Date Received: 10-09-2020 / Date Accepted: 24-11-2020
This study was conducted to determine the effects of the ratio of digestible lysine/metabolisable energy (ME) in the diets of pregnant sows on reproductive performance, feed conversion ratio, loss of body weight, and post-weaning time to returned estrus. This study included 2 experiments, one in a closed housing condition in Ba Vi pig farm and one in an opened housing condition in Pho Yen pig farm. In each experiment, 30 pregnant sows (Landrace and Yorkshire crossbred) from 2 to 4 parities were arranged according to a completely randomized design into 30 individual pens with 3 treatments (with the digestible lysine/ME ratios of 1,56; 1,76 và 1,95 g/Mcal), each treatment consisted of 10 animals in 10 pens, 1 sow/pen and each pen was considered a replicate. The results showed that in both opened and closed housing conditions, an increase in the ratio of digestible lysine/ME in pregnant sow diets increased neonatal and weaning piglet weight (per litter and per head), and reduced feed consumption per kg of weaned piglets and weight loss of lactation sows. The appropriate digestible lysine/ME ratio in the diet of pregnant sows was from 1.76 to 1.95 g/Mcal.
