Influence of temperature and humidity conditions on rumen pH and fatty acids in dairy cows

The aim of this study was to investigate the variations of rumen pH and fatty acids (acetic acid, propionic acid, iso-butyric acid, n-butyric acid, iso-valerianic acid, n-valerianic, caproic acid and total fatty acids) in 245 multiparous Holstein dairy cows in relation to different natural environmental conditions. The animals were divided into six groups and rumen fluid was collected by rumenocentesis on 22 dairy cows in April (Group A), 33 in May (Group B), 43 in June (Group C), 48 in July (Group D), 36 in September (Group E) and 60 in October (Group F). One-way measures analysis of variance (ANOVA), followed by the Bonferroni’s test, showed a significant effect of environmental variations on all studied parameters (P<0.0001). Changes in studied parameters can be explained in relation to the microbial population and shift in the optima for rumen conditions associated with variations of environmental conditions. We can affirm that the microbial assemblages that underlie energy and protein supply to wild ruminant are evident especially in relation to temperature and humidity conditions.