ABSTRACT
The objective of this study was to evaluate feed intake and digestibility and ruminal characteristics of development-stage calves fed mulatto II (Brachiaria sp.) grass hay (MGH) and a protein supplement (PS) consisting of increasing levels of the parota (Enterolobium cyclocarpum) pod (PP). We used eight Swiss-zebu calves in growth stage with an average age of 11 months and initial average weight of 157.6 ± 8.5 kg. They were distributed in a repeated 4 × 4 Latin square design with 4 treatments (period 30 days): 0% (PP0), 25% (PP25), 50% (PP50), and 75% (PP75) of the PP. Calves in the PP0 and PP25 treatments had higher intake of PS and MGH as dry matter (DM) than those in the PP50 and PP75 treatments (p < 0.05). Organic matter intake (OMI) of the PP75 calves was lower than that of PP0 and PP25 calves. Crude protein intakes (CPI) of PP0 and PP25 calves were higher than those of PP50 and PP75 calves (p < 0.05). Apparent digestibility of crude protein was higher in the PP0, PP25, and PP50 treatments compared with that in treatment PP75 (p < 0.05). The treatments did not affect total bacterial count, cellulolytic bacterial count, cellulase enzymatic activity, volatile fatty acids, or the acetate/propionate ratio (p > 0.05). Rumen pH in the PP0 calves was higher than that of the PP25 calves, whereas the protozoa count and ammonia content were higher in PP0 calves than in PP75 (p < 0.05). In conclusion, the inclusion of 25% PP in the PS for forage-fed calves is a feeding alternative.
Subject(s)
Animal Feed , Rumen , Animal Feed/analysis , Animals , Cattle , Diet/veterinary , Dietary Fiber/metabolism , Digestion , Eating , Fermentation , Rumen/metabolism , WeaningABSTRACT
ABSTRACT Objective. To measure the in vitro fermentation variables of a cellulolytic bacteria consortium (CBC) isolated from a water buffalo rumen in coculture with total ruminal bacteria (TRB) on two fibrous substrates. Materials and methods. A CBC was isolated from the ruminal fluid of a female water buffalo in selective cellulolytic media. The experimental design was completely random with a 3x2 factorial arrangement; factors were treatments [TRB, CBC, and coculture (TRB + CBC)] and substrates (cobra grass and corn stover). Total gas and methane (CH4) production were measured at different time intervals. At 72 h, measurements were taken of pH, ammoniacal nitrogen (NH3-N), dry matter degradation (DMD), neutral detergent fiber degradation (NDFD) and total bacteria population. Results. Gas production with both substrates was highest (p≤0.05) in the coculture at 3, 6 and 24 h. At 48 and 72 h, gas production in the cobra grass was highest (p≤0.05) in the coculture. The coculture and TRB did not differ (p>0.05) in terms of CH4, DMD and NDFD values at 48 and 72 h. With the cobra grass, NH3-N concentration was higher (p≤0.05) in the coculture than in the TRB. Conclusions. The gas production and dry matter degradation values of the water buffalo rumen cellulolytic bacteria consortia indicate them to be a promising alternative for improving cobra grass structural carbohydrates degradation when in coculture with bovine ruminal bacteria.
RESUMEN Objetivo. Determinar las variables fermentativas in vitro de un consorcio bacteriano celulolítico (CBC) aislado de una búfala de agua en cocultivo con bacterias ruminales totales (BRT) en sustratos fibrosos. Materiales y métodos. Un CBC se aisló de fluido ruminal de una búfala de agua en medios selectivos celulolíticos. El diseño experimental fue un diseño completamente al azar con arreglo factorial 3x2, los factores fueron tratamientos [BRT, CBC y un cocultivo (BRT + CBC)] y sustratos (pasto pangola y rastrojo de maíz). La producción de gas total y metano (CH4) se midieron a diferentes intervalos de tiempo. Además, se estimó pH, nitrógeno amoniacal (N-NH3), degradación de materia seca (DMS) y de fibra detergente neutro (DFDN), y la población de bacterias totales a 72 h de incubación. Resultados. El cocultivo produjo mayor (p≤0.05) cantidad de gas a las 3, 6 y 24 h en ambos sustratos. A las 48 y 72 h, el cocultivo produjo mayor (p≤0.05) gas en pasto cobra. El cocultivo y las BRT no presentaron diferencias (p>0.05) en la producción de CH4 a 48 y 72 h, y en DMS y DFDN (p>0.05). En el pasto cobra, la concentración de N-NH3 con el cocultivo fue mayor (p≤0.05) que con BRT. Conclusiones. La producción de gas y degradación de materia seca de los consorcios bacterianos celulolíticos procedentes del rumen de una búfala de agua muestran que son una alternativa para mejorar la fermentación de carbohidratos estructurales del pasto cobra cuando se cocultivan con bacterias ruminales bovinas.
