Optimizing Cost and Environmental Impact of Pig Diets

Abstract Text:

Livestock production is one of the major causes of the world's environmental problems such as climate change impact. Researchers are looking for sustainable pig diet formulations within the Climate Change Mitigation and Adaptation in Agriculture (CCMAA) program. The single-objective diets including least cost, least climate change impact, least water, and least land use were modeled using Windows-based User Friendly Feed Formulation (WUFFDA) linear models. Baseline US pig diets for 1 nursery, 2 sow, and 5 grow phases formulated by the University of Arkansas’ pig nutritionist included corn, soybean and fish meal, fat, lactose, dry whey, amino acids, minerals, vitamins, and additives. We added the U.S. pig industry top 80 most used feed ingredients to the WUFFDA models. Nutrient characteristics, inclusion limits, cradle-to-farm gate life-cycle assessment (LCA) environmental impacts, and cost data for feed ingredients were obtained from the U.S. Animal Feed Database available in Pig Production Environmental Calculator (PPEC). Preliminary results show potential to lower cost and environmental footprint in pig producer’s feeding systems (Table 1). The linear models input data are changeable including feed costs and availability, pig production practices, environmental footprints and maximum inclusion rates. Thus, so far we can only conclude that the solution to increase sustainability of pig production for different criteria in the United States is to diversify feed ingredients, in particular for the least water and least land use diets. The formulated diets are currently being validated by swine nutritionists to check models and diets and propose recommendations to improve their economic and environmental feasibility. Nutritionists have an important role because they create connection between the scientific research, validation, and pig producers. Also, we will perform the multi-objective analysis and evaluate the potential to reduce simultaneously cost and environmental impacts. The proposed diets will be available in the PPEC for pig producers which will allow pig producers to make informed decisions that can help reduce costs and environmental impacts throughout pig life-cycle.

Table 1. Pig diet weight, cost, and environmental impact results for optimized diets per kg market pig, live weight.

Cradle-to-farm-gate LCA	Average U.S. pig diet	Least cost	Least climate change impact	Least water depletion	Least land use
Diet weight (kg)	3.09	3.12	2.99	3.14	3.14
Total pig diet cost ($)	0.91	0.87	1.13	2.04	1.46
Climate change impact (kg CO2e)	3.08	2.80	1.99	3.14	2.60
Water depletion (m3)	0.24	0.24	0.14	0.07	0.11
Land use (m2a)	4.25	7.75	6.04	11.05	1.49

Keywords: pig diets, linear optimization, pig production, life cycle assessment