3. Results
3.1. Trial 1: familiar foods at constant locations In Trial 1, we determined if lambs foraged at locations that contained food that
Ž complemented their nutrient imbalance, and if they preferred a variety of foods Foods P
. Ž
. Ž
. and E to only one food Food P or E at a location Table 2 .
3.1.1. Protein status Basal diet affected BUN levels of lambs. Lambs fed a diet low in protein had lower
Ž .
BUN levels than lambs fed a diet low in energy 7 vs. 53 mgrdl; P - 0.0001 . The Ž
. normal range of BUN for sheep is 10 to 26 mgrdl Merck, 1986 .
3.1.2. Familiar foods at constant locations Lambs fed basal diet P ate more Food E than Food P, whereas lambs fed basal diet E
Ž .
ate more Food P than Food E P - 0.05, Table 3 . Lambs fed basal diet P ate more E at Ž
. location mid — nearest source of Food E — than at location far P - 0.05, Table 3 .
Lambs fed basal diet E ate more P at locations near and mid — nearest sources of Food Ž
. P P - 0.05, Table 3 . The average intake at the near, mid, and far locations was 43, 52,
and 20 g, respectively, for both groups of lambs. Diet, location, and day did not interact Ž
. P 0.05 .
3.1.3. Variety location Basal diet affected food choice at the variety location. Lambs fed basal diet P ate
more Food E when Foods P and E were offered at one location than at separate locations Ž
. 98 vs. 38 g ; they ate the same amount of Food P whether it was offered with Food E or
Ž .
singly 14 vs. 14 g . Conversely, lambs fed basal diet E ate similar amounts of Food P Ž
. whether it was offered with Food E or singly 76 vs. 73 g ; they ate more Food E when
Ž .
it was offered with Food P than when it was offered singly 23 vs. 2 g . 3.2. Trial 2: familiar foods at changing locations
Lambs fed nutrient-imbalanced diets changed foraging location as the locations of the Ž
. foods changed on days 24 and 25 Table 2 . Lambs maintained on basal diet P fed most
Table 3 Ž
. Ž
Intake gr15 min of foods by lambs fed a basal diet that was either low in energy and high in protein Food .
Ž .
P or high in energy and low in protein Food E during Trial 1
1
Basal diet Location and Foods
Near Mid
Far P
P E
E SE
a a
a b
Ž .
Food P low energy 14
14 98
38 8.4
a a
a b
Ž .
Food E low protein 73
76 23
2 8.4
1
See Table 1 for composition of Foods P and E.
a,b
Ž .
Means in rows within a food type having different superscripts differ P -0.05 .
Table 4 Ž
. Intake gr15 min of foods at three locations by lambs fed a basal diet that was either high in protein and low
Ž .
Ž .
in energy Food P or high in energy and low in protein Food E during Trial 2 when foods changed location
1
Basal diet Locations and Foods
Near Mid
Far P
E P
E P
E Food P
a a
a a
day 24 –
153 6
– 0.5
19
a a
a a
day 25 24
130 –
37 0.5
– Food E
b b
a a
day 24 –
58 101
– 10
11
b b
a a
day 25 90
66 –
18 9
– SE
12.9 12.9
12.9 12.9
12.9 12.9
1
Ž .
See Table 1 for composition of basal diets and foods .
a,b
Ž .
Means in a column having a different superscript differ P -0.05 .
Ž at the near location — the nearest source of Food E — on days 24 and 25 P - 0.05,
. Table 4 . Lambs maintained on basal diet E fed most at the mid location — nearest
source of Food P — on day 24, and at near location — nearest source of Food P — on Ž
. Ž
day 25 P - 0.05, Table 4 . Lambs fed basal diet P ate less at the mid location 6 vs. .
Ž .
101 g on day 24 and more at the mid location 37 vs. 18 g on day 25 than lambs fed Ž
. basal diet E Table 4, P - 0.05 . Lambs fed basal diet E ate more Food P than lambs fed
Ž .
basal diet P 95 vs. 15 g; P - 0.05 . Conversely, lambs fed basal diet P ate more Food E Ž
. than lambs fed basal diet E 169 vs. 82 g; P - 0.05 .
3.3. Trial 3: noÕel foods at constant locations In Trial 3, lambs fed at the near location with the novel foods in favor of the far
location with familiar foods. Lambs in both treatments fed a significant amount at the Ž
. near location, and they preferred wheat to soybean meal Table 5 . Lambs fed basal diet
Table 5 Ž
. Ž
Intake gr15 min of foods by lambs fed a basal diet that was either high in protein and low in energy Food .
Ž .
P or high in energy and low in protein Food E during Trial 3
1
Ž .
Locationr Food gr 15 min
Basal diet SE
Ž .
Ž .
Food P high proteinrlow energy Food E high energyrlow protein
Near Location
a,c a,c
wheat 79
64 17
a,d a,d
soybean meal 23
25 17
Far Location
a,c b,c
Food P 8
77 17
a,d b,d
Food E 84
28 17
1
For ingredients and chemical composition of Food P and Food E see Table 1. Calculated values for wheat Ž
. Ž
. Ž
. and soybean meal for digestible energy DE , digestible protein DP , and crude protein CP are based on
Ž .
Ž .
values as fed basis obtained from the Nutrient Requirements of Sheep NRC, 1985 : wheat — 11 DP, 14 CP, 3.41 Mcalrkg DE; soybean meal — 42 DP, 45 CP, 3.48 Mcalrkg DE.
a,b
Means within row, and
c,d
means within a column and location, having different superscripts differ Ž
. LSD
s 35 .
0.05
Table 6 Ž
. Ž
Intake gr15 min of foods by lambs fed a basal diet that was either low in energy and high in protein Food .
Ž .
P or high in energy and low in protein Food E during Trial 3
1
Food offered Day
SE 1
2 3
Familiar foods
a a
a
Food E 59
52 57
4
a a
a
Food P 46
42 39
4 Novel foods
a a,b
b
wheat 57
77 81
4
a b
b
soybean meal 20
21 31
4
1
Ž See Table 1 for composition of Foods P and E and Table 5 for composition of novel foods wheat and
. soybean meal .
a,b
Ž .
Means with different superscripts differ P s 0.05 .
P ate less Food P and more Food E than lambs fed basal diet E, whereas the reverse was Ž
. true for lambs fed basal diet E P - 0.007; Table 5 . Throughout the 3-day trial, lambs
Ž .
in both groups did not change the amount of Foods P and E eaten P 0.05; Table 6 , but intake of the novel foods — wheat and soybean meal — increased over days
Ž .
P - 0.002, Table 6 . Lambs increased the amount of novel foods eaten at the near Ž
. location 77 vs. 98 vs. 112 g , and did not change the amount of familiar foods eaten at
Ž .
Ž the far location 105 vs. 94 vs. 98 g from days 26 to 28 LSD
s 11; location = day
0.05
. interaction, P - 0.0007 .
4. Discussion
Kategori