中文摘要：

【目的】三河牛是1983年验收的中国自主培育的乳肉兼用牛品种，因起源于内蒙古呼伦贝尔市三河地区而得名，具有耐粗饲、宜牧、抗寒、适应性强的特点。研究旨在估计三河牛目标性状的边际效益，为制定三河牛育种规划提供基础。【方法】依据内蒙古谢尔塔拉种牛场三河牛中心产区2011年的生产和育种数据，参照奶牛和肉牛营养需要获得三河牛的生产性能、市场经济、营养学方面的参数，根据三河牛生产和育种体系，确定三河牛育种目标性状，以效益方程法建立三河牛的生物经济利润模型，计算三河牛乳用性状、肉用性状、功能性状的边际效益，并对影响经济效益的各个因素进行了敏感性分析。【结果】（1）确定了三河牛10个育种目标性状，包括3个乳用性状（产奶量，乳蛋白率和乳脂率），3个肉用性状（初生重，育肥期日增重和屠宰率）和4个功能性状（首次产犊日龄，产犊间隔，体细胞数和母牛使用年限）：（2）牛群规模固定时，三河牛的总效益为4 808.26元。对收益进行分类，产奶和淘汰母牛的收益分别占总收益的67.08%和7.8%，育肥牛的收益占总收益的20.58%。成本方面，可变成本占总成本的96.89%，其中饲养费用是影响可变成本的主要因素，青年母牛、泌乳母牛和育肥公牛的饲养成本分别占总成本的45.69%、20.46%和13.15%；（3）以乳成分和质量（乳脂率、乳蛋白率、体细胞数）定价时，三河牛10个目标性状的边际效益为：产奶量（kg）2.26元、乳脂率（%）40.48元、乳蛋白率（%）61.39元、体细胞数-231.52元、初生重（kg）6.19元、育肥期日增重（g？d-1）1.39元、屠宰率（%）76.70元、使用寿命（天）0.25元、首次产犊日龄（天）-1.62元、产犊间隔（天）-2.71元；（4）乳用性状、肉用性状、功能性状的相对经济权重比例为62﹕14﹕22，近似于3﹕1

英文摘要：

The Sanhe cattle is a domestic dual purpose breed formed and approved in China in 1983, which was named after its origin of Sanhe region in Hulunbuir pasture land. Sanhe cattle is famous for its durability, suitability for grazing, cold resistance and strong adaptability. This study was conducted to estimate the marginal profits of traits in breeding goal and provide a base for designing breeding plan in Sanhe cattle. 【Method】 The performance, economic and nutrition parameters of Sanhe cattle were obtained according to theoretical nutrition demand of dairy and beef cattle, as well as the production and breeding data in 2011 from Xiertala Cattle Breeding Farm in Inner Mongolia, China, which are the central production region of this breed. Also, the breeding objective traits were proposed based on the production and breeding system of Sanhe cattle. A bio-economic profit model was fitted using Profit Equation method, and the marginal profits were calculated for the milk performance, beef performance and functional traits, then the sensitivity analysis was run. 【Result】The results indicated that ten breeding objective traits for Sanhe cattle included three milk performance traits （milk yield, fat percentage, and protein percentage）, three beef performance traits （birth weight, fattening daily gain, and dressing percentage）, and four functional traits （somatic cell count, age at first calving, calving interval, and productive life）. The total profit of Sanhe cattle was RMB 4 808.26 with a fixed scale of the population. The profit generated by milk production, culling cows and fattening bulls account for 67.08%,7.8% and 20.58% of the total profit, respectively. For the cost, the variable cost accounts for 96.89% of the total cost. Feeding cost is the main factor affecting the variable cost. The feeding cost of the heifers, milking cows and fattening bulls account for 45.69%, 20.46%, and 13.15% of the total cost, respectively. When raw milk price considering milk compositions and quality （fat perce