Leo Penu, C.L.O., Fitzpatrick, L.A., and Parker, A.J. (2012) The influence of incubation media on the gas production of In vitro rumen fluid cultures. In: Posters from the 2nd Australian and New Zealand Societies of Animal Production Joint Conference . p. 6. From: 2nd Australian and New Zealand Societies of Animal Production Joint Conference , 2-5 July 2012, Christchurch, New Zealand.

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Abstract

The incubation media is a factor that may influence the gas production (GP) concentrations of in vitro ruminal fermentation and degradability of feedstuffs (Mould et al., 2005). Cumulative In vitro GP is associated with feedstuff degradation (Mould et al. 2005). However, GP alone does not provide direct information on either the extent of degradation or the quantity of fermentative end products. Some authors have questioned the use of complex buffer solutions such as the Goering Van Soest media, suggesting a simplified in vitro media would improve safety and reduce cost without negatively impacting on analytical precision (Mould et al., 2005). The current experiment was conducted to compare the Goering-Van Soest and Kansas State incubation media as commonly used in ruminal in vitro studies to evaluate feedstuffs (Goering and Van Soest, 1970; Marten and Barnes, 1979). The in vitro gas production (GP) was completed using a commercial wireless GP apparatus (AnkomRF GP System). The study included eight replicates and two controls for each of the two treatments. Each module (250ml) was filled with 1g of ground Rhodes grass (Chloris gayana) hay, and either 105ml of the Goering Van Soest or Kansas State buffer solutions preheated to 39°C. Rumen fluid was collected 3h after the morning feeding from fistulated Brahman steers consuming Rhodes grass hay. The rumen inoculums (25ml) were poured into each of the vessels. Anaerobic conditions were maintained throughout the preparation and conduct of the experiment. The apparatus was set up to record GP every 15 minute to avoid super-saturation of the liquid phase. Results are described in Figure I.

The Goering-Van Soest buffer allowed greater GP than the Kansas State buffer in this experiment at 24, 48 and 72h (P<0.001). The Goering-Van Soest media demonstrated a greater buffering capacity for in vitro fermentation and degradability studies of Rhodes grass hay as demonstrated by GP. The pH declined (p<0.05) for both treatments throughout the experiment. The Goering Van Soest treatment declined from 7.4 to 6.81 whereas the Kansas State buffer decreased from 6.80 to 6.39. The decline in pH may have affected the cellulolytic bacterial population in the Kansas State Buffer treatment. When undertaking or comparing in vitro studies using cellulolytic substrates consideration needs to be given to the incubation media used.

Item ID:	23200
Item Type:	Conference Item (Poster)
Keywords:	rumen, microbial, in vitro, cattle , ruminants
Additional Information:	The 29th Biennial Conference of ASAP and the 72nd Annual Conference of NZSAP were held as the 2nd Joint meeting of the two Societies at Lincoln University, New Zealand in July 2012.
Date Deposited:	10 Sep 2012 04:32
FoR Codes:	07 AGRICULTURAL AND VETERINARY SCIENCES > 0702 Animal Production > 070204 Animal Nutrition @ 100%
SEO Codes:	83 ANIMAL PRODUCTION AND ANIMAL PRIMARY PRODUCTS > 8303 Livestock Raising > 830301 Beef Cattle @ 100%
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