Ruminant production in the red soils region of southern China and in northern Australia

• CSIRO Sustainable Ecosystems, Australia
• Jiangxi Agricultural University, China
• Department of Rural and Social Development, Jiangxi, China
• Chinese Academy of Agricultural Sciences, China

The red soils region of central southern China covers an area the size of Western Australia (2.6 million km2) to the south of the Yangtze River. The region is characterised by high and soil erosive rainfall in spring, high evaporation rates in summer and cold winters. Almost half of this area has become seriously eroded as a result of excessive deforestation. There is increasing pressure to develop these soils for agricultural production, due to population pressure and economic growth. Three previous ACIAR projects have delivered technologies for establishment and persistence of pasture forages to help control erosion. The challenge for this project is converting these adapted forages into economic benefits for farmers, by developing a forage-based ruminant production system that integrates well with other activities of smallholder farmers.

The provincial government in Jiangxi, through the Ministry of Science and Technology and Planning Commission, had allocated 150 million Yuan (A$34 million) for the development of forages to increase ruminant production. In China technology development is focussing on 'cut-and-carry' systems of beef production, to avoid the negative effects that free-range cattle would have on the soils and farming infrastructure. Education and training in feeding strategies are also being made easier with stall-fed animals.

The project aimed to develop economically viable pasture-based beef production systems in the degraded red and yellow soils regions of southern China, in order to meet the rapidly expanding domestic beef market in China and to reduce erosion. The project focused on strategies for using forages, crop residues and by-products. Computer software packages to predict animal performance in China and tropical Australia were developed through the project.

Two initial surveys were conducted, the first to benchmark the productivity of cattle owned by smallholder farmers and the second to compile an inventory of feedstuffs available in both regions. Various forages were grown on sites in Jiangxi and Hunan Provinces and fed to cattle using a cut-and-carry system. Protocols for the establishment of forage species were developed, along with techniques for conserving and enhancing the quality of crop residues and forages to feed cattle during winter.
Annual feed budgets were developed in order to match numbers of productive livestock with available nutrients from forage and other feed resources. Husbandry techniques and management practices for cattle in a cut-and-carry system in China were also developed. Chinese scientific and extension staff received training in research methods, cattle husbandry and management, as these were not areas of core strength for Chinese scientific institutions in the red-soils region.
In northern Australia project scientists developed decision support systems to predict weight gain of cattle grazing pasture of known nutritive value and fed supplements containing specified amounts of molasses-based dietary formulations.

In China the team gathered and collated data about reproductive efficiency, growth rates, mortality, herd structure, age and weight at sale from around 240 households in three counties in Jiangxi and 300 in three counties in Hunan. These data became the benchmarks for later assessment of productivity gains.
The team also completed an inventory of available feed resources, identifying suitable local feedstuffs and by-products. Crop residue feed resources included straws from rice, peanut, sweet potato, and soybean, together with corn stalks. Crop by-products (energy/ protein rich meals) available in Jiangxi include rice bran and cottonseed meal while only rice bran was readily available in Hunan.
A list of recommended perennial summer growing grass species was drawn up for commercial use by smallholder farmers. Research showed that these species are advantageous due to their superior dry matter production in this environment, over-wintering capabilities and a growth habit more suitable for harvesting in a cut-and-carry system. Annual grass species were successfully integrated into rice-growing with beef production where fresh forages were used as the feed resource. The majority of the legumes tested were low yielding and considered to be of marginal suitability for beef production. A spin-off has been their suitability as ground cover for inter-rows in citrus orchards grown on slopes. In this situation they have met with success to control soil erosion and as a source of nitrogen for the fruit trees. Ammonia treatment of rice straw was successful, and in some areas this may be a preferred alternative to silage for winter feed.
Fourteen cattle growth experiments were completed during the project. Based on the results from these studies, the team developed and validated technologies for year-round feeding of beef cattle. This technology delivers annual liveweight gains of 100-200 kg. The team produced seasonal calendars on CD-ROM, integrating land requirements, fodder production and dietary alternatives for cattle production. As well a household economic model, incorporating data from the village surveys and also forage evaluation and animal feeding studies conducted in China, has been developed for a smallholder crop-forage-livestock system. These data include the use of higher nutritive value forage resources (fresh forages and treated straws) based on the forage year profiles, and improved liveweight gain and feed conversion ratios from the project experiments.
The team in Australia studied molasses supplementation, determining the relationship between amount of supplement and frequency of molasses ingestion on intake of forage and the substitution effect. More is now known about rumen function and rumen dynamics with differing amounts of supplement and the consequences for forage intake, also the effect of high molasses intake on drinking water intake and fluid kinetics. Other areas of better understanding include digestion of dietary components, the effect of molasses inclusion rate on forage (fibre) digestion, level of supplementation, interaction with forage quality and liveweight gain. In the study of grazing cattle, researchers determined how level of supplementation affected grazing behaviour, spatial distribution of cattle within paddocks, and liveweight gain.
Two decision support software models - CamBeef and GrazFeed - were evaluated. But these models do not predict feed intake of forage and molasses diets with the required degree of precision. Negotiations are in progress to enable modification of the CamBeef software to accommodate diets with substantial inclusion rates of molasses.