| By measuring feed intake, weight gain, rumen fermentation indicators, blood, wool and urine indicators to analyze the correlation between Tan pica sheep and indicators described above to study the mechanism of pica caused by protein deficiency. On this basis, nutritional and balanced dietary were fed to the pica sheep to study the actual effects of nutritional regulation under the test conditions. The experiment was divided into two parts:Part one:Studies on the mechanism of pica caused by protein deficiency12 Healthy Tan sheep wethers with permanent ruminal cannulas were selected and were used in a single-factor completely random design. Test sheep were fed with a dietary that the content of protein was lower than nutritional needs to build their pica model. Pica Tan sheep as the test group, the vitamins, minerals of dietary were referred to NRC standards and Inner Mongolia fine-wool sheep feeding standards (4～18 months), the crude protein levels were up to 2/3 nutritional needs as Group I and 1/2 as Group Ⅱ. Non-pica Tan sheep as the control group, the dietary was prepared by reference standards.The results showed that:compared with control group, the dry matter intake and weight gain of test group showed a down trend and the ratio of feed and weight of test group were significantly decreased (P<0.01). The crude protein apparent digestibility and nitrogen utilization of 1/2 protein group were extremely significant lower than control group(P<0.01). The rumen NH3-N concentrations, rumen total volatile fatty acids and rumen acetic acid were significantly reduced (P<0.01).The rumen propionic acid and butyric acid of test group Ⅱ were significantly reduced (P<0.01). The serum total protein was significantly decreased(P<0.01). Meanwhile serum urea nitrogen was decreased (P<0.05). Glu and serum β-hydroxybutyrate were little changed. The wool growth rate was slower than control group. The amount of wool sulfur deposition was significantly reduced (P<0.05). The urinary nitrogen of test group was significantly lower than the control group (P<0.01), urinary zinc content decreased, while the content of the urine copper and urine pH were no significant changed. When Tan sheep dietary was lack of protein they would suffer from pica. The rumen NH3-N, rumen VFA(include rumen acetic acid, propionic acid and butyric acid), serum TP, serum BUN, wool length growth, wool density, wool’s sulfur content and the urinary nitrogen could be analyzed to determine whether the dietary of pica Tan sheep was lack of protein.Part two:Studies on the nutritional regulation technology of pica in stabling Tan sheep16 pica Tan sheep were selected and divided into two groups and find out the main factors that caused Tan sheep pica occurred through nutrition examination techniques. The experimental group was fed on a nutritional and balanced dietary that was referred to NRC standards and Inner Mongolia fine-wool sheep feeding standards (4～18 months). The other group was fed on the original nutritional incomplete dietary as the control group to study the actual effects of nutrition regulation under the test conditions.The results showed that:The end of the weight and average daily weight gain in the experimental group were significantly higher than the control group(P<0.01), and the weight gain reached twice over the control group. The DMI was significantly higher than control group(P<0.01), meanwhile the ratio of feed and weight of experimental group were significantly lower than the control group(P<0.01).The serum TP and BUN content of the experimental group were extremely significant improved(P<0.01),while the Glu was significantly increased(P<0.05). The ratio of wool growing of experimental group has been improved, the density of wool was significantly higher than control group(P<0.05). The wool’s sulfur content of experimental group was significantly higher than control group(P<0.01) and was increased to more than 2%. The content of wool copper, zinc had an increased trend and zinc content was significantly higher than control group on the later time (P<0.05). Although the urinary nitrogen content of the experimental group was significantly higher than control group(P<0.01)), The nitrogen utilization was better than control group. The results showed the pica Tan sheep’ body condition could be improved by nutritional regulation. |
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