Comparison of performance and blood parameters of replacement ewe-lambs at different levels of replacing cotton seed meal with slow-release urea

The present experiment was performed to study the effect of slow-release urea on performance traits and some blood parameters of replacement ewe lambs during its replacement with cotton seed meal. The livestock included 16 heads of Afshari replacement ewe lambs. Treatments include: Control containing cottonseed meal, treatment 1 contains 4 grams of slow-release urea in the daily diet (equivalent to 4.45% of dietary crude protein), treatment 2 contains 8 grams of slow-release urea in the daily diet (equal to 8.8% of dietary crude protein), treatment 3 contains 12 grams of slow-release urea in the daily diet (equal to 13.3% of dietary crude protein). The experimental duration included two weeks of acclimatization and forty days of fattening. The studied traits included functional traits and blood parameters. Functional traits included final body weight, feed intake, added daily gain and feed conversion ratio. Blood parameters included total serum protein, glucose, urea, AST, ALT, cholesterol, triglycerides, estrogen, albumin and LDL. The results showed that there was no significant difference between the four treatments in blood parameters. There was no significant difference in final body weight, feed intake, added daily gain and feed conversion ratio between the treatments. Based on the results, it is possible to use up to 12 grams of slow-release urea daily in the diet of ewe lambs without a negative effect on performance.