02537naa a2200277 a 450000100080000000500110000800800410001902400320006010000160009224501200010826000090022850001110023752016240034865000190197265300190199165300180201065300260202865300190205465300170207365300240209065300230211465300230213770000190216070000160217977300640219510576522017-10-12       2016    bl uuuu     u00u1 u    #d7 a10.3168/jds.2016-110232DOI1 aMENDOZA, A.  aDigestive response of dairy cows fed diets combining fresh forage with a total mixed ration.h[electronic resource]  c2016  aArticle history: Published online: August 18, 2016.//Accepted: May 11, 2016.//Received: February 11, 2016.  aAbstract The objective of this experiment was to quantify the response of dairy cows fed a total mixed ration (TMR) to increasing access to high-quality temperate fresh forage with respect to energy intake, rumen fermentation, microbial protein flow, passage rate, nutrient digestion and utilization, and metabolic and endocrine profiles. Nine Holstein cows fed a TMR were assigned to the following treatments according to a 3×3 Latin square replicated 3 times with 20-d periods and sampling on the last 10 d of each period: 0 (T0), 4 (T4), or 8 (T8) h of daily access to fresh forage. The forage (Lolium multiflorum; 17.1% crude protein, 26.5% acid detergent fiber) was cut daily and offered ad libitum beginning at 0800h, and a TMR (16.1% crude protein, 22.9% acid detergent fiber) was offered ad libitum during the remaining time. Energy intake and balance were higher in T0 than in T8, which was reflected in higher blood glucose and insulin concentrations in T0. Total volatile fatty acid concentrations in the rumen were higher in T0 and T4 than in T8, pH was lower in T4 than in T8, and ammonia-N was higher in T0 than in T8. No differences among treatments were detected in microbial protein flow to the duodenum, digestibility of nutrients, apparent efficiency of energy, or N utilization for milk production, but the total mean retention time of feed in the digestive tract was higher in T8 than in T0. It is concluded that more than 4h of daily access to high-quality fresh forage in the diet of dairy cows fed a TMR reduced energy intake and balance but had no effects on nutrient digestion or utilization.  aVACAS LECHERAS  aDIGESTIBILIDAD  aDIGESTIBILITY  aFERMENTACIÓN RUMINAL  aFORRAJE FRESCO  aFRESH FORAGE  aRACIÓN MIXTA TOTAL  aRUMEN FERMENTATION  aTOTAL MIXED RATION1 aCAJARVILLE ,C.1 aREPETTO, J.  tJournal of  Dairy Sciencegv. 99, n.11, p. 8779-8789, 2016.