Effect of substrate and feed antibiotics on in vitro production of volatile fatty acids and methane in caecal contents of chickens

A note on changes in the concentration of short-chain fatty acids in the caecal content of laying hens due to addition of fresh grass to the diet

“…The total concentration of SCFAs (Table 2) decreased by 27% (P≤0.05) after addition of grass, which might be a result of reduced microbial activity, as SCFAs are the main products of microbial fermentation in poultry caeca (Marounek et al, 1999). No significant changes in the mutual proportions of acetic, propionic and butyric acids were observed (Table 2), which may indicate that caecal microflora had altered activity, while interactions between populations were stable.…”

“…In most poultry species the ceacum is the main site of microbial fermentation (Goldstein, 1989;Pinchasov and Elmaliah, 1994;Vispo and Karasov, 1997;Jamroz et al, 1998). The final products of that process include short-chain fatty acids (SCFA), ammonia, carbon dioxide and methane (Marounek et al, 1999). Organic acids produced during dietary fibre breakdown are similar to those present in the rumen; these include butyric, iso-butyric, acetic, lactic, propionic, valeric and iso-valeric acids (Jamroz et al, 1994).…”

In vitro fermentation profiles of palm kernel meal (PKM)-based diet supplemented with xylanase or cellulase using caecal digesta of broiler chickens as inoculums

“…In vitro gas production profile, fermentation kinetics and IVDMD Fermentation model differed in cultures with different feed substrates [3] and, there is a close association between microbial fermentation and gas production [31]. The measurement of gas production has been an important means in the determination of feed digestibility by microorganisms [10], as well as the effect of feed additives such as enzymes [6].…”

“…Therefore, the digestion of these substances is commonly achieved by chemical digestion in crop, physical digestion in the gizzard and mostly through the microbial degradation by bacteria in the caecum [2]. Undigested carbohydrates such as NSPs are fermented in the caeca of poultry into volatile fatty acids (VFAs) and gases [3]. There are few factors affecting the fermentation of dietary fibers including the type and amount of dietary fibers, age of the birds, the caeca development [4] and feed additives [5].…”

Inclusion of antibiotics in feed alters greenhouse gas emissions from feedlot manure during composting

“…Massé et al (2000) also reported that CH 4 production from anaerobic digestion of swine slurry was reduced by CTC, but not by TYL or sulfamethazine (SMZ). Amoxicillin, oxytetracycline and thiamphenicol were also reported to have no effect on CH 4 production during anaerobic digestion of swine manure (Lallai et al 2002) and TYL had no effect on CH 4 production when chicken feces were incubated in slurry form for 20 h under anaerobic conditions (Marounek et al 1999). In contrast, Sponza and Demirden (2007) showed that during anaerobic digestion in a sequential up flow reactor, CH 4 production was higher when sulfamerazine was present at 90 mg L -1 as compared to 10 mg L -1 .…”