| Integrated crop-livestock production systems are important agricultural systems within China and contribute greatly to the food supply. This research was conducted in Quzi township of Gansu province's Huanxian county, in the Longdong Loess Plateau region, in north-west China. This is a traditional crop-livestock mixed farming region. The main objectives of this research were to characterize the current farming systems and livestock feed resources (type and availability); analyze the nutritive value of those feedstuffs and identify key limiting factors to livestock production in the region (as determined by animal live weight changes and body condition score). Seven forage crops, maize (Zea mays L.); sudan grass(Sorghum sudanense Stapf); proso (Echinochloa crusgalli var. frumentacea); millet (Setaria italica); oats (Avena sativa L.), mix crop (maize, millet and sorghum mixed together and planted) and lucerne (Medicago sativa L.), were cultivated in the region and forage dry matter production, nutritive value were determined, soil water balance and crop water use and water use efficient were calculated. Balance of livestock feed demand and supply were analyzed. Two computer models were used to identify the animal nutrient demand and annual livestock feed year planning making. A total of 13 farms were surveyed and 65 sheep/goats closely monitored from September 2008 to March 2010. The results showed as follows:The average farm area was 19.2 mu, of which the majority was sown with lucerne (approximately 8.9mu), followed by wheat, maize and other cash crops (2.8mu,2.6mu and 4.9mu, respectively).The majority of farms were found to possess mixed livestock, the most common being cashmere goats (approximately 13 goats per farm), followed by cattle, sheep and chickens (approximately 1 sheep,1 head of cattle, and 5 chickens per farm, respectively)The main bulk feeds utilized in livestock rations were lucerne, maize stovers, sorghum stovers, wild grasses, and tree leaves, accounting for approximately 90% of the feed types in the region, whereas lucerne ration came to 41%. Main concentrate meals are maize, soy oilseed meals as well as by-products (of tofu production). In general, feedstuffs were found to be of reasonable quality with bulk feeds having an averaged CP, NDF and ADF content of 11%,52% and 32%, respectively, average ME value of 8.9 MJ/kg DM and dry matter digestibility of 55%, and average feed relative value (RFV) was 122. Feed availability, especially in late winter/early spring, was found to be the predominant factor limiting livestock production, with lower nutrient feed supply. The estimated feedstuff deficiency was 2000 kg/year for each family in the region.Cashmere goats were the major livestock in the region. The goat productivity was different between classes. The liveweight of male goats were increased monthly and their performance in terms of body conditions score were between 2.5-. The female goats body condition score of between 2-2.5 is indicative of the deficiency of the dry matter intake.Maize had the highest dry matter yield over 2 years, averaging 9.5t/hm2·year where as the average was 5.8 t/hm2·year for the sudan grass, with the crop yield decreasing with oats (5.4t/hm2·year), proso(4.0 t/hm2·year), millet (3.7 t/hm2·yea) and lucerne (3.7t/hm2·year). Mixed crops had the lowest production (2.6t/hm2·year). The forage quality was also evaluated. Maize was superior 1(RFV=169.1) amongst the cultivated crops, followed by lucerne with RFV 158.8, oats(135), mixed crop(128.9), proso(97.8), sudan grass(95), millet had the lowest RFV value with 86.6.Under five different crop rotation sequences, MVO (Maize-Vetch-Oats sequence) systems had the highest dry matter production with 7.4 t/hm2·year, followed by SVO (Sudan grass-Vetch-Oats sequence),5.6 t/hm2·year; PVO (Proso-Vetch-Oats sequence),4.8 t/hm2·year; lucerne,3.4 t/hm2·year; MVM (Millet-Vetch-Mixed crop sequence),2.9 t/hm2·year. For the nutrient production of rotation sequence, lucerne was highest, followed by PVO, MVO, SVO and MVM rotation sequence.For WUE, maize had the highest (36 kg/hm2·mm), followed by oats (32 kg/hm2·mm), the average WUE value over 2 years is maize＞oats＞sudan grass＞proso＞millet＞mixed crop＞lucerne.The depth of soil water storage was influenced by the precipitation conditions. In the surface 60cm, soil water moisture content was more active than the water storied in deeper soil. The dynamics of soil water below 60cm is relative stable.It can be concluded that water consumed by crops in the growing season was mainly sourced from the rainfall and soil water can be recovered in the winter fallow season for the annual crops. But this change was not found in the lucerne field, for the soil water had been used to over 250cm in the second year.A model was used to determine the livestock feed demand and to optimize the livestock feed requirement and supply in the region. The result showed that home-product straw can supply 64% livestock feed demand in the current livestock system. Annual forage planning management was made under different strategies.Overall, the livestock feed supply was better in the nutritive value, but unbalanced in the year. Cashmere goats were found to be suited to the production systems in Quzi region. The supply of ME and CP to pregnant and lactating ewes/nannies was frequently below requirements as farmers in the region tended to feed all livestock the same amount on a purely per head basis, seldom taking into consideration the additional nutrition and DM requirements of the larger goats and the additional nutrient requirements necessary for successful pregnancy and lactation. Following research should aimed at developing more efficient feeding and animal management strategies that can be trialled and implemented on farm to optimise livestock production whilst protecting farmer food security.
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