Limitation and Potential Effects of Different Levels of Aging Corn on Performance, Antioxidative Capacity, Intestinal Health, and Microbiota in Broiler Chickens

SIMPLE SUMMARY: Corn is an important ingredient and staple food in China; thus, corn storage has a certain importance to ensure domestic food resources. Normally, corn has been stored for 3 or more years under the proper storage conditions in national barns before it is used as a feed ingredient. This study aimed to investigate the effect of different levels of aging corn (AC) on performance, antioxidative capacity, intestinal health, and microbiota in broilers. In the present study, AC grains were stored for 4 years under the proper storage conditions at the national storage facility. The results indicated that a lower level of AC diet showed improved performance and overall bird health than a higher level of AC, and comparable with a normal corn diet. However, antioxidative capacity is reduced by AC diets. ABSTRACT: Three-hundred and sixty-day-old male broilers underwent three treatments with six replicates of 20 birds per treatment. The experimental diets included NC: normal corn diet; ACL: lower level (39.6–41.24%) of AC; and ACH: a higher level (56.99–59.12%) of AC. During phase 1 (0–21 d), broilers fed on AC showed lower (p < 0.05) body weight (BW), body weight gain (BWG), and feed conversion ratio (FCR) as compared with the NC group. During phase 2 (22–42 d), the NC group and ACL group showed better (p < 0.05) BW, BWG, and FCR than the ACH group. The footpad lesion score (p = 0.05) and litter moisture percentage (p < 0.05) were found to be higher in the ACH group. During phase 1, the ACL group showed a lower level of malondialdehyde (MDA) contents (p < 0.05) in serum; moreover, catalase (CAT) (p < 0.05) and glutathione peroxidase (GSH-Px) activities (p < 0.05) were found lower in both AC-containing groups. During phase 2, CAT activity in serum was found higher (p < 0.05) in the ACH group. During phase 1, the NC group showed higher CAT (p = 0.05), GSH-Px (p < 0.05), and superoxide dismutase (SOD) activity (p = 0.03); however, it showed lower MDA (p < 0.05) and total-antioxidative capability (T-AOC) (p < 0.05) in the liver. During phase 1, in breast muscle, CAT, SOD, and T-AOC were higher (p < 0.05) in the NC group. During phase 1, total cholesterol and high-density lipoprotein were found to be lower (p < 0.05) in the ACL group. Similarly, triglyceride and low-density lipoprotein were found to be lower (p < 0.05) in the ACL group than the ACH group. During phase 1, villus height was found to be higher (p < 0.05) in the ACH group. Moreover, the goblet cell (GC) was found to be higher (p < 0.05) in the NC group than the ACL group. During phase 2, GC was found to be higher (p < 0.05) in the ACL group. In ileal digesta, during phase 1, acetic acid, propionic acid, and butyric acid (BA) levels were found to be higher (p < 0.05) in the ACL group. In cecal digesta, BA was significantly lower (p < 0.05) in the NC group.