RESUMO
The aim of the study was to evaluate the effect of graded levels of Enterolobium cyclocarpum pods in the ration on feed intake and digestibility by Pelibuey lambs. Five dietary treatments were imposed where ground pods replaced concentrate diet at 0, 20, 30, 40 and 50 % of dry matter (DM), respectively. The concentrate portion was composed of ground sorghum, soybean meal, cane molasses and minerals. Five entire Pelibuey lambs with initial bodyweight 34 ± 2 kg were allocated in the treatments in a 5 × 5 Latin square design. Values of dry matter intake (DMI) and dry matter (DMD) and organic matter (OMD) digestibility were measured and metabolisable energy intake (MEI) estimated. Rumen degradation constants for E. cyclocarpum were also measured. There were no differences (P > 0.05) in average DMI (86.6 g/kg(0.75)) and OMI (81.2 g/kg(0.75)) among treatments. As the level of incorporation of E. cyclocarpum pods increased, voluntary DMI and OMI increased, whereas apparent DMD and OMD decreased linearly. Average digestible DM (65 g/kg(0.75)) and OM (61 g/kg(0.75)) intakes were similar (P > 0.05) among treatments. Similarly, MEI (0.976 MJ ME kg(0.75)/day) was not different (P > 0.05) among treatments. The potential rumen degradation (A + B) of ground pods of E. cyclocarpum was 866.4 g/kg DM. Ground pods of E. cyclocarpum can be employed for lamb feeding up to 50 % of the ration, without affecting DMI, DM apparent digestibility and MEI.
Assuntos
Ração Animal/análise , Criação de Animais Domésticos/métodos , Digestão/efeitos dos fármacos , Fabaceae/química , Comportamento Alimentar/efeitos dos fármacos , Carneiro Doméstico/fisiologia , Animais , Dieta , Relação Dose-Resposta a Droga , Fezes/química , Masculino , México , Rúmen/metabolismo , Sementes/química , Carneiro Doméstico/crescimento & desenvolvimento , Clima TropicalRESUMO
El objetivo de la investigación fue evaluar el efecto del tamaño de la partícula de la fuente de fibra sobre digestabilidad aparente (DA) de la MS, MO y PC, conducta ingestiva (CI) y aporte de proteína microbial (APM). Se utilizaron 6 vacas (450±60.7 kg PV) Bos indicus x Bos Taurus canuladas en el rumen conmutativo 2 x 2. El experimento se realizó en la Facultad de Medicina Veterinaria y Zootecnia-Universidad Autónoma de Yucatán, Mérida, Yucatán, México. La dieta fue mixta forraje: concentrado (40:60). El forraje consistió en un heno con predominancia de zacate Jonson (Sorghum halapense). La diferencia en las dietas fue el tamaño de partícula del heno (36 g PC/kgMS) que fue molido con criba de 3 mm (pequeña, FP) y de 25 mm (grande, FG). El contenido de PC de la dieta fue 150 g/kg MS. La energía Metabolizante (9.3 MJ/kg MS) fue estimada a 1.5 veces el requerimiento de mantenimiento. Se midió la DA de la MS, MO y PC; la producción de saliva se estimó mediante la colecta de bolos. Se utilizó Polietilenglicol para determinar la cinética de líquidos. Se determinó el balance de nitrógeno (N) y la excreción de derivados de purina (DP) en orina. El efecto de la FP y FG sobre la DA de la MS, MO y PC, el balance de nitrógeno y la APM fue similar (P>0.05). La CI presentó mayor actividad de rumia (233 vs 159 min/d) y producción de saliva (74.17 vs 55.77 L/d) para la dieta con FG (P<0.05). No hubo efecto sobre la tasa de flujo y de recambio de líquidos. En conclusión, el tamaño de partícula afectó el tiempo de rumia. La digestabilidad de la MS, MO y PC, así como el APM al duodeno no mostró diferencias significativas entre las dietas.
The effect of fibre particle size on apparent digestibility, ingestive behaviour and microbial-N supply was investigated. Six Bos indicus x B. taurus cows (450 ± 60.7 kg LW) fitted with ruminal canulas were used in a 2 x 2 cross-over design. The diet was made of 40% roughage and 60% concentrate. The difference amongst them was the particle size of hay (36 g CP/kg DM) which was reduced to 3 mm (small particle) and 25 mm (large particle). Diets had 150g CP and 9.3 MJ /kg DM. Apparent digestibility of DM, OM and CP and N balance were measured. Saliva production was estimated via bolus collection at the rumen. PEG was used to measure rumen liquid kinetics. Microbial-N supply was assessed with the urinary purine derivatives technique. No effects were found due to particle size on DM, OM, CP and Microbial-N supply (P>0.05). Large particle size caused and increase on the time devoted for rumia (233 vs 159 min/d) and saliva production (74.17 vs 55.77 L/d) (P<0.05). However, liquid outflow rate and rumen turnover rate were not affected (P>0.05). It was concluded that fiber particle size can increase time devoted to rumia. However, apparent DM, OM and CP digestibility, as well as microbial-N supply are not affected.