Effect of dehydrated alfalfa on ruminal characteristics and amino acids flow through lambsʹ duodenum

Two experiments were carried out. In the first experiment, four sheep (45 kg) with a cannula in the rumen were used to determine the extent of rumen protein degradation of dehydrated alfalfa (DA), applying the nylon bag technique. In the second experiment, five lambs (25 kg) with cannulas in the rumen and duodenum were fed all-concentrate, pelleted isonitrogenous (about 16% crude protein kg−1 dry matter) and isoenergetic (about 12.8 MJ metabolizable energy kg−1 dry matter) diets containing 0, 5, 10, 15 and 20% of DA in a 5 × 5 Latin square arrangement of treatments. 24 h incubation period in the rumen, 61.2% DA protein was not degraded in this forestomach. The pH of rumen fluid increased only slightly with the increase of the DA concentration in the diets, while the level of NH3N in the rumen fluid decreased from 9.42 to 4.44 mM l−1 fluid. Total ruminal volatile fatty acid concentration dropped together with the increase of the DA content in diets (from 72.1 to 65.2 mM l−1), whereas acetate to propionate ratio increased significantly (P < 0.05) from 1.61 to 2.08. The highest and statistically significant (P < 0.05) flow of total N (23.17 g day−1), non-ammonia N (22.37 g day−1) and essential (53.74 g day−1), non-essential (77.07 g day−1) and total amino acids (130.81 g day−1) was observed in lambs fed 10% DA.