Improvement of Growth performance, Biochemical Blood Profiles, and Meat Peroxidation by the Inclusion of Mustard Seed Extract in Broilers' Drinking Water

Growth promoters are used in the broiler industry of Iraq, and herbal plants are believed to be one of the safest growth-promoting agents in modern poultry production. This study aimed to investigate the effect of aqueous mustard (Brassica juncea) seed (MS) extract on broiler production. A total of 160 unsexed day-old Ross 308 broiler chicks were selected and exposed to different doses of MS included in drinking water for six weeks. Afterward, MS was added to the treatment groups of T1 (control), T2, T3, and T4 in the dosage of 0mL, 3mL, 5 mL, and 7 mL per liter of drinking water, respectively. Results indicated that the birds that were given extract (T2, T3, T4) for the three weeks were fed significantly more diet, compared to the control treatment group (189.4 g vs. 159.6g) (P<0.05). Accordingly, the Body Weight (BW) of these birds recorded on days 28 (1232, 1252, 1300g) and 35 (1840, 1900, 1960g) were significantly higher, compared to the birds in the control treatment on days 28 (1147g) and 35 (1657g), respectively. On days 28 and 35, the birds in T2, T3, T4 treatment groups had significantly higher Body Weight Gain (BWG) (P<0.05), compared to the control group (G1). Improved Feed Conversion Ratio (FCR) was observed in the 5^th week for the birds that were administrated MS extract (5 and 7mL /liter), compared to the control group (P<0.05). The total serum level of protein, phosphorus, and calcium was increased in birds in the treatment group T4 (7.5 g/dL). Moreover, lower cholesterol values and higher values of alkaline phosphatase were obtained in birds in the treatment groups T2, T 3, and T4 (P<0.05). On day 35, higher meat peroxidation was observed in the fresh samples (after 24 h of slaughtering) of birds receiving different levels of MS extract, compared to the birds in the control group. The obtained results revealed that 5-7 mL of MS extract can be considered a functional growth- promoter for commercial broilers, although further studies are needed to confirm MS as a growth promoter.