Animals and Experimental Design

As shown in Figure 1, a 2 × 2 two-factor design was adopted in this study. In this study, six 21-day-old piglets [Duroc × Landrace × Yorkshire, body weight (BW) about 6.15 ± 0.02 kg] were selected from the same litter of 20 sows, and 3 among them were randomly selected as a replicate and to be weaned, and the others were continued to suckle until 28 days old before weaning. As soon as the piglets were weaned, the replicates were randomly allocated into two treatments, fed with basal diet as the control group or fermented diet as the fermented group, respectively. The feed trial was finished when the piglets were at the age of 42 days old. Piglets with approximate average BW were randomly selected from each replicate to slaughter and sample at the age of 28 and 42 days old, respectively. The basal diet (Table 1) was formulated according to NRC (17) to meet the nutritional requirements of piglets about 7–11 kg (17) without high copper and zinc supplementation. The nutrient composition of the experiment diet before and after fermentation is shown in Table 3. During the whole experiment, the animals were free to access feed and water. Once the experiment was finished, ADG, ADFI, and feed to gain ratio (F:G) were calculated.

Diagram of the experimental design. Six 21-day-old piglets with similar body weight were randomly selected from the same litter of 20 sows, and then three of them were randomly selected as a replicate and to be weaned immediately, and the others continue to suckle until 28 days old before weaning. As soon as weaned, the piglets were randomly allocated into two treatments, fed with basal diet as the control group and fermented diet as the fermented group, respectively. The experiment was finished at the age of 42 days old. 21d-CD, 21-day-old weaned piglets fed the control diet. 21d-FD, 21-day-old weaned piglets fed the fermented diet. 28d-CD, 28-day-old weaned piglets fed the control diet. 28d-FD, 28-day-old weaned piglet fed the fermented diet. The same as below.

Nutrient levels in before and after fermentation.

^aCP, crude protein. ^bGE, gross energy. ^cEE, ether extract. ^dCF, crude fiber. ^eNDF, neutral detergent fiber. ^fADF, acid detergent fiber. The nutrient levels were determined value based on dry matter.