Complex of Lauric Acid Monoglyceride and Cinnamaldehyde Ameliorated Subclinical Necrotic Enteritis in Yellow-Feathered Broilers by Regulating Gut Morphology, Barrier, Inflammation and Serum Biochemistry

SIMPLE SUMMARY: Under the background of total prohibition, it has always been the goal of the broiler industry to improve the harm of necrotizing enteritis and the performance of broiler chickens. As a potential green and healthy feed additive, lauric acid monoglyceride and cinnamaldehyde have important research significance. The results showed that 350 and 500 mg/kg combined plant essential oils of lauric acid monoglyceride and cinnamaldehyde could increase ADG and F:G, improve intestinal morphology and antioxidant capacity, and downregulate the expression of inflammatory factors. ABSTRACT: This experiment investigated the benefits of plant essential oil (EO) composed with lauric acid monoglyceride and cinnamaldehyde on necrotic enteritis-challenged broilers. A total of 180 1-day-old healthy yellow-feathered broilers were randomly divided into 4 groups with 3 replicates of 15 chicks each. The experimental groups were as follows: the control group (CON) was fed with the basal diet and was not challenged by Eimeria acervulina (EA) and Clostridium perfringens (CP); CPEA group was also fed with a basal diet, but infected with CP and EA; CPEA_EO350 group and CPEA_EO500 group were fed with a basal diet supplemented with 350 and 500 mg/kg EO, respectively, and all infected with CP and EA. On the 7th day, each bird in the CPEA group, CPEA_EO350 group and CPEA_EO500 group was orally administrated with 1 mL Eimeria acervulina containing 5000 oocytes/mL, and the birds of the CON group were orally administrated with 1 mL normal saline. From the 15th day, 1 mL of CP type A CVCC-2030 strain (about 5 × 10(8) cfu/mL) was orally inoculated into each bird of the CPEA, CPEA_EO350 and CPEA_EO500 groups for three consecutive days. Similarly, the CON group was orally given 1 mL of normal saline. The CPEA stimulation reduced the average daily gain (ADG) of broilers, increased the feed-to-gain ratio (F:G), and increased the intestinal lesions of the broilers (p < 0.01), indicating that CPEA stimulation was clinically successful. Compared with the CPEA group, the ADG of CPEA_EO350 and CPEA_EO500 increased, the F:G decreased (p < 0.01), and the intestinal score of CPEA_EO500 decreased (p < 0.01). The expression of the tight junction protein of the jejunum and ileum on 21d was upregulated (p < 0.01), and the expression of jejunum inflammation factors TNF-α on 21d and jejunum and ileum inflammatory factor IL-6 on 28d were also downregulated. The CPEA_EO350 and CPEA_EO500 increased antioxidant capacity. To sum up, 350 and 500 mg/kg of lauric acid monoglyceride and cinnamaldehyde complex plant essential oils can improve ADG and F:G, improve intestinal morphology and the body’s antioxidant capacity, and downregulate the expression of inflammatory factors. The concentration of 500 mg/kg performed even better.