The application effect of Bacillus subtilis in livestock and poultry production

    Bacillus subtilis is an aerobic Gram positive bacterium that can form spores. It has the characteristics of temperature resistance, rapid resurrection, and strong enzyme secretion. It is one of the two types of Bacillus subtilis allowed by the Ministry of Agriculture as a feed additive. It has been increasingly developed into microbial preparations and has become one of the most common microbial preparations in animal husbandry research and production. Its formulation has the characteristics of disease prevention and resistance, improving animal production performance, and being non-toxic, harmless, and residue free to animals. It is a new type of feed additive that is high-quality, efficient, low residue, pollution-free, and environmentally friendly. Bacillus subtilis products exist in the form of endospores and have strong resistance to adverse environments such as dryness, high temperature, high pressure, and oxidation. Bacillus subtilis has strong activities such as protease, lipase, amylase, etc. It can produce antibiotics and has strong biological oxygen scavenging ability in animal intestines. These characteristics play an important role in promoting the digestion and absorption of animal nutrition, improving animal feed conversion rate and disease prevention, and promoting growth.

1. Application effect in poultry production

1.1 Impact on Growth Performance

    Many research results indicate that Bacillus subtilis can improve the production performance of animals.

    Broiler: Adding Bacillus subtilis to the diet can increase the weight gain of broiler chickens, significantly improving the average daily weight gain of broiler chickens at 21, 30, and 40 days old, as well as the average daily weight gain of broiler chickens throughout their growth period (0-6 weeks old). At the same time, it can significantly improve the feed conversion efficiency and feed conversion rate throughout the growth period (0-6 weeks old) of broiler chickens. Bacillus subtilis can significantly improve the utilization efficiency of calcium, phosphorus, and crude ash. The use of Bacillus subtilis preparations in the diet of broiler chickens at higher nutritional levels can effectively promote their growth, improve feed conversion efficiency and economic benefits, without adverse effects on the carcass quality and nutritional composition of chicken meat. It can also improve the amino acid composition of chicken meat, increase the total amino acid content, essential amino acid content, and umami amino acid content, and enhance the umami taste of chicken meat. In addition to adding it to the diet, adding Bacillus subtilis for poultry to the drinking water of broiler chickens can also improve the quality of slaughter, increase daily weight gain, increase feed intake, and significantly reduce the feed to meat ratio. Adding 0.5kg/t Bacillus subtilis for poultry has the best effect.

    Egg laying hens: Bacillus subtilis preparations can improve feed to egg ratio, reduce mortality rate, significantly reduce egg breakage rate, and have a trend of increasing individual egg weight and eggshell thickness. Bacillus subtilis preparations can also significantly improve the digestibility of crude protein and organic matter in the diet.

    Meat goose: Adding 250g/t Bacillus subtilis to meat goose feed can improve dry matter and energy retention rate, and its growth promoting effect on meat geese is equivalent to 5mg/kg erythromycin.

    Meat duck: Bacillus subtilis can reduce the feed to meat ratio of meat duck by 0.06-0.07, with a reduction range of 2.4% to 2.7%; In terms of the impact on the cost of medication, the dosage and experimental conditions vary greatly, resulting in a reduction of 0.08 to 0.30 yuan per feather, with a reduction rate of 11.4% to 40.0%. Meanwhile, Bacillus subtilis has a tendency to increase the growth rate, reduce feed consumption, and improve survival rate of meat ducks. The addition of 100g/t and 300g/t Bacillus subtilis preparations increased weight gain by 6.24% and 6.63%, respectively, and improved feed to meat ratio by 3.87% and 4.50%, respectively, compared to the addition of erythromycin group.

1.2 Impact on gut microbiota

    Adding Bacillus subtilis selectively increases the number of beneficial bacteria (lactobacilli) and reduces the number of harmful bacteria (Salmonella) in the cecum of broiler chickens, but the effect on the number of Escherichia coli varies. Yan Fenglan et al. reported that Bacillus subtilis had no significant effect on the number of Escherichia coli, while Wang Xiaoxia et al. and Yi Zhonghua et al. reported that Bacillus subtilis can reduce the number of Escherichia coli in the cecum of broiler chickens. As broiler chickens grow, the effect of increasing beneficial bacteria and reducing harmful bacteria becomes more pronounced.

1.3 Effects on immunity

    Adding an appropriate amount of Bacillus subtilis to the diet can improve the antioxidant capacity and immune function of broiler chickens, significantly increasing the total antioxidant capacity and glutathione peroxidase activity in serum and liver; The levels of malondialdehyde (MDA) in serum and liver were significantly reduced. In addition, adding Bacillus subtilis to the diet significantly increased the thymus index, bursa index, and serum IgG levels in broiler chickens.

1.4 Effects on Blood Biochemical Indicators

    0.2% Bacillus subtilis can significantly increase the serum total protein, total cholesterol content, alkaline phosphatase, and alanine aminotransferase activity in broiler chickens. Adding 0.4% Bacillus subtilis can significantly increase the serum total protein content, alanine aminotransferase activity, and alkaline phosphatase activity.

1.5 Other

    Adding Bacillus subtilis for poultry to broiler drinking water can significantly improve fecal consistency and reduce ammonia odor in the house. Simultaneously using Bacillus subtilis can also improve the drying and shaping of feces throughout the entire breeding process in Cherry Valley meat duck farms, significantly improve the breeding environment, and reduce the frequency of bedding replacement. This is closely related to the ability of Bacillus subtilis to improve the intestinal microbiota environment of animals.

2. Application effect in pig production

2.1 Impact on Growth Performance

    Adding Bacillus subtilis preparations to piglet diets can significantly improve the growth performance of weaned piglets. Bacillus subtilis can significantly improve the weight gain effect of weaned piglets, increase the feed utilization and conversion rate of weaned piglets, improve the digestive function of pigs, and reduce the feed to meat ratio.

2.2 Treatment for Diarrhea

    Bacillus subtilis can enhance the disease resistance and immunity of weaned piglets, alleviate and prevent the diarrhea rate of weaned piglets. Reduce weight loss during weaning and improve the uniformity of piglet populations. Bacillus subtilis can not only treat diarrhea in pigs, but also has a higher cure rate than enrofloxacin and acetaminophen, and can replace antibiotics to treat diarrhea in pigs.

3. Application effect in ruminant animal production

3.1 Impact on Milk Production Performance

    Bacillus subtilis probiotics can significantly increase milk production in dairy cows, and different dosages, i.e. different numbers of live bacteria, have different effects on milk production. At the same time, they can also increase the content of fat and protein in milk. Li Jiemei and others reported that Bacillus subtilis can significantly increase milk fat production and milk fat percentage; However, there were no significant changes in indicators such as milk protein, lactose, and non fat solids. At the same time, Bacillus subtilis promoted the synthesis of long-chain and medium short chain fatty acids in milk fat. The mixed preparation of Bacillus subtilis and yeast culture can also significantly increase the feed intake and milk production of dairy cows. As the dosage increases, the milk production and economic benefits also increase. Especially for low nutrient and low yield dairy herds, the increase in milk production is significant, which can significantly improve economic benefits.

3.2 Treatment and Prevention of Bacterial Intestinal Diseases

    Bacillus subtilis live bacterial preparations have the effect of treating bacterial intestinal diseases in calves and dairy cows, as well as treating and preventing bacterial intestinal diseases in lambs. No adverse reactions were found in animals during the observation period. The dosage for diarrheal calves is/head, once a day, with a dosage of 1-3 times; The therapeutic dose for diarrhea producing cows is 120mL/head, once a day, administered 1-3 times, which has a good therapeutic effect; The therapeutic dose for diarrhea lambs is 10mL/lamb, once a day, administered continuously for 3 times; the preventive dose is 5mL/lamb, once a day, administered 1-3 times.