How to control dairy cow mastitis? These feed additives can be used
Feed additives for controlling dairy cow mastitis
(Agricultural Wealth Network) 1 Vitamin E and selenium
Research in recent years has shown that mastitis infection is affected by plasma vitamin E and selenium levels. Adding vitamin E and selenium to the diet can enhance the mammary gland's natural resistance to infection. Vitamin E has an antioxidant effect and is an essential component of all lipid membranes; it can eliminate free radicals on cell membranes, thereby protecting the cell membranes of neutrophils from free radical attack and peroxidative damage. Vitamin E has an important effect on the body's immune response. It can not only enhance the body's humoral immune response, but also improve cellular immune function and the ability of neutrophils to kill Staphylococcus aureus and Escherichia coli. Numerous experiments have proven that vitamin E can improve the function of certain immune cells in dairy cows, improve udder health, and reduce the morbidity and mortality of calves.
Smith et al. (1984) first reported that adding 749 IU of vitamin E to the diet of dry cows reduced the incidence of clinical mastitis and intramammary infection in the next lactation by 37% and 42%, respectively. The duration of clinical symptoms in cows supplemented with both vitamin E and selenium was shorter than in cows supplemented with only vitamin E and selenium. Smith et al. (1985), when adding vitamin E (1 000 IU/d) and selenium (0.3 mg/kg) to the diet of first-calf heifers from 60 d before calving through the entire lactation period, found that the number of newly infected quarters at calving and the incidence of clinical mastitis in the first 4 d of lactation were reduced by 42% and 57%, respectively, and the duration of infection was also shorter. Starting from 60 d before calving and continuing until the end of lactation, selenium (0.3 mg/kg) and vitamin E (total intake of 1 000 IU per head per day) were added to the diet of first-calf heifers; in the supplemented group, the number of infected quarters was significantly reduced, the incidence of infection during the entire lactation period decreased, clinical mastitis decreased, the duration of infection was shortened, and the somatic cell count in milk was reduced. Erskine supplemented lactating cows with 0.1 mg/kg selenium, which enabled them to more effectively resist invasion of the udder by Escherichia coli. In addition, Batra and Hidiroglou reported that after supplementing dairy cows with vitamin E at 1 000 IU per head per day, the incidence of clinical mastitis decreased and the clinical duration was shortened. Hogan et al. reported that adding vitamin E to the diet improved the ability of bovine neutrophils to kill Staphylococcus aureus and Escherichia coli. Weiss and Hogan, when investigating dairy herds in which contagious mastitis had been controlled, found that vitamin E and selenium had a certain relationship with the incidence of clinical mastitis and milk somatic cell count. Higher serum selenium concentrations were accompanied by a decrease in clinical mastitis and a reduction in milk somatic cell count. The vitamin E content in the diet was negatively correlated with the incidence of clinical mastitis.
2 Chinese herbal medicine additives
At present, a variety of formulations have been developed for using Chinese herbal medicines as additives to prevent dairy cow mastitis. Xie Huisheng et al. reported that using "Zengru San", composed of Codonopsis pilosula, Angelica sinensis, Astragalus membranaceus, Paeonia lactiflora, etc., once daily at 180 g each time for 21 d had an obvious milk-increasing effect, and the detection rate of subclinical mastitis in the treated group was 24.23% lower than that in the control group (P<0.01=). Zhang Miaotao et al. selected Chinese herbal medicines such as Angelica sinensis, Ligusticum chuanxiong, Paeonia lactiflora, Astragalus membranaceus, Taraxacum mongolicum, Salvia miltiorrhiza, and Leonurus japonicus, formulated them into a feed additive, and fed it to dairy cows with subclinical mastitis, then measured changes in bovine lymphocyte stimulation index and neutrophil phagocytic activity. The results showed that this Chinese herbal medicine additive could significantly increase the bactericidal rate of lymphocytes (P<0.05=) and neutrophil phagocytic activity (P<0.05=), and could significantly reduce the incidence of subclinical mastitis in dairy cows. Zhang Xiuying et al. used a galactopoietic health-care powder composed of 10 Chinese herbal medicines including Astragalus membranaceus, Ligusticum chuanxiong, Taraxacum mongolicum, and Angelica sinensis as an additive, mixed it evenly into concentrate, and allowed the cows to eat freely, adding it 3 times per day per head, with a daily addition of 180 g per head. The results showed that the detection rate of subclinical mastitis in the experimental group was 13% lower than before medication, while that in the control group increased by 5% during the same period, with an extremely significant difference. Yan Ming et al. used Dairy Cow No. 2 Chinese medicine additive composed of pine needles, Leonurus japonicus, rice sprouts, Atractylodes macrocephala, Crataegus pinnatifida, Codonopsis pilosula, Astragalus membranaceus, Poria cocos, Angelica sinensis, Glycyrrhiza uralensis, and trace sodium selenite, mixed it into concentrate at 100 g per head. The results showed that the mastitis incidence index in the treated group was significantly lower than that in the control group (P<0.05), indicating that this additive has an obvious effect on preventing and treating mastitis.
3 Humic acid
Humic acid exists widely in nature. It is composed of a loose "sponge-like" structure containing many voids, is an amorphous polymer compound containing aromatic rings, and appears as a black or brown solid. It has strong water retention and adsorption capacity and can form complexes with many compounds. It is distributed in soil, wetlands, coal, shale, and other organic minerals. It is a feed additive that can replace antibiotics. Its main function is disease prevention and growth promotion, and it can also be used to treat a variety of diseases. It also has broad resources, low cost, convenient use, and no drug residues, and belongs to ecological preparations; moreover, its cost is low, it can both prevent and treat diseases, and it can promote growth and improve feed returns. It is a new type of multifunctional disease-preventing and growth-promoting feed additive.
Practice has proven that adding a certain amount of sodium humate to dairy cow feed has an obvious effect on improving the prevention of dairy cow mastitis and increasing milk yield. The reason may be that giving humic acid additive feed during lactation causes a short-term decrease in somatic cells in milk, after which immune function is quickly activated, manifested as an increase in lymphocytes summarized in the blood and a large migration of group cells to the udder, so somatic cells in milk subsequently increase, thereby improving the body's cellular immune capacity. Because whey protein content increases sharply, the content of immunoglobulins and serum proteins transferred from blood into milk increases accordingly, thereby improving the body's humoral immune function. This provides a theoretical basis for humic acid feed additives to effectively prevent and treat subclinical mastitis in dairy cows.
Liu Yu et al. used the method of mixing sodium humate into feed and administering it orally, which had a good effect on preventing and treating both subclinical and clinical mastitis in dairy cows. Comparing the mastitis incidence rate before and after administration, the experimental group decreased significantly (from 31.58% to 23.68%), while the control group increased significantly (from 36% to 45.32%). After dairy cows took sodium humate, the total number of white blood cells in the blood increased significantly, especially lymphocytes, whose transformation rate increased from 47.5% to 57.1%. This indicates that sodium humate has the effect of enhancing the body's cellular immune function. Wang Zhongxin et al. fed each dairy cow 25 g of humic acid additive daily, which had a good effect on preventing and treating subclinical mastitis. The quarter positive rate in the experimental group decreased from 53.57% to 40%, while the quarter positive rate in the control group showed no obvious change (around 78%). Gu Zilin et al. directly mixed biochemical fulvic acid preparation into the mixed concentrate of affected cows, twice a day, with the first dose at 200-250 g per head, and thereafter 150 g per head each time. The experimental results showed that adding biochemical fulvic acid to the dairy cow diet could significantly increase milk yield, with a daily increase of 1.82-3.81 kg, and reduce the incidence of subclinical mastitis in dairy cows.
4 Vitamin A and β-carotene
Vitamin A is a nutrient necessary for maintaining normal vision, reproduction, and growth in livestock. It has the function of protecting the integrity and soundness of epithelial tissue structure, forming a barrier that prevents external bacteria from invading the body, and regulating and enhancing the body's immune function. β-carotene is converted into vitamin A in the gastrointestinal mucosa and other tissues. It is not only an essential raw material for synthesizing vitamin A, but also an indispensable substance for dairy cow reproduction. Vitamin A and β-carotene can improve the humoral and cellular immune responses of dairy cows. Michal et al., from 4 weeks before to 4 weeks after calving, supplemented Holstein dairy cows with 300 or 600 mg of β-carotene daily; the lymphocyte proliferation response in vitro stimulated by ConA, PHA, and PWM in the supplemented group was higher than that in the control group. Kizaki et al. reported that adding β-carotene in vitro to bovine mononuclear leukocyte culture fluid could increase the production of polyclonal antibody IgM stimulated by PWM. Yu Deqiang et al. added 173 000 IU of vitamin A to feed, which could resist pathogens of subclinical mastitis (streptococci, Staphylococcus aureus, etc.), reduce the incidence of dairy cow mastitis (from 67% to 18%), and promote udder health. When vitamin A was used together with β-carotene, the incidence rate was lower than when vitamin A was used alone (from 18% to 13%). In summary, giving dairy cows appropriate amounts of vitamin A and β-carotene can enhance the body's immune function and reduce the incidence of dairy cow mastitis.
5 Levamisole
Levamisole is safe and effective when mixed into feed and taken orally at 7.5 mg per kilogram, with no side effects. Levamisole has immune activity, can improve the immunity of the body's immune system, and plays a role in preventing and treating diseases. Xiang Xiangchun et al. dissolved levamisole powder in an appropriate amount of water, mixed it evenly into concentrate, and fed it. The first dose was 4.0 g per head, and the second and third doses were 2.5 g per head each time, with an interval of 7 d
administered once. The results showed that levamisole had a good therapeutic effect on subclinical mastitis in dairy cows. The positive rate by number of dairy cows decreased from 65.56% before medication to as low as 45.56%, and the quarter positive rate decreased from 31.73% to as low as 16.15%, with a significant difference compared with the control group. The use of levamisole does not involve the problem of antibiotic residues and does not affect economic benefits. Li Zengju et al. mixed 7.5 mg per head of levamisole hydrochloride with concentrate and fed it once, then administered a second dose after 20 d. At 20 d after the first administration, the quarter positive rate of subclinical mastitis in the experimental group decreased from 42% to 17%. At 20 d after the second administration, the quarter positive rate of subclinical mastitis in the experimental group decreased from 42% to 8%, with a cure rate of 80%. Among the 24 quarters of the experimental dairy cows, no quarter developed new subclinical mastitis during treatment, while in the control group, 20% developed new subclinical mastitis during treatment. It can thus be seen that levamisole not only has a good therapeutic effect on subclinical mastitis in dairy cows, but also has a good preventive effect.
At present, humanity calls for health and a return to nature, which requires green food, and of course also includes green feed additives. Therefore, researchers are seeking ideal green feed additives from natural substances that are non-toxic, residue-free, highly efficient and broad-spectrum, antibacterial, and growth-promoting, and are using them in dairy cattle production. In order to produce high-quality milk and prevent and treat dairy cow mastitis, on the basis of comprehensive measures such as improving the sanitary conditions of dairy cows and pregnant cows, dairy cows must be fed a complete diet, inferior feed must be removed, metabolic poisoning caused by harmful substances must be prevented, and effective, safe, residue-free green feed additives must be used according to the respective needs of dairy farms to ensure milk quality.
Research in recent years has shown that mastitis infection is affected by plasma vitamin E and selenium levels. Adding vitamin E and selenium to the diet can enhance the mammary gland's natural resistance to infection. Vitamin E has an antioxidant effect and is an essential component of all lipid membranes; it can eliminate free radicals on cell membranes, thereby protecting the cell membranes of neutrophils from free radical attack and peroxidative damage. Vitamin E has an important effect on the body's immune response. It can not only enhance the body's humoral immune response, but also improve cellular immune function and the ability of neutrophils to kill Staphylococcus aureus and Escherichia coli. Numerous experiments have proven that vitamin E can improve the function of certain immune cells in dairy cows, improve udder health, and reduce the morbidity and mortality of calves.
Smith et al. (1984) first reported that adding 749 IU of vitamin E to the diet of dry cows reduced the incidence of clinical mastitis and intramammary infection in the next lactation by 37% and 42%, respectively. The duration of clinical symptoms in cows supplemented with both vitamin E and selenium was shorter than in cows supplemented with only vitamin E and selenium. Smith et al. (1985), when adding vitamin E (1 000 IU/d) and selenium (0.3 mg/kg) to the diet of first-calf heifers from 60 d before calving through the entire lactation period, found that the number of newly infected quarters at calving and the incidence of clinical mastitis in the first 4 d of lactation were reduced by 42% and 57%, respectively, and the duration of infection was also shorter. Starting from 60 d before calving and continuing until the end of lactation, selenium (0.3 mg/kg) and vitamin E (total intake of 1 000 IU per head per day) were added to the diet of first-calf heifers; in the supplemented group, the number of infected quarters was significantly reduced, the incidence of infection during the entire lactation period decreased, clinical mastitis decreased, the duration of infection was shortened, and the somatic cell count in milk was reduced. Erskine supplemented lactating cows with 0.1 mg/kg selenium, which enabled them to more effectively resist invasion of the udder by Escherichia coli. In addition, Batra and Hidiroglou reported that after supplementing dairy cows with vitamin E at 1 000 IU per head per day, the incidence of clinical mastitis decreased and the clinical duration was shortened. Hogan et al. reported that adding vitamin E to the diet improved the ability of bovine neutrophils to kill Staphylococcus aureus and Escherichia coli. Weiss and Hogan, when investigating dairy herds in which contagious mastitis had been controlled, found that vitamin E and selenium had a certain relationship with the incidence of clinical mastitis and milk somatic cell count. Higher serum selenium concentrations were accompanied by a decrease in clinical mastitis and a reduction in milk somatic cell count. The vitamin E content in the diet was negatively correlated with the incidence of clinical mastitis.
2 Chinese herbal medicine additives
At present, a variety of formulations have been developed for using Chinese herbal medicines as additives to prevent dairy cow mastitis. Xie Huisheng et al. reported that using "Zengru San", composed of Codonopsis pilosula, Angelica sinensis, Astragalus membranaceus, Paeonia lactiflora, etc., once daily at 180 g each time for 21 d had an obvious milk-increasing effect, and the detection rate of subclinical mastitis in the treated group was 24.23% lower than that in the control group (P<0.01=). Zhang Miaotao et al. selected Chinese herbal medicines such as Angelica sinensis, Ligusticum chuanxiong, Paeonia lactiflora, Astragalus membranaceus, Taraxacum mongolicum, Salvia miltiorrhiza, and Leonurus japonicus, formulated them into a feed additive, and fed it to dairy cows with subclinical mastitis, then measured changes in bovine lymphocyte stimulation index and neutrophil phagocytic activity. The results showed that this Chinese herbal medicine additive could significantly increase the bactericidal rate of lymphocytes (P<0.05=) and neutrophil phagocytic activity (P<0.05=), and could significantly reduce the incidence of subclinical mastitis in dairy cows. Zhang Xiuying et al. used a galactopoietic health-care powder composed of 10 Chinese herbal medicines including Astragalus membranaceus, Ligusticum chuanxiong, Taraxacum mongolicum, and Angelica sinensis as an additive, mixed it evenly into concentrate, and allowed the cows to eat freely, adding it 3 times per day per head, with a daily addition of 180 g per head. The results showed that the detection rate of subclinical mastitis in the experimental group was 13% lower than before medication, while that in the control group increased by 5% during the same period, with an extremely significant difference. Yan Ming et al. used Dairy Cow No. 2 Chinese medicine additive composed of pine needles, Leonurus japonicus, rice sprouts, Atractylodes macrocephala, Crataegus pinnatifida, Codonopsis pilosula, Astragalus membranaceus, Poria cocos, Angelica sinensis, Glycyrrhiza uralensis, and trace sodium selenite, mixed it into concentrate at 100 g per head. The results showed that the mastitis incidence index in the treated group was significantly lower than that in the control group (P<0.05), indicating that this additive has an obvious effect on preventing and treating mastitis.
3 Humic acid
Humic acid exists widely in nature. It is composed of a loose "sponge-like" structure containing many voids, is an amorphous polymer compound containing aromatic rings, and appears as a black or brown solid. It has strong water retention and adsorption capacity and can form complexes with many compounds. It is distributed in soil, wetlands, coal, shale, and other organic minerals. It is a feed additive that can replace antibiotics. Its main function is disease prevention and growth promotion, and it can also be used to treat a variety of diseases. It also has broad resources, low cost, convenient use, and no drug residues, and belongs to ecological preparations; moreover, its cost is low, it can both prevent and treat diseases, and it can promote growth and improve feed returns. It is a new type of multifunctional disease-preventing and growth-promoting feed additive.
Practice has proven that adding a certain amount of sodium humate to dairy cow feed has an obvious effect on improving the prevention of dairy cow mastitis and increasing milk yield. The reason may be that giving humic acid additive feed during lactation causes a short-term decrease in somatic cells in milk, after which immune function is quickly activated, manifested as an increase in lymphocytes summarized in the blood and a large migration of group cells to the udder, so somatic cells in milk subsequently increase, thereby improving the body's cellular immune capacity. Because whey protein content increases sharply, the content of immunoglobulins and serum proteins transferred from blood into milk increases accordingly, thereby improving the body's humoral immune function. This provides a theoretical basis for humic acid feed additives to effectively prevent and treat subclinical mastitis in dairy cows.
Liu Yu et al. used the method of mixing sodium humate into feed and administering it orally, which had a good effect on preventing and treating both subclinical and clinical mastitis in dairy cows. Comparing the mastitis incidence rate before and after administration, the experimental group decreased significantly (from 31.58% to 23.68%), while the control group increased significantly (from 36% to 45.32%). After dairy cows took sodium humate, the total number of white blood cells in the blood increased significantly, especially lymphocytes, whose transformation rate increased from 47.5% to 57.1%. This indicates that sodium humate has the effect of enhancing the body's cellular immune function. Wang Zhongxin et al. fed each dairy cow 25 g of humic acid additive daily, which had a good effect on preventing and treating subclinical mastitis. The quarter positive rate in the experimental group decreased from 53.57% to 40%, while the quarter positive rate in the control group showed no obvious change (around 78%). Gu Zilin et al. directly mixed biochemical fulvic acid preparation into the mixed concentrate of affected cows, twice a day, with the first dose at 200-250 g per head, and thereafter 150 g per head each time. The experimental results showed that adding biochemical fulvic acid to the dairy cow diet could significantly increase milk yield, with a daily increase of 1.82-3.81 kg, and reduce the incidence of subclinical mastitis in dairy cows.
4 Vitamin A and β-carotene
Vitamin A is a nutrient necessary for maintaining normal vision, reproduction, and growth in livestock. It has the function of protecting the integrity and soundness of epithelial tissue structure, forming a barrier that prevents external bacteria from invading the body, and regulating and enhancing the body's immune function. β-carotene is converted into vitamin A in the gastrointestinal mucosa and other tissues. It is not only an essential raw material for synthesizing vitamin A, but also an indispensable substance for dairy cow reproduction. Vitamin A and β-carotene can improve the humoral and cellular immune responses of dairy cows. Michal et al., from 4 weeks before to 4 weeks after calving, supplemented Holstein dairy cows with 300 or 600 mg of β-carotene daily; the lymphocyte proliferation response in vitro stimulated by ConA, PHA, and PWM in the supplemented group was higher than that in the control group. Kizaki et al. reported that adding β-carotene in vitro to bovine mononuclear leukocyte culture fluid could increase the production of polyclonal antibody IgM stimulated by PWM. Yu Deqiang et al. added 173 000 IU of vitamin A to feed, which could resist pathogens of subclinical mastitis (streptococci, Staphylococcus aureus, etc.), reduce the incidence of dairy cow mastitis (from 67% to 18%), and promote udder health. When vitamin A was used together with β-carotene, the incidence rate was lower than when vitamin A was used alone (from 18% to 13%). In summary, giving dairy cows appropriate amounts of vitamin A and β-carotene can enhance the body's immune function and reduce the incidence of dairy cow mastitis.
5 Levamisole
Levamisole is safe and effective when mixed into feed and taken orally at 7.5 mg per kilogram, with no side effects. Levamisole has immune activity, can improve the immunity of the body's immune system, and plays a role in preventing and treating diseases. Xiang Xiangchun et al. dissolved levamisole powder in an appropriate amount of water, mixed it evenly into concentrate, and fed it. The first dose was 4.0 g per head, and the second and third doses were 2.5 g per head each time, with an interval of 7 d
administered once. The results showed that levamisole had a good therapeutic effect on subclinical mastitis in dairy cows. The positive rate by number of dairy cows decreased from 65.56% before medication to as low as 45.56%, and the quarter positive rate decreased from 31.73% to as low as 16.15%, with a significant difference compared with the control group. The use of levamisole does not involve the problem of antibiotic residues and does not affect economic benefits. Li Zengju et al. mixed 7.5 mg per head of levamisole hydrochloride with concentrate and fed it once, then administered a second dose after 20 d. At 20 d after the first administration, the quarter positive rate of subclinical mastitis in the experimental group decreased from 42% to 17%. At 20 d after the second administration, the quarter positive rate of subclinical mastitis in the experimental group decreased from 42% to 8%, with a cure rate of 80%. Among the 24 quarters of the experimental dairy cows, no quarter developed new subclinical mastitis during treatment, while in the control group, 20% developed new subclinical mastitis during treatment. It can thus be seen that levamisole not only has a good therapeutic effect on subclinical mastitis in dairy cows, but also has a good preventive effect.
At present, humanity calls for health and a return to nature, which requires green food, and of course also includes green feed additives. Therefore, researchers are seeking ideal green feed additives from natural substances that are non-toxic, residue-free, highly efficient and broad-spectrum, antibacterial, and growth-promoting, and are using them in dairy cattle production. In order to produce high-quality milk and prevent and treat dairy cow mastitis, on the basis of comprehensive measures such as improving the sanitary conditions of dairy cows and pregnant cows, dairy cows must be fed a complete diet, inferior feed must be removed, metabolic poisoning caused by harmful substances must be prevented, and effective, safe, residue-free green feed additives must be used according to the respective needs of dairy farms to ensure milk quality.