SAMY EMANUELLE CAVALCANTE, VANIA RODRIGUES VASCONCELOS, ADIBE LUIZ ABDALLA, ARNAUD AZÊVEDO ALVES, ANDRESSA SANTANNA NATEL, DINESHKUMAR DHANASEKARAN, LILIA RAQUEL FÉ DA SILVA, JEFFERSON COSTA SIQUEIRA
Federal University of Piaui, Zoothecny, Brazil
University of São Paulo, Centre for Nuclear Energy in Agriculture, Brazil
Federal University of Maranhão, Zoothecny, Brazil
In vitro techniques are simple method to determine feed value and most common source of microorganisms are fresh rumen liquor from fistulated animals. However, there is need to use alternative inoculum due to the costly management of fistulated animals, surgical procedure is an highly invasive technique which many countries has restricted its use accounting to animal's welfare issues. Hence, the objective of the present study was to evaluate the degradability of dry matter (DDM), crude protein (DCP) and neutral detergent fiber (DNDF) of three substrates on in vitro and in situ assays. Experiment was conducted at Laboratory of Animal Nutrition, CENA / USP - Brazil. Four adult fistulated Santa Ines animals were selected as inoculum donors of rumen liquor and fecal inoculum and animals were supplemented with 70:30 ratio of roughage: concentrate. Disappearance percentage of DM, CP and NDF were calculated in terms of weight difference between weighing before and after incubation in situ (rumen inoculum) and in vitro (fecal inoculum). The study was investigated in a completely randomised design for 24h and 48h incubation with a 32 factorial arrangement (feeds (100% concentrate, (70:30) maintenance ration and 100% Tifton hay) and two inoculants (rumen and fecal). Treatment means were compared by Tukey test at 5% probability and correlation analysis was performed. There was interaction effect on substrateinoculum for DDM (), DCP () and DNDF (). On average, substrates incubated in situ resulted in greater potential degradation () compared to in vitro incubation for DDM (63.3640.67), DCP (67.7844.63) and DNDF (56.0631.99) with regardless of incubation time. Among the three substrates tested, concentrate had higher DDM values (88.16 and 57.36), DCP (85.38 and 52.04) and DNDF (88.07 and 60.39) followed by maintenance ration (57.30 and 39.10, 70.45 and 64.93; 54.12 and 34.43) and Tifton hay (44.62 and 25.55, 47.52 and 16.91, 27.98 and 1.14) incubated in situ or in vitro respectively. Our study concludes that although fecal inoculum showed lower degradability of feed constituents, it may be used as alternative microbial source for in vitro techniques.
Keywords: Alternative inoculum, degradation, faeces
Full paper: http://www.tropentag.de/2015/abstracts/full/553.pdf