The Effect of Different Levels of Barley Bran on Performance, Nutrient Digestibility, some Blood Metabolites and Ruminal Parameters in Dalagh Ewes

 The limitation of water and soil resources, as well as the import of major food items used in animal nutrition, shows the necessity of using alternative food sources and the use of industrial and agricultural by-products in animal nutrition. Also, cereal grains are the main food for humans, and considering the growth of human population, especially in developing countries, it is not logical to use them in animal rations. In addition, it has been reported that the trend of grain production in the world is decreasing. Barley is an important source of energy in the whole world and is the basic energy unit in livestock nutritional standards. The content of digestible energy, crude protein, starch and lysine of barley is between corn and oats. Barley grain is similar to oats in some ways, but the shell of the barley grain is smaller and hardly attached to the kernel. For this reason, it should be processed before feeding. Due to having a coating, the amount of crude fiber in barley is higher than non-coated grains such as corn, sorghum, wheat and rye. Barley should be considered intermediate between oats and other grains in terms of nutritional value and characteristics, but its density is similar to corn and its starch digestion in the small intestine is slightly less than corn. In most varieties of barley, the seed is surrounded by a coat that constitutes 10 to 14% of the seed weight. The average crude protein content of barley grain is close to 10% of dry matter, which is of low quality and lacks amino acid lysine. The main protein of endosperm is prolamin, which forms the majority of seed protein. In the past, many attempts have been made to minimize the use of cereal grains in animal diets with different alternatives. In line with the optimal use of agricultural by-products in livestock feeding, a lot of research has been done, which is the replacement of by-products such as cereal bran instead of cereal grains in the concentrate.

In order to investigate the effect of using different levels of barley bran on performance, nutrient digestibility, some blood metabolites and ruminal parameters in Dalagh ewes, 20 ewes that Three Abdomen Births and Dalagh race with a mean weight of 36.3 ± 3.7 was used. This experiment was conducted in a completely randomized design with four treatments and five replications. Treatments included: control treatment (diet without barley bran), treatment (diet containing 7 percent barley bran), treatment (diet containing 14 percent barley bran) and treatment (diet containing 21 percent barley bran). The consumed feed and the remaining feed were weighed on a daily basis, and the animals were weighed every two weeks fasting, after 16 hours of starvation, using a digital scale, and all statistical analyzes of this project were performed in SAS software version 9.1.

 The results of this experiment showed that using different levels of barley bran in ewes caused no significant difference in daily weight gain, final weight and feed conversion ratio (p>0.05) However, daily feed intake was affected by experimental treatments in treatment consumer 21% of barley bran reduces daily feed intake (p<0.05). There was no significant difference in the digestibility of dry matter (DM), organic matter (OM), crude protein (CP), insoluble fiber in acidic detergent (NDF) and ether extract(ET) between treatments receiving different amounts of barley bran (p>0.05) but the digestibility of insoluble fiber in neutral detergent. With increasing consumption of barley bran, it decreases so that the control treatment has the highest percentage of digestibility of insoluble fiber in neutral detergent (p<0.05). protozoan population was not affected by experimental treatments during fasting and three hours after feeding (p>0.05), but protozoan population decreased at six hours after morning feeding in barley bran receiving treatments compared to the control treatment (p<0.05). There was no significant difference in ruminal pH during fasting, three and six hours after morning feeding between treatments receiving different amounts of barley bran (p>0.05), but ruminal ammonia concentration in treatment receiving 14% barley bran. Significance was higher than other treatments (p<0.05). There was no significant difference in blood glucose, cholesterol, triglyceride, urea, total protein, albumin and globulin levels among different ewes of different levels of barley bran (p>0.05), also, use of barley bran at different levels in relation to nutritional behavior and ruminal activity does not have a significant effect (p>0.05).

 According to the results of this experiment, without reducing feed intake and upsetting the rumen balance, barley bran up to 14% can be used in Dalagh ewes and this substitute of barley, which is also cheap, is a substitute for cereals, and the results of this research can be applied to sheep's rations to reduce nutritional costs.