The effect of high and low dietary crude protein and inulin supplementation on nutrient digestibility, nitrogen excretion, intestinal microflora and manure ammonia emissions from finisher pigs

Abstract

A 2 3 2 factorial experiment was performed to investigate the interaction between a high-and low-crude-protein (CP) diet (200 v. 140 g/kg) and inulin supplementation (0 v. 12.5 g/kg) on nutrient digestibility, nitrogen (N) excretion, intestinal microflora, volatile fatty acid (VFA) concentration and manure ammonia emissions from 24 boars (n 5 6, 74.0 kg live weight). The diets were formulated to contain similar concentrations of digestible energy and lysine. Pigs offered the high-CP diets had a higher excretion of urinary N (P , 0.001), faecal N (P , 0.01) and total N (P , 0.001) than the pigs offered the low-CP diets. Inulin supplementation increased faecal N excretion (P , 0.05) and decreased the urine N : faeces N ratio (P , 0.05) compared with the inulin-free diets. There was no effect (P . 0.05) of dietary treatment on N retention. There was an interaction (P , 0.05) between dietary CP concentration and inulin supplementation on caecal Enterobacteria spp. Pigs offered the diet containing 200 g/kg of CP plus inulin decreased the population of Enterobacteria spp. compared to those with the inulinsupplemented 140 g/kg CP diet. However, CP level had no significant effect on the population of Enterobacteria spp. in the unsupplemented diets. Inulin supplementation increased caecal Bifidobacteria (P , 0.01) compared with the inulin-free diets. There was no effect of inulin supplementation on VFA concentration or intestinal pH (P . 0.05). Pigs offered the 200 g/kg CP diets had higher (P , 0.05) manure ammonia emissions from 0 to 240 h of storage than pigs offered the 140 g/kg CP. In conclusion, inulin supplementation resulted in an increase in Bifidobacteria concentration and a reduction in Enterobacteria spp. at the high CP level indicating that inulin has the ability to beneficially manipulate gut microflora in a proteolytic environment.

Dried chicory root (Cichorium intybus L.) as a natural fructan source in rabbit diet: effects on growth performance, digestion and caecal and carcass traits

“…There was a significantly lower CTTAD of CP in rabbits fed the chicory diets, a finding that is consistent with similar findings in rats (Levrat et al, 1993;Vanhoof and De Schrijver, 1996) and pigs (Lynch et al, 2007;Hedemann and Knudsen, 2010) when inulin-rich diets were fed. Additionally, the CTTADs of EE and starch were significantly lower in rabbits fed the chicory diets, probably because of the higher ADF/starch ratio of these diets (Gidenne et al, 2000).…”

Effect of crude protein concentration and sugar-beet pulp on nutrient digestibility, nitrogen excretion, intestinal fermentation and manure ammonia and odour emissions from finisher pigs

“…This equals a 5% reduction in ammonia emission per day per 10 g/kg reduction in CP. Lynch et al (2007) reported a 6.6% reduction in ammonia emissions per 10 g/kg reduction in dietary CP in vitro while Hayes et al (2004) achieved an 8.1% reduction per 10 g/kg CP in vivo. The 42% reduction in N excretion as dietary CP was reduced to 150 g/kg means that there may be less ammonical N available for volatilisation in the low-CP diet.…”

“…The reductions found in the current study in total N excretion may be in agreement with those reported in previous studies (Canh et al, 1998b;Carpenter et al, 2004). Lynch et al (2007) reported a 6% reduction in total daily N excretion for each one-percentage unit reduction in dietary CP to 148 g/kg.…”

“…However, isovaleric acid and isobutyric acid are produced exclusively from the deamination and decarboxylation of leucine and valine, respectively (Mackie et al, 1998), and contribute to malodour (Mackie et al, 1998). It is generally accepted that -E-mail: john.vodoherty@ucd.ie the reduction of dietary crude protein (CP) can significantly reduce excess N excretion and ammonia emissions (Hayes et al, 2004;Leek et al, 2005;O'Connell et al, 2006;Lynch et al, 2007). Recent data have shown that fermentable carbohydrates can have similar effects in reducing ammonia emissions (O'Connell et al, 2005;Garry et al, 2007).…”

Evaluating the potential of dietary crude protein manipulation in reducing ammonia emissions from cattle and pig manure: A meta-analysis

“…This has been highlighted in many studies which report that the presence of nitrogenous compounds (primarily as urea in urine) along with a high manure pH are the main factors leading to NH 3 emissions from manure (Lynch et al 2007;Feilberg and Sommer 2013). The potential of reduced CP in animal diets to decrease both the amount of N and pH of manure has been demonstrated in various studies (Canh et al 1998;Lynch et al 2007;Le et al 2009). Due to concerns of farmers regarding animal productivity and also due to the safety margins implemented by the feeding industries, dietary CP is usually fed in excess of what is required by the animals.…”