The Reduction of Crude Protein with the Supplementation of Amino Acids in the Diet Reduces the Environmental Impact of Growing Pigs Production Evaluated through Life Cycle Assessment

Abstract

Two experiments were performed to determine the digestibility of diets with crude protein (CP) reduction supplemented with amino acids (18.15; 17.15; 16.15 and 15.15%) to growing pigs (30–50 kg), to assess the use of nutrients and account for the manure excretion, and to evaluate the performance, backfat thickness, Longissimus lumborum depth, and plasma urea, aiming to evaluate the environmental impact through life cycle assessment (LCA); for the first time in Brazil interacting experiments were developed to evaluate the CP reduction and LCA. The CP reduction resulted in greater daily weight gain (p = 0.011), final weight (p = 0.020), better use of N and P, through the greater N and P retained (p = 0.003 and p = 0.017, respectively). There was a linear reduction in acidification potential (p = 0.015), eutrophication potential (p = 0.001), and land occupation (p = 0.005) when dietary CP decreased from 18.15 to 15.15%. The reduction in CP and supplementation of amino acids in diets for growing pigs (30–50 kg) improved final and daily weight gain. Through LCA, and performance and metabolism data, it was concluded that for the acidification, eutrophication and land occupation categories, impacts were reduced as the protein concentration was reduced.

Advances, Implications, and Limitations of Low-Crude-Protein Diets in Pig Production

“…Apart from improvements in growth performance and carcass characteristics, the swine feed industry has been pushed to reduce dietary CP and simultaneously the excretion of nitrogen, which can contribute to greenhouse gas emissions [ 14 , 17 , 18 ]. In this way, it is well established the benefits of reduced CP diets on lowering the environmental impact of pig production [ 14 , 17 , 70 ].…”

“…In this way, it is well established the benefits of reduced CP diets on lowering the environmental impact of pig production [ 14 , 17 , 70 ]. However, the relationship between low CP and the environment was not the focus of the present review and may be found elsewhere [ 18 , 77 ]. Meanwhile, new research should continue to focus on strategies utilizing low-CP diets while not compromising growth performance and pig profitability.…”

“…Concerning both economic and environmental perspectives, the reduction of dietary CP coupled with supplementation of crystalline amino acids is an effective strategy for the swine industry to reduce cost and pollution [ 13 , 14 ]. Although the economic efficiency of low-CP diets may vary with the price of ingredients and pig performance [ 15 , 16 ], the benefits for the environment due to lower nitrogen excretion are well established [ 17 , 18 ].…”

Nutrients Profile of 52 Browse Species Found in Semi-Arid Areas of South Africa for Livestock Production: Effect of Harvesting Site

“…Fiber fraction degradation and VFA production is promoted by microbial production for utilization by animals. Protein quality is when all essential amino acids (AAs) are available in correct proportions for a certain individual animal and vice versa [25] and a lack of a certain AA can affect animal productivity through a reduction in feed conversion efficiency due to nutritional deficiency [26].…”

Effects of supplementation of graded level of glutamic acid to crude protein reduced diets on the performance of growing pigs

“…With the development of industrial synthetic amino acid technology, supplementary feed grade amino acids have become available for use in livestock diets. A portion of dietary crude protein replacement in poultry and swine diets with grain and synthetic amino acid has been reported to reduce feed cost, and it contributes in the reduction of nitrogen excretion (Chen et al, 2011; Hernandez et al, 2011; He et al, 2016; van Harn et al, 2019; Esteves et al, 2021). However, when pigs are fed low‐protein diets, net energy level of the diet increases as grain and synthetic amino acids replace protein sources in the diet thereby affecting metabolism and feed efficiency leading to increase in fatness (Wang et al, 2018).…”