The Effect of Virginiamycin, Medicinal Plants Powder, Alone and in Combination on Parameters of Blood Biochemistry, Microbial Population and Intestinal Morphology in Laying Hens

Microbial resistance is one of the major problems leading to the spread of illness and death in the worldwide. Virginiamycin is one of those antibiotics that have been approved for use in the poultry, but in recent years, attention has been paid to replacing these compounds with natural additives such as powder and extracts of medicinal herbs, in livestock nutrition and poultry.

In this experiment, 125 hens of white Leghorn chicken (Hay-line) were used at age 64 weeks. Hens were divided into five groups with five replicate cages containing five hens each for each group. In this study, the effects of garlic and sage powder in the diet of laying hens, alone or in combination, with an emphasis on antimicrobial properties, were evaluated in comparison with antibiotic Virginiamycin, and the effect of these compounds on some biochemical parameters, blood and histomorphology of the intestine were investigated. The experiment was conducted in a completely randomized design with 5 treatments and 5 replications with 5 observations in each replication

The results showed that different experimental treatments, including garlic powder, sage or their mixture, also Virginiamycin resulted in a significant increase in villi height (P<0.05) and villi height to crypt depth ratio (P<0.05), while the effect of sage powder and Virginiamycin on crypt depth was not significant. Furthermore, the addition of different experimental treatments significantly altered the intestinal microflora, and except for Lactobacillus that decreased significantly, the reduction in the number of germs including E. coli, Salmonella and total bacteria was significant.

It seems that a large part of the antimicrobial properties of these compounds in this study can be due to the ability of herbs active compounds or essential oils that are capable of eliminating bacteria due to the instability of membranes, including mitochondria membrane and imbalance in the membrane integrity of bacteria, and possibly reduce the damage to intestinal erythrocytes, also reduced the cellular requirements for the proliferation of new cells in the intestine. So that, the use of experimental treatments led to  higher villi height and less crypt depth.