Swine diets: Impact of carbohydrate sources on manure characteristics and gas emissions

Challenges and opportunities for improving nitrogen utilization efficiency for more sustainable pork production

“…Results from these studies have shown low NUE (30 to 43%) based on the amount of N retained as a percentage of total dietary N consumed. These N-flow values are supported by data conducted using an animal metabolism crate manure storage system designed to simulate manure storage conditions in typical swine facilities (Trabue and Kerr, 2014;Kerr et al, 2018;Trabue et al, 2019a;Trabue et al, 2019b;Kerr et al, 2020;Trabue et al, 2021a;Trabue et al, 2021b;Trabue et al, 2022). In these studies, calculated mass balance of N did not, however, account for all of the consumed N, with these researchers speculating that the difference may be due to ammonia losses from metabolism crates and flooring surfaces during the fecal and urine collection process which has been shown to represent 19 to 25% of the N consumed (Burton and Beauchamp, 1986;van Kempen et al, 2003;Li et al, 2011;Costa, 2017).…”

“…This reduction in N concentration in manure also has an impact on aerial ammonia emissions (Latimier et al, 1993;Pfeiffer, 1993) which indicates a direct linkage between nutrient inputs into the animal and subsequent environmental impact. Additional studies conducted since the Kerr (2003) review consistently show that N excretion is reduced by 6 to 10% for each one percentage reduction in dietary CP (Canh et al, 1998c;Noblet et al, 2001;Shriver et al, 2003;Portejoie et al, 2004;Leek et al, 2005;Kerr et al, 2006;Leek et al, 2007;Lynch et al, 2007;Powers et al, 2007;Le et al, 2009;Jarret et al, 2011b;Osada et al, 2011;Li et al, 2015;Monteiro et al, 2017;Trabue et al, 2021a;Ball et al, 2022;Vonderohe et al, 2022), with concomitant reductions in ammonia emissions (Canh et al, 1998c;Hayes et al, 2004;Portejoie et al, 2004;Leek et al, 2005;Philippe et al, 2006;Leek et al, 2007;Lynch et al, 2007;Le et al, 2009;Li et al, 2015;Liu et al, 2017). As a result, replacing dietary CP concentrations with crystalline AA to meet estimated requirements can reduce N excretion up to 50% depending upon the magnitude of decreased dietary CP and the availability of crystalline AA.…”

Impact of diet on hydrogen sulfide production: implications for gut health

“…Although it is impossible to know if either of the diets impacted H 2 S production specifically, given the general relationships between protein and fiber intake on H 2 S production in both humans and animals [17], both diets underscore the importance of fiber to support gut health, regardless of protein intake. Considering dietary fiber content has enormous clinical nutrition implications, particularly for inflammatory conditions in the gut, such as ulcerative colitis, where protein intake is traditionally prioritized to meet the metabolic demands of inflammation.…”

“…Considering dietary fiber content has enormous clinical nutrition implications, particularly for inflammatory conditions in the gut, such as ulcerative colitis, where protein intake is traditionally prioritized to meet the metabolic demands of inflammation. The capacity of fiber to reduce H 2 S production capacity [15 ▪ ,17], and findings of disease improvement with increased fiber intake, both in the context of reduced [10 ▪▪ ] and increased protein intake [24], would suggest that dietary protein can negatively impact gut health [16,25], especially in the context of a low-fiber intake.…”

“…In contrast, increased dietary fiber intake is associated with decreased H 2 S production in animals and humans [15 ▪ ,17]. In a protein-controlled feeding trial (16.3% crude protein) conducted in swine, compared with a low-fiber diet, a high-fiber diet led to lower protein-associated gas emissions in feces, including a 30% lower ammonia and 17% lower H 2 S [17]. In humans, the total fiber in grams, the insoluble fiber in grams, and carbohydrate content reduced H 2 S production [15 ▪ ].…”