| 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 dietary replacement of fish meal with algae single cell protein (ASCP) on growth performances, carcass characteristics and nutrient utilization of chickens. In Exp. 1, three hundred and fifty-two black native chickens at 49 days of age were randomly divided into 4 treatments × 4 replications (2 replicates for male and female each) experimental design with 22 birds in each pen. In Exp. 2, three hundred and eighty-four day-old Arbor Acres broilers were randomly allotted into 4 treatments × 4 replications with 24 birds in each pen. The 4 treatments were: BD (basal diet), FM1.25 (diet with fish meal 1.25%), ASCP1.25 (diet with ASCP1.25%), ASCP2.5 (diet with ASCP2.5%). Feed and water were provided ad libitum. Birds were weighed individually and feed consumption were recorded at 70, 84, and 98 days of age in Exp.1; at 14, 28, and 38 days of age in Exp. 2. Eight birds from each treatment were randomly selected at the end of growth trial for serum biochemistry, carcass characteristics, muscle composition and meat quality test. In Exp. 1 eight birds from each treatment were placed into individual cages for metabolic test at 84 days of age (average male BW 2491 ± 98 g; female BW 2160 ± 91 g). In Exp. 2, another twenty-four male Arbor Acers broilers at 28 days of age (average BW 1323 ± 35 g) were randomly allotted into 24 individual cages with 4 treatments × 6 replications. The results in Exp. 1 showed that the ASCP2.5 group of female chicken significantly increased average daily gain and improved feed conversion ratio (F/G) (3.29 vs. 3.70) compared to the BD groups at 56-70 days of age (P < 0.05). The results of metabolic test showed that the protein retention rate of female birds was significantly improved when ASCP1.25 group was compared to BD group (27.42 vs. 20.80%) (P < 0.05), however, the utilization of dry matter, crude fat and ash were not significantly different among treatment groups. The results of carcass characteristics showed that the breast meat percentage of female chicken with ASCP2.5 group was higher than that of FM1.25 group (22.54 vs. 21.34%) and ASCP1.25 group had higher wing percentage than FM1.25 group (8.71 vs. 7.86%) (P < 0.05). Serum triglyceride concentration of male birds were significantly decrease in the ASCP1.25 and ASCP 2.5 groups as compared to the FM1.25 group (30.00、27.50 vs. 39.75 mg/dL). The results of muscle composition and meat quality showed that there were not significantly different among treatments, in contrast, the shear values in the breast muscle with ASCP1.25 and ASCP2.5 groups were significantly higher than that of BD group (5.23、5.31 vs. 3.21 kg). The results in Exp. 2 showed that the birds with ASCP1.25 group were significantly increased in body weight, (2326.57 vs. 2249.06 g), average daily gain (59.89 vs. 57.86 g) and improved feed conversion ratio (F/G) (1.65 vs. 1.68) as compared to the BD group at 0-38 days of age. The crude fat utilization (91.70 vs. 89.35%) and crude protein utilization (65.75 vs. 62.22%) were significantly increased in ASCP1.25 group as compared to the FM1.25 group. The carcass characteristics were not different among treatments, however, the FM1.25 group were significantly increased liver weight percentage compared to the ASCP1.25 and ASCP2.5 groups (2.47 vs. 2.17、2.07%). The ASCP1.25 and ASCP2.5 groups decreased total cholesterol and triglyceride concentration of the serum, but were not significantly different. The overall results indicated that the replacement of fish meal with ASCP in chicken diets can save feed cost without negatively affecting growth performances and carcass traits.
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