نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه تغذیه دام و طیور، دانشکده علوم دامی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان
2 دانشگاه علوم کشاورزی و منابع طبیعی گرگان
3 گروه تغذیه دام و طیور - دانشکده علوم دامی -دانشگاه علوم کشاورزی و منا بع طبیعی گرگان-گرگان-ایران
4 4دانشجوی کارشناسی ارشد گروه تغذیه دام و طیور، دانشکده علوم دامی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Abstract
Introduction: To maintain a competitive position in the global market, the animals industry is actively looking for sustainable and practical strategies. The purpose of these strategies is to produce and provide food protein and minerals, while simultaneously ensuring the proper performance and maintaining the optimal health level of the animal. With the increase in global demand for livestock and poultry production, identifying alternative raw materials that can replace soybean meal has become increasingly critical. Soybean meal has long been used as the most appropriate plant supplement to provide protein needs in animal rations. But due to the existence of problems such as product price fluctuations, currency leaving the country, and the increase in the price of rations, its use has been limited. A high percentage of soybean meal is broken down in the rumen and its protein is broken down in favor of making microbial protein, which is undesirable. Mixed meal is the name of a mixture that contains amounts of bloodless meat powder, cotton scraps, rice bran, wheat bran, corn meal, pistachio powder and liquid gluten, and it can be used as a protein source in animal feed. The important advantage of this flour is to provide vegetable and animal proteins at the same time, and it seems that it can be a substitute for vegetable flour. Making a combination containing both types of vegetable and animal protein sources, in addition to reducing the price, creates a balance of proteins. Materials and Methods: To perform this experiment, 32 dairy ewes of the Atabai breed with an average weight of 41±2.8 kg were used in 4 treatments and 8 repetitions in a completely randomized design. In the experimental treatments, mixed meal was replaced with soybean meal at zero, 33, 67 and 100% levels. The length of the test period was 56 days. The rations used in this experiment were prepared and adjusted according to the tables of the National Sheep Research Society and were given to the ewes at two times in the morning (8 o'clock) and in the evening (16 o'clock). The daily feed was supplied to the animals in a completely mixed form. During the entire experiment, the animals had free access to clean drinking water. The ewes were weighed at the beginning and end of the period. Also, the feed given and post-feed of each animal was recorded daily to calculate the dry matter consumption. Sampling of rumen fluid was done on the last day. The pH value of the rumen contents was measured and recorded immediately after extraction by a mobile digital pH meter that was calibrated at the same place. In order to determine the amount of rumen ammonia nitrogen from the samples three hours after feeding, the method of Kang and Broderick (1980) was used using a spectrophotometer at a wavelength of 630 nm. The method of Males and Dehority (1984) was used to count protozoa. Volatile fatty acids were determined using a gas chromatography device with a capillary column. In order to measure the activity of rumen hydrolytic enzymes including carboxy-methyl-cellulase and microcrystalline-cellulase, rumen sap was extracted in different parts according to the method of Hristov (2001). The activity of hydrolytic enzymes in each animal was calculated according to the method of Agarwal (2000). Results and Discussion: The results showed that, among the experimental treatments, there was a significant difference in dry matter intake in receiving different amounts of mixed meal, so that with the increase in the level of mixed meal in the diet, the dry matter intake also increased (P<0.05). There was a significant difference between different replacement levels in pH, ammonia nitrogen and rumen protozoa population, so that with increasing replacement levels of mixed meal with soybean meal, rumen ammonia nitrogen increased while pH and rumen protozoa population decreased (P˂0.05). so that with the increase in the level of mixed meal in the diet, the dry matter intake also increased (P<0.05). There was a significant difference between different replacement levels in pH, ammonia nitrogen and rumen protozoa population, so that with increasing replacement levels of mixed meal with soybean meal, rumen ammonia nitrogen increased while pH and rumen protozoa population decreased (P˂0.05).so that with the increase in the level of mixed meal in the diet, the dry matter intake also increased (P<0.05). There was a significant difference between different replacement levels in pH, ammonia nitrogen and rumen protozoa population, so that with increasing replacement levels of mixed meal with soybean meal, rumen ammonia nitrogen increased while pH and rumen protozoa population decreased (P˂0.05).With the increase of mixed meal replacement, the amount of acetate decreased and propionate increased (P<0.05) and no significant difference was observed in the amounts of butyrate, isobutyrate, valerate, isovalerate and total volatile fatty acids (P>0.05). The ratio of acetate to propionate increased with the increase in the amount of mixed meal, so that it reached from 1.84 in the treatment receiving 0% mix meal replacement to 2.76 in the treatment receiving 100% mixed meal replacement (P˂0.05). There was a significant difference between the activity of carboxymethyl cellulose and microcrystalline cellulose enzymes among the treatments receiving different levels of mixed meal, so that with the increase in the replacement levels of mixed meal with soybean meal, the activity of enzymes in the intracellular and extracellular parts, solid part and total activity decreased (P˂0.05). Conclusion: According to the results, mixed meal can be completely replaced by soybean meal in the diet of Atabai ewes.
کلیدواژه‌ها [English]
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