Effects Of Different Energy And Protein Levels On Growing Performance, Nutrients Digestibility And Economical Benefits Of Tans Sheep

The test was conducted to evaluate the effects of different energy and protein levels on production performance, apparent digestiblity and blood biochemical indexes of Tan sheep by feeding experiment. The objective of this experiment was to provide the theory basis for high efficient fattening techniques.A total of 112 Tan sheep(56males and 56 females) at 4 months of age were randomly divided into 4 treatments, 4 replicates(2 each for males and females) of 7 sheep per treatment. The experiment was divided into 3 periods according to weight gain target: 22~28 kg, 28~35 kg and 35~45 kg. In the first period, according to fattening energy requirement of the lamb have 22 kg body weight and 200 g daily gain, Group 1 DE: 7.92 MJ/kg, CP:9.90%; Group 2 DE: 9.05 MJ/kg, CP: 11.32%; Group 3 DE: 10.19 MJ/kg, CP: 12.73%; Group 4 DE: 11.32 MJ/kg, CP: 14.15%. In the second period, according to fattening energy requirement of the lamb have 29 kg body weight and 200 g daily gain, Group 1 DE: 7.45 MJ/kg, CP: 8.28%; Group 2 DE: 8.52 MJ/kg, CP: 9.46%; Group 3 DE: 9.58 MJ/kg, CP: 10.65%; Group 4 DE: 10.65 MJ/kg, CP: 11.83%. In the third period, according to fattening energy requirement of the lamb have 36 kg body weight and 200 g daily gain, Group 1 DE: 7.08 MJ/kg, CP: 8.04%; Group 2 DE: 8.09 MJ/kg, CP: 9.19%; Group 3 DE: 9.10 MJ/kg, CP: 10.34%; Group 4 DE: 10.11 MJ/kg, CP: 11.49%. At the every time we set up 84%, 96%, 108%and 120%standard nutrition diet. The digestion trial was carried out by means of collection full excrements analysis method for 9 days(a 6-day adaptation period). Blood sample collection from external jugular vein was made when every period was finished.(1) Group 4 was 12.8% higher than group 3(P>0.05), 27.96% higher than group 2(P<0.01), 31.77% higher than group 1(P<0.01) in the first period of the test. Group 4 was 15.66% higher than group 3(P>0.05), 21.36% higher than group 2(P>0.05), 34.73% higher than group 1(P<0.05) in the second period of the test. Group 4 was 22.10% higher than group 3(P>0.05), 33.60% higher than group 2(P<0.05), 41.46% higher than group 1(P<0.05) in the third period of the test. With the increase of dietary nutrient levels the daily gain of Tan gradually increase and descend, the feed conversion decreased.(2) With the improvement of nutrients levels, each of the pilot phase of sheep body high, tube circumference, chest circumference, body length, tail width, tail length and average daily value of the base of the tail growth was increasing, and body height, chest circumference, body length and tail changed significantly. Group 4 had the highest nutrition levels and had the fastest growing.(3) In the first period of the test, as for crude protein apparent digestibility, group 4 was 5.71% higher than group 3(P>0.05), 12.01% higher than group 2(P>0.05), 21.75% higher than group 1(P<0.05) and as for gross energy apparent digestibility, group 4 was 8.76% higher than group 3(P>0.05), 20.96% higher than group 2(P<0.01), 25.62% higher than group 1(P<0.01). In the second period of the test, as for crude protein apparent digestibility, group 4 was 8.35% higher than group 3(P>0.05), 9.49% higher than group 2(P>0.05), 18.47% higher than group 1(P<0.05) and as for gross energy apparent digestibility, group 4 was 12.41% higher than group 3(P>0.05), 8.29% higher than group 2(P>0.05), 18.02% higher than group 1(P<0.01). In the third period of the test, as for crude protein apparent digestibility, group 4 was 3.47% higher than group 3(P>0.05), 8.04% higher than group 2(P>0.05), 15.27% higher than group 1(P>0.05) and as for gross energy apparent digestibility, group 4 was 14.14% higher than group 3(P<0.01), 18.25% higher than group 2(P<0.01), 24.90% higher than group 1(P<0.01). In every period, the apparent digestibility of DM、CP、GE、NDF and ADF were gradually increased with the increase of dietary nutrition levels.(4) At each test period, there are differences among the groups on dextrose, total protein and total cholesterol, but there are no any significant difference in other indicators. With dietary nutrient levels increasing, serum urea nitrogen and glucose index increases. Serum hormoneconcentrations with increasing nutrient levels rise.(5) About gross profits, group 4 was 0.66 yuan higher than group 3(P>0.05), 1.48 yuan higher than group 2(P<0.05) and 1.52 yuan higher than group 1(P<0.05). In the second period of the test, group 4 had a significant increase in weight gain profit compared to other groups(P<0.05). As for gross profits, group 4 was 0.7 yuan higher than group 3(P>0.05), 0.59 yuan higher than group 2(P>0.05) and 1.55 yuan higher than group 1(P>0.05). In the third period of the test, group 3 and group 4 had a significant increase in weight gain profit compared to group 1 and group 2(P<0.05). As for gross profits, group 4 was 0.85 yuan higher than group 3(P>0.05), 1.33 yuan higher than group 2(P>0.05) and 0.92 yuan higher than group 1(P>0.05). In every period, weight gain profits and gross profits were gradually increased with the increase of dietary nutrition levels.(6) Under the experimental conditions, group 4 had the highest level of nutrition and got the best fattening, highest efficiency, namely 120% standard nutrition level diet. The first stage: DE 11.32 MJ/kg, CP 14.15%. The second stage: DE 10.65MJ/kg, CP 11.83%. The third stage: DE 10.11 MJ/kg, CP 11.49%.