Effects of slow release urea and molasses on eating behavior and feed intake rate in fattening lambs

The aim of this experiment was to investigate the effects of slow release urea and molasses on eating behavior and feed intake rate in fattening lambs. The experiment was conducted in a completely randomized design with 5 treatments (experimental diets) including, control (without sources of non-protein nitrogen), two sources of non-protein nitrogen (common urea and SRU) with or without molasses and 7 replicates and with using 35 Arabian lambs. Forage to concentrate ratio of diets was 30 to 70. During the fattening period, the lambs were fed the total mixed ration, individually and ad libitum, twice daily at 8 am and 4 pm. At the end of the fattening period, eating behavior was measured visually every 5 minutes over a 24-hour period and feed intake rate over a 8-hour period. The results showed that the addition of molasses reduced the ruminant duration (P<0.001) and increased the feed intake rate (P<0.05), but the duration of chewing activity was not affected by the nitrogen source and the addition of molasses. Diets containing non-protein nitrogen sources reduced the eating duration compared to the control diet (P=0.02). Compared to the control diet, using common urea, reduced the feed intake rate (P<0.05). The results of this experiment showed that the replacement of common urea with slow-release urea and the association of molasses with it, did not have adverse effects on eating behavior and feed intake rate.