Effect of Aspergillus oryzae on ruminal fermentation, feed intake and dry matter digestibility in cows fed forage-based diets.

The present study was conducted to investigate the effect of Aspergillus oryzae inclusion on ruminal fermentation, feed intake and dry matter (DM) apparent digestibility in cows fed Cenchrus purpureus forage and concentrate. Cows were randomly assigned in a replicated 4 × 4 Latin square design, into four treatments: control and three doses of A. oryzae culture (1, 2 and 3 g/d). Experimental periods had 21 days, in which 14 days were allowed for treatment adaptation and 7 days for sampling. Addition of 2 g/d increased (p = 0.0054) total anaerobic bacteria. For cellulolytic bacteria and fungal populations increases (p < 0.0001) with all doses were observed. Highest concentrations of total short chain fatty acids (SCFAs), acetate, isovalerate and valerate were observed with 2 g/d of additive. Propionate concentration and acetate: propionate (Ac:Pr) ratio were unaffected by treatments. A. oryzae addition did not modify ruminal pH. A decrease of ammonia-N was observed with 2 g/d of additive. Dry matter intake and apparent digestibility of DM were increased (p = 0.0171 and p = 0.0023, respectively) with the fungal culture addition. It is concluded that Aspergillus oryzae strain H/6.28.1 stimulates ruminal fermentation and improves feed intake and dry matter apparent digestibility in cows feeding with Cenchrus purpureus forage and concentrate.

Feeding of tropical trees and shrub foliages as a strategy to reduce ruminal methanogenesis: studies conducted in Cuba.

The aim of this paper was to present the main results obtained in Cuba on the effects of feeding tropical trees and shrubs on rumen methanogenesis in animals fed with low quality fibrous diets. More than 20 tree and shrub foliages were screened for phytochemicals and analyzed for chemical constituents. From these samples, seven promising plants (Samanea saman, Albizia lebbeck, Tithonia diversifolia, Leucaena leucocephala, Trichantera gigantea, Sapindus saponaria, and Morus alba) were evaluated for methane reduction using an in vitro rumen fermentation system. Results indicated that the inclusion levels of 25% of Sapindo, Morus, or Trichantera foliages in the foliages/grass mixtures (grass being Pennisetum purpureum) reduced (P < 0.01) methane production in vitro when compared to Pennisetum alone (17.0, 19.1, and 18.0 versus 26.2 mL CH(4)/g fermented dry matter, respectively). It was demonstrated that S. saman, A. lebbeck, or T. diversifolia accession 23 foliages when mixed at the rate of 30% in Cynodon nlemfuensis grass produced lower methane compared to the grass alone. Inclusion levels of 15% and 25% of a ruminal activator supplement containing 29% of L. leucocehala foliage meal reduced methane by 37% and 42% when compared to the treatment without supplementation. In vivo experiment with sheep showed that inclusion of 27% of L. leucocephala in the diet increased the DM intake but did not show significant difference in methane production compared to control diet without this foliage. The results of these experiments suggest that the feeding of tropical tree and shrub foliages could be an attractive strategy for reduction of ruminal methanogenesis from animals fed with low-quality forage diets and for improving their productivity.