The effect of feeding oak fruit processed with sodium hydroxide and urea on growth performance, apparent digestibility of nutrients, carcass characteristics and some blood parameters of Zell and Atabai mixed lambs

Background and objectives: Due to the climatic conditions and the altitude above the sea level, the northern areas of the Alborz mountain range, from Talash forests to Gorgan forests, which are home to several species of oak trees; The use of oak tree fruit due to its nutritious compounds and relying on the appropriate processing method to reduce anti-nutritional compounds and increase its digestibility, has the potential to be investigated in the discussion of feeding livestock. Therefore, the aim of this study was to investigate the effect of different levels of oak fruit processed with sodium hydroxide and urea on performance, apparent digestibility of nutrients, quantitative and qualitative traits of the carcass and some blood parameters of Zell fattening male lambs.
Materials and methods: To perform this study, 20 fattening Zell and Atabai mixed lambs with an mean age of 5.5±0.38 months and an initial weight of 27±0.4 kg were used in a completely random design for 90 days. The experimental treatments included the control group (without oak fruit + polyethylene glycol) and treatments containing levels of 10, 20 and 40% in the dry matter of oak fruit processed with sodium hydroxide and urea. The feed consumed by the lambs was in the form total mixed ration at the level of appetite on two occasions (at 8:00 and 17:00). The oak fruit (Quercus castaneifolia) used in this research was collected in the late summer and early autumn from oak trees of the Bolandmazo species, Mazandaran province, Sari city. Experimental animals were weighed every 14 days with 12 hours of feed deprivation. To measure the quantitative and qualitative traits of the carcass at the end of the 90th day of the experiment and after 24 hours of the last feed weighing, 3 lambs were selected from each treatment and killed after 12 hours of feed deprivation. To determine blood parameters at the end of the experiment, 3 to 4 hours after feeding, blood was taken from the jugular vein of the lambs using vacuum tubes containing anticoagulant.
Results: The results of the growth performance showed that the treatment of 40% of processed oak fruit significantly had the highest amount of dry matter intke, daily weight gain, final weight and also the lowest feed conversion ratio (P<0.05). The results of apparent digestibility of nutrients showed that there was a significant difference between experimental treatments in crude protein and NDF (P<0.05). The highest apparent digestibility of crude protein and NDF was observed in the treatment of 20% and 40% of processed oak fruit, respectively. The results of some blood parameters showed that there was a significant difference in the concentration of blood glucose and urea nitrogen between the experimental treatments (P<0.05). The highest concentration of blood serum glucose was observed in the treatment of 40% processed oak fruit. In blood urea nitrogen concentration, the control group had the highest concentration and the 40% processed oak fruit treatment had the lowest concentration. In quantitative and qualitative characteristics of the carcass, the highest slaughter weight, hot carcass weight, cold carcass weight, Leg and Shoulder percentage were found in the treatment of 40% processed oak fruit and the highest carcass yield was found in the treatment of 20% processed oak fruit (P<0.05).
Conclusion: The general results of the present study showed that the fattening end weight, daily weight gain, dry matter intake, lowest feed conversion ratio, as well as valuable parts of the carcass in fattening lambs were improved by consuming 40% processed oak fruit treatment. Apparent digestibility of raw protein and NDF was improved by using 20% and 40% levels of processed oak fruit, respectively.