Use of ensiled sweetpotato roots and vines for pig feed in Vietnam

The ensiled form of 80% sweetpotato (SP) roots with 20% rice bran resulted in the highest weight gain of 47.74 kg in pigs, while 99.5% fresh SP vines with 0.5% salt (T1) resulted in the lowest total weight gain of 40.05 kg; but the feed cost for every kg weight gain was the highest at 10,780 VND. When to T1 was added 6% cassava meal and 10% chicken manure (T3), this led to the highest weight gain of 51.55 kg (which was 28.5% higher than that of T1), with a daily weight gain of 554 g. When we increased T1 by 10% (T1+10%) more SP silage (DM basis) in the total diet, this became the best pig feeding ration. T1+10% resulted in the highest total weight gain of 49.64 kg, with a daily weight gain of 539 g/day and a weight gain by 278% compared with the initial weight. Thus, the feeding cost per kg weight gain of T1+10% was the lowest at 8,182 VND/kg (US$0.52/kg) The production parameters for the pig production cycle of one GTP was more beneficial than that of the GNP. For GTP, the number of days per cycle was 14 days less, the number of pigs per cycle was on average 5.3 pigs more, and the feed to meat conversion rate was 0.8 lower than that of GNP. Also, the number of cycles per year was 0.4 higher than for GNP. Labour requirement per cycle for GTP was 11 man-hours less than for GNP, while labour for selling pigs for GTP was 62 man-hours lower than for GNP. Especially the female share of the labour input of GTP was 2.2% lower than for GNP. The mean income of GTP increased by 58,843 VND (US$3.72) per pig per month.