Energy Indicators for Organic Livestock Production: A Case Study from Andalusia, Southern Spain

Energy Assessment of Pastoral Dairy Goat Husbandry from an Agroecological Economics Perspective. A Case Study in Andalusia (Spain)

“…The energy cost associated with the external purchase of feed is estimated at 87.43, 55.98, and 46.69 GJ LSU −1 , representing 70.5, 59.4, and 46.7% of the CED of F1, F2 and F3, respectively. This result is consistent with those obtained by Pérez Neira et al [40], who estimated the weight of animal feed at 71.3% of the CED for organic goat rearing in Andalusia. The use of natural and cultivated pastures is also related with smaller requirements of non-renewable energy, which in F3 and F2 are comparatively lower than in the more intensive F1 (13.09 and 15.15, as compared to 26.48 GJ LSU −1 ).…”

“…The energy cost of producing the two types of feed is calculated based on data taken from Naredo and Campos [29] and Pimentel [58]. More specifically, the energy cost of producing hay is assumed to be 2.5 MJ kg −1 , while for oats, barley, sunflower, peas, broad beans, corn, soya, and wheat, the energy cost of production is estimated at 4.3, 4.2, 5.4, 4.4, 4.7, 4.1, 5.9, and 4.9 MJ kg −1 , respectively (adapted from [40,56]). In the case of flour/oil cakes, the expenses of cleaning, mixing, and packing (0.36 MJ kg −1 ), and, additionally, milling (0.46 MJ kg −1 ) need to be added to the energy cost of fodder (adapted from [59,60]).…”

“…The livestock standard unit (LSU) (one goat = 0.15 LSU) and one liter of milk are the two reference units selected to express the results. The analysis is articulated into three levels of study (adapted from [39,40]) (Figure 1). Level 1 measures the consumption of indirect energy, particularly the energy cost of producing and transporting the inputs and capital used during the livestock production process.…”

“…The agroecological redefinition of output, input, and energy efficiency is thus reflected in Equations (4) and (5), which generate a new energy indicator, the "final EROI" (Equation (6)). In addition, and keeping in mind these very specifications, the percentage of the livestock's gross energy requirements covered with purchased feed is an additional energy indicator ("external feed dependence") that allows identifying the level of intensiveness/extensiveness of the livestock management and, consequently, the level of energy dependence/autonomy of the farm [40] (Equation (7)). …”

“…Despite this, the use of properly managed natural pasture could help reduce dependence on non-renewable energy associated with feeding [40] and alleviate the pressure on croplands. A possible measure of this environmental benefit would be the agricultural area required to grow alternative animal feed to pasture, i.e., the avoided land cost of natural pasture consumed during grazing.…”