Observations on the Use of Chromic Oxide for Estimating the Fecal Output of Dairy Animals

Abstract

l'w(, trims emldoying d~iry heil"ers t'ed eithm' t'resh-eut alfalfa (Trial ill or mixed hay ('l?ri~d 2), and one trial using lactating cows which received '~ complete ration, have been conducted to study further the usefulness of chromic oxide for predieting fecal output. Total fecal collections were made during etwh trial. In addition, pat'tlal fecal samples were ohtt~ined at 6 a.~.r., 12 yoox, 6 ~,.?~i., mM ]2 M:IDNIGHT OIl each day of erich collection period. The results indicate ttmt periods o1! from three to seven days may be required for the indicator to retlch a st~lble level in the feces. The mean recovery rates of chromic oxide from totally collected feces and from the (,omhined 6 .~.-~. and 6 I'.:M:. samples for Trials 1, 2, ~md 3, respectively, were 89.4 ~md 89.7% ; 97.5 and 96.4% ; 90.0 mid 8!).7%. Average daily fecal I)M outgo w~ls estim~lted from the (,hromie oxide (,oncentrtltion ot; the eoml)ined 6 A.m. ;rod 6 r..~r, seraph,s, with mt error el! ;d)out 12%. ()nly in Trim 2 were s'/tisf:,(.t<)ry estil,mtes <)btaim,(l.