Analysis of the characteristics of anti nutritional factors in Shengxuebao mixture residue and its impact on the production performance of New Zealand rabbits
With the development of China’s social economy, people’s demand for livestock products is gradually increasing, and the livestock industry has also entered a stage of rapid development. The nutrients contained in feed affect the survival, growth, and reproductive performance of livestock and poultry. Anti nutritional factors (ANFs), also known as “toxic factors” or “nutrient inhibitory factors”, refer to special factors produced by feed source plants during evolution that can resist adverse external factors and have adverse effects on animal digestion and absorption. ANFs mainly include lignin, xylan, pectin, tannins, and phytic acid, which through different mechanisms of action cause animals to develop intolerance to nutrients in feed, resulting in the loss of some nutritional value of the feed itself. At present, research has found that excessive anti nutritional factors in feed can delay the development of the body, and also cause a series of problems such as digestive and metabolic disorders, weakened immunity, and the occurrence of diseases, thereby threatening the health of poultry and livestock. Therefore, ANFs are a key indicator for detecting feed composition.
Shengxuebao Mixture is a tonic traditional Chinese patent medicines and simple preparations made from seven Chinese medicinal materials, namely Polygoni Multiflori Radix Praeparata, Ligustri Lucidi Fructus, Mulberry Mori Fructus, Eclipta Herba, Paeoniae Radix Alba, Astragali Radix, Cibotii Rhizoma. It is used to nourish the liver and kidney, replenish qi and blood, and clinically to treat various anemia diseases. Pharmaceutical companies generate a large amount of Shengxuebao mixture drug residue (SXBR) during the pharmaceutical process, and its resource utilization is mainly used for cultivation substrates, wastewater treatment, catalytic cracking to produce fuel, enzymatic fermentation to produce ethanol, and animal feed production. There have been more studies on the use of Huangqi and Ligustrum lucidum residue as feed additives in the seven single herbs of Shengxuebao mixture, while there have been fewer studies on the feed utilization of this compound residue. Developing it as a feed resource can not only solve the problem of drug residue pollution in pharmaceutical enterprises and reduce the waste of traditional Chinese medicine resources, but also develop new feed resources, achieving coordinated and sustainable development of the traditional Chinese medicine industry and animal husbandry.
After preliminary experiments, SXBR contains rich active ingredients such as terpenes, flavonoids, and amino acids, which can enhance the antioxidant stress resistance of animals. In order to accelerate its feed development process, this study focuses on exploring its anti nutritional shortcomings. Based on the characteristics of SXBR, the content of five anti nutritional factors that SXBR may contain was first determined and compared with common feed materials. Secondly, the nutritional level of SXBR added to feed was characterized, and the impact of SXBR on the apparent digestibility of nutrients and production performance of New Zealand rabbits was explored. Finally, the blood toxicity components of SXBR fed in high proportion to New Zealand rabbits were identified. This study aims to provide reference for the subsequent industrialization of traditional Chinese medicine production and further promote the green and circular utilization of Chinese medicine resources.

 

Analysis of levels and characteristics of anti nutritional factors in SXBR. The types, classifications, physicochemical properties, mechanisms of action, and determination methods of anti nutritional factors in conventional feed have been extensively studied and reported by scholars. Total cellulose is composed of cellulose, hemicellulose, and lignin. Lignin is an anti nutritional factor that is difficult to degrade and hinders the digestion and absorption of other nutrients. Its special cross-linking structure with cellulose and hemicellulose reduces the contact between digestive enzymes and nutrients; Phytic acid is a strong chelating agent that can bind to nutrients such as proteins and mineral elements, thereby hindering the digestion and absorption of nutrients; Although studies have shown that pectin has various biological activities such as antioxidant, antibacterial, anti-inflammatory, lipid-lowering, and promoting the growth of intestinal probiotics, excessive pectin can increase satiety and increase intestinal viscosity after absorbing water, thereby reducing animal feed intake and apparent digestibility of nutrients such as protein and minerals; Tannin is a phenolic substance that exists in almost all plants and has various pharmacological effects such as antiviral, anti-inflammatory, antibacterial, and promoting wound healing. It can be used as a feed additive to a certain extent. However, tannins are astringent and can affect the palatability of feed when consumed excessively. They can also reduce the apparent digestibility of nutrients by inhibiting enzyme activity, generating insoluble substances with proteins, and chelating vitamins and mineral ions; Xylan is a non starch polysaccharide widely present in plant cell walls. Qin et al.’s research has shown that when the content of xylan in feed is below 10%, it does not cause adverse reactions in animals. However, excessive xylan can hinder animal absorption of nutrients by increasing intestinal viscosity, reducing digestive enzyme activity, and disrupting intestinal microbiota. At present, there is limited research on the nutritional composition and anti nutritional factors of traditional Chinese medicine residue feed. This study characterizes SXBR in terms of anti nutritional factors and compares it with 13 common feed materials. The research results indicate that in terms of anti nutritional factors, tannins in SXBR are at a moderate level. However, Liu et al.’s study showed that a tannin content of 0.5% in feed had no adverse effects on rabbits. Therefore, it is believed that tannins are functional organic compounds in SXBR, and their anti nutritional properties are not significant when the addition ratio of SXBR is within 20%. The high content of lignin and phytic acid in SXBR can be the main direction to solve its anti nutritional problems. In addition, this study also measured the content of anti nutritional factors in seven single herbs of Shengxuebao mixture, in order to analyze the main sources of anti nutritional factors in the medicinal residue, providing reference for further reducing the anti nutritional effect of SXBR in the future. This study established a characterization method for anti nutritional factors of SXBR, providing a reference for the characterization of anti nutritional factors in the development of other Chinese medicine residue feed.

The impact of SXBR on the production performance of New Zealand rabbits and its solutions. Pharmaceutical companies will generate a large amount of drug residue during the production of Shengxuebao mixture, and waste disposal will consume a lot of costs and cause serious environmental pollution and resource waste. The development of Shengxuebao mixture residue into feed has practical significance for solving the capital consumption of pharmaceutical enterprises, developing new industrial chains, realizing the green recycling of traditional Chinese medicine resources, and solving the problem of feed shortage. Based on the previous findings that SXBR can improve animal antioxidant stress function, this study further explores its shortcomings in feed development. It was found that although SXBR has considerable nutritional value when added to feed, its lignin anti nutritional properties become more prominent as the proportion of SXBR increases. Although it has no significant effect on rabbit weight growth, the apparent digestibility of crude protein in New Zealand rabbits shows a significant downward trend. The main solutions to this problem are: (1) controlling the proportion of SXBR added to feed, with 10% being appropriate; (2) Select medicinal herbs with high lignin content such as dogspine, Ligustrum lucidum, and Polygonum multiflorum; (3) Adding ligninase to feed to reduce the inhibitory effect of lignin on nutrient absorption; (4) Add easily digestible high-quality protein feed additives to the feed.
SXBR toxicity testing and its effects on the liver and intestines. Previous studies have shown that anthraquinones and stilbene glycosides in Polygonum multiflorum can cause liver damage through various pathways such as oxidative stress, mitochondrial dysfunction, and induction of cell apoptosis. Due to the presence of Polygonum multiflorum in the single ingredient of Shengxuebao mixture, considering its toxic side effects on the liver, this study used the TOF data collected from the Con group serum as a reference and found that there were no toxic substances entering the bloodstream in the serum of the SXBR-H group, and no abnormalities were observed in the liver pathological sections. Additionally, previous studies have reported that LD50 could not be obtained by gavage of mice with a concentrated solution of Shengxuebao mixture at 225 times the clinical dosage, indicating the safety and reliability of the dosage used in this study.

In summary, this study characterized the anti nutritional factors of SXBR and found that the lignin level in its anti nutritional factors is prominent, which can have a significant impact on the apparent digestibility of crude protein in New Zealand rabbits. Therefore, reducing lignin content and increasing feed protein digestibility can be the main research directions to solve the anti nutritional problems of SXBR. This study reveals the anti nutritional characteristics of Shengxuebao medicinal residue, which has positive significance for promoting its feed development process and realizing its green recycling.