Effects of conditioners (single-layer, double-layer and retention-conditioner) on the growth performance, meat quality and intestinal morphology of growing and finishing pigs

This experiment was conducted to investigate the effects of feed conditioners (single-layer, double-layer and retention-conditioner) on the growth performance, meat quality and intestinal morphology of pigs throughout the growing to finishing phase. A total of 96 growing pigs ((28.70±3.20) kg) were selected and randomized into three treatment groups with four replicates per group. Eight pigs were used per replicate for the 17-week feeding trial. The grower diet was given at 0 to 6 weeks and a finisher diet was given at 6 to 17 weeks. The treatments were as follows: SC diet (control; single-layer conditioning), DC diet (double-layer conditioning), and RC diet (retention-conditioning). Starch gelatinization was significantly higher (P<0.05) in the RC treatment than in the SC treatment, however, there was no significant difference in the starch gelatinization between the DC group and the RC group. In the growing phase, the feed to gain index (F:G) was significantly lower (P<0.05) in the RC group than in the SC and DC groups. Between growing and finishing, the F:G was the lowest (P<0.05) in the SC group compared to the RC or DC group. Drip loss, a measurement of meat quality, was significantly lower (P<0.05) in longissimus dorsi tissue collected from pigs fed the RC diet than in tissues collected from pigs fed the SC diet. The intestinal quality of the duodenum and jejunum tissues showed a significant increase (P<0.05) in the crypt depth and villus height in the RC group compared to the SC- or DC-treated pigs. These results demonstrated that the retention-conditioner treatment decreased the F:G in growing pigs, improved intestinal morphology and enhanced the meat quality in the finishing pigs. However, the retention-conditioner treatment had a negative impact on growth performance in the finishing pigs.