Parâmetros ruminais em vacas em alta produção leiteira alimentadas com dieta total

Abstract

The search of better quality of the milk induces that changes and advances should be reached trought manipulation of de diet of the animals. The evaluation of the food absorption processes have been a very important in the investigation of the animal nutrition. The objective was to evaluate the on ruminal fermentation parameters in high yielding dairy cows fed total mixed ration (TMR). Eighteen Holstein cows in initial third of lactation were distributed to three groups. Cows were fed ad libitum thirty a day. The diet containing corn silage, barley, cottonseed and commercial ration, with forage:concentrate ratio of 45:55. Ruminal fluid was used for sampling at 0, 2, 4 and 6 hours after first meal for determination of ammonia, pH and VFA. The daily average intakes of nutrients, coefficients digestibility and milk production was evaluated how index of the production. There was no effect for averages of molar ruminal concentration ammonia. Was different, 4 hour after fed for the parameters: pH, VFA, acetic, butyric acids evidencing intense ruminal fermentative activity. Total VFA and pH was different in 4 hour after fed. The values of the propionic acid had followed the same trend of the AGV but they had not presented significant difference, the relation acetate: propionato was remained above of 3, keeping adjusted the text of fat of milk. This study demonstrates that the use of total diet provided a ruminal environment with adequate conditions of fermentation without large oscillations, what it diminishes the incidence of metabolic riots in cows of high production.