Effects of yeast culture and galacto-oligosaccharides on ruminal fermentation in holstein cows.
Four nonlactating, ruminally cannulated Holstein cows were used in a 4 x 4 Latin square design, balanced for residual effects, to evaluate the effects of supplementing dairy cow diets with yeast culture (Trichosporon sericeum; YC), galacto-oligosaccharides (GOS), or the mixture of YC and GOS on ruminal fermentation, microbial N supply, in situ degradation, and energy and nitrogen metabolism. Treatments were arranged in a 2 x 2 factorial as follows: 1) basal diet, 2) basal diet plus 10 g/d YC, 3) basal diet plus 2% GOS, 4) basal diet plus a mixture of 10 g/d YC and 2% GOS. Nitrogen losses in urine were lower, and retained N was higher, for cows supplemented with a mixture of YC and GOS. Ruminal pH was lower in cows supplemented with GOS alone compared with other treatments. Total VFA concentration was higher in cows fed control and GOS-supplemented diets than in those fed YC containing diets. The molar proportion of propionate was higher, and the molar proportion of acetate was lower, in cows fed control diets. Microbial N supply was higher in cows fed control diets. There were no major positive effects of supplements observed in this study. However, supplementation of a mixture of YC and GOS had a tendency for synergistic effects on N metabolism and in situ degradation of a soluble fraction of oat straw DM and CP of concentrates compared with supplementation of YC or GOS alone.
Mwenya
B
B
Department of Animal Science, Obihiro University of Agriculture and Veterinary Medicine, 080-8555, Japan.
Santoso
B
B
Sar
C
C
Pen
B
B
Morikawa
R
R
Takaura
K
K
Umetsu
K
K
Kimura
K
K
Takahashi
J
J
D000821:Animal Feed; D000818:Animals; D002417:Cattle / Q000378:metabolism*; D004734:Energy Metabolism; D005232:Fatty Acids, Volatile / Q000032:analysis / Q000378:metabolism; D005260:Female; D005285:Fermentation; D005690:Galactose / Q000737:chemistry; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D011897:Random Allocation; D012417:Rumen / Q000378:metabolism / Q000382:microbiology*; D014250:Trichosporon / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*
D005232:Fatty Acids, Volatile; D009844:Oligosaccharides; D009584:Nitrogen; D005690:Galactose