Environmental footprint of beef production: integrated intensive and extensive systems
Year: 2017
Type: dissertation
Abstract: The environmental footprint of the food supply chain has emerged as one of the most important issues in public debate. Livestock systems have an important role in the food supply chain, contributing to nearly 40 percent of the global value of agricultural output. The livestock systems characteristics at regional level depend on the regional eco-climatic conditions and their interactions with the socio-economic features of the regional anthropic society. The output derived from the different livestock systems and its consequences on anthropic and natural systems depend on how all these elements interact. Focusing on beef production systems, the extensive grazing ruminant systems rely on fibrous and human-inedible feedstuffs and on low resource intensity and quality, providing various multi-functional valuable goods and services. At the same time, unbalances among productive systems, environment and society could emerge, leading to disruptive effects such as overgrazing, soil degradation, biodiversity losses due to natural ecosystems clearance as well as threats for food security and poverty level. Conversely, the intensive beef systems rely on great amount of energetic and protein feedstuffs, most of them imported through national and international trade, and on improved production efficiency to obtain the greatest amount of food output per one unit of input. The specialization, aggregation and decoupling from local eco-climatic conditions, while affording to cover the increasing demand of animal-derived food, have led to notable alterations in the biogeochemical cycles related to greenhouse gases (GHG) emissions and to nutrients such as nitrogen and phosphorus. Different indicators and methods were developed in order to cope with the increasing awareness about the livestock systems environmental footprint, and Life Cycle Assessment (LCA) has arisen as one the most suitable methodologies to evaluate the positive and negative outputs due to a product throughout its life cycle. The procedure is composed of goal and scope definition (definition of the aims and the structure of the LCA model), life cycle inventory (collection of all the inputs and outputs of the system, inventorying the resources used, the emissions produced and the wastes generated), life cycle impact assessment (classification and characterization of the impacts) and interpretation. An increasing number of studies has been published on the environmental footprint of livestock sector using a LCA procedure in the last decade, mainly concerning GHG emissions. The application of LCA method to livestock systems needs to take into account the peculiarities of each regional livestock system. This is the case of the integrated France-Italy beef production system, a particular system that integrates the suckler cow-calf system located in the Massif Central semi-mountainous area (central France), and based on extensive pasture system, with the intensive fattening system located in north-eastern Italy, where beef calves are imported and reared using total mixed rations based on maize silage and concentrates. The aim of this PhD thesis was the assessment of the environmental footprint of the north-eastern Italy beef production system through a multi-indicator approach based on LCA, considering also the whole supply chain obtained with the integration of the French suckler cow-calf system as well as investigating some sources of variation of the environmental footprint of the beef fattening phase. This PhD thesis is composed by three chapters. The first chapter aimed at evaluating the environmental impact of the north-eastern Italy beef fattening system through a partial LCA method. The study involved 342 fattening batches (i.e., a group of animals homogenous for genetic type, sex, origin, fattening farms and finishing period) reared in 16 fattening farms during 2013. Data on animal performance were recorded for each batch. Diet composition and feed intake were collected for each beef category (combination of genotype and sex) within farms. On- and off-farm feed production data and materials used were recorded for each farm. Impact categories regarded (mean values and standard deviation per kg BW gain are provided between brackets): global warming potential (GWP, 8.4±1.6 kg CO2-eq), acidification potential (AP, 197±32 g SO2-eq), eutrophication potential (EP, 65±12 g PO4-eq), cumulative energy demand (CED, 62±16 MJ), and land occupation (LO, 8.9±1.7 m2/year). The contribution to GWP, AP and EP was greater for the on-farm than off-farm stages, whereas the opposite pattern was found for CED and LO. This contribution gave a preliminary analysis of the north-eastern Italy beef production system, developing a methodological framework that was used in the following chapters for assessing the environmental footprint of the whole beef supply chain (chapter 2) and for evaluating some factors affecting the environmental footprint of the Italian beef fattening system (chapter 3). The second chapter considered the whole beef production supply chain, with a cradle-to-farm-gate LCA approach. The aim of this chapter was to evaluate the environmental footprint of the integrated France-Italy beef system (extensive grassland-based suckler cow-calf farms in France with intensive cereal-based fattening farms in north-eastern Italy) using a multi-indicator approach, which combines environmental impact categories computed with a cradle-to-farm gate LCA, and food-related indicators based on the conversion of gross energy and protein of feedstuffs into raw boneless beef. The study involved 73 Charolais batches kept at 14 Italian farms. Data from 40 farms originating from the Charolais Network database (INRA) were used to characterize the French farm types, which were matched to the fattening batches according to the results of a cluster analysis. The impact categories assessed were as follows (mean ± SD per kg BW): GWP (13.0±0.7 kg CO2-eq, reduced to 9.9±0.7 kg CO2-eq when considering the carbon sequestration due to French permanent grassland), AP (193±13 g SO2-eq), EP (57±4 g PO4-eq), CED (36±5 MJ) and LO (18.7±0.8 m2/year). The on-farm impacts outweighed those of the off-farm stages, except in the case of CED. On average, 41 MJ and 16.7 kg of dietary feed gross energy and protein were required to provide 1 MJ or 1 kg of protein of raw boneless beef, respectively, but nearly 85% and 80%, respectively, were derived from feedstuffs not suitable for human consumption. Emission-related (GWP, AP, EP) and resource utilization categories (CED, LO) were positively correlated. Food-related indicators showed positive correlations with emission-related categories when the overall feedstuffs of the diet were considered but were negatively correlated when only the human-edible portions of the beef diets were considered. The third chapter aimed at investigating the effect of some diet-related factors and of the beef category (genotype x sex) on the environmental impact of the north-eastern Italy beef fattening system computed according to a partial LCA method. The study involved 245 batches reared in 17 fattening farms in 2014. Data on animal performance and farm input were collected for each batch and farm, respectively. Data on feed allowance, ingredients composition of the diets as well as diet sample for the chemical analysis were monthly collected for each batch. Impact categories assessed (mean ± SD per kg BW gain into brackets) were: GWP (8.8±1.6 kg CO2-eq), AP (142±22 g SO2-eq), EP (55±8 g PO4-eq), CED (53±18 MJ) and LO (7.9±1.2 m2/year). Impact values were analysed with a linear mixed model including farm (random effect) and the fixed effect of beef category, season of arrival and classes of initial BW, self-sufficiency rate diet (SELF), crude protein (CPI) and phosphorus (PI) daily intake. Beef category and classes of SELF, CPI and PI significantly affected the impact categories values. Impact mitigation was observed with enhancing SELF and reducing CPI and PI values, with no detrimental effects on farm economic profitability expressed as income over feeds cost. The results of this PhD thesis give interesting insights about the environmental footprint of the France-Italy beef production system. The assessment at the batch level allowed to investigate the factors, such as beef category and diet characteristics, that may influence the environmental footprint of the beef fattening phase, allowing the implementation of mitigation strategies. Moreover, the necessity to use indicators related to different issues not only regarding to the environmental impact, in a multi-indicator approach within LCA, should be considered in order to obtain a more consistent and accurate evaluation of the environmental footprint of livestock systems.
Author: Marco Berton
Language: English
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
Funder: Università degli Studi di Padova
Award: G6601971500
OpenAlex ID: W2779538557