251
where the amount of concentrate on offer was equivalent to 33% and 66% of ad
libitum concentrate intake, respectively; and T100, where concentrate was fed ad
libitum allowing 10% refusals from the daily concentrate allowance.
2.2 Feeding Management
Animals were given a 3-week adaptation period during which they were treated
with ivermectin for internal and external parasites. Goats were stall-fed in groups of
four animals per pen. Grass hay was offered ad libitum allowing 20% refusals from
the daily hay allowance. Concentrate was fed twice daily, at 9:00 and 15:00 hrs,
while water was offered ad libitum. During an experimental period of 90 days, feed
allowances and refusals were recorded daily for each group.
2.3 Sampling of LD, MM and OF for Fatty Acid Analyses
At the end of the experimental period, goats were fasted for 16 h before slaughter.
At 45 minutes post-mortem, each carcass was dissected longitudinally into two
equal halves through the median plane using a band saw. The carcasses were chilled
at 0 °C for 24 hours before sampling. The M. longissimus dorsi (LD) was excised
from each left-half carcass and split into blocks measuring approximately 7 cm in
length. One block, at the posterior end of LD, was used for fatty acid analyses. The
remaining left-half carcasses were dissected into muscle, fat and bone. The muscle
and fat tissue from each half-carcass was thoroughly mixed together to represent the
total edible tissue in a carcass and minced using a 5 mm sieve; three subsamples of
the minced meat (MM) were then taken for fatty acid analyses. Approximately 10 g
of omental fat (OF) was sampled for fatty acid analyses. All samples were packed
in PVC bags and frozen at -25 °C until analyses were complete.
2.4 Fatty Acid Analyses
Analyses of fatty acids in the samples were carried out at the Department of Animal
and Aquacultural Sciences at the Norwegian University of Life Sciences. Synthesis
of fatty acid methyl esters (FAME) was conducted using the direct method of
O’Fallon et al. (2007). Following the synthesis of FAME, 3 mL of hexane was
added to each reaction tube after which the tubes were vortex-mixed for 5 min on a
multi-tube vortex. The tubes were centrifuged for 5 min at 3000 rpm in a tabletop
centrifuge (Wifug Ltd., England). The hexane layer containing the FAME was
transferred from each tube into a gas chromatography (GC) vial. Each vial was
capped and brought to −20 °C before fatty acid separation in a GC.
Effects of Concentrate Supplementation on the Fatty Acid Composition of Fat Depots…
where the amount of concentrate on offer was equivalent to 33% and 66% of ad
libitum concentrate intake, respectively; and T100, where concentrate was fed ad
libitum allowing 10% refusals from the daily concentrate allowance.
2.2 Feeding Management
Animals were given a 3-week adaptation period during which they were treated
with ivermectin for internal and external parasites. Goats were stall-fed in groups of
four animals per pen. Grass hay was offered ad libitum allowing 20% refusals from
the daily hay allowance. Concentrate was fed twice daily, at 9:00 and 15:00 hrs,
while water was offered ad libitum. During an experimental period of 90 days, feed
allowances and refusals were recorded daily for each group.
2.3 Sampling of LD, MM and OF for Fatty Acid Analyses
At the end of the experimental period, goats were fasted for 16 h before slaughter.
At 45 minutes post-mortem, each carcass was dissected longitudinally into two
equal halves through the median plane using a band saw. The carcasses were chilled
at 0 °C for 24 hours before sampling. The M. longissimus dorsi (LD) was excised
from each left-half carcass and split into blocks measuring approximately 7 cm in
length. One block, at the posterior end of LD, was used for fatty acid analyses. The
remaining left-half carcasses were dissected into muscle, fat and bone. The muscle
and fat tissue from each half-carcass was thoroughly mixed together to represent the
total edible tissue in a carcass and minced using a 5 mm sieve; three subsamples of
the minced meat (MM) were then taken for fatty acid analyses. Approximately 10 g
of omental fat (OF) was sampled for fatty acid analyses. All samples were packed
in PVC bags and frozen at -25 °C until analyses were complete.
2.4 Fatty Acid Analyses
Analyses of fatty acids in the samples were carried out at the Department of Animal
and Aquacultural Sciences at the Norwegian University of Life Sciences. Synthesis
of fatty acid methyl esters (FAME) was conducted using the direct method of
O’Fallon et al. (2007). Following the synthesis of FAME, 3 mL of hexane was
added to each reaction tube after which the tubes were vortex-mixed for 5 min on a
multi-tube vortex. The tubes were centrifuged for 5 min at 3000 rpm in a tabletop
centrifuge (Wifug Ltd., England). The hexane layer containing the FAME was
transferred from each tube into a gas chromatography (GC) vial. Each vial was
capped and brought to −20 °C before fatty acid separation in a GC.
Effects of Concentrate Supplementation on the Fatty Acid Composition of Fat Depots…