TY  - JOUR
T1  - Role of Lactulose as a Modifier in Rumen Fermentation
AU - Hayirli, Armagan AU - Umucalilar, Huzur Derya AU - Gulsen, Nurettin AU - Citil, Ozcan Baris 
JO  - Journal of Animal and Veterinary Advances
VL  - 9
IS  - 19
SP  - 2537
EP  - 2545
PY  - 2010
DA  - 2001/08/19
SN  - 1680-5593
DO  - javaa.2010.2537.2545
UR  - https://makhillpublications.co/view-article.php?doi=javaa.2010.2537.2545
KW  - Lactulose
KW  -rumen fermentation
KW  -gas production
KW  -cumulative
KW  -proportions
KW  -quadrate
AB  - This <I>in vitro</I> experiment was conducted to examine the effects of lactulose (0, 2 or 4%) on ruminal fermentation of mixtures differing in the forage:concentrate ratio (F:C; 20:80, 40:60 or 60:40). Ruminal fluids collected from two Holstein steers were incubated with the mixtures for 48 h. Data were subjected to 2 way ANOVA. Lactulose did not alter ruminal fluid pH, ammonia and lactate concentrations, individual and total Volatile Fatty Acid (VFA) concentrations and gas production. There was a linear increase in ruminal fluid pH from 6.71-6.76 (p&lt;0.0001), a linear decrease in ammonia concentration from 15.84-11.77 mmol L<SUP>-1</SUP> (p&lt;0.0001), a quadratic increase in lactate concentration from 25.51-26.91 mmol L<SUP>-1</SUP> (p&lt;0.04) as the F:C ratio increased from 10:80-60:40. Moreover, increasing the forage level caused linear increases in the acetate (from 53.89-55.69%; p&lt;0.0002) and valerate (from 3.05-3.25%; p&lt;0.003) proportions and a linear decrease in the butyrate proportion (from 19.74-17.32%; p&lt;0.0001) and a linear decrease in cumulative gas production from 41.14-33.54 mL (p&lt;0.0001). The effects of the F:C ratio and lactulose level on gas kinetics parameters were variable. Lactulose addition failed to modify alterations in rumen fermentation characteristics of the mixtures varying in the F:C ratio. In conclusion, lactulose fermentation in ruminal fluids had minimal effects on fermentability of the mixture consisting of different F:C ratios suggesting that lactulose does not modify alterations in rumen fermentation in cattle during their growth and lactation phases.
ER  -