Lactobacillus plantarum is a kind of multifunctional lactic acid bacteria, belonging to the homozygous fermentation bacteria of lactic acid bacteria. It has good acid resistance and rich metabolites. Its metabolism can produce biologically active substances such as organic acids, small molecular peptides, hydrogen peroxide, etc., and has a good bacteriostatic effect. , has inhibitory effect on Gram-negative bacteria and Gram-positive bacteria, and has good palatability, safety, and no side effects. It has been widely used in dairy products, meat products and food additives. This experiment aims to provide reference for the design and formulation of antibiotic-free diets by studying the effects of using Lactobacillus plantarum instead of chlortetracycline + bacitracin zinc on the growth performance and diarrhea rate of piglets.
Effects of Lactobacillus plantarum and antibacterial metabolites instead of antibiotics on growth performance of piglets
1 Materials and methods
1.1 Test material
Lactobacillus plantarum is developed and provided by Haoshiwo Bio, and its main components are: Lactobacillus plantarum (inactivated) and antibacterial metabolites, the number of effective bacteria is ≥1.0×1010CFU/g; Chloromycin and Bacitracin zinc are purchased by the enterprise itself , chlortetracycline content ≥ 15%, bacitracin zinc content ≥ 10%.
1.2 Experimental animals and groups
The experiment was carried out in a farm of an enterprise in Tangshan, Hebei Province. The experiment selected 120 Duchang ternary piglets (half male and female) with good health, similar body weight and age (about 42±2 days old), and randomly divided them into A and B. , C, a total of 3 treatment groups, each treatment has 4 replicates, and each replicate has 10 piglets.
1.3 Experimental Design
The basal diet of each treatment group was the same. The basal diet group was used as the blank control group, and the two treatment groups with antibiotic combination and Lactobacillus plantarum products were respectively added as the experimental groups. The experimental design of each treatment group was as follows:
Table 1: Experimental Design
group Test plan
Test group A basal ration
Test group B Basic Diet + Chlortetracycline 75ppm + Bacitracin Zinc 40ppm
Test group C Basic diet + Lactobacillus plantarum 250g/ton
Note: The basal diet does not contain other bacteriostatic and growth-promoting additives.
1.4 Feeding management
The experiment was carried out in a fully enclosed pig house, which was raised flat on the cement floor. During the test period, the epidemic prevention and disinfection were carried out according to the normal management of the farm, and the pigs had free access to food and water. Before and after the feeding experiment, the piglets in each replicate were weighed and recorded on an empty stomach. The feed intake of each replicate and the number and days of diarrhea were recorded daily. During the experiment, the house was cleaned every day. The experiment date was from March 16, 2020 to 2020. April 27, 2008.
1.5 Test index
Average head weight gain = (end average weight – initial average weight)/test days
Average daily feed intake of heads = total feed intake / (number of heads * days)
Feed to meat ratio = total feed intake / total weight gain
Diarrhea rate %=(diarrhea head count×diarrhea days)÷(total number of test pigs×test days)×100%
1.6 Data Analysis
The experimental data were analyzed using SAS9.0 for one-way ANOVA and Duncan’s method for multiple comparisons.
2 Results and Analysis
2.1 Effects on growth performance of piglets
It can be seen from Table 2 that, compared with the blank control group, the addition of antibiotic combination (test group B) and Lactobacillus plantarum (test group C) to the piglet diet can significantly improve the feed intake, daily gain and feed meat of piglets. The feed intake increased by 6.6% and 6.2% respectively, the daily weight gain increased by 13.9% and 13.6% respectively, and the feed-to-meat ratio decreased by 6.3%, indicating that both the antibiotic combination and Lactobacillus plantarum can improve the feed conversion efficiency and increase the Piglet growth rate.
Table 2: Effects on piglet growth performance and diarrhea rate
project Test group A Test group B Test group C
Initial average weight/kg 11.63±0.86 12.16±0.35 12.34±0.63
End average weight/kg 29.75±1.89a 32.79±2.33b 32.88±3.19b
Average daily feed intake/(kg) 0.815±0.079a 0.869±0.037b 0.866±0.052b
Average daily gain of head/(kg) 0.431±0.036a 0.491±0.062b 0.489±0.087b
meat to meat ratio 1.89±0.22a 1.77±0.25b 1.77±0.23b
Diarrhea rate 10.2% 4.6% 4.8%
Note: Different letters in the shoulders of the peer data indicate significant differences (P0.05)
2.2 Influence on the diarrhea rate of piglets
It can be seen from Table 2 that the diarrhea rate of piglets in the control group was 10.2%, while the diarrhea rates of the antibiotic group (test group B) and the Lactobacillus plantarum group (test group C) were 4.6% and 4.8%, respectively, which were significantly reduced. There was no significant difference between group B and test group C. It shows that Lactobacillus plantarum can achieve a similar effect to the combination of chlortetracycline + bacitracin zinc, reducing the diarrhea of piglets, thereby reducing the use of antibiotics in piglets’ diets. Analysis of its mechanism may be related to the characteristics of lactic acid bacteria. First, lactic acid bacteria are endogenous bacteria in the intestine, their adhesion to the intestinal wall and the metabolite lactic acid can inhibit the reproduction of pathogenic bacteria, maintain the intestinal microecological balance, and repair intestinal damage; second, Lactobacillus plantarum and antibacterial metabolites It has obvious inhibitory effect on Escherichia coli, thereby reducing the incidence of bacterial diarrhea. At the same time, lactic acid bacteria can also regulate the immunity of the body, improve the disease resistance of pigs, and reduce the occurrence of diseases.
The combination scheme of chlortetracycline + bacitracin zinc and Lactobacillus plantarum can both improve the growth rate of piglets, increase the feed remuneration and reduce the diarrhea rate.