In ovo injection of cinnamon or clove alters the physiology and growth of broilers in a hot tropical environment.

A study was conducted to evaluate the influence of in ovo feeding of clove and cinnamon on broilers. The experiment used 700 broiler (Ross 308) hatching eggs that were incubated at the recommended temperature of 37.8 °C. On day 17.5 of incubation, 100 eggs were randomly assigned to each of the following seven treatments: uninjected eggs (OE), eggs injected 0.5 mL distilled water (DH), 2 mg of clove, 4 mg of clove, 2 mg of cinnamon, 4 mg of cinnamon, and 3 mg of ascorbic acid (AC). During the posthatch period, the chicks were raised for 56 days. Data on physiological parameters, growth performance, and intestinal histomorphology were collected. Results revealed that the plasma triiodothyronine (T3) of AC and CV2 chicken was higher than the others. Additionally, the plasma malondialdehyde levels of the chickens of AC, CV2, and CM2 were improved significantly ( < 0.05). The initial weights of CV2 birds were comparable with AC CV4, CM4, and CM2 birds but heavier than those of OE and DW. The bodyweight gain in the CV2 group was similar to AC, CV4, and CM2 groups but heavier than OE, DW, and CM4 birds. Feed intake of OE and DW groups was similar to AC, CV2, CV4, and CM2 but higher than CM4. The feed conversion ratio of OE and DW chickens was comparable but higher than the value obtained in chickens of other treatments. The intestinal morphology of the birds did not follow a particular trend. The study concluded that the in ovo injection of 2 mg of clove improved broiler birds' metabolic and antioxidant status at hatch. The high and low doses of clove and the low dose of cinnamon improved the performance of broiler chickens at the market age in a hot tropical environment.