Feed Additives for controlling Dairy Cow mastitis

(agricultural Wealth Network) 1 Vitamin E and selenium

Recent studies have shown that the infection of mastitis is affected by plasma vitamin E and selenium levels. Adding vitamin E and selenium to the diet can improve the breast's natural resistance to infection. Vitamin E has the effect of antioxidation and is an essential component of all lipid membranes. It can eliminate free radicals on the cell membrane and protect the cell membrane of neutrophils from free radical attack and peroxidation damage. Vitamin E has an important effect on the immune response of the body. it can not only enhance the humoral immune response, but also improve the cellular immune function and the ability of neutrophils to kill Staphylococcus aureus and Escherichia coli. Many experiments have proved that vitamin E can improve the function of some immune cells, improve breast health and reduce the morbidity and mortality of calves.

Smith et al. (1984 first reported that the incidence of clinical mastitis and intramammary gland infection in the next lactation period decreased by 37% and 42% respectively when the dry cow diet was supplemented with 749 IU vitamin E. At the same time, the duration of clinical symptoms of dairy cows supplemented with vitamin E and selenium was shorter than that of cows supplemented with vitamin E and selenium only. Smith et al. (1985) when vitamin E (1000 IU/d) and selenium (0.3 mg/kg) were added to the diet of parturient cows from 60 days before delivery to the whole lactation period, the number of newly infected milk areas during calving and the incidence of clinical mastitis 4 days before lactation were reduced by 42% and 57%, respectively, and the duration of infection was also short. From 60 days before calving to the end of lactation, when selenium (0.3mg/kg) and vitamin E were added to the diet of parturient cows (the total intake was 1 000IU / d), the number of infection in milk area decreased significantly, the incidence of infection decreased during the whole lactation period, the clinical mastitis decreased, the duration of infection shortened and the somatic cell count in holes decreased. Erskine supplementation of 0.1 mg/kg selenium to lactating cows can more effectively resist the invasion of Escherichia coli to the breast. In addition, Batra and Hidiroglou reported that the incidence of clinical mastitis decreased and the clinical duration shortened after supplementation of vitamin E 1 000 IU/ per day in dairy cows. Hogan et al reported that dietary vitamin E increased the ability of bovine neutrophils to kill Staphylococcus aureus and Escherichia coli. Weiss and Hogan found that there was a certain relationship between vitamin E and selenium and the incidence of clinical mastitis and somatic cell count in milk when investigating dairy cows whose contact infectious mastitis had been controlled. Higher serum selenium concentration is accompanied by a decrease in clinical mastitis and a decrease in somatic cell count in milk. The content of vitamin E in diet was negatively correlated with the incidence of clinical mastitis.

2 Chinese herbal medicine additive

At present, a variety of prescriptions have been developed for the prevention of dairy cow mastitis by using Chinese herbal medicine as an additive. Xie Huisheng reported that the milk-increasing effect of "Zengru San" composed of Codonopsis pilosula, Angelica sinensis, Radix Astragali and Radix Paeoniae Alba once a day for 21 days was obvious, and the detection rate of recessive mastitis in the treatment group was 24.23% lower than that in the control group (P < 0.01). Zhang Xiaotao and others selected Chinese herbal medicines such as Angelica sinensis, Ligusticum chuanxiong, Paeonia lactiflora, Radix Astragali, dandelion, Salvia miltiorrhiza and Leonurus to feed dairy cattle with recessive mastitis. The changes of lymphocyte stimulation index and neutrophil phagocytosis were detected. The results showed that the Chinese herbal medicine additive could significantly increase the bactericidal rate of lymphocytes (P < 0.05) and neutrophil phagocytosis (P < 0.05). And can significantly reduce the incidence of recessive mastitis in dairy cattle. Zhang Xiuying and others used the milk-promoting health powder composed of 10 Chinese herbs such as Radix Astragali, Ligusticum chuanxiong, dandelion and Angelica as additives to be evenly mixed in the concentrate, and the cattle were fed freely, each head was added three times a day, and the daily addition amount of each cow was 180g. The results showed that the detection rate of recessive mastitis in the test group was 13% lower than that before treatment, while that in the control group increased by 5% in the same period, and there was a very significant difference. Yan Ming and others were mixed with dairy cow No. 2 traditional Chinese medicine additive composed of pine needle, motherwort, millet sprout, Atractylodes macrocephala, Hawthorn, Codonopsis pilosula, astragalus, Poria cocos, Angelica sinensis, licorice and trace sodium selenite, 100 g per head. The results showed that the incidence index of mastitis in the treatment group was significantly lower than that in the control group (P < 0.05), indicating that the additive had obvious effect on the prevention and treatment of mastitis.

3 humic acid

Humic acid exists widely in nature, which is composed of a loose "sponge" structure with many voids and an amorphous polymer compound containing aromatic rings in a black or brown solid state. It has strong water retention and adsorption, and can form complexes with many compounds. It is distributed in soil, wetland, coal, shale and other organic minerals, and it is a kind of feed additive instead of antibiotics. Its main function is to prevent disease and promote growth. It can also be used for the treatment of a variety of diseases and has a wide range of resources, low cost, easy to use, and no drug residue, so it belongs to an ecological preparation; and low cost can not only prevent and cure diseases, but also promote growth and improve feed returns. It is a new type of multi-functional feed additive for disease prevention and growth.

Practice has proved that adding a certain amount of sodium humate to cow feed has an obvious effect on the prevention of mastitis and milk yield. The reason may be: giving humic acid additive feed during lactation will cause the somatic cells in the milk to decrease for a short time, and then the immune function will be activated quickly, which is shown in the increase of lymphocytes collected in the blood, and a large number of group cells migrate to the breast, so the somatic cells in the milk increase, thus improving the cellular immunity of the body. Due to the sharp increase in the content of whey protein, the content of immunoglobulin and serum protein transferred from blood to milk increased, thus improving the humoral immune function of the body. It provides a theoretical basis for humic acid feed additive to effectively prevent and treat recessive mastitis in dairy cows.

Liu Yu and others used the method of sodium humate mixing and administration, which had a good effect on the prevention and treatment of recessive and clinical mastitis in dairy cows. The incidence of mastitis decreased significantly in the test group (31.58% to 23.68%). The control group increased significantly (36% to 45.32%). After taking sodium humate, the total number of leukocytes in blood, especially lymphocytes, increased from 47.5% to 57.1%. It is suggested that sodium humate can enhance the cellular immune function of the body. Wang Zhongxin et al fed each cow with humic acid additive 25g a day has a good effect on the prevention and treatment of recessive mastitis. The positive rate of milk area in the test group decreased from 53.57% to 40%, while there was no significant change in the control group (about 78%). Gu Zilin et al directly mixed biochemical fulvic acid preparation into the mixed concentrate of affected cattle twice a day, 200g / head at the first time, and 150g / cow at a later time. The results showed that the addition of biochemical fulvic acid to the diet could significantly increase the milk yield of dairy cows and increase 1.82 ~ 3.81 kg per day to reduce the incidence of recessive mastitis in dairy cows.

4 Vitamin An and β-carotene

Vitamin An is a necessary nutrient to maintain normal vision, reproduction and growth of livestock. It has the function of protecting the integrity and integrity of epithelial tissue structure, forming a barrier to prevent external bacteria from invading the body, regulating and enhancing the immune function of the body. β-carotene is transformed into vitamin An in gastrointestinal mucosa and other tissues. It is not only an essential raw material for the synthesis of vitamin A, but also an indispensable substance for dairy cow reproduction. Vitamin An and β-carotene can improve the humoral and cellular immune response of dairy cows. From the first 4 weeks to 4 weeks postpartum, the proliferation response of lymphocytes of Holstein cows supplemented with 600mg β-carotene or 600mg β-carotene to ConA,PHA,PWM stimulation was higher than that of the control group. Kizaki et al reported that the production of polyclonal antibody IgM stimulated by PWM could be increased by adding β-carotene to bovine mononuclear leukocyte culture medium in vitro. Yu Deqiang et al added 173,000 IU vitamin A to feed to resist the pathogens of recessive mastitis (streptococcus, Staphylococcus aureus, etc.), reduce the incidence of mastitis in dairy cows (67% to 18%), and promote breast health. The incidence of vitamin An in combination with beta-carotene was lower than that of vitamin An alone (18% to 13%). To sum up, giving appropriate amount of vitamin An and β-carotene to dairy cows can enhance the immune function and reduce the incidence of mastitis in dairy cows.

5 levamisole

Levamisole is taken orally with 7.5 mg per kilogram, which is safe and effective with no side effects. Levamisole has immune activity, which can improve the immunity of the immune system and play a role in the prevention and treatment of diseases. Xiang Xiangchun et al dissolve levamisole powder with proper amount of water, then evenly mix it into concentrate and feed it, 4.0 g / head for the first time, 2.5 g / head for the second and third times, every 7 days.

The drug was administered once. The results showed that levamisole was effective in the treatment of recessive mastitis in dairy cows. The positive rate of cow head number decreased from 65.56% before treatment to 45.56%, and the positive rate of milk area decreased from 31.73% to 16.15%, which was significantly different from that of the control group. The use of levamisole does not have the problem of antibiotic residues and does not affect the economic benefits. Li Zengju et al were fed with 7.5 mg/ levamisole hydrochloride mixed with concentrate for the second time on the 20th day. On the 20th day after the first administration, the positive rate of occult mastitis in the test group decreased from 42% to 17%. On the 20th day after the second administration, the positive rate of occult mastitis in the test group decreased from 42% to 8%, and the cure rate was 80%. New occult mastitis occurred in the non-breast area during treatment, while 20% of the control group was infected with new occult mastitis during treatment. Thus it can be seen that levamisole not only has a good therapeutic effect on recessive mastitis in dairy cows, but also has a good preventive effect.

At present, when human beings call for health and return to nature, they need green food, including green feed additives. Therefore, researchers are looking for ideal non-toxic, non-residual, high-efficiency, broad-spectrum, antibacterial and growth-promoting green feed additives from natural substances, and used in the breeding and production of dairy industry. In order to produce high quality milk and prevent cow mastitis, on the basis of comprehensive measures such as improving the hygienic conditions of dairy cows and pregnant cows, dairy cows must be raised at full price, inferior feed must be removed, metabolic poisoning caused by harmful substances should be prevented, and effective, safe and residue-free green feed additives should be used according to the needs of dairy farms to ensure milk quality.