Studies On Optimal Management Strategies Of Household Ranch In Pastoral Area Of Qilian Mountains

Natural grasslands are not only the important parts of land ecological environment of our country, but also productive and living resources that herdsmen depend on for their survival. In recent years, however, the production efficiency of grassland animal husbandry was seriously threatened by continuous degeneration of natural grasslands, which was caused by factors such as overgrazing. The only way of achieving sustainable development of grassland animal husbandry is to balance forage and animal. In the process of forage-animal balancing, optimized distribution of resources inside family pasture, which is the most basic unit of grassland husbandry, is a significant way to transform productive modes, enhance productivity, reduce grazing capacity and finally achieve forage-animal balance.This study, being carried out at Kangle Township, Sunan County, Gansu Province, took family pasture as object and previous research achievements as basis. Through model investigation analyzing and experimental verifying, research and practice were done on optimizing distribution of production factors in family pastures; in the meantime of positively abiding relevant laws and regulations, production efficiency and benefit of family pastures were enhanced, so that sustainable development of grassland animal husbandry can be achieved fundamentally.1. Forage-animal balance status of Sunan family pastures were analyzed according to forage-animal balance evaluation model which using metabolic energy as index and the results showed: by supplementary feeding from February to the middle of June, livestock’s metabolic energy demand and pastures’ metabolic energy supply achieved a balance during this time; but from October to the middle of February, metabolic energies balance of livestock were imbalanced. Different kind of livestock with different stocking rates were fed by applying pasture system optimizing model and the results showed: the net income of herdsmen would increase with the rise of feed investment when the stocking rate was below 2.05 sheep unit/hm2; while the net income would gradually decrease with the rise of feed investment when the stocking rate was above 2.05 sheep unit/hm2. In livestock breeding rate increase to 150%, the economic benefits of family farm is increased by 44.7%.2. Hormone treatment was applied to increase reproductive rate of Gansu alpine fine-wool sheep and the results showed that the treatment, which injecting 600 IU of PMSG(pregnant mare serum gonadotropin) after 12.5 days of using progesterone plug and removing the plug on 14 th day, had the highest reproductive rate of 150%. Treatment of injecting 550 IU of PMSG and the removal of the plug on 14 th day had the highest survival rate, and the net income of each ewe was 773.7 RMB.3. The method of changing grazing rhythm was used to raise the utilization efficiency of four season pastures. In summer, the lambs in treatment group were transferred to winter pastures instead of following ewes to go to the summer pastures, which can improve ewes’ body condition and, after transition, ewes’ averaged body weight was 45.63 kg, significantly higher than that of control group ewes(P<0.05); in autumn, lambs in treatment group were transferred to winter pastures for rapidly fattening trial instead of following ewes to go to the spring-autumn pastures, the daily gain of lambs in treatment group was 104 g and dressing percentage was 42.62%, both significantly higher than that of control group, with the economic benefit being remarkable.4. Soil analysis and fertilizer application were applied to increase the grass yield of natural grassland and the results showed that the yield in experimental group was increased by 115.8kg/hm2, significantly higher than that of control group.Economic benefit can be increased by 75.49 yuan per hectare pasture.5. With long-term precise management in Sunan pasturing area, the productive level of fine-wool sheep was significantly improved. Compare with 2011, in 2014, the body weight of ewes before mating was increased by 0.47 kg, the wool yield and the marketing weight were increased by 0.31 kg and 2.42 kg, and economic income was increased by 32.8%. Continued analysis of livestock in family pastures was made under the guidance of precise management model and the results showed that the number of sheep could be reduced by 10.4% with the premise of keeping herdsmen’s economic income unchanged.