The effect of diet composition on the development of rumen digestion in lambs.

Abstract

The effect of composition of feed concentrate on the development of rumen digestion in suckling lambs was investigated. The experimental group of lambs was offered special concentrate diets (SCD I and SCD II), which, compared to routinely produced commercial mixtures CCD 1 and CCD 2, were completely cleared of milk protein, enriched with legumes and alfalfa meal and supplemented with cut alfalfa of the particle size 1 cm. Significantly higher concentrations of total volatile fatty acids (VFA) were recorded in experimental lambs at the age of 7, 9 and 11 weeks. The highest concentration of total VFA was observed at the age of 11 weeks (118.2 mmol.l-1 in the experimental group and 110.2 mmol.l-1 in the control group). The cellulase activity (endoglucanase E.C.3.2.1.4. and cellobiohydralase E.C 3.2.1.91.) of the rumen content of experimental lambs was significantly higher at the age of 9, 11 and 15 weeks, in comparison with the control animals, reaching the highest values at 11 weeks of age (19.32 micrograms.ml-1 in the experimental group, 15.84 micrograms.ml-1 in the control group), while the increase of number of cellulolytic bacteria in experimental lambs was insignificant. Scanning electron microscopy showed more pronounced colonization of the rumen epithelium by adherent rumen microflora in experimental lambs. Average daily weight gains over the whole investigated period reached 0.235 kg in the experimental group and 0.221 kg in the control group.