The effects of humic acid addition to ration on the fattening performance and some oxidative stress parameters in anatolian merino lambs

In this study, it is aimed to determine the effects of adding humic acid to ration of Anatolian Merino lambs on the fattening performance and some oxidative stress level by using thiol / disulfide balance measurement method. In the study, singleton 32 male Anatolian Merino lambs with an average age of 2.5 months were used. The experiment was carried out by forming a control group without additives and four trial groups, three of which were added with humic acid (2, 4, 6 g/kg), with 8 replications in each group for a total of 70 days. The lambs housed in the group partitions were fed with 350g/day/head of alfalfa grass as roughage and lamb grower feed ad-libitum containing 2750 kcal/kg DM ME, 16% HP until the end of the trial. At the end of the research; intra-group native thiol (NTL, μmol/L) values increased on the 30 th day (P<0.05) in all groups except the control group, while total antioxidant status (TAS, mmol/L), total thiol (TTL, µmol/L) and disulfide values increased on the 60 th day in all groups including the control group ( P≤0.001) was observed. In terms of lambs' feed consumption, live weights, body weight gains, feed conversion ratios, TAS, total oxidant status (TOS, μmol/L), OSI, TTL, NTL and disulfide was found that there was no significant difference between groups (P˃0.05). It was concluded that the humic acid additive was not effective on the fattening performance, but 4 or 6 g/kg could be added to the lamb rations due to the increase in thiol groups, which have an important role in the antioxidant defense system.