Effect of type roughage and level of barley supplementation on digestibility, rumen fermentation and microbial-N yield
MetadataShow full item record
Four cannulated ewes were used in a factorial (2 x 3) design to study the effect of two sources of roughage (alfalfa hay vs ammonium-treated straw, UTS) and three levels of ground barley grain supplementation (F:C ratio: 100:0; 66:33; 33:66. respectively) on rumen digestibility, fermentation pattern
and microbial N yield. Diets were restricted to maintenance level (1.6 Mcal ME/d). Rumen (0.40 vs 0.34; P=0.07) and total tract DM digestibility were higher (0.77 vs 0.68; P<0.001) when ewes were fed with alfalfa diets and digestibility increased linearly with concentrate supply (P<0.001). Alfalfa diets also promoted higher rumen ammonia (31 vs 20 mg N-NH3/100ml; P=0.003) and VFA concentrations (144 vs 82 mmol/l; P<0.001). Among levels of barley supply only the highest (F:C. 33:66) depressed significantly pH and acetate proportion (P=0.008). Protozoa counts increased significantly (P<0.05) with moderated barley supplementation (3.2·105 vs 8.2·105 vs 7.6·105 cells/ml). The highest and the lowest duodenal N flow corresponded to un-supplemented alfalfa and un-supplemented straw diets as a result of a significant (P<0.001) interaction (forage x supplementation). Moreover, rumen microbial yield was maximal when animals received non-supplemented alfalfa (9.0, 12.1 and 8.0 g/d using 15N, purine bases (PB) and DNA sequences, respectively). Using specific DNA sequences it was possible to distinguish between bacterial and protozoal N flow in duodenal digesta. Protozoal N in duodenal digesta ranged between 2.4 and 8.3 percent of total microbial flow and peaked at the highest level of grain supply (F:C 33:66). However, the possibility for DNA degradation by gastric digestion could not be ruled out. Barley supplementation promoted a linear decrease in microbial protein synthesis efficiency (g/kg OM digested in the rumen) using PB and DNA as microbial markers (37 vs 27 vs 23; P<0.05).
Is part ofOptions Méditerranéennes. Series A: Mediterranean seminars, 2011, núm. 99, p. 75-83
Showing items related by title, author, creator and subject.
Study of the effect of presence or absence of protozoa on rumen fermentation and microbial protein contribution to the chyme Belanche, A.; Abecia, Leticia; Holtrop, G.; Guada, J. A.; Castrillo, C.; de la Fuente Oliver, Gabriel; Balcells Terés, Joaquim (American Society of Animal Science, 2011-06-29)The aim of this study was to investigate the effect of presence or absence of protozoa on rumen fermentation and efficiency of microbial protein synthesis under different diets. Of 20 twin paired lambs, 1 lamb of each pair ...
Effect of diet and absence of protozoa on the rumen microbial community and on the representativeness of bacterial fractions used in the determination of microbial protein synthesis Belanche, A.; de la Fuente Oliver, Gabriel; Pinloche, Eric; Newbold, C. Jamie; Balcells Terés, Joaquim (American Society of Animal Science, 2012-04-21)Accurate estimates of microbial synthesis in the rumen are vital to optimize ruminant nutrition. Liquid- (LAB) and solid-associated bacterial fractions (SAB) harvested from the rumen are generally considered as microbial ...
Effect of substituting barley with sorghum on starch digestion, rumen microbial yield and growth in Iranian Baluchi lambs fed high concentrate diets Yahaghi, M.; Liang, J. B.; Balcells Terés, Joaquim; Valizadeh, R.; Seradj, Ahmad Reza; Alimone, R.; Ho, Y.W. (Elsevier, 2013-07-12)This study investigated the effects of substituting barley (B) with sorghum (S) on site and extent of in vivo disappearance of dry matter (DM), starch and nitrogen in the gastrointestinal tract (GIT), microbial protein ...