How can nutritional strategies and feed technologies in pig production affect the logistical costs of manure distribution?

ABSTRACT The objective with this study was to evaluate the impact of different swine nutritional strategies and technologies, as well as the land spread system, on logistical costs of pig manure distribution. For this, pigs were fed a conventional diet (C0) or a diet supplemented with 0.01% phytase (C1); organic minerals (40% substitution; C2); synthetic amino acids at reduced dietary crude protein levels (C3); or a combination of the three strategies (C4). All pig manure was weighed, then its chemical composition was determined. The mineral values and volume of manure produced were extrapolated to corresponding pig farm sizes in Sao Paulo state (300, 650, and 1000 sows) from real pig manure levels to produce simulations. To determine the logistical cost of manure distribution, two distribution systems were considered: vacuum tank tractor and vacuum tank truck (4.30 and 15 m3, respectively). The land spread truck system had the highest cost/hour worked due to the higher fuel consumption. However, this cost might be different over greater distances. Manure production, as well as the nutrient levels of N, P, and K, were lower for swine fed diets supplemented with nutritional technologies. Therefore, the different nutritional technologies reduced the transportation and distribution cost of pig manure by reducing the area and, consequently, the distances that need to be traveled for distribution. However, from an agronomic point of view (i.e., to meet a crop fertilization demand per hectare), manure from pigs fed diets supplemented with nutritional technologies had a higher application rate on land.

摘要
本研究旨在评估不同生猪营养策略与技术，以及粪肥土地还田系统对猪粪肥分发物流成本的影响。为此，试验生猪分别喂食常规日粮（C0），或添加0.01%植酸酶（phytase）的日粮（C1）、采用有机矿物质（organic minerals）替代40%用量的日粮（C2）、低饲粮粗蛋白（crude protein）水平下添加合成氨基酸的日粮（C3），以及三种策略联合应用的日粮（C4）。收集所有试验生猪的粪肥并称重，随后测定其化学成分。基于实际粪肥产生水平，将试验测得的粪肥矿物元素含量与产肥量外推至巴西圣保罗州不同规模的生猪养殖场（母猪存栏量分别为300、650和1000头），开展模拟分析。为测算粪肥分发的物流成本，本研究选取两种作业系统进行评估：真空罐式拖拉机（vacuum tank tractor）与真空罐式卡车（vacuum tank truck），二者额定容积分别为4.30与15立方米。由于燃油消耗更高，真空罐式还田卡车系统的单位作业小时成本最高，但该成本随运输距离的增加可能发生变化。喂食添加营养技术日粮的生猪，其粪肥总产量以及氮、磷、钾养分含量均更低。因此，不同营养技术通过缩小粪肥还田面积、进而缩短运输配送距离，降低了猪粪肥的转运与分发成本。但从农艺角度而言（即满足每公顷作物的施肥需求），喂食添加营养技术日粮的生猪所产粪肥的土地施用量更高。