Influence of humic substances on growth performance and blood serum parameters in fattening turkeys

The present study was conducted to evaluate the effect of humic substances on performance and selected blood biochemical parameters in turkeys. A total of twenty 6-week-old turkey hybrids (Big 6) were divided into two groups. The first group of turkeys was fed the basal diet without any supplementation of humic substances as a control group. The second group was fed the basal diet supplemented with 5 g of humic substances per kg of diet. The study lasted 35 days, until the 11th week of age of the turkeys. The addition of humic substances had no effect on the live body weight, body weight gain, feed intake, feed conversion ratio, or growth rate of turkeys. Similarly, the monitored blood biochemical parameters, except for the levels of P, Mg, and Na, were not significantly affected by the addition of humic substances. The addition of humic substances led to a significant decrease in the concentration of P (p<0.05), Mg (p<0.05), and Na (p<0.01) in the blood serum of turkeys. It was concluded that the addition of humic substances may lead to a reduction of some mineral substances in the blood of animals, which may be due to their chelating effects. This may indicate a reduced availability of some biologically important minerals for the body, which could subsequently manifest itself in some health issues and a decrease in animal production. During the duration of our study, there were no signs of disturbance in the health of the animals. In view of the achieved results, further studies will be necessary to determine the appropriate concentration and duration of administration of the monitored preparation and to evaluate its influence on the availability of nutrients and feed conversion and its possible use as a safe non-antibiotic growth stimulator in turkey nutrition.