NRIS Study with Knapweed
Develop fecal NIRS equations for predicting percent spotted knapweed and grass in a sheep’s diet.
A
feeding trial will be conducted for the development
of NIRS equations for predicting intake of spotted knapweed
from fecal samples. Twelve mature ewes will be individually
fed diets comprised of 4 different sources of spotted
knapweed (4 different growth stages ranging from pre-bud
to flowering) and 3 different background forages (alfalfa
hay and two different grass hays) for 3 consecutive
7-day feeding periods. Diets will consist of 0% spotted
knapweed (period 1), 10% spotted knapweed (period 2),
50% spotted knapweed (period 3) and 50% alfalfa (period
4) with the remainder of the diet consisting of the
appropriate background forage. Fecal samples will be
collected on days 5, 6 and 7 of each feeding period.
Daily samples (approximately 15 to 20 fecal pellets)
will be collected from each sheep daily, either by rectal
palpitation or picked up off the floor of a collection
pen.
Care
will be used to minimize contamination with urine, feed
and dirt if the latter method is utilized. Daily samples
will be dried at 55? C and ground through a 1 mm mesh
screen in a sample mill at the end of the three-day
collection period equal aliquot samples will be combined
from each of the three daily collections into a final
sample with a total weight of approximately 20g. Samples
will be sent to the Texas Experiment Station in San
Angelo, Texas for scanning, calibration development
and validation.
