The preference for water nipples vs. water bowls in pregnant ewes

Abstract

This study included 6 groups of 6 pregnant ewes with a change-over design. In period 1 group 1, 2 and 3 had access to the water nipples and group 4, 5 and 6 had access to water bowls and vice versa in period 2. In period 3 all six groups had access to both types of water dispensers. The ewes’ water intake was significantly higher when drinking only from water nipples (3.27 ± 0.29 l/ewe and day) than only from water bowls (2.04 ± 0.22 l/ewe and day) (F = 78.28, P < 0.001). The water wastage for nipples was 36% of water usage and negligible for bowls. When offered both dispensers the ewes` water intake tended to be higher from water nipples (t = 0.69, P < 0.10), and there seemed to be no specific preference for water nipples or bowls in ewes.

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The preference for water nipples vs. water bowls
in pregnant ewes
Knut Egil Bøe, Ingjerd Dønnem, Cecilie Blakstad Løkken & Stine Grønmo
Kischel
To cite this article: Knut Egil Bøe, Ingjerd Dønnem, Cecilie Blakstad Løkken & Stine Grønmo
Kischel (2021): The preference for water nipples vs. water bowls in pregnant ewes, Acta
Agriculturae Scandinavica, Section A — Animal Science, DOI: 10.1080/09064702.2021.1886321
To link to this article: https://doi.org/10.1080/09064702.2021.1886321
© 2021 The Author(s). Published by Informa
UK Limited, trading as Taylor & Francis
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Published online: 23 Feb 2021.
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The preference for water nipples vs. water bowls in pregnant ewes
Knut Egil Bøe
a
, Ingjerd Dønnem
a
, Cecilie Blakstad Løkken
a
and Stine Grønmo Kischel
b
a
Department of Animal- and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway;
b
Department of Research and
Development, Farm Advisory Services, TINE SA, Ås, Norway
ABSTRACT
This study included 6 groups of 6 pregnant ewes with a change-over design. In period 1 group 1, 2
and 3 had access to the water nipples and group 4, 5 and 6 had access to water bowls and vice
versa in period 2. In period 3 all six groups had access to both types of water dispensers. The
ewes’water intake was significantly higher when drinking only from water nipples (3.27 ± 0.29 l/
ewe and day) than only from water bowls (2.04 ± 0.22 l/ewe and day) (F= 78.28, P< 0.001). The
water wastage for nipples was 36% of water usage and negligible for bowls. When offered both
dispensers the ewes` water intake tended to be higher from water nipples (t= 0.69, P< 0.10),
and there seemed to be no specific preference for water nipples or bowls in ewes.
ARTICLE HISTORY
Received 16 June 2020
Accepted 2 February 2021
KEYWORDS
Dry ewes; water dispensers;
preferences
Introduction
Dry matter intake, environmental temperature, advan-
cing pregnancy and lactation are important factors for
the need for water in sheep (Forbes, 1968). Long term
water deprivation is shown to lead to body weight loss
in ewes up to 26% (More & Sahni, 1978). It is however
interesting to notice that in lactating ewes with free
access to water and with the same management and
feeding regime, the variation between individuals in
daily water intake (FWI) was surprisingly large (CV =
27.6%), and that there also was a large variation from
day to day within individuals (Kischel et al., 2017).
When sheep and goats are kept indoors drinking
water can be provided either by water nipples or
water bowls. In freestall housing for dairy cows, water
troughs are also commonly used (Teixeira et al., 2006).
The fact that water nipples are simpler and cheaper
than water bowls is advantageous, but the high water
wastage from water nipples (piglets: 56%, Torrey et al.,
2008, growing-finishing pigs: 26%, Li et al., 2005, dairy
goats: 30%, Bøe et al., 2011) is disadvantageous.
The provision of water from different types of dispen-
sers might have an effect on both water intake, feed
intake and daily weight gain. Torrey et al. (2008) did
not find any effect on water intake, feed intake and
daily gain in weaned piglets when providing water
from nipples or bowls, whereas Bøe & Kjelvik (2011)
found that water intake and feed intake in weaned
piglets day 7–13 after weaning was higher for piglets
provided water from nipples. For dairy calves Hepola
et al. (2008) found no effect on water intake, feed
intake or daily gain when providing drinking water
from a bucket or a nipple. Providing water to dairy
goats either from nipples or bowls did not have an
effect on water intake (Bøe et al., 2011).
Another important issue is the animals’own prefer-
ence for different types of water dispensers. Torrey and
Widowski (2006) found that weaned piglets preferred a
bite nipple drinker to push-lever bowl drinker, but do
not mention anything about individual variation. In
dairy goats the preference for type of water dispenser
seem to vary both between groups and between individ-
uals (Bøe et al., 2011). In an experiment with dry dairy
goats, 3 of 6 groups preferred to drink from a nipple
rather than from a bowl, whereas 1 group preferred the
bowl and 2 groups showed no preference. Further, in
the same experiment testing lactating goats, none of
the 6 groups showed any preference for nipple or bowl.
To our knowledge, there are no data on the preference
for different types of water dispensers in sheep.
The aim of the present study was to examine the
water intake and water wastage when pregnant ewes
had access to drinking water from either water nipples
or water bowls and the ewes’preference for drinking
from nipples or bowls when having access to both
nipples and bowls. We predicted that the ewes would
prefer to drink from the nipples because of improved
water quality.
© 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-nc-
nd/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built
upon in any way.
CONTACT Knut Egil Bøe knut.boe@nmbu.no
ACTA AGRICULTURAE SCANDINAVICA, SECTION A —ANIMAL SCIENCE
https://doi.org/10.1080/09064702.2021.1886321

Materials and methods
The experiment were performed in January and Febru-
ary in 2014 at the sheep facilitiy at the Norwegian Uni-
versity for Life Sciences. The experiment was
performed according to Norwegian regulations concern-
ing animal use in experiments.
Experimental design
Thirty-six pregnant ewes were randomly allotted into
six groups with six ewes in each group and allocatedto
one of the six experimental pens 10 days before the
experiment started in order to get accustomed to
both types of water dispensers and the experimental
pens. In experimental period 1 (7 days) group 1, 2
and 3 had only access to the water nipples and group
4, 5 and 6 had only access to water bowls. In exper-
imental period 2 (7 days) group 1, 2 and 3 had only
access to the water bowls and group 4, 5 and 6 had
only access to water nipples. In experimental period 3
(7 days) all the six groups had access to both types of
water dispensers.
Housing and water equipment
The experiment was conducted in an insulated,
mechanically ventilated room with a mean air tempera-
ture of 6.2°C (range 4.3–7.9°C). Before the experiment
started, the ewes had been kept in the same room, in
pens with expanded metal flooring and with drinking
water supplied in water bowls. During the experiment
each group of six ewes were kept in expanded metal
flooring pens measuring 2.15 × 3.25 m, providing
1.16 m
2
per ewe.
One float water bowl (CF7, art no. 972 824 90
DeLaval®) and one nipple drinker (Lund Nipple
drinker no. 7, Lund Maskinfabrik A/S) was installed
in each pen 0.55 and 0.66 m above floor level on
the back wall of the pens, respectively. The flowrate
for each water dispenser was tested both before
and after the experiment, and for the nipple drinkers
the mean flowrate was 2.4 l/min (range 2.3–2.7 l/min)
and for the water bowls 2.7 l/min (range 2.0–4.0 l/
min). If the stockperson observed that there was hay
or manure in the water bowl, the bowl was cleaned,
and the polluted water was emptied in the waste-
water containers below the bowl.
Animals and feeding
A total of 36 pregnant ewes of the Norwegian White
Sheep breed from the University herd were selected so
that each group of six ewes had three ewes in first preg-
nancy, two ewes in second pregnancy and one ewe in
third pregnancy. At the start of the experiment, the
mean number of days in pregnancy was 40.8 + 1.8, and
there were only minor differences between groups.
When the ewes only had access to water nipples two
ewes were not observed drinking by the stockpersons
during the daily husbandry practices. Because of that
one ewe was removed from the experiment in exper-
imental period 1 after 6 days and another ewe was
removed after 4 days in experimental period 2. The
remaining 34 ewes had a mean body weight of 87.3 ±
11.1 kg at the start of the experiment and 87.9 ±
11.6 kg at the end of the experiment.
Grass hay (680 g DM/kg) was offered for ad libitum
intake twice daily at 08:00 and 14:00. Feed intake was
recorded by weighing the feed leftovers and the new
feed on an electronic balance both at the morning and
afternoon feeding for the three last days of each exper-
imental period. The ewes were supplied a mineral and
vitamin mixture, a mixture containing vitamin E, sel-
enium and biotin and had free access to salt lick (all Fell-
eskjøpet, Norway).
Water usage, water wastage and water intake
The water supply pipeline of each water dispenser was
connected to a water meter (Altaïr N°C05 A4). A small con-
tainer with a top made of metal grids was located under
each water dispenser in order to collect possible water
wastage (Figure 1). Every morning at 08:00 for the last
four days of each experimental period the water usage
was recorded by reading the water meters and the
water wastage in the containers were weighed on an
electronic balance. The water intake of the group was
then calculated as water usage minus water wastage.
All the water meters were calibrated both before and
after the experimental period.
Water quality
Water samples were collected from each water dis-
penser the last day in experimental period 1 and 2
and poured into sterilized and sealed plastic bottles.
In addition, a water sample was collected from a ster-
ilized water faucet in the animal room (control). The
samples were analysed for heterotrophy germs at
22°C (CFU/ml, method: NS-EN ISO 6222), coliform bac-
teria (cfu/100 ml, method: ISO 9308-1), turbidity (FNU,
method: NS EN ISO 7027-2) and Escherichia coli (CFU/
100 ml, method: NS-EN ISO 9308-1) at a certified
laboratory.
2K. E. BØE ET AL.

Behavioral observations
In order to obtain individual data, all the pens were
videorecorded for the three last 24 h periods (72 h in
total) in experimental period 3 by video cameraes
(FosCam Outdoor HD, model F19805W) suspended
right over the water dispensers and connected to a com-
puter using the video program Blue Iris 3. All the ewes
were marked on the neck/back in order identify the indi-
vidual animal. The duration of each drinking bout for
each ewe was scored from the video tapes using the
Solomon Coder and then summarized for each 24 h
period using the following ethogram:
.Drinking from the water nipple (the ewe has the
upper lip over the water nipple)
.Drinking from the water bowl (the ewe has her mouth
over the water bowl)
.Secondary drinking (drinking the wastewater from
another ewe drinking from the water nipple before
it comes down into the bucket)
Statistical analysis
This current study was a small study and hence a simple
descriptive approach was chosen when presenting the
results. The effect of treatment (water nipple and
water bowl) on water usage, water wastage, water
intake and feed intake (dry matter intake of hay) was
tested using a one-way analysis of variance (in Excel).
The mean ± SE for water usage, water intake and
wastage over the four observation days for each group
and the mean ± SE for feed intake over the three
sampling days for each group was used as statistical
unit. A paired t-test (in Excel) was used to test if the
Figure 1. The picture shows the set-up with the water nipple (left) and the water bowl (right) on the pen wall in experimental period
3. A bucket with a top made of metal grids is located under each water dispenser to collect possible water wastage.
Table 1. Water usage, water wastage and water intake (mean ± se, minimum and maximum in brackets) and dry matter intake of hay
(mean ± se) when providing drinking water from water bowls or water nipples.
Water nipple Water bowl F P
Number of ewes in each treatment 34 36
Water usage (l/ewe and day) 5.10 ± 0.26 (4.05 - 5.77) 2.05 ± 0.22 (1.26 - 2.88) 80.40 < 0.001
Water wastage (l/ewe and day) 1.83 ± 0.20 (1.16 - 2.48) 0.02 ± 0.01 (0.00 - 0.07) 78.28 < 0.001
Proportion water wastage (% of water usage) 36.1 0.7
Water intake (l/ewe and day) 3.27 ± 0.29 (2.57 - 4.50) 2.04 ± 0.22 (1.25 - 2.87) 11.21 <0.01
CV water intake (%) 8.9 10.9
Dry matter intake of hay (kg/ewe and day) 1.59 ± 0.03 1.67 ± 0.05 4.96 > 0.1
Note: One-way ANOVA was used to test differences between treatments. Proportion of water wastage and CV water intake (mean of 6 groups) is also
calculated.
ACTA AGRICULTURAE SCANDINAVICA, SECTION A —ANIMAL SCIENCE 3

water intake was higher from water nipples than from
water bowls in period 3.
Results
Water consumption and water wastage when
access to either nipple or bowl (Period 1 and 2)
Water usage was more than twice when water was pro-
vided from water nipples compared to when water was
provided from water bowls (Table 1). Water wastage
from water bowls was almost negligible (0.7% of water
usage) whereas mean water wastage from water
nipples was 36.1% of water usage. The water intake
was significantly higher when the ewes had access to
the water nipple than when the ewes had access to
the water bowl (Table 1).
However, the difference between groups within treat-
ments were large (see Table 1). When providing water in
water bowls, the water intake was more than double for
the group with the highest intake (2.87 l/ewe and day)
compared to the group with the lowest intake (1.25 l/
ewe and day). Even if the water intake was generally
higher when providing water in water nipples, the vari-
ation between groups (CV) was proportionally less (see
Table 1). The highest and lowest intake of water were
4.50 and 2.57 l/ewe and day when providing water in
water nipples.
In addition to the variation in water intake between
groups, there were also variation within groups
between observation days. When having access to
water nipples, the differencebetween the day with the
lowest and the day with the highest water intake was
minimum 0.45 l per ewe and maximum 1.46 l per ewe.
When having access to water bowls, the difference
between the day with the lowest and the day with the
highest water intake was minimum 0.45 l per ewe and
maximum 1.62 l per ewe. This is equivalent to 23.4% of
the water intake when using water nipples and 43.3%
of the water intake when using water bowls.
There was no difference between the groups in daily
hay intake (see Table 1).
Water consumption and water wastage when
access to both nipple and bowl (period 3)
The water intake tended to be higher from water nipples
than water bowls (t= 0.69, P< 0.10) when the ewes had
access to both types of water dispensers (Table 2), but
there were large differences between the groups. Four
groups had a numerical higher intake from water
nipples (> 60% of water intake) than from water bowl.
One of these four groups had as much as 92.3% of the
water intake from water nipple. The two last groups
had a numercial higher water intake (76.4% and 82.5%
of water intake) than from water nipples.
Individual preferences (behavioral observations)
Mean total drinking time (sum of drinking from bowl and
nipple per ewe) was 258.5 ± 32.1 sec/24 h ranging from
57.7 sec/24 h to 903.6 sec/24 h.
When both dispensers were offered,, three of the ewes
did not drink from the water bowl, but only from the
water nipple and two other ewes did not drink from the
nipple drinker, but only from the water bowl over the
72 h observation period. Of the other 29, 8 ewes did not
drink from the water nipple for 1 or 2 days, whereas 7
ewes did not drink from the water bowl for 1 or 2 days.
Twelve of the 34 ewes showed a clear preference (> 70%
of the time spent drinking) for water nipples whereas 14
ewes showed a clear preference for water bowls (Table 3).
Eight ewes showed no specific preference. Except from
group 3, where all the ewes preferred to drink from the
water bowl, all the other groups had some ewes preferring
the water nipple and some ewes preferring the water bowl.
Six ewes were observed to be secondary drinkers, and
three of these ewes 3–30% of their drinking time as sec-
ondary drinkers. Apart from this, they preferred to drink
from the water bowl.
Water quality
The water quality was better in the water nipples com-
pared to the water bowls (see Table 4).
Table 2. Water intake (mean over the four lasts days) from water
nipples and water bowls in experimental period 3.
Group
Water nipple
(l/ewe and
day)
Water bowl
(l/ewe and
day)
Total (l/
ewe and
day)
Proportion from
water nipple (% of
water intake)
1 0.5 1.5 2.0 23.6
2 1.9 0.8 2.7 71.2
3 0.5 2.2 2.7 17.5
4 1.6 0.6 2.2 71.7
5 2.7 0.2 2.9 92.8
6 1.8 1.1 2.9 62.4
Mean 1.5 1.1 2.6 58.3
Table 3. Individual preferences (> 70% of the time spent
drinking) for drinking from water nipples and water bowls.
Group
Preference for water
nipple (number of
ewes)
Preference for water
bowls (number of
ewes)
No preference
(number of ewes)
11 3 2
24 1 1
30 4 1
43 2 1
54 1 0
60 3 3
Total 12 14 8
4K. E. BØE ET AL.

Discussion
The water wastage was almost negligible from water
bowls, which is in agreement with other studies in
piglets (Phillips & Phillips, 1999, Torrey et al., 2008) and
in goats (Bøe et al., 2011). However, in piglets the
water wastage from bowls can be significant although
less than for nipples (Bøe and Kjelvik, 2011). For the
water nipples the water wastage was more than 36%
of water usage, which is comparable to studies on
dairy goats (Bøe et al, 2011), growing-finishing pigs (Li
et al., 2005) and piglets (Torrey et al., 2008; Bøe and
Kjelvik, 2011). One reason for the high water wastage
can be that the water in the nipple is provided faster
than the ewes actually can swallow, and that the
surplus water then will be water wastage. Li et al.
(2005) found that water wastage from water nipples
increased with increased flow rate in growing-finishing
pigs and that also the height of the nipple affected the
water wastage. In a housing system with totally slatted
floor pens this high water wastage will probably not
be a problem, but in pens with solid flooring/straw
bedding the waste water would make the bedding
surface wet, and this is of course disadvantageous.
Interestingly, the actual water intake was significantly
higher when water was provided from nipples than from
bowls. This is also shown in previous studies on piglets
(Torrey et al., 2008; Bøe & Kjelvik, 2011) but not for
dairy goats (Bøe et al., 2011) or dairy calves (Hepola
et al., 2008). One possible explanation is that the water
flows directly into the ewes’mouth and water is
ingested faster than natural drinking speed. Another
explanation is that they experienced that the water in
some way was ‘better’from the nipples. The water
quality analysis confirm that the water quality was
better from the water nipples. Phillips and Phillips
(1999) found that piglets at weaning consumed signifi-
cantly less water from uncleaned water bowls compared
to water bowls that were routinely cleaned.
The differences in water intake between the groups in
experimental period 1 and 2 were large, especially
between groups within treatments, and the relative
differences (CV) between groups seemed to be highest
on drinking bowls. It is difficult to explain these differ-
ences between the groups. Other studies of water
intake have mainly presented means and looked at
how factors like feed type and intake and temperature
affect water intake (eg. Forbes, 1968). In the present
study the intake of hay was numerically higher in the
water bowl treatment, even if the intake of water was
significantly lower. Interestingly, data presented by
Kischel et al. (2017) show that the daily intake of water
can be very different between individuals and also
between days within individuals.
Two ewes were removed from the experiment
because we were not sure that they had learned to
operate the nipple drinker. This may indicate that
some older ewes have problems learning this task.
However, in other studies with water nipples, equivalent
problems have not been mentioned (ewes: Bøe et al.,
2012, piglets: Torrey et al., 2008, goats: Bøe et al., 2011,
calves: Hepola et al., 2008). Phillips and Phillips (1999)
reported that weaned piglets, unfamiliar with nipple
drinkers consumed significantly less water the first day
when they were introduced to nipples, but at day four
the intake was higher than from bowls. This suggest
that these ewes probably were drinking when the stock-
persons were not in the barn looking after the ewes.
Data from period 3, when the ewes had access to
both nipples and bowls, showed that the intake of
water tended to be higher from nipples than from
bowls. The variation between groups were however
large. Two groups had numerically higher water intake
from water bowls and four groups from the water
nipple. When considering the fact that the ewes drank
significantly more from the water nipples than from
the water bowls in period 1 and 2, this result is as
expected. Also data from dairy goats (Bøe et al., 2011)
showed that water intake tended to be higher from
water nipples than from water bowls, and that the differ-
ences between groups are considerable.
Data from the behavioral observations of drinking
behavior in period 3 showed that some ewes never
drank from the water nipple and some ewes never
drank from the water bowl. Further, 12 of the 34 ewes
showed a clear preference (< 70% of the time spent
Table 4. Water quality when using water bowls and water nipples.
Period Pen
Test 1 2 3456Control
1 Heterotrophy germs at 22°C (cfu/ml) 60 70 140 >300 >300 >300 <1
1 Coliform bacteria (cfu/100 ml) <1 <1 <1
1 Turbidity (FNU) 0.1 0.1 0.1 0.77 4.1 1.9 <0.1
2 Heterotrophy germs at 22 °C (cfu/ml) >300 >300 >300 >300 >300 >300
2 Coliform bacteria (cfu/100 ml) <1 <1 <1
2 Turbidity (FNU) 5.6 2.6 3.4 0.27 0.54 0.33
Note: The shadows marks the results for the water nipples.
ACTA AGRICULTURAE SCANDINAVICA, SECTION A —ANIMAL SCIENCE 5

drinking) for water nipples whereas 14 ewes showed a
clear preference for the water bowl and eight ewes
showed no specific preference. Hence, there seem to
be no specific preference for either water nipples or
water bowls in ewes, which is in agreement with
results from dairy goats (Bøe et al., 2011). The data for
individual preferences must however be interpreted
with some caution. The data are based on observations
of drinking behavior and not actual intake of water. In
the behavioral observations we scored for drinking
when the ewe’s mouth was in contact with the nipple
or bowl, but the video pictures are not so detailed that
we know when water was actually ingested. Another
important factor to consider would be the speed of
drinking, and also drinking speed would probably vary
between individuals.
Because the ewes did not show any preference for
either water nipples or water bowls, we cannot rec-
ommend one over the other. However, water nipples
can be recommended due to better water quality, and
water bowls can be recommended due to low water
wastage.
We conclude that the water intake in ewes were sig-
nificantly higher when ewes had access only to water
nipples than when ewes only had access to water
bowls. The water wastage from water bowls was
almost negligible whereas mean water wastage from
water nipples was36.1% of water usage. When having
access to both water nipples and water bowls, water
intake only tended to be higher from water nipples
but there seem to be no specific preference for either
water nipples or water bowls in ewes.
Disclosure statement
No potential conflict of interest was reported by the author(s).
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