Abstract
Total mixed rations (TMR) based diet is a high energy diet, which negatively deteriorates the rumen health through pH reduction. This study investigated the effect of different protocols of alfalfa hay supplementary on ruminal characteristics and performance of growing Naemi lambs fed TMR. Four groups, each of 3 months old growing Naemi male lambs (28.85 +/- 1.09 kg), were fed on TMR (NDF=41. 95%) (T1). TMR plus 100 g alfalfa hay (NDF=43.3%) daily (T2), TMR plus 200 g alfalfa hay (NDF=43.3%) every two days (T3) and TMR plus 300 g alfalfa hay (NDF=43.3%) every three days (T4). Rumen fluid samples were analyzed for volatile fatty acids and ammonia nitrogen levels. Acetic acid improved significantly in experimental groups, while propionic acid decreased significantly in T1. Valerie acid and butyric acid decreased significantly in T1 and T2 while isovolaric acid and the ratio of acetic acid and propionic acid and glucose increased significantly in T1. In conclusion, feeding TMR with alfalfa hay, regardless of the supplementary protocol, causes a significant change in rumen fermentation patterns as a result of increasing the intake level of NDF from the alfalfa hay. This shift in the fermentation pattern may positively affect the rumen environment and consequently growing lambs' health and productivity.