Nutritional Evaluation And Feed Effects Of Solidago Canadensis In Rex Rabbits

For developing Solidago Canadensis L as feed, a series of experiments were conducted to systematically evaluate nutrition value of Solidago Canadensis L. and its effects.on performance of Rex Rabbits. Main nutrients of Solidago Canadensis L. were examined in Expt.1. Expt.2 was conducted to assess the rumen degradation characteristics of Solidago Canadensis L.; In Expt.3, the apparent digestibility of Solidago Canadensis L. was measured. Effects of Solidago canadensis L. on Performance of Rex Rabbits were evaluated.Experiment 1. Solidago Canadensis L. was collected in April, June, August and October. Fresh weight and plant height of Solidago Canadensis L were recorded. The nutrients and minerals of Solidago Canadensis L were examined using the conventional method and atomic absorption spectrophotometry. Results showed that Solidago Canadensis L. in October was the highest (298.00±14.81cm), while the lowest (42.81±4.12cm) in September. The nutrients of Solidago Canadensis L. were dynamic change in different growth periods, its crude protein (CP) were the 11.45%, 4.88% and 14.20%, neuter detergent fiber (NDF) 31.06%,48.64% and 66.66% respectively in Apr., Aug. and Oct. There was no significant difference of trace mineral concentration between the growth periods. It seems that calcium content increased in the early stage and decreased in later stage, while iron content constantly decreased.Experiment 2. Using three Hu-Yang sheep fitted permanent rumen fistula, an experiment was conducted to study degradation characteristics of Solidago Canadensis L in rumen by nylon bag technique, with Aneurolepidium Chinense as the control. Results showed that crude fiber (CF), acid detergent fiber (ADF) and lignin of Solidago Canadensis L were 37.85%,44.79% and 9.00%, higher than those of Aneurolepidium Chinense. CP of Solidago canadensis L and energy contents were 4.35% and 3853cal/g respectively, slightly lower than those of Aneurolepidium Chinense. Compared with Aneurolepidium Chinense, the disappearance rate of dry material (DM), energy, and CF of Solidago Canadensis was faster in the early stage, and was overtaken later, while that of ADF was almost lower along the period. The disappearance rate and total degradability (a+b) of DM, CF, ADF and energy of Solidago canadensis in 72h were lower than those of Aneurolepidium Chinense, among them, the these of DM were 42.67% and 43.05%, respectively, lower than those of Aneurolepidium Chinense by 21.55% and 34.22%. The experiment suggested that the nutritional value of Solidago canadensis was lower than that of Aneurolepidium Chinense.Experiment 3. Thirty-two Rex rabbits (health, nearly weight, and adolescence) were randomly allocated into 4 groups. CP and CF of Solidago Canadensis L. were 4.55% and 40.31%. One group fed basal diets containing 14.5% Solidago Canadensis L. was used to study different days of collecting feces on digestibility. Other three groups were used to study different substitution proportion (5%,10%, and 15%) on digestibility of Solidago Canadensis L. Results found that there was no digestibility difference among different sampling days (2d,3d and 4d) (P>0.05). It seems that three days sampling was right. Solidago Canadensis L. digestibility was no significant different between 10% and 15% substitution proportion (P>0.05). The digestibility of DM, CP and CF was 41.78%-30.66%,78.39%-72.72% and 21.89%-23.64% respectively.Experiment 4. This experiment was conducted to study the effect of Solidago Canadensis L. adding level in diet on the growth performance, digestibility, slaughter performance and digestive system development of Rex rabbit. A total of 120 healthful Rex rabbits with similar body weight and at the age of 50-60 d were randomly divided into four groups. The 4 groups were fed diets with 0%(CR),11%(Ⅱ),22%(Ⅲ), 33%(Ⅳ) Solidago canadensis L. respectively. Results showed that daily gain, feed intake and feed/gain ratio was not different among the treatments (P>0.05). The slaughter rate of Rex rabbit in treatmentⅢwas higher than that in treatmentⅡsignificantly (P<0.05). The flesh color B in treatmentⅡwas 14.6 better than CR significantly (P<0.05). The diet with Solidago canadensia L. had little influence on absolute weight and relative weight of cecum and intestinal material in cecum. The digestibility of Calcium, Iron and Manganese were significant different among the treatments (P<0.05), whether in the early or later stage. The digestibility of Iron and Chromium were found significant different among treatment groups in the later stage (P<0.05). It seems that Copper digestibility increased with calcium in the early stage and Manganese digestibility decreased with Zinc in the later stage. Other nutrient digestibility difference was not found among the treatments either (P>0.05). Based on the results, the appropriate ratio of Solidago canadensis L. was 11%～33% and the best effectiveness was 11% in diet of Rex rabbit of growing.In conclusion, Solidago canadensia L. may be major roughage of herbivore. On one hand, spreading of Solidago Canadensis L. may be delayed, negative response resulted from rapid spread can be alleviate. On the other hand, the contradiction of husbandry's excessive growth and less feed resources may be solved to a certain extent. The study makes a new pathway of solidago canadensis's comprehensive utilization.