Dihydropyridine was first discovered by the former Soviet Union. At that time, it was only used as an antioxidant in animal and vegetable oils to prevent oil rancidity. It was not until the 1970s that dihydropyridine was found to not only have antioxidant effects, but also promote the growth of livestock and poultry.
1.1 Antioxidant effect
Dihydropyridine has antioxidant effects, can inhibit the oxidation of biofilms in the body, increase the activity of 6-phosphate glucose enzyme in biofilms, stabilize tissue cells, and thus has some functions of natural antioxidant VE. Zou Xiaoting et al. (1997) reported that dihydropyridine can significantly increase serum SOD activity. SOD is the main scavenger of superoxide free radicals in the body and inhibits the peroxidation process of lipid compounds. Valdman et al. also reported that dihydropyridine can reduce the oxidative loss of VA, carotene and other nutrients in feed, improve the utilization of these substances, and can also prevent the oxidative rancidity of oil and extend the storage period of oil.
1.2 Regulate the endocrine of livestock and poultry
Zou Xiaoting, (19977), Wu Xianjun, (1999), Xu Zirong (1999), etc. have all confirmed that dioxypyridine can significantly increase serum thyroid hormone (T3) levels. T3 is important for the normal growth and development of the body and the maintenance of normal reproduction. It can promote the differentiation of organs and tissues and has a “permissive effect” on growth hormone. Dihydropyridine can also significantly increase serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels, indirectly promoting the growth and development of follicles. In addition, dihydropyridine can also promote the synthesis of various proteins in the body, thus promoting the growth and development of livestock and poultry.
1.3 Improve the immunity of livestock and poultry
Dihydropyridine can improve the body’s immune function and enhance the body’s immunity.
1.4 Promote the digestion and absorption of minerals
Yue Wenbin et al. (1997) reported that adding dihydropyridine and iron and zinc preparations to the diet of laying hens can improve feed utilization and promote the absorption and utilization of mineral elements.
2. Application of dioxypyridine in livestock and poultry production
Due to the wide range of applications of dioxypyridine, reports on its effects at home and abroad vary. Generally speaking, they all have positive effects, and no reports of negative effects have been found so far. Relevant scholars at home and abroad have successively conducted feeding experiments on dihydropyridine for dairy cows, breeding bulls, chickens, ducks, pigs, mink and other livestock and poultry, and the results have been obvious. Taken together, it is reflected in the following aspects:
2.1 Improve daily weight gain and feed utilization of livestock and poultry, and improve product quality
Dvinskaya-LM et al. (1997) reported that adding dihydropyridine to broiler diets can increase daily weight gain and feed utilization. Dihydropyridine has a good effect on promoting growth and reducing feed consumption in pigs.
Research shows that when dihydropyridine is added to the diet of fattening pigs, the average daily weight gain of the test group increases by 5.2% compared with the control group, and the feed-to-meat ratio decreases by 3.4%.
Dihydropyridine was used to feed calves, mature cattle and crossbred beef cattle, and the average daily weight gain increased by 32.9%, 14.9% and 12.5% respectively compared with the control group.
Feeding minks with dihydropyridine can also increase daily weight gain.
Adding dihydropyridine to broiler diets can significantly increase daily weight gain and the content of umami substances in muscles;
Adding dihydropyridine to the feed of fattening pigs at the 60-100kg weight stage can significantly promote the growth and development of fattening pigs, increase the slaughter rate and lean meat rate, and can significantly increase the inosinic acid content and improve the quality of the meat. .
2.2 Improve the reproductive performance of livestock and poultry
The experimental results of Li Keyu (1991) on feeding breeding bulls showed that dihydropyridine can increase sperm motility by 16.6%, acrosome integrity rate by 18.7%, and ejaculate volume by 12.9%, while the sperm deformity rate decreases. 37.20%. Chen Jufang et al. (1993) reported that adding clopyridine to rabbit pellet feed can significantly improve the semen quality of male rabbits and the autumn conception rate of female rabbits. Adding dihydropyridine to sheep diets increased the conception rate of ewes by 6.11%, the semen collection volume of rams by 13.75%, the sperm density by 8.53%, and the total sperm count by 39.6%. Adding dihydropyridine to rabbit diets increased the semen volume of male rabbits by 28.3% and 45.28% respectively compared with the control group. Sperm motility increased by 53.13% and 78.13% respectively, the difference was extremely significant. The pregnancy rates of female rabbits increased by 10.02% and 100.03% respectively. According to Piskove-NL (1986), dihydropyridine can increase the pregnancy rate of dairy cows by 30%. Adding 0.01% dihydropyridine to the diet of lactating sows can increase piglet weight gain by 6.06% from 15 to 20 days before delivery of pregnant pigs to 20 days of age. Bukyal et al. (1997) reported that when dihydropyridine was added to the diet of laying hens at a concentration of 150 mg/kg, phenylboric acid had no effect on the fertilization rate of chickens, but it could improve the hatchability of fertilized eggs. Plebn-A et al. (1978) reported that adding fg dihydropyridine had a significant effect on egg production rate, egg quality and egg weight. Studies by Chen Jufang and others have shown that adding dihydropyridine can not only increase the fertilization rate, but also increase the hatching rate and egg production rate. The above results show that dihydropyridine has a good effect on the reproductive performance of livestock and poultry.
2.3 Increase milk production of livestock
As early as the 1970s, Valdmen et al. added dihydropyridine to dairy cow feed and found that milk production increased by an average of 33.9% and the milk fat rate by 4.2% 3 months postpartum. Tang Bolin also conducted experiments on dairy cows, and the results showed that milk production could be increased by 7.15%. Zheng Xiaoting et al. (1998) reported that adding dihydropyridine to the diet can significantly increase milk production of dairy cows (P<0.05). Wuhan Dairy Company (1985) added 0.01% dihydropyridine to the diet of dairy cows, which increased the total milk production by 13.1% and the yield per unit of lactating cows.��7.13%. Dihydropyridine can not only increase the food intake of dairy cows, but also has a very significant effect in promoting milk production without leaving any residue in milk. In addition, a feeding test was conducted on lactating sows, and the litter weight of piglets was higher than that of the control group, indicating that adding dihydropyridine is beneficial to increasing the milk production of lactating sows.
2.4 Increase poultry egg production
Chen Jufang et al. (1993) added 0.015% dihydropyridine to the feed of laying hens, which can increase the egg production rate in the later period, thereby extending the laying period and reducing the feed coefficient. The egg production rate in the later period of laying hens can be increased by 11.61%. ~17.17%, cost saving 13.48%. Adding 0.015% dihydropyridine to the diet of breeding ducks can increase the egg production rate of female ducks by 6.4% and the feed return by 4.8%. Zou Xiaoting et al. (1997) reported that 150 mg/kg dihydropyridine in laying hen feed has the best effect. The egg production rate increased by 11.08% compared with the control group, the feed-to-egg ratio decreased by 10.36%, and it also increased the thickness of egg shells and the egg yolk. The role of index. Wu Xianjun et al. (1999) reported that adding 150 mg/kg fat-soluble dichloropyridine to the diet of laying hens can significantly increase the egg production rate. Xu Zirong (1999) reported that adding dihydropyridine increased the average egg production rate of laying hens by 4.57%. % (P<0.05).
3.1 Safety of dihydropyridine
Odydants et al. conducted systematic pharmacological and toxicological studies on dihydropyridine. 14C-Dichloropyridine has been tested on rats and rabbits in terms of distribution, excretion, blood and embryos. The results show that dihydropyridine is absorbed through the gastrointestinal tract in the animal body and excreted in the urine. Labeled metabolites account for 97% to 99% of food intake. It rarely persists in other organs and tissues and does not cause mutations or embryotoxicity in animals. Toxicity test, oral administration of dihydropyridine to male mice, its LD50>10000mg/kg body weight, is a non-toxic substance; mouse bone marrow micronucleus test, Salmonella mutagenicity test were negative. All of this proves that clopyridine is non-toxic and safe to feed.
3.2 Dosage of dihydropyridine
Dihydropyridine is suitable for livestock and poultry such as pigs, chickens, ducks, cattle and sheep, as well as rabbits, silkworms and minks. Addition amount in feed: 0.015% for chickens and ducks, 0.01% to 0.015% for cattle or 4 to 6 mg per kilogram of body weight, 0.01% for sheep, 0.02% for pigs, 0.025% for Landrace rabbits, and 0.1% for mink. Bombyx mori 0.05% solution. Adding method: first mix this product with a small amount of concentrate, and then gradually mix it with all the feed. It can be made into powder or granular material, but it should be fed as it is prepared and mixed as it is, so as to obtain the ideal Effect.
4. Application prospects
As a green feed additive, dihydropyridine has been widely used in production abroad. A large number of test results show that dihydropyridine has a strong stabilizing effect on VA, VE and carotene, and can improve the conception (sperm) rate, hatching rate, egg production rate, semen quality, milk production, and daily growth rate of livestock and poultry. It is a multi-functional feed additive with low dosage and high efficiency, which combines feed remuneration and reduces feeding costs. It has broad application prospects.
