Experiment 2- NH3
concentration in rumen fl uid
in farm animals
Animals and feeding
Forty-two swamp buffaloes (30 females
and 12 males) ranging in age from 20 to 30 months
and having an average body weight of 330 kg and
42 local yellow cattle (30 females and 12 males)
ranging in age from 20 to 28 months withan
average body weight of 210 kg were selected for
the experimental study.
The animal were grazed for half of each day
in the same pasture (the grass had a composition
of DM: 29.6%; ash: 9.3% and CP: 10.9%) and for
the other half of the day were kept indoors and fed
rice straw (80.9% DM; 6% CP and 12% ash) at
25 g dry matter per kg M0·75 for 10 days without
any addition. The animals had access to water ad
libitum.
Rumen fl uid sampling
The sampling time started at 5 a.m. and
continued until the process was fi nished before
grazing or feeding, The instruments used included
syringes and PVC stomach tubes. In the process
of rumen fl uid sampling, the fl uid was obtained by
rumen intubation through the mouth and throat. The
tubes were moved about in the rumen to obtain fl uid
from different locations. The rumen fl uid collected
was put into 50 ml bottles, kept cool with ice, then
soon analyzed for NH3-N in the laboratory using a
Kjeltec apparatus (2200 Kjeltec Auto Distillation,
Foss Tecator, Sweden Tecator) for separating
ammonia from the rumen fl uid.
The sampling working groups included
students and farmers to be sure all the animal were
sampled at the same time.