Fachbereich Veterinärmedizin



    Effect of the forage-to-concentrate ratio on DMI and ruminal fermentation based on timing of feeding relative to feed restriction (2012)

    Albornoz, R.I.
    Aschenbach, Jörg R. (WE 2)
    Barreda, D.R.
    Penner, G. B.
    JAM 2012 Animal Meeting
    Arizona, 17.07.2012
    Animal science; 90(Suppl. 3) — S. 478
    ISSN: 1357-7298
    Institut für Veterinär-Physiologie

    Oertzenweg 19 b
    14163 Berlin
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    Abstract / Zusammenfassung

    The objective of this study was to evaluate the interaction between
    the forage-to-concentrate ratio (F:C) of diets fed before (baseline) and
    during short-term feed restriction (FR; collectively denoted as PRE) and
    those fed post-feed restriction (POST) on DMI and rumen fermentation.
    Twenty ruminally cannulated heifers (477 ± 38 kg BW) were exposed
    to 14 d for adaptation followed by 5 experimental periods; 5-d baseline,
    5-d FR, and 3 wk of recovery (R1, R2, and R3). Heifers were fed, ad
    libitum, a high forage diet (HF; F:C = 92:8) or a moderate forage diet
    (MF; F:C = 60:40) during baseline, and FR was imposed at 25% of
    ad libitum DMI. During recovery, one half of the HF and MF heifers
    remained on the same diet, and the other half were exposed to an abrupt
    switch (e.g., HF/HF, HF/MF, MF/HF, and MF/MF). PRE × period (
    P= 0.02) and POST × period (
    P= 0.04) interactions were detected for
    DMI. Although DMI, within periods, was not different for HF and MF,
    heifers fed HF PRE increased DMI from R1 to R3. Heifers fed HF POST
    had higher intake during R1 than heifers fed MF with no differences
    observed between diets within other periods. A PRE × POST × period
    interaction was detected for butyrate concentration (
    P= 0.01). Butyrate
    was higher for cows fed MF PRE than HF PRE. Butyrate concentration
    decreased from baseline to FR and returned to baseline values by R3;
    although the extent of the increase was greater for heifers fed HF PRE
    than MF PRE. PRE × period (P= 0.02) and POST × period (
    P< 0.01)interactions were detected for mean pH. For the PRE × period interac
    -tion, heifers fed HF had higher pH than those fed MF during baseline,
    but pH did not differ between diets during FR. Despite this, pH was
    higher during FR than baseline and decreased for all heifers during R1
    with mean pH returning to baseline values by R2 for HF heifers. For
    the POST × period interaction, mean pH during R1 was lower for MF
    than HF, but no other differences were detected among treatments. This
    study indicates that feeding MF before, and HF after FR reduces risk
    for ruminal acidosis following FR