عنوان مقاله [English]
Background and objectives: Barley is always the common grain used in sheep fattening feed, as the only source of starch, but due to the rapid fermentation of barley in the rumen, which may lead to increased digestive problems such as ruminal acidosis and thus reduced performance. Livestock will follow. Barley kernels are surrounded by a fibrous shell that has low digestibility. Unlike corn kernels, which are well crushed by chewing, barley grains are resistant to this action, and if whole grains are used to feed livestock, a significant amount of them will be excreted in the feces The process of adding steam to the food mixture is called condioning.In order to increase the humidity and temperature of the mesh, the food mixture is exposed to saturated vapor so that it will eventually cause starch gelatination and the activity of other bonding agents in the feed. The objectives of the study were to determine the effect of conditioning of dietary concentrate and the effect of grain type used in the concentrate and the interaction of conditioning and grain type on yield, nutrient digestibility and rumen and blood parameters of fattening lambs.
Materials and methods: In order to investigate the effect of concentrate concentration and type of dietary grain on yield, nutrient digestibility, ruminal and blood parameters on 20 male Dalagh lambs with an average live weight of 31 ± 0.50 kg and age 4- 5 months were done in a completely randomized design with 2×2 factorial arrangement with two processing methods (with and without conditioning) and two types of grain (barley and corn). Experimental treatments include 1- Concentrate without conditioning and barley grain, 2- Concentrate with conditioning and barley grain, 3- Concentrate without conditioning and corn grain, 4- Concentrate with conditioning and corn grain. Each treatment was assigned 5 replications and in total, 20 lambs were tested for 98 days. The duration of the experiment included 14 days of habituation period and 84 days of experimental period.
Results: There was no significant difference between treatments in the type of processing for performance (growth, daily weight gain, feed intake, feed conversion ratio) (P> 0.05). The weight of lambs receiving concentrate containing corn grain on day 56 was higher than the lambs receiving concentrate containing barley grain (P <0.05). Concentrate treatment containing corn kernels performed better than barley grain concentrate treatment in the first month as well as in the first month weight gain and first month feed conversion ratio (P <0.05). Also, in the consumption of feed in the second month, the treatment containing concentrate of corn grain had more consumption than the concentrate containing barley grain (P <0.05). There was no difference in the digestibility of dry matter, organic matter and protein between treatments. In the digestibility of ethereal extract, concentrate containing barley grain had a better performance than concentrate containing corn grain (P <0.05). No difference was observed between treatments in ammonia nitrogen concentration and pH (P> 0.05). There was no difference between treatments in blood parameters (P> 0.05). In the amount of nitrogen in blood urea, the concentrate treatment without conditioning had a higher number than the conditioning treatment (P <0.05).
Conclusion: The results of this experiment show that concentrate processing by conditioning numerically improves livestock performance in weight gain, feed conversion ratio, nutrient digestibility and ruminal parameters. Oh and it becomes bloody. The use of barley or corn grain in lamb fattening was not significantly different. And the use of concentrate with corn grain conditioning numerically has better performance in growth, daily weight gain, feed conversion ratio, feed intake, nutrient digestibility,