2.4. Feed sampling and data collection
A period of 10 days was allowed for the animals to
get used to the feeding stalls. Each period consisted of
2 weeks, with a 7-day preliminary period and 7-day
collection period. Grass hay was weighed prior to
feeding, and refusals were collected and weighed the
following morning. Ten percent of the refusals for
each period were bulked for 7 days and later subsampled
for laboratory chemical analysis. Milk produced
by each cow was weighed daily, and during the
collection period, about 400 ml of milk from morning
and evening milking sessions were taken once a week
(on the last day of each period) for milk composition
analysis and odour testing. A panel of testers comprised
of four people in experiment 1 and six people
in experiment 2. The testers used organoleptic test to
score the degree of unpleasant odour in the milk.
About 100 ml of milk of each animal from the
composite sample of a period was placed in a beaker
and tested by the panel on the last day of the period.
Every beaker was labeled by a number and the testers
scored against the number. Scoring was as follows:
1 = very bad smell; 2 = bad smell; 3 = slight bad smell
and 4 = no bad smell. The same people were involved
in scoring the odours on each testing occasion. They