Jm. Hatt et al., Use of artificially applied n-alkanes as markers for the estimation of digestibility, food selection and intake in pigeons (Columba livia), ANIM FEED S, 94(1-2), 2001, pp. 65-76
The experiment was conducted to determine the accuracy with which food sele
ction, intake, and apparent digestibility of protein could be estimated wit
h n-alkanes in comparison to observed intakes and digestibility estimated t
hrough total excreta collection. Four pigeons (Columba livia) were used as
study subjects and four pigeons as controls. All animals were individually
caged. In Trial I the birds were fed a pelleted diet ad libitum which had b
een labelled with the n-alkanes octacosane (C-28 2000 ppm dry matter (DM)),
dotriacontanc (C-32 1500 ppm DM), and hexatriacontane (C-36 2000 ppm DM).
The birds had 6 days of adaptation to the diet followed by 4 days of total
excreta collection. On the basis of observed intakes and total excreta coll
ection n-alkane recoveries were estimated and compared to published data fo
r chickens. The intakes obtained using hentriacontane (C-31) and C-32 corre
cted for relative recoveries were very similiar to the observed intakes. Wh
en alkanes were not corrected for relative recoveries, the alkane method si
gnificantly underestimated the intake. The recovery rate Of C36 n-alkane wa
s 80% and the protein digestibility coefficients obtained after correction
with the recovery rate did not differ significantly from digestibility obta
ined with total excreta collection.
In Trial 2 selective intake was measured in four birds offered three differ
ent pelleted feeds ad libitum for 3 days of adaptation followed by 5 days o
f sample collection. Pellet I was labelled with n-alkanes, C-28 (2000 ppm D
M), C-32 (1500 ppm DM), and C-36 (2000 ppm DM), pellet 2 was labelled with
hexacosane (C-26 3000 ppm DM), and pellet 3 with triacontane (C-30 3000 ppm
DM). Very accurate estimates of pellet selection were obtained using the p
atterns of n-alkanes in excreta, being in average within +/-2.5% of the act
ual pellet selection in individual birds.