| چکیده انگلیسی مقاله |
Extended Abstract
Introduction and Objective: Considering that the main source of protein for animal feed is soybean meal, which is an imported product, it seems necessary to use agricultural and industrial side sources or a mixture of them with the same value as soybean meal, which are cultivated in any climate. On the other hand, more than half of the soybean meal protein is digested in the rumen and turns into microbial protein, which is unpleasant; so, one should look for a balanced source of digestible and passable protein that helps improve the growth and performance of livestock. Mixed meal is a mixture of bloodless meat powder, cotton scraps, rice bran, wheat bran, corn flour, pistachio powder and liquid gluten, which can be used as a protein source. Mixed meal is made from plant and animal products that provide the animal with passable protein and non-degradable protein at the same time, and it seems that in addition to helping and improving the growth and performance of the animal, it also reduces the price of feed and environmental pollution. Considering that there is not much information in the country about the effect of mixed meal in the nutrition of ruminants, this study was conducted to investigate the effect of using different levels of mixed meal in the diet of lactating ewes on performance, digestibility, rumination behavior and blood parameters.
Materials and Methods: In order to perform this experiment, a number of 32 dairy ewes of the Atabai breed with an average weight of 41±2.8 kg were used in 4 treatments and 8 replications in a completely randomized design. The treatments include: the control treatment (diet without adding mixed meal), the second treatment (diet containing 33% replacement of soybean meal with mixed meal), the third treatment (diet containing 67% replacement of soybean meal with mixed meal) and the fourth treatment (diet containing 100% replacing soybean meal with mixed meal). The length of the test period was 56 days. The daily feed was completely mixed and the remaining feed for each animal was weighed and recorded every day. To calculate weight changes, ewes were weighed weekly. For the samples related to digestibility, first the samples of feed, residue and feces collected from each animal on day 51 to 55 were collected for five days, and then the samples were mixed together and a 100 gram sample of each was collected for each animal. They were removed and dried in an oven at a temperature of 94 degrees Celsius for 48 hours. The chemical composition of feed, residue and feces samples were determined for insoluble fibers in neutral detergent by the Van soest method. Also, crude protein, crude fat and crude ash by AOAC. Feed consumption behavior was measured during the 55th and 56th days of the experiment as a 24-hour activity record. On the last day of the experiment, before morning feeding, a blood sample was taken from the jugular vein of the animals. In order to measure blood metabolites including glucose, triglyceride, cholesterol, urea, total protein, albumin and globulin, Pars Azmoun chemical kits and autoanalyzer were used.
Results: Increasing levels of mixed meal did not have a significant effect on the weight at the end of the period, total weight gain, daily weight gain and feed conversion ratio of ewes, but with the complete replacement of mixed meal, the consumption of dry matter increased (P=0.0141). There was no significant difference in the amounts of organic matter, ether extract and insoluble fibers in neutral detergent, while the digestibility of dry matter and crude protein was associated with a significant increase with the complete replacement of mixed meal. With the increase in the level of mixed meal, eating, ruminating and chewing activities increased significantly and jaw rest decreased significantly, but no significant change was found in the activities of drinking water, unusual behaviors, standing and lying down. At different replacement levels, no significant difference was observed in the amounts of glucose, cholesterol, triglycerides, total protein, albumin, globulin, and the ratio of albumin to globulin. With complete replacement, the amount of blood urea in the treatment of 100% mixed meal was associated with a significant increase (P=0.0011).
Conclusion: In general, the results of this research showed that the complete replacement of soybean meal with mixed meal was possible and had no negative effect on the performance and health of Atabai ewes.
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