Prediction of rabbit caecal fermentation characteristics from faeces by in vitro gas production technique: roughages

• Published in: Journal of animal physiology and animal nutrition 2008-06, Vol.92 (3), p.260-271
• Main Authors: Bovera, F., Calabrò, S., Cutrignelli, M. I., Infascelli, F., Piccolo, G., Nizza, S., Tudisco, R., Nizza, A.
• Format: Article
• Language: English
• Subjects: Ammonia - analysis; Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Bacteria - metabolism; Biomass; caecal content; Cecum - metabolism; Cecum - microbiology; Dietary Fiber - metabolism; Dietary Fiber - microbiology; faeces; Fatty Acids, Volatile - analysis; Feces - chemistry; Fermentation; Gases; Hyla; in vitro gas production technique; Kinetics; rabbit; Rabbits - metabolism; roughages; Triticum aestivum
• ISSN: 0931-2439; 1439-0396
• DOI: 10.1111/j.1439-0396.2007.00748.x

Summary To find equations able to estimate the fermentation characteristics of the caecum from that of faeces, caecal content and faeces of 10 hybrid Hyla rabbits were used as inocula for an in vitro gas production trial. About 1 g of 12 roughages, 11 hays (ryegrass, alfalfa, sulla, oat, vetch, sulla‐lolium, vetch‐oat, sulla‐oat, clover, ryegrass‐clover, sulla‐vetch‐oat) and a wheat straw, was weighed, in triplicate per inoculum, in 120‐ml flasks; 75 ml of anaerobic medium and 4 ml of reducing solution were added and the flasks were placed at 39 °C. Caecal content and faeces were diluted respectively 1:2 (CI) and 1:8 (FI) with anaerobic medium and were introduced into their respective flasks (10 ml). Gas production was recorded 20 times at 2–24 h intervals throughout fermentation (120 h). The fermentation characteristics (i.e. degraded organic matter, OMd; potential gas production, A; maximum fermentation rate, Rmax; volatile fatty acid, VFA; ammonia, NH3) were studied by inocula and substrates. The two inocula did not differ in OMd but CI produced significantly higher gas (A, 213.1 vs. 199.4 ml/g, respectively, for CI and FI, p