| With the rapid development of China’s breeding industry,the demand for high-quality and low-cost feed is also increasing.At present,the current situation of feed in China cannot meet the actual demand,so it is imperative to develop new feed resources.Toona sinensis,a tall perennial tree originated in China,has a long history of cultivation and a wide planting area.Toona sinensis bud has been a popular seasonal vegetable since ancient times.Toona sinensis industry produces a large number of mature leaves every year,which are basically discarded at present,resulting in huge waste.In this study,mature leaves of Toona sinensis with different varieties and harvest periods ate used as raw materials,and the contents of total polyphenols and total flavonoids were analyzed and compared.The antioxidant activities were compared and determined by DPPH,ABTS and total reducing power.The contents of protein,amino acids,mineral elements and nitrite in Toona sinensis mature leaves were determined,and the suitable varieties and harvest time were screened out for feed preparation,and the antibacterial experiment were carried out on the mature leaves of Toona sinensis.Secondly,using the basic formula of mutton sheep feed,adding Toona sinensis compound leaves,alfalfa meal and methionine,and replacing part of soybean meal with cottonseed meal to optimize the feed formula,so as to obtain a low-cost,nutritious and functional mutton sheep feed formula.Finally,the nutrition and safety of the obtained mutton sheep feed formula were evaluated.The main results are as follows:(1)The mature leaves of Toona sinensis are rich in polyphenols and flavonoids,and their antioxidant activity and antibacterial activity are much higher than alfalfa meal,which is commonly used as feed material for mutton sheep.The variety and harvesting period of Toona sinensis had a significant effect on the content of active substances in Toona sinensis leaves.After July,the content of polyphenols and flavonoids in Toona sinensis leaves showed an obvious upward trend,until October,the content of polyphenols and flavonoids reached the peak,up to 94.15 mg/g and 32.40 mg/g.At this time,the antioxidant activity was also the best(DPPH free radical scavenging rate was 98.19%,ABTS free radical scavenging rate was97.80%,the total reducing power was 2.7mg/m L in terms of Vc equivalent).Therefore,the mature leaves of Toona sinensis in Ankang after July can be considered as feed materials.(2)The content of protein in Toona sinensis mature leaves decreased with the increase of maturity,but it was all above 20% before October,and the content of protein in Bashanhong Toona sinensis was the highest(26.02%),which is much higher than some traditional feed materials.Therefore,Toona sinensis mature leaves can be used as a highprotein feed material.At the same time,the nitrite content in Toona sinensis mature leaves showed a "V" shape,with the lowest content in July and August.Considering the nutritional value and functional activity of Toona sinensis leaves,Toona sinensis in Ankang and Bashan from July to August were selected as feed materials for meat sheep.(3)In the experiment of feed formula optimization for mutton sheep,the response surface methodology(RSM)was used to optimize the supplementation levels of Toona sinensis leaves,methionine,alfalfa meal and cottonseed meal.The results showed that when the supplementation levels were 5%,0.06%,10% and 10% respectively,the digestibility of feed protein was the highest,which was 66.72%,and the feed was formulated under this condition.At the same time,in the experiment of feed nutrition and safety evaluation,it was found that the feed added with Toona sinensis mature leaves was better than the commercial feed in nutritional composition,biological activity and hygiene safety. |
PDF Full Text Request