Browsing by Person "Mendoza Huaitalla, Roxana"

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    Intensive pig production and manure management in Beijing, North China Plain
    (2014) Mendoza Huaitalla, Roxana; Gallmann, Eva
    China, at the forefront of the livestock revolution, has experienced a more industrialized change, with an increment of the large livestock farms and of the decoupling between the livestock and arable land. Meat production in China is dominated by pork, which comprises approximately 50% of worldwide pig production. The description of the pig husbandry and manure management systems in the large animal operations of the NCP is not widely available. In order to describe the status quo of the pig production and manurial management systems in the NCP, a large-size pig farm with a dimension of 10 ha and an annual stock of 12,000 breeding swine and 20,000 market pigs or porkers was selected. An intensive sampling plan as far as feasible of pig manure, wastewater, drinking water, and feed, the main pig farm inputs and outputs, was started in 2009. The manurial system identified in the farm was denominated as “gan qing fen” or “cleaning the manure dryly”. In this system, the pig manure (faeces with some remains of urine) was collected manually by scraping the mainly non-slatted floors of the pigsties twice a day, and the floors were then flushed with water. The results showed that the pig manure was characterized by high nutrient and heavy metal contents that might be due to the solid fraction separation from the liquid fraction under the gan qing fen manurial management system. The piggery wastewater was characterized by very low concentrations of nutrients and heavy metals as a result of their dilution with flushing water, mainly used for cleaning the pigsties. Manure and wastewater samples from weaning pigs contained the highest concentrations of nutrients and heavy metals; that could be due to the high supplementation rates of these minerals in the weaner diets. In general, it seems that the manual daily collection of pig manure in the gan qing fen system is an efficient practice in order to maintain nutrient contents in pig manure, but the use of flushing water should be reduced as it can lead to further environmental pollution. China has issued a range of environmental standards in recent years. The Chinese national standards are adoptions of international standards and are consistent across all of China. Chinese and German recommendations were compiled in order to compare them with the results obtained in this study. Based on the comparisons, it is stated that pig drinking water sourced from groundwater wells was of optimum quality as it is used for both pigs and humans. Trace minerals in pig feeds, such as lead (Pb), chromium (Cr) and cadmium (Cd), were found to be within the range of values given by the Chinese and German feeding recommendations. However, high mineral concentrations of zinc (Zn), manganese (Mn), copper (Cu), and arsenic (As), mainly found in the weaning feed samples, surpassed the given thresholds by almost ten times. Pig manure was compared with the German and Chinese standard for biowaste due to the nonexistence of a specific standard for animal manure in both countries. It was observed that maximum Cd, Cu and Zn concentration values surpassed the thresholds established in those recommendations. Similarly, trace mineral concentrations in the piggery wastewater were compared with the Chinese standard for irrigation water, however, it was not compared with any German standard due to the different nature of the effluent generated from the Chinese gan qing fen manurial management system, and it was found that Pb, Cd, Cr, Cu, and Zn did not comply with the irrigation water quotes. Furthermore, there is a need to re-evaluate the current Chinese standards and to strengthen the recommendations focused on the disposal, reuse and recycling of manure and wastewater of livestock origin in general. In order to evaluate the air pollutants produced in the pig farm, i.e. gas concentrations of carbon dioxide (CO2) and ammonia (NH3), and particulate matter, were measured making use of four different measurement devices. High dust concentrations were identified in the pig barns, especially during the feeding and manure cleaning events inside the farrowing and weaning barns with slatted floors. The highest NH3 concentration was recorded in the weaning barn during the summer season, while the highest CO2 concentration was reported in the gestation barn during the winter season. To conclude, using the example of an intensive pig farm near Beijing, it was identified that the main issues were the decoupling between the cropland and the pig farm, the existence of nutrient surpluses in the pig manure originating from the uncontrolled nutrient supply into the pig feeds, the manure mismanagement (open manure storage), a lack of infrastructure (broken curtains, windows, inoperative fans), aerial pollutants (high indoor concentrations of CO2, NH3 and PM1-10), extensive hand labour, and obsolete know-how with respect to resource conservation, among the most significant.