Growth, Carcass Composition, Haematology and Immunity of Broilers Supplemented with Sumac Berries (Rhus coriaria L.) and Thyme (Thymus vulgaris)

SIMPLE SUMMARY: Widespread use of antibiotics is known to cause resistance in bacteria, yet they are routinely used to improve growth performance in meat chickens. We investigated two medicinal plants, thyme and sumac berries, for their ability to function as an alternative to antibiotics in the diet of broilers. The actual plants or parts of the plants have rarely been fed before as supplements, mostly their extracted oils have been used instead. In our study, they were fed at 1–3% of the diet to investigate if the effects were dependent on the dose. We found evidence of improved immune systems with both medicinal plants when the chickens were tested for resistance to Newcastle Disease and influenza. Sumac berries, and to a lesser extent thyme, reduced the fat content of the birds’ abdomen, by 62 and 41%, respectively, reflecting an observed reduction in lipids in the blood. It is concluded that these two medicinal plants offer potential to replace antibiotics in the diet of meat chickens, as well as offering benefits in reducing the fat content of the birds. ABSTRACT: Alternatives to antibiotics as growth promoters for broilers could reduce bacterial resistance to antibiotics, while at the same time maintaining growth and improving carcass composition. We investigated the benefits of adding the medicinal plants sumac and thyme at 1, 2 or 3% of the diet for male Ross broiler chicks, with four replicates of ten birds in each treatment group and a Control. Feed intake was reduced for chickens fed the sumac supplements, and, at the two higher doses, defeathered body weight was also reduced. Abdominal fat was reduced by 41% in chickens fed thyme and 62% in those fed sumac. This reflected reduced low density lipoproteins in their blood, and in higher dose thyme treatments and all sumac treatments, reduced high density lipoproteins in blood. Apart from this, there was little effect of the supplements on carcass composition. Blood glucose was reduced in the supplemented chickens. There was evidence of higher antibody titers to Newcastle disease and influenza in supplemented chickens. It is concluded that both thyme and sumac offer potential to reduce fat content and improve disease responsiveness in broiler production systems.