Effects of inoculation with rumen fluid on nutrient digestibility, growth performance and rumen fermentation of early weaned lambs

Thirty weaned male lambs (28 days old) with live weight of 10.3 kg were randomly assigned to one of 3 treatments for a 56 days feeding period to study effects of inoculation with rumen fluid from mature sheep on growth performance and rumen fermentation. Treatments consisted of: (1) starter grain ration (SGR, control), (2) fed SGR and inoculated with 100 ml fresh rumen fluid (FRF) daily for 7 days and (3) fed SGR and inoculated with 100 ml lyophilized rumen fluid (LRF) for 7 days. Results showed that there were no differences in DM intake, apparent digestibilities of crude protein and acid detergent fiber (ADF), ruminal pH, and ruminal concentrations of ammonia N and total volatile fatty acid (VFA). However, both inoculations decreased feed conversion rate (FCR) (P<0.01). Inoculation of FRF increased average daily gain (ADG), apparent digestibilities of DM (P<0.01) and neutral detergent fiber (NDF) (P<0.05), while inoculation of LRF increased apparent digestibility of fat (P<0.05). There were significant interactions between treatment and sampling time for all individual ruminal VFA (P<0.05), except butyric acid and the ratio of acetic to propionic acid (P<0.001). In conclusion, FRF inoculation was beneficial to improving growth performance of lambs during the transition. Further research is needed to explain the mechanism of action of the FRF as probiotic.