Response of layer chicks to the dietary inclusion of allicin-rich extract

Abstract

Nutraceuticals of natural origin (for example, garlic) have proven to enhance the immunity, health and performance of birds just as the synthetic types (antibiotics). However, health-related concerns about the use of synthetic feed additives call for more studies to be conducted on the use of phytogenics, which are natural growth promoters obtained from plants. Thus, a 5-week feeding trial was carried out to assess the response of layer chicks to the dietary inclusion of allicin-rich extract. Six hundred (600) 21-day old Bovans Brown layer chicks were allocated to six (6) treatments with five replicates (20 chicks each) using a completely randomized design (CRD). The treatments consisted of negative control (T0), positive control (T1) was supplemented with antibiotics, whereas the experimental groups T2 was supplemented with garlic powder (0.50 g/kg), and T3, T4 and T5 were supplemented with an allicin-rich extract from garlic in the proportion of 0.10, 0.30, and 0.50 ml/kg in the diet, respectively. The results showed that feed intake was increased (P = <0.001) at the highest level of inclusion (0.50 ml/kg) during week 8. Lymphocyte percent of the blood was superior (P = 0.042) in all the groups compared to the negative control. Mean corpuscular volume was significantly (P = 0.025) lower in T2 compared to the control groups. The total protein concentration of the serum was statistically (P = 0.015) higher in the allicin-rich extract groups compared to the positive control. Histopathological examination revealed that lymphocytes increased with decreasing neutrophils in the ileum as the levels of allicin-rich extract increased. It can be concluded that allicin-rich extract supplementation improved the immunity of chicks by inhibiting microbial infections and inflammations.