| Summary: | 碩士 === 國立屏東科技大學 === 動物科學與畜產系所 === 101 === The objectives of this study were to evaluate the effects of different types of organic acids, included microencapsulated sorbic acid-based blend (SAB), sodium diformate (NDF) and sodium butyrate (NB) on growth performances, nutrient utilization and intestinal microflora in broilers. In each experiment, three hundred and sixty day-old male Avian broilers were randomly allotted into 6 treatments × 3 replications experimental design with 20 birds in each pen. In Exp. 1, the 6 treatment groups were: BD (basal diet), SAB 0.02 (BD + SAB 0.02%), SAB 0.05 (BD + SAB 0.05%), NDF 0.15 (BD + NDF 0.15%), NDF 0.3 (BD + NDF 0.3%) and NB (BD + NB starter 0.2%, grower 0.15%, finisher 0.1%). In Exp. 2, the 6 treatment groups were: BD (basal diet), NDF 0.15 (BD + NDF 0.15%), NDF 0.3 (BD + NDF 0.3%), BDM 0.15 (matrix value diet + NDF 0.15%), BDM 0.3 (matrix value diet + NDF 0.3%) and NB (BD + NB starter 0.2%, grower 0.15%, finisher 0.1%). Feed and water were provided ad libitum. Birds were weighed individually and feed consumption was recorded at 14, 28, 35 and 39 days of age. After growth trial, nine birds were randomly selected from each treatment, three birds for pH values of gastrointestinal tract (GI-tract) and gut microflora test, and other six birds for serum biochemistry, carcass characteristics, and morphology of the jejunum and ileum mucosa determination. Thirty-six male Avain broilers at 28 days of age (average BW: Exp. 1 1292.79 ± 12.36 g; Exp. 2 1258.06 ± 16.79 g) were randomly allotted into 36 individual cages with 6 treatments × 6 replications. Metabolic test which were conducted from 28 to 35 days of age.
The results in Exp. 1 and Exp. 2 showed that the growth performances of the SAB, NDF, and NB groups were improved at 39 days of ages. Furthermore, the BDM 0.3 group were significantly increased body weight (2227.01 vs. 2116.03 g), average daily feed intake (97.87 vs. 92.71 g) and average daily gain (56.05 vs. 53.20 g) compared to the BD group. The results of metabolic test in Exp. 1 showed that the crude fat utilization was significantly improved when NDF 0.15 group was compared to BD group (91.63 vs. 90.45%) (P < 0.05), however, the nutrient utilization of dry matter, crude protein and ash were not significantly different among groups. In Exp. 2, the results indicated that there were no significant differences of nutrient utilization among all treatment groups. The result of intestinal properties in Exp. 1 and Exp. 2 showed no differences on pH values of GI-tract among treatments, in contrast, the number of coliforms in the jejunum and rectum were significantly reduced in all groups supplemented with organic acids (P < 0.05) and the lactobacilli counts were increased. Moreover, in Exp. 1 the NDF 0.3 and NB groups were significantly increased jejunum villus height (1720.96、1692.63 vs. 1268.35 µm) (P < 0.05) and ileum villus height/crypt depth (7.87、7.90 vs. 6.67) (P < 0.05) compared to the BD group. In Exp. 2, The organic acids supplemented groups improved morphology of the jejunum and ileum, but there were not significantly different among groups. The results of carcass characteristics in Exp. 1 and Exp. 2 showed no differences on carcass yield, breast, thigh, abdominal fat and giblets percentage among treatments. However, the NDF 0.3 group in Exp. 1 and BDM 0.3 group in Exp. 2 were significantly increased wing percentage compared to the BD group (Exp. 1 7.93 vs. 7.51%; Exp. 2 8.10 vs. 7.71%) (P < 0.05). The results of serum biochemistry in Exp. 1 and Exp. 2 indicated that there were no differences on serum total cholesterol, triglyceride, calcium and phosphorus concentration among treatments. In addition, supplementation of SAB and NDF reduced the pH value and buffering capacity value of broiler feed.
In conclusion, the supplementation of different types of organic acids resulted in manipulating the intestinal microflora, improving gut muscosa morphology, promoting gut health and increasing nutrient utilization, hence, improving growth performances in broilers. With decreasing fat supplementation, the BDM 0.15 and BDM 0.3 groups also improved broiler growth performances and reduced the feed cost.
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