for Y sows. Treatment 100L resulted in significantly lower mean piglet and total litter weaning weight for both MC and Y sows, but the differences between 0L and 50L were not significant. Sow feed consumption to produce 1 kg of piglet at weaning was higher in treatment 100L than in 0L and 50L. Sow LW losses during the lactation period, and weaning to service interval, were higher for treatment 100L for both MC and Y sows. The differences for all other parameters measured between 50L and 0L were small and non-significant.

It is concluded that the optimum level of replacement of soybean meal by a mixture of foliages in pregnancy and lactation diets is 50% for both MC and Y sows. MC sows appear to be better adapted to high levels of foliages in the diet than Y sows.