Study On The Optimum Design Of Dairy Cattle's Diet And Evaluation Its Application Effect By CNCPS And GI

In this study, two sets of nutrient balance, cost ideal low-cost diet formulation was carried out through the theory and techniques GI put forward by Lu (2001) to screening and combination for rough forage and in conjunction with the theory and computer technology CPCPS put forward by Cornell University to optimize and design on the diet. And application in the production to test and evaluate their effects.The results are as follows:1. Analysis of feed nutrientsIn addition to use the nutritional content of indicators in "quality of feed and feed detection technology " edited by Yang (1993) , but also determination a number of more detailed indicators, such as SP, NPN, ADIP, NDIP and Starch. These measured data are compared with corresponding data in the database of CNCPS to identify differences between them. According to the further formula of CHO and CP set out in CNCPS to get the corresponding data, and to reflect on the nutritional value of more scientific and accurate.2. Detection of Dietary by CNCPSCNCPS has detection function. Find the nutritional deficiencies through CNCPS software to provide a reliable reference for the next step optimizing the design of diets. Test results show that: dietary energy, protein, the content of Ca and P is obviously insufficient, and the K content was significantly exceeded.3. To determination GI values of four rough foragesFour rough forages of GI values were get out according to Lu (2001) proposed method of calculating GI roughage combined with four of the nutrients measured. The four rough forages of GI values were alfalfa, 112.15MJ; silage maize, 105.38MJ; corn stalks, 68.90MJ; straw, 9.55MJ respectively. And the nutritional quality is alfalfa> Silage corn> corn stalks> straw.4. Optimization and screening of mixed forage formulationsAccording to GI maximize or the principle of lowest cost, and combine considering 24-hour IVDOM, MCP, VFA, and many other indicators, a group of rough forages ideal formula was selected, that is, corn silage: straw: alfalfa = 70:10:20, GI value of this formula was 97.15MJ, price of 0.48 yuan / kg.. 5. Optimization dietary with CNCPSThe selection of the coarse feed formulas can not use in practice as a result of cattle Conditions is limited, so use of cattle rough feed formulas. Therefore, the use of software CNCPS to optimization diet and combination is a formula cattle fodder. Two diets are the corn soybean meal-based diet and the corn miscellaneous meal-based diet respectively based on CNCPS optimization. Their cost are 0.86 yuan / kg and 0.82 yuan / kg. And the cost of diet of cattle farm is 0.93 yuan / kg.6. Test diet with animal experimentSelect the early lactation cows to do the test animals and with the similar parity, weight and age, six in each group. The results showed that average milk production of soybean meal-based diet, meal-based miscellaneous diet and diet of cattle farm were 29.13kg, 27.81kg and 27.06kg respectively. The three groups of the milk diet of conventional indicators were stability and not significant.7. Cost-effectiveness analysisThree groups for dietary intake of 12kg / d of feed and 22.5kg / d of crude feed. The ratio of feed : milk of soybean meal-based diet miscellaneous meal-based diet and diet of cattle farm are 1:2.48,1:2.37 and 1:2.30, respectively. Combined with the cost of diet and milk income, gross profit of three groups of diet are 57.71 yuan, 55.30 yuan and 49.22 yuan ,respectively.