Energy utilization of sodium hydroxide treated or untreated straw supplemented with protein or concentrates by adult sheep. 2. Rumen digestion.
NaOH treated (T) or untreated (UT) barley straws were supplemented either with protein (P) or with concentrates based on maize (M) or beet pulp (BP), the two last at rates of 25 and 50% of the diet. Each of the 10 diets was fed to two sheep ad libitum. Two diets were also fed at limited intakes. For these 12 diets in sacco cellulolytic activity in the rumen and ruminal fermentation were measured. Cellulolytic activity was measured with the studied straws, so that their digestion rate was also determined. NaOH treatment increased rate of digestion of straw, while high levels of concentrates decreased it. In contrast NaOH treatment and high levels of concentrate decreased cellulolytic activity but neither type of concentrate nor limitation of intake altered it. NaOH treatment only slightly modified pH because a higher level of VFA in rumen balanced NaOH presence. An important negative effect on pH of high levels of concentrate was observed, but there was no effect or type of concentrate or limitation of intake. Fermentation pattern was only slightly influenced by studied factors: +2.2 units of butyric acid and -2.1 units of acetic acid with treated straw; lower level of acetic acid occurred when concentrate was increased, especially for maize. Limitation of intake increased acetic acid molar proportion.
Dulphy
J P
JP
Laboratoire d'Etude du Métabolisme Energétique, I.N.R.A.--Theix, Ceyrat, France.
Grenet
E
E
Vermorel
M
M
D000641:Ammonia / Q000378:metabolism; D000821:Animal Feed; D000818:Animals; D004044:Dietary Proteins / Q000378:metabolism; D004063:Digestion; D004734:Energy Metabolism; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005285:Fermentation; D001467:Hordeum; D006863:Hydrogen-Ion Concentration; D012417:Rumen / Q000378:metabolism*; D012756:Sheep / Q000378:metabolism*; D012972:Sodium Hydroxide
D004044:Dietary Proteins; D005232:Fatty Acids, Volatile; D012972:Sodium Hydroxide; D000641:Ammonia