animals
A icle
Cha ac e iza ion o he No mal Po al and Hepa ic
Blood Flow o Adul Hols ein-F iesian Cows
J. Daniel Ba ei o-Vázquez 1,2 , Ma a Mi anda 1,2,* , M. Isabel Ba ei o-Vilano a 2,3,
F. Ja ie Diéguez 1and And és Ba ei o-Lois 1,2
1Depa men o Ana omy, Animal P oduc ion and Clinical Ve e ina y Sciences, Facul y o Ve e ina y
Medicine, Uni e sidade de San iago de Compos ela, 27002 Lugo, Spain;
josedaniel.ba ei [email p o ec ed] (J.D.B.-V.); anciscoja ie [email p o ec ed] (F.J.D.); and es.ba ei [email p o ec ed] (A.B.-L.)
2Ve e ina y Teaching Hospi al “Ro -Codina”, Facul y o Ve e ina y Medicine,
Uni e sidade de San iago de Compos ela, 27002 Lugo, Spain
3Depa men o Physiology, Facul y o Ve e ina y Medicine, Uni e sidade de San iago de Compos ela,
27002 Lugo, Spain; ma iaisabel.ba ei [email p o ec ed]
*Co espondence: Ma a Mi anda. [email p o ec ed]
Recei ed: 21 Ma ch 2019; Accep ed: 19 June 2019; Published: 22 June 2019
Abs ac :
In he pas , hepa ic blood low in cows was in asi ely cha ac e ized o in es iga e
di e en pa hologies and physiological condi ions. Howe e , hepa ic blood low can be easily
e alua ed wi h ansabdominal Dopple ul asound. Six een heal hy adul non-lac a ing, non-p egnan
Hols ein-F iesian cows we e examined using B-mode and Dopple ul asound be ween he igh
lank and 9
h
in e cos al space o es ablish he bes app oach o he di e en pa s o he po al and
hepa ic ein sys ems, and de e mine no mal blood low cha ac e is ics. The main po al ein was
cha ac e ized by a u bulen , high- eloci y low due o he opposing con luence o he splenic and
c anial mesen e ic eins, while hepa ic and caudal ena ca a eins ha e lamina blood low, in which
he phasici y is conside ed mainly espi a o y in o igin. Re e ence alues we e de e mined in ela ion
o he ana omical poin o obse a ion. In conclusion, ansabdominal Dopple ul asound o he
po al sys em is a simple echnique ha allows non-in asi e cha ac e iza ion o po al and hepa ic
blood haemodynamics in cows.
Keywo ds: Dopple ul asound; cow; po al low; hepa ic low; po al ein; caudal ena ca a
1. In oduc ion
B-mode ul asound o he bo ine li e is well desc ibed bo h in physiologically no mal and
pa hological condi ions, and has also been used o guide pe cu aneous sampling and o he ypes
o expe imen s [
1
–
3
]. In asi e echniques ha e been used o s udy hepa ic hemodynamics [
1
,
3
–
6
].
Howe e , mo e ecen ly, Dopple ul asound has gained u he impo ance as a non-in asi e
echnique [
2
,
7
]. Dopple ul asound is a non-in asi ely diagnos ic imaging echnique ha has been
widely used in human and e e ina y medicine o cha ac e ize he blood low associa ed wi h
no mal and pa hological condi ions o he li e o as a e lec ion o sys emic condi ions in hepa ic
ci cula ion [
8
–
10
]. I has been used in cows o cha ac e ize he blood low in di e en essels and
condi ions (i.e., “milk ein” [
11
], musculoph enic ein in heal hy cows [
12
], d y and lac a ing
pe iods [
13
,
14
], and ca o id a e y and ex e nal jugula ein [
15
]). Only one epo has desc ibed he
po al ein low in cases o a y li e disease [
2
], and, as a we a e awa e, no Dopple e e ence alues
o po al and hepa ic eins ha e ye been published in he ele an li e a u e.
Animals 2019,9, 386; doi:10.3390/ani9060386 www.mdpi.com/jou nal/animals
Animals 2019,9, 386 2 o 12
The aim o his s udy was o de e mine he no mal ea u es o po al and hepa ic blood low in
dai y ca le as a basis o u he cha ac e iza ion o di e en physiological a ia ions and pa hologies,
and o s anda dize an ul asonog aphic Dopple p o ocol as in o he species.
2. Ma e ials and Me hods
All expe imen s pe o med ollowed Spanish s anda ds o he p o ec ion o animals used o
scien i ic pu poses. The p ocedu es applied we e supe ised by he Bioe hics Commi ee o he
Ro -Codina Ve e ina y Teaching Hospi al, Uni e si y o San iago de Compos ela (Lugo, Spain), and
quali ied as non-in asi e.
2.1. Animals
Six een heal hy non-lac a ing, non-p egnan adul Hols ein-F iesian cows anging in age
om 4.3 o 10.1 yea s (mean 6.0 yea s), wi h a mean weigh o 540 kg ( ange om 470 o 604 kg) we e
used. Animals ecei ed a daily main enance a ion o hay p o ided ad libi um and 2 kg o concen a e
(gi en in wo equal a ions a abou 8:00 and 19:00) h oughou he whole s udy pe iod. All animals had
a no mal hema ological, biochemical, and u ine analyses [
16
]. The cows we e held in he ins alla ions
o he Ro -Codina Ve e ina y Teaching Hospi al, Uni e si y o San iago de Compos ela, Spain.
2.2. B-Mode and Colo Dopple Ul asonog aphy
Fo his p ocedu e, animals we e s anding in s ocks wi hou seda ion. Hai was clipped and he
skin washed be ween he igh lank and he 5
h
igh in e cos al space (ICS) [
1
], and be ween he
do sum and a line c ossing om he elbow o he igh knee. Ul asound gel was hen applied o
ensu e good con ac be ween he p obe and he skin. A comple e B-mode [
1
], colo , and pulsed-wa e
Dopple ul asound examina ion o he po al and hepa ic ein sys ems was pe o med wi h a con ex
a ay ansduce (1–9 MHz) (Esao e MyLab-ClassC
®
, Esao e, Ba celona, Spain) by he same ope a o
(JDBV), be ween 17:00 and 19:00 (a schema ic d awing o he ana omy unde in es iga ion is shown
in Figu e 1).
Animals 2019, 9, x 2 o 12
po al ein low in cases o a y li e disease [2], and, as a we a e awa e, no Dopple e e ence
alues o po al and hepa ic eins ha e ye been published in he ele an li e a u e.
The aim o his s udy was o de e mine he no mal ea u es o po al and hepa ic blood low in
dai y ca le as a basis o u he cha ac e iza ion o di e en physiological a ia ions and
pa hologies, and o s anda dize an ul asonog aphic Dopple p o ocol as in o he species.
2. Ma e ials and Me hods
All expe imen s pe o med ollowed Spanish s anda ds o he p o ec ion o animals used o
scien i ic pu poses. The p ocedu es applied we e supe ised by he Bioe hics Commi ee o he
Ro -Codina Ve e ina y Teaching Hospi al, Uni e si y o San iago de Compos ela (Lugo, Spain), and
quali ied as non-in asi e.
2.1. Animals
Six een heal hy non-lac a ing, non-p egnan adul Hols ein-F iesian cows anging in age om
4.3 o 10.1 yea s (mean 6.0 yea s), wi h a mean weigh o 540 kg ( ange om 470 o 604 kg) we e
used. Animals ecei ed a daily main enance a ion o hay p o ided ad libi um and 2 kg o
concen a e (gi en in wo equal a ions a abou 8:00 and 19:00) h oughou he whole s udy pe iod.
All animals had a no mal hema ological, biochemical, and u ine analyses [16]. The cows we e held
in he ins alla ions o he Ro -Codina Ve e ina y Teaching Hospi al, Uni e si y o San iago de
Compos ela, Spain.
2.2. B-Mode and Colo Dopple Ul asonog aphy
Fo his p ocedu e, animals we e s anding in s ocks wi hou seda ion. Hai was clipped and he
skin washed be ween he igh lank and he 5 h igh in e cos al space (ICS) [1], and be ween he
do sum and a line c ossing om he elbow o he igh knee. Ul asound gel was hen applied o
ensu e good con ac be ween he p obe and he skin. A comple e B-mode [1], colo , and pulsed-wa e
Dopple ul asound examina ion o he po al and hepa ic ein sys ems was pe o med wi h a
con ex a ay ansduce (1–9 MHz) (Esao e MyLab-ClassC®, Esao e, Ba celona, Spain) by he same
ope a o (JDBV), be ween 17:00 and 19:00 (a schema ic d awing o he ana omy unde in es iga ion
is shown in Figu e 1).
Figu e 1. Schema ic d awing o he main essels included in his s udy. Blue essels = A—Caudal
ena ca a, B—Hepa ic essels; G een essels = C—C anial mesen e ic ein, D—Splenic ein,
Figu e 1.
Schema ic d awing o he main essels included in his s udy. Blue essels =A—Caudal ena
ca a, B—Hepa ic essels; G een essels =C—C anial mesen e ic ein, D—Splenic ein, E—Main Po al
ein, F—Po al b anches. G.B. =Gall Bladde . A ows show di ec ion o blood. Numbe s indica e
speci ic in e cos al spaces.
Animals 2019,9, 386 3 o 12
Fo comple e cha ac e iza ion o hepa ic blood low, we conside ed he main po al ein and i s
ibu a ies (c anial mesen e ic and splenic eins), in ahepa ic po al b anches, caudal ena ca a, and
hepa ic eins.
Fo each essel s udied, Dopple measu emen s we e made by aligning he p obe as needed o
ob ain a sagi al image o he essel wi h he smalles achie able angle o insona ion (always less han
60
◦
o angle co ec ion in Dopple measu emen s), wi h a sample olume o 4–9 mm loca ed in he
cen e o he essel (depending on essel size) o ob ain he blood low spec um. The Dopple spec um
was quali a i ely e alua ed o ca diac and espi a o y phasici y by compa ing he oscilla ions in he
Dopple ace wi h he ca diac equency (ob ained by pulse palpa ion and p io Dopple e alua ion
o he ao a) and wi h espi a o y mo ions ( isually obse ed). Mean eloci y (Vmean), maximum
eloci y (Vmax), e e se maximum eloci y (V e ), and blood low (F) we e measu ed a leas 3 imes
in each essel o each access poin wi h he buil -in so wa e o he ul asound machine and he
maximum eloci y me hod [
17
] o Vmean and F. In o de o calcula e he F pa ame e , he diame e o
he essel was measu ed in he same image and sagi al plane as he Dopple spec um.
2.3. S a is ical Analysis
All s a is ical analyses we e conduc ed using SPSS o Windows (Ve sion 21, IBM Co p.,
A monk, NY, USA
). The no mali y o da a dis ibu ion was checked using he Kolmogo o -Smi no
es . One-way ANOVA was used o check o possible di e ences a ibu able o age and weigh .
3. Resul s and Discussion
3.1. Gene al
In all cows, he li e was clea ly isible by ul asonog aphy be ween he igh lank and he igh
8
h
ICS, as p e iously desc ibed [
1
], excep in one cow in which i was only isible om he 11
h
ICS.
None o he cows examined had any B-mode ul asonog aphic abno mali ies in he li e o adjacen
s uc u es. The po al ein and i s po al b anches we e en ola e al o he hepa ic enous sys em and
caudal ena ca a, as p e iously desc ibed [1,18].
Dopple measu emen s we e made be ween he igh lank and he 9
h
ICS. No u he c anial
Dopple signals could be ob ained because o he absence o li e pa enchyma, small essel size, o he
pa enchyma being hidden by he lung.
The mean eloci y can be ob ained by di e en me hods [
17
,
19
]: di ec ly wi h he ul asound
so wa e, including he whole essel diame e wi hin he sample size (uni o m insona ion me hod); o
by es ima ion, de e mining he maximum eloci y (by one-o measu emen o om a ace, as in ou
case) o he Dopple spec um and mul iplied by an a i hme ic ac o o 0.57 o co ec ly es ima e mean
eloci y [
17
]. We applied he a e age maximum eloci y me hod o ou measu emen s o iden i y
whe he u bulence was a ibu able o a dis u bed low o issue noise (main p oblem wi h he uni o m
insona ion me hod). Di e en au ho s ha e used a non-co ec ed a e age maximum eloci y p o ile
me hod, and a co ec ion ac o o 0.57 mus hus be applied o he alues epo ed [
2
,
7
,
13
,
14
] o bo h
Vmean and F alues (which depend on he i s ac o ). In he maximum eloci y me hod, he Dopple
spec um is measu ed o e a small egion ( e e ed o as “sample olume”) in he cen e o he essel.
Howe e , as a esul o espi a o y mo emen s, which sligh ly al e he posi ion o he abdominal
s uc u es, he sample is no always in he cen e o he essel. This can lead o a i ac ual u bulence
due o issue mo ion, as in he insona ion me hod. Howe e , in ou expe ience, issue mo ion does no
g ea ly a ec he Dopple spec um ob ained, as he essel diame e is la ge enough o ensu e ha he
sample emains wi hin he essel lumen mos o he ime.
As wi h enous low, measu emen s mus be adequa e o depic he ype o low (lamina s.
u bulen ) and phasici y, i i exis s. Fo his pu pose, some au ho s ha e used pulsa ili y indices
( enous pulsa ili y index (VPI)) as desc ibed o humans [
2
,
20
], unde he assump ion ha he
a ia ions encoun e ed in po al low a e ca diac in o igin. As we ound no signi ican ca diac in luence
Animals 2019,9, 386 4 o 12
bu a espi a o y in luence in Dopple wa e o m, we conside ed ha VPI was no app op ia e o
cha ac e izing he po al ein Dopple spec um. We ob ained Vmax and V e in addi ion o F and
Vmean o cha ac e ize he po al and hepa ic blood low, simila ly o o he au ho s [
7
,
13
,
14
], and
ep esen di e ences be ween lamina and u bulen low (di e ence be ween Vmax, V e , and Vmean).
As age and weigh did no in luence any o he a iables, all cows we e included in a single g oup.
The esul s a e p esen ed as a i hme ic means, 95% con idence in e al (CI), median, minimum, and
maximum alues. As measu emen s can a y depending on he access poin , we conside ed hose
measu es aken h ough he ICS wi h he highes numbe o alid obse a ions ob ained (mos equen
ICS o each essel) in o de o es ablish e e ence alues.
3.2. Po al Sys em
In o de o cha ac e ize he po al sys em, we conside ed he splenic and c anial mesen e ic eins,
which a e he main essels con o ming he po al ein (no p e iously desc ibed used ul asound).
They ha e a cha ac e is ic ypical iden i iable in e ed T-shape image (Figu e 2), which can be use ul
o iden i ying hese essels in he ul asound examina ion. This image is ob ained in an oblique
ans e se plane, whe e he splenic ein comes om he medial side o he abdomen joining he c anial
mesen e ic ein ha a els wi h a caudola e al o c aniomedial di ec ion, o con o m a sho hick
main po al ein in an almos pe pendicula o ien a ion om he a o emen ioned wo essels.
Animals 2019, 9, x 4 o 12
app op ia e o cha ac e izing he po al ein Dopple spec um. We ob ained Vmax and V e in
addi ion o F and Vmean o cha ac e ize he po al and hepa ic blood low, simila ly o o he au ho s
[7,13,14], and ep esen di e ences be ween lamina and u bulen low (di e ence be ween Vmax,
V e , and Vmean).
As age and weigh did no in luence any o he a iables, all cows we e included in a single
g oup. The esul s a e p esen ed as a i hme ic means, 95% con idence in e al (CI), median,
minimum, and maximum alues. As measu emen s can a y depending on he access poin , we
conside ed hose measu es aken h ough he ICS wi h he highes numbe o alid obse a ions
ob ained (mos equen ICS o each essel) in o de o es ablish e e ence alues.
3.2. Po al Sys em
In o de o cha ac e ize he po al sys em, we conside ed he splenic and c anial mesen e ic
eins, which a e he main essels con o ming he po al ein (no p e iously desc ibed used
ul asound). They ha e a cha ac e is ic ypical iden i iable in e ed T-shape image (Figu e 2), which
can be use ul o iden i ying hese essels in he ul asound examina ion. This image is ob ained in
an oblique ans e se plane, whe e he splenic ein comes om he medial side o he abdomen
joining he c anial mesen e ic ein ha a els wi h a caudola e al o c aniomedial di ec ion, o
con o m a sho hick main po al ein in an almos pe pendicula o ien a ion om he
a o emen ioned wo essels.
Figu e 2. Ul asound image showing he ypical in e ed “T” shape o he image due o he
con luence o he splenic (a owhead) and c anial mesen e ic eins (*), con o ming he main po al
ein (#) a he po a hepa is. Image ob ained in a sligh ly c aniocaudal o ien a ion in he 11 h in e cos al
space (dep h is shown on he igh o he image). Do sal loca ion is on he le o he image. Caudal
ena ca a is loca ed o he le o he image (small a ow).
The c anial mesen e ic (Table 1) and splenic eins (Table 2) we e mainly isualized in he 12 h
and 11 h ICS. Some di icul ies may be encoun e ed when ying o align he c anial mesen e ic ein
app op ia ely o Dopple examina ion be ween he ibs, because o i s pa allel posi ion in ela ion o
he abdominal wall. The ansduce mus he e o e be angled o ob ain adequa e insona ion angles
(<60°). Al hough he splenic ein always has a sui able angle o insona ion, i s deep loca ion can
some imes dec ease he Dopple signal. These essels ha e a ypical lamina hepa ope al low ha
g adually u ns in o a u bulen low when hey use o o m he main po al ein, whe e he
u bulence is maximal (Figu e 3).
Figu e 2.
Ul asound image showing he ypical in e ed “T” shape o he image due o he con luence
o he splenic (a owhead) and c anial mesen e ic eins (*), con o ming he main po al ein (#) a he
po a hepa is. Image ob ained in a sligh ly c aniocaudal o ien a ion in he 11
h
in e cos al space (dep h
is shown on he igh o he image). Do sal loca ion is on he le o he image. Caudal ena ca a is
loca ed o he le o he image (small a ow).
The c anial mesen e ic (Table 1) and splenic eins (Table 2) we e mainly isualized in he 12
h
and 11
h
ICS. Some di icul ies may be encoun e ed when ying o align he c anial mesen e ic ein
app op ia ely o Dopple examina ion be ween he ibs, because o i s pa allel posi ion in ela ion o
he abdominal wall. The ansduce mus he e o e be angled o ob ain adequa e insona ion angles
(<60
◦
). Al hough he splenic ein always has a sui able angle o insona ion, i s deep loca ion can
some imes dec ease he Dopple signal. These essels ha e a ypical lamina hepa ope al low ha
g adually u ns in o a u bulen low when hey use o o m he main po al ein, whe e he u bulence
is maximal (Figu e 3).
Animals 2019,9, 386 5 o 12
Animals 2019, 9, x 5 o 12
Figu e 3. Dopple spec um o he po al sys em, om a e en essels o i s main bi u ca ion wi hin
he li e . The images clea ly show how po al low changes om a mainly lamina o a u bulen
low, e u ning g adually o lamina . (A) splenic ein, (B) c anial mesen e ic ein (Mes C ), (C) main
po al ein, and (D) igh po al b anch (Po a D). Whi e a owhead depic s maximum e e se low
in he main po al ein.
Table 1. Resul s o ul asonog aphy examina ion o he c anial mesen e ic ein exp essed as mean
(95% con idence in e al) and median (minimum-maximum). Values ob ained in he mos equen
loca ion a e highligh ed in bold.
Loca ion Flank 12 ICS 11 ICS 10 ICS 9 ICS
No. o obse a ions (no. cows)
Gene al 10 (3) 34 (8) 30 (7) 3 (1) NA
Re e se maximum eloci y 4 (1) 17 (5) 17 (6) 3 (1) NA
Mean eloci y (cm/s)
Mean (95% CI) 15.0 (12.8–17.3) 16.0 (15.0–17.1) 13.8 (13.1–14.6) 17.5 (7.2–27.7) NA
Median (min-max) 13.7 (11.4–20.5) 15.7 (10.8–21.7) 14.2 (9.7–17.1) 15.4 (14.8–22.2)
Maximum eloci y (cm/s)
Mean (95% CI) 37.8 (32.9–42.7) 39.1 (35.7–42.4) 34.3 (32.4–36.3) 41.0 (10.8–71.2) NA
Median (min–max) 37.0 (29.0–51.0) 36.0 (28.0–60.0) 34.5 (24.0–47.0) 35.0 (33.0–55.0)
Re e se maximum eloci y (cm/s)
Mean (95% CI) 23.0 (9.8–36.2) 19.9 (16.1–23.7) 16 (13–19) 21.7 (16.5–26.8) NA
Median (min–max) 25.5 (11.0–30.0) 19.0 (9.0–34.0) 17.0 (8.0–26.0) 21.0 (20.0-24.0)
Blood low (F)
L/min Mean (95% CI) 3.44 (2.37–4.51) 3.93 (3.37–4.48) 2.98 (2.66–3.31) 4.35 (3.05–5.65) NA
Median (min–max) 2.78 (1.08–6.01) 3.57 (1.93–7.78) 3.14 (1.01–4.06) 4.19 (3.92–4.93) NA
ml/min/kg Mean (95% CI) 6.88 (4.41–9.35) 7.42 (6.5–8.34) 5.86 (5.11–6.61) 8.14 (5.71–10.6) NA
Median (min–max) 5.2 (3.25–12.8) 7.4 (3.63–13.1) 6.05 (1.81–9.16) 7.85 (7.34–9.24) NA
ICS: in e cos al space; NA: no accessible; CI: con idence in e al.
Figu e 3.
Dopple spec um o he po al sys em, om a e en essels o i s main bi u ca ion wi hin
he li e . The images clea ly show how po al low changes om a mainly lamina o a u bulen low,
e u ning g adually o lamina . (
A
) splenic ein, (
B
) c anial mesen e ic ein (Mes C ), (
C
) main po al
ein, and (
D
) igh po al b anch (Po a D). Whi e a owhead depic s maximum e e se low in he
main po al ein.
Table 1.
Resul s o ul asonog aphy examina ion o he c anial mesen e ic ein exp essed as mean
(95% con idence in e al) and median (minimum-maximum). Values ob ained in he mos equen
loca ion a e highligh ed in bold.
Loca ion Flank 12 ICS 11 ICS 10 ICS 9 ICS
No. o obse a ions (no. cows)
Gene al 10 (3) 34 (8) 30 (7) 3 (1) NA
Re e se maximum eloci y 4 (1) 17 (5) 17 (6) 3 (1) NA
Mean eloci y (cm/s)
Mean (95% CI) 15.0 (12.8–17.3) 16.0 (15.0–17.1) 13.8 (13.1–14.6) 17.5 (7.2–27.7) NA
Median (min-max) 13.7 (11.4–20.5) 15.7 (10.8–21.7) 14.2 (9.7–17.1) 15.4 (14.8–22.2)
Maximum eloci y (cm/s)
Mean (95% CI) 37.8 (32.9–42.7) 39.1 (35.7–42.4) 34.3 (32.4–36.3) 41.0 (10.8–71.2) NA
Median (min–max) 37.0 (29.0–51.0) 36.0 (28.0–60.0) 34.5 (24.0–47.0) 35.0 (33.0–55.0)
Re e se maximum eloci y (cm/s)
Mean (95% CI) 23.0 (9.8–36.2) 19.9 (16.1–23.7) 16 (13–19) 21.7 (16.5–26.8) NA
Median (min–max) 25.5 (11.0–30.0) 19.0 (9.0–34.0) 17.0 (8.0–26.0) 21.0 (20.0-24.0)
Blood low (F)
L/min Mean (95% CI) 3.44 (2.37–4.51) 3.93 (3.37–4.48) 2.98 (2.66–3.31) 4.35 (3.05–5.65) NA
Median (min–max) 2.78 (1.08–6.01) 3.57 (1.93–7.78) 3.14 (1.01–4.06) 4.19 (3.92–4.93) NA
ml/min/kg Mean (95% CI) 6.88 (4.41–9.35) 7.42 (6.5–8.34) 5.86 (5.11–6.61) 8.14 (5.71–10.6) NA
Median (min–max) 5.2 (3.25–12.8) 7.4 (3.63–13.1) 6.05 (1.81–9.16) 7.85 (7.34–9.24) NA
ICS: in e cos al space; NA: no accessible; CI: con idence in e al.
Animals 2019,9, 386 6 o 12
Table 2.
Resul s o ul asonog aphy examina ion o he splenic ein exp essed as mean (95% CI) and
median (minimum–maximum). Values ob ained in he mos equen loca ion a e highligh ed in bold.
Loca ion Flank 12 ICS 11 ICS 10 ICS 9 ICS
No. o obse a ions (no. cows)
Gene al 3 (1) 35 (10) 40 (12) 9 (3) NA
Re e se maximum eloci y 3 (1) 19 (6) 8 (3) 2 (1) NA
Mean eloci y (cm/s)
Mean (95% CI) 27.2 (12.2–42.2) 24 (22.5–25.4) 24 (22.7–25.2) 20 (18.5–21.5) NA
Median (min–max) 26.2 (21.7–33.6) 23.9 (17.7–33.9) 23.4 (16.5–31.9) 19.9 (17.7–23.4) NA
Maximum eloci y (cm/s)
Mean (95% CI) 68.3 (36.4–99.9) 56.8 (53.3–60.2) 55.1 (52.5–57.7) 47 (42.5–51.5) NA
Median (min–max) 63 (59–83) 56 (39–79) 55 (41–78) 45 (42–57) NA
Re e se maximum eloci y (cm/s)
Mean (95% CI) 19.3 (9.9–28.7) 19.2 (16.1–22.3) 19.4 (15.6–23.2) 13.5 (7.1–19.8) NA
Median (min–max) 21.0 (15.0–22.0) 18.0 (10.0–31.0) 18.5 (13.0–26.0) 13.5 (13.0–14.0) NA
Blood low (F)
L/min Mean (95% CI) 4.17 (1.42–6.92) 3.95 (3.48–4.43) 3.58 (3.04–4.13) 2.37 (1.94–2.8) NA
Median (min–max) 3.63 (3.44–5.44) 3.73 (1.71–7.44) 3.17 (1.78–9.62) 2.24 (2–3.78) NA
ml/min/kg Mean (95% CI) 7.99 (2.71–13.3) 7.5 (6.56–8.43) 6.74 (5.82–7.67) 4.3 (3.65–4.95) NA
Median (min–max) 6.95 (6.58–10.4) 7.03 (3.37–13.4) 5.62 (3.5–16.2) 4.07 (3.38–6.36) NA
ICS: in e cos al space; NA: no accessible; CI: con idence in e al.
Conside ing he alues ob ained a he mos equen ICS o each essel, he splenic ein (12
h
ICS)
had highe alues o Vmean and Vmax han and simila F and V e alues o he c anial mesen e ic
ein (11 h ICS), indica ing a compa able con ibu ion o he po al blood low.
The po al ein and i s po al b anches could no be obse ed in he lank ( Table 3; Table 4).
The main po al ein can be explo ed longi udinally in a c aniocaudal o ien a ion mos ly in he 11
h
ICS (12/16). As al eady men ioned, i is some imes di icul o align he ul asound p obe wi hin he
in e cos al space o Dopple examina ion due o a small window o ul asound eco ding be ween
he ibs. The po al ein apidly ami ies in many po al b anches o di e en size ha a el in
mul iple di ec ions, obse ed c anially o he 12
h
ICS un il he 9
h
ICS. The igh and caudal lobe
b anches a e mul iple, a iable, and small, eme ging di ec ly om he main po al ein o om a
single/mul iple igh unk and, as lobe sepa a ion is no e iden in he bo ine li e , hese b anches
canno be con iden ly labelled by ul asound examina ion. This inding is consis en wi h desc ip ions
in he ana omical li e a u e [
18
,
21
] and is e e ed o occasionally as “s ella e b anches” [
1
] (Figu e 4A).
The la ges b anch ha can be iden i ied a elling deep en omedially co esponds o he p oximal
pa o he le po al ein o pa s ans e sa [18,21] (Figu e 4B).
Animals 2019, 9, x 6 o 12
Table 2. Resul s o ul asonog aphy examina ion o he splenic ein exp essed as mean (95% CI) and
median (minimum–maximum). Values ob ained in he mos equen loca ion a e highligh ed in
bold.
Loca ion Flank 12 ICS 11 ICS 10 ICS 9 ICS
No. o obse a ions (no. cows)
Gene al 3 (1) 35 (10) 40 (12) 9 (3) NA
Re e se maximum eloci y 3 (1) 19 (6) 8 (3) 2 (1) NA
Mean eloci y (cm/s)
Mean (95% CI) 27.2 (12.2–42.2) 24 (22.5–25.4) 24 (22.7–25.2) 20 (18.5–21.5) NA
Median (min–max) 26.2 (21.7–33.6) 23.9 (17.7–33.9) 23.4 (16.5–31.9) 19.9 (17.7–23.4) NA
Maximum eloci y (cm/s)
Mean (95% CI) 68.3 (36.4–99.9) 56.8 (53.3–60.2) 55.1 (52.5–57.7) 47 (42.5–51.5) NA
Median (min–max) 63 (59–83) 56 (39–79) 55 (41–78) 45 (42–57) NA
Re e se maximum eloci y (cm/s)
Mean (95% CI) 19.3 (9.9–28.7) 19.2 (16.1–22.3) 19.4 (15.6–23.2) 13.5 (7.1–19.8) NA
Median (min–max) 21.0 (15.0–22.0) 18.0 (10.0–31.0) 18.5 (13.0–26.0) 13.5 (13.0–14.0) NA
Blood low (F)
L/min Mean (95% CI) 4.17 (1.42–6.92) 3.95 (3.48–4.43) 3.58 (3.04–4.13) 2.37 (1.94–2.8) NA
Median (min–max) 3.63 (3.44–5.44) 3.73 (1.71–7.44) 3.17 (1.78–9.62) 2.24 (2–3.78) NA
ml/min/kg Mean (95% CI) 7.99 (2.71–13.3) 7.5 (6.56–8.43) 6.74 (5.82–7.67) 4.3 (3.65–4.95) NA
Median (min–max) 6.95 (6.58–10.4) 7.03 (3.37–13.4) 5.62 (3.5–16.2) 4.07 (3.38–6.36) NA
ICS: in e cos al space; NA: no accessible; CI: con idence in e al.
Conside ing he alues ob ained a he mos equen ICS o each essel, he splenic ein (12 h
ICS) had highe alues o Vmean and Vmax han and simila F and V e alues o he c anial
mesen e ic ein (11 h ICS), indica ing a compa able con ibu ion o he po al blood low.
The po al ein and i s po al b anches could no be obse ed in he lank ( Table 3; Table 4).
The main po al ein can be explo ed longi udinally in a c aniocaudal o ien a ion mos ly in he 11 h
ICS (12/16). As al eady men ioned, i is some imes di icul o align he ul asound p obe wi hin he
in e cos al space o Dopple examina ion due o a small window o ul asound eco ding be ween
he ibs. The po al ein apidly ami ies in many po al b anches o di e en size ha a el in
mul iple di ec ions, obse ed c anially o he 12 h ICS un il he 9 h ICS. The igh and caudal lobe
b anches a e mul iple, a iable, and small, eme ging di ec ly om he main po al ein o om a
single/mul iple igh unk and, as lobe sepa a ion is no e iden in he bo ine li e , hese b anches
canno be con iden ly labelled by ul asound examina ion. This inding is consis en wi h
desc ip ions in he ana omical li e a u e [18,21] and is e e ed o occasionally as “s ella e b anches”
[1] (Figu e 4A). The la ges b anch ha can be iden i ied a elling deep en omedially co esponds
o he p oximal pa o he le po al ein o pa s ans e sa [18,21] (Figu e 4B).
Figu e 4. B anching o he main po al ein. (A) One o he small b anches ha eme ge om he main
unk and en e he igh and middle hepa ic lobes. (B) The le po al ein is he la ges b anch ha
can be easily isualized owa ds he dis al and en al pa o he li e (le lobe). Tu bulen low can
be seen in bo h essels.
A B
Figu e 4.
B anching o he main po al ein. (
A
) One o he small b anches ha eme ge om he main
unk and en e he igh and middle hepa ic lobes. (
B
) The le po al ein is he la ges b anch ha
can be easily isualized owa ds he dis al and en al pa o he li e (le lobe). Tu bulen low can
be seen in bo h essels.
Animals 2019,9, 386 7 o 12
Rega ding blood low (Tables 3and 4), u bulence and F a e highe in he main po al ein
(cha ac e ized by high peak Vmax and high V e alues) and g adually dec ease in he po al b anches
owa ds he pe iphe y as he essels ape , eaching hei lowes eloci y a he 9
h
ICS. The esul s
indica e an inc ease in eloci y and low om he a e en essels, he splenic and c anial mesen e ic
eins, o he con luen main po al ein, which dis ibu es blood h oughou he li e pa enchyma
wi h a consequen ly g adually slowe speed and low as he po al eins dec ease in size. Simila ly,
u bulence a ies om minimum in he splenic and c anial mesen e ic eins o maximum in he main
po al ein, and hen dec eases g adually.
Ou indings a e consis en wi h hose o an in asi e expe imen [
5
], in which i was ound ha
he u bulen na u e o he po al ein low was due o a high angle o inse ion be ween splenic
and c anial mesen e ic eins. We hypo hesized ha u bulence in he main po al ein will no be a
consequence only o he opposi e o ien a ion o he splenic and mesen e ic eins, bu also o a la ge
inc ease in he diame e o he ein om hese o he main po al ein ha also gene a es u bulence in
longi udinal essels, no only in ami ica ions [19].
Table 3.
Resul s o ul asonog aphy examina ion o he po al ein exp essed as mean (95% CI) and
median (minimum–maximum). Values ob ained in he mos equen loca ion a e highligh ed in bold.
Loca ion Flank 12 ICS 11 ICS 10 ICS 9 ICS
N◦o obse a ions (n◦cows)
Gene al NA 16 (4) 48 (12) 25 (7) NA
Re e se maximum eloci y NA 16 (4) 48 (12) 21 (6) NA
Mean eloci y (cm/s)
Mean (95% CI) NA 26.6 (22.4–30.8) 23.4 (21.8–25) 25.5 (23–28) NA
Median (min–max) NA 23.9 (17.1–39.9) 24.2 (10.8–33.1) 23.9 (16.5–41.6) NA
Maximum eloci y (cm/s)
Mean (95% CI) NA 71.7 (59.2–84.3) 64.8 (60.3–69.2) 65.3 (58.9–71.7) NA
Median (min–max) NA 60 (46–111) 68.5 (29–93) 62 (46–113) NA
Re e se maximum eloci y (cm/s)
Mean (95% IC) NA 38.2 (31.5–44.9) 24.9 (22.2–27.5) 22.5 (17.5–27.4) NA
Median (min–max) NA 41 (16–57) 25.5 (8–43) 20 (9–54) NA
Blood low (F)
L/min Mean (95% CI) NA 13.3 (9.75–16.9) 13.1 (11.7–14.5) 12.4 (11.5–13.3) NA
Median (min–max) NA 12.2 (3.78–23.6) 13.5 (3.04–21.0) 12.1 (9.31–17.0) NA
ml/min/kg Mean (95% CI) NA 26.5 (18.9–34.2) 25.5 (23–28.1) 22.5 (21– 23.9) NA
Median (min–max) NA 23.1 (8.05–50.3) 27 (5.82–40.8) 21.8 (16.4–29.3) NA
ICS: in e cos al space; NA: no accessible; CI: con idence in e al.
Table 4.
Resul s o ul asonog aphy examina ion o he in ahepa ic po al eins exp essed as mean
(95% CI) and median (minimum–maximum). Values ob ained in he mos equen loca ion a e
highligh ed in bold.
Loca ion Flank 12 ICS 11 ICS 10 ICS 9 ICS
N◦o obse a ions (n◦cows)
Gene al NA 43 (9) 77 (15) 43 (12) 15 (4)
Re e se maximum eloci y NA 30 (7) 55 (14) 29 (9) 10 (2)
Mean eloci y (cm/s)
Mean (95% CI) NA 16.4 (15.0–17.8) 18.3 (17.3–19.2) 16 (14.5–17.5) 13.1 (10.5–15.7)
Median (min–max) NA 16.0 (9.1–29.1) 17.7 (8.0–28.5) 16.0 (5.1–25.9) 10.3 (8.0–20.5)
Maximum eloci y (cm/s)
Mean (95% CI) NA 44.5 (40.3–48.8) 50.9 (47.4–54.4) 42.3 (38.6–45.9) 34.3 (29.8–38.8)
Median (min–max) NA 42 (26–80) 46 (30–94) 42 (12–67.6) 33 (20.2–46)
Re e se maximum eloci y (cm/s)
Mean (95% CI) NA 22.2 (19.3–25) 21.6 (19.2–24) 18.1 (16.1–20.1) 18.2 (15.1–21.3)
Median (min–max) NA 24 (8–37) 19.2 (9–46) 19 (6–29) 18 (11–26)
Blood low (F)
L/min Mean (95% CI) NA 1.94 (1.47–2.4) 2.63 (2.25–3) 2.02 (1.52–2.51) 1.26 (0.92–1.6)
Median
(min–max) NA 1.84 (0.07–6.69) 2.31 (0.22–9.44) 1.79 (0.04–6.99) 1.18 (0.47–2.62)
ml/min/kg Mean (95% CI) NA 3.81 (2.84–4.77) 4.89 (4.22–5.57) 3.87 (2.97–4.77) 2.65 (1.79–3.51)
Median
(min–max) NA 3.62 (0.14–14.2) 4.26 (0.42–16.3) 3.68 (0.07–12) 2.47 (0.81–5.97)
ICS: in e cos al space; NA: no accessible; CI: con idence in e al.
Animals 2019,9, 386 8 o 12
Al hough he po al ein Dopple spec um is cha ac e ized by a ma ked u bulen hepa ope al
low, some phasici y can be obse ed and co ela ed wi h espi a o y mo emen s ha consequen ly
change abdominal p essu e and po al low (Figu e 5), as seen in dogs [
17
] and also in cows a e
in asi e examina ion [5].
Animals 2019, 9, x 8 o 12
Median (min–max) NA 3.62 (0.14–14.2) 4.26 (0.42–16.3) 3.68 (0.07–12) 2.47 (0.81–5.97)
ICS: in e cos al space; NA: no accessible; CI: con idence in e al.
Al hough he po al ein Dopple spec um is cha ac e ized by a ma ked u bulen hepa ope al
low, some phasici y can be obse ed and co ela ed wi h espi a o y mo emen s ha consequen ly
change abdominal p essu e and po al low (Figu e 5), as seen in dogs [17] and also in cows a e
in asi e examina ion [5].
Figu e 5. Va ia ion in Dopple phasici y o he po al ein a es (A) and wi h deep espi a o y
mo emen s (B), ob ained consecu i ely in he same animal and ana omical poin (11 in e cos al
space). Whi e a ows indica e inspi a ion mo emen s.
S a ke [2] conside ed he a ia ions ca diac in o igin and, as in his s udy, no ECG co ela ion
was ob ained, as he Dopple spec a could no be di ec ly co ela ed wi h ca diac cycle. Only 3 o
he 16 cows p esen ed e e se low in sys emic eins (Tables 5 and 6), showing ha pulsa ili y due o
ca diac cycle is much less likely o cause a ia ion in he po al ein blood low. We belie e ha i
hese a ia ions we e ca diac in o igin, phasici y in he hepa ic eins would be expec ed wi h
synch onous ca diac in luence as in humans o dogs; howe e , his was no obse ed. The e o e, we
should no e e o “pulsa ili y” o he po al ein, as he low is no pulsa ile, and he a ia ions
mus be caused by changes in abdominal p essu e (i.e., espi a o y cycle) and in he amoun o blood
emi ed by he gas oin es inal ac and spleen. Fu he mo e, based on s udies in humans [22],
sheep [23], and ca le [2,6,24,25], he po al blood low depends on pos u e, physical ac i i y, eed
in ake, age, and milk yield, which also in luence he size and hickness o he li e as body weigh
does. The co ela ion be ween s age o p egnancy and diame e o he po al ein may also in luence
he po al blood low [25]. In his s udy, as all cows we e gi en he same die and we e nei he
p egnan no lac a ing a he ime o in es iga ion, hese ac o s we e no in es iga ed and mus be
conside ed in u u e esea ch. Body weigh and age did no signi ican ly in luence he esul s, which
could he e o e be aken as e e ence alues o e alua e o he ac o s such as die , p egnancy, and
milk yield.
3.3. Caudal Vena Ca a and Hepa ic Veins
Hepa ic eins and caudal ena ca a we e bes isualized be ween he lank and he 11
h
ICS, bu
could be examined un il he 9
h
ICS o smalle and dis al hepa ic b anches. The bes app oach o he
caudal ena ca a (Table 5) was ob ained om he igh lank, whe e he ul asound p obe could be
Figu e 5.
Va ia ion in Dopple phasici y o he po al ein a es (
A
) and wi h deep espi a o y
mo emen s (
B
), ob ained consecu i ely in he same animal and ana omical poin (11 in e cos al space).
Whi e a ows indica e inspi a ion mo emen s.
S a ke [
2
] conside ed he a ia ions ca diac in o igin and, as in his s udy, no ECG co ela ion
was ob ained, as he Dopple spec a could no be di ec ly co ela ed wi h ca diac cycle. Only 3 o
he 16 cows p esen ed e e se low in sys emic eins (Tables 5and 6), showing ha pulsa ili y due o
ca diac cycle is much less likely o cause a ia ion in he po al ein blood low. We belie e ha i hese
a ia ions we e ca diac in o igin, phasici y in he hepa ic eins would be expec ed wi h synch onous
ca diac in luence as in humans o dogs; howe e , his was no obse ed. The e o e, we should no
e e o “pulsa ili y” o he po al ein, as he low is no pulsa ile, and he a ia ions mus be caused
by changes in abdominal p essu e (i.e., espi a o y cycle) and in he amoun o blood emi ed by
he gas oin es inal ac and spleen. Fu he mo e, based on s udies in humans [
22
], sheep [
23
], and
ca le [
2
,
6
,
24
,
25
], he po al blood low depends on pos u e, physical ac i i y, eed in ake, age, and milk
yield, which also in luence he size and hickness o he li e as body weigh does. The co ela ion
be ween s age o p egnancy and diame e o he po al ein may also in luence he po al blood
low [
25
]. In his s udy, as all cows we e gi en he same die and we e nei he p egnan no lac a ing a
he ime o in es iga ion, hese ac o s we e no in es iga ed and mus be conside ed in u u e esea ch.
Body weigh and age did no signi ican ly in luence he esul s, which could he e o e be aken as
e e ence alues o e alua e o he ac o s such as die , p egnancy, and milk yield.
3.3. Caudal Vena Ca a and Hepa ic Veins
Hepa ic eins and caudal ena ca a we e bes isualized be ween he lank and he 11
h
ICS, bu
could be examined un il he 9
h
ICS o smalle and dis al hepa ic b anches. The bes app oach o he
caudal ena ca a (Table 5) was ob ained om he igh lank, whe e he ul asound p obe could be bes
aligned (c aniocaudal di ec ion), al hough i was achie able om he 12
h
(8/16) and he 11
h
ICS (4/16).
The igh and middle hepa ic eins and hei b anches a e ana omically a iable [
18
] bu
consis en ly isualized wi h an easy alignmen o Dopple in es iga ion because o hei la e omedial
o ien a ion, which allows insona ion angles close o 0◦in many ins ances (Figu e 6).
Animals 2019,9, 386 9 o 12
Animals 2019, 9, x 9 o 12
bes aligned (c aniocaudal di ec ion), al hough i was achie able om he 12
h
(8/16) and he 11
h
ICS
(4/16).
The igh and middle hepa ic eins and hei b anches a e ana omically a iable [18] bu
consis en ly isualized wi h an easy alignmen o Dopple in es iga ion because o hei
la e omedial o ien a ion, which allows insona ion angles close o 0° in many ins ances (Figu e 6).
Figu e 6. Dopple spec a o he caudal ena ca a (A) and a hepa ic ein (B). A ypical lamina
enous low can be obse ed in bo h cases.
Table 5. Resul s o ul asonog aphy examina ion o he caudal ena ca a exp essed as mean (95% CI)
and median (minimum–maximum). Values ob ained in he mos equen loca ion a e highligh ed in
bold.
Loca ion Flank 12 ICS 11 ICS 10 ICS 9 ICS
No. o obse a ions (no. cows)
Gene al 56 (11) 29 (8) 16 (4) NA NA
Re e se maximum eloci y 12 (3) 0 (0) 0 (0) NA NA
Mean eloci y (cm/s)
Mean (95% CI) 19.9 (17.9–21.8) 18.1 (16.6–19.7) 16.5 (13.7–19.2) NA NA
Median (min–max) 18.6 (6.8–42.2) 18.2 (9.1–24.4) 15 (10–27) NA NA
Maximum eloci y (cm/s)
Mean (95% CI) 50.3 (45.8–54.9) 42.6 (39.3–46) 39 (33.4–44.6) NA NA
Median (min–max) 49 (18–110) 43 (17–57) 37 (23–61) NA NA
Re e se maximum eloci y (cm/s)
Mean (95% CI) 17.9 (13.1–22.7) * * NA NA
Median (min–max) 14.5 (8–30) * * NA NA
Blood low (F)
L/min Mean (95% CI) 4.58 (3.83–5.33) 6.09 (5.24–6.93) 3.94 (2.76–5.12) NA NA
Median (min–max) 4.33 (0.47–12.40) 5.51 (1.77–10.40) 3.04 (1.60–8.81) NA NA
ml/min/kg Mean (95% CI) 9.17 (7.51–10.80) 11.30 (9.71– 12.80) 7.17 (4.93– 9.41) NA NA
Median (min–max) 8.38 (1.08–30.10) 10.90 (3.05– 19.20) 5.52 (2.85– 16.90) NA NA
ICS: in e cos al space; NA: no accessible. * No e e se eloci y obse ed.
Hepa ic eins a e mainly ound be ween he 12
h
(11/16) and he 10
h
ICS (12/16), bu a e also
ound be ween he lank (4/16) and he 9
h
ICS (8/16) in some indi iduals (Table 6).
Table 6. Resul s o ul asonog aphy examina ion o he hepa ic eins exp essed as mean (95% CI)
and median (minimum–maximum). Values ob ained in he mos equen loca ion a e highligh ed in
bold.
Loca ion Flank 12 ICS 11 ICS 10 ICS 9 ICS
No. o obse a ions (no. cows)
Gene al 12 (4) 52 (11) 43 (12) 42 (11) 26 (8)
Re e se maximum eloci y 3 (1) 2 (1) 4 (1) 2 (1) 4 (1)
Mean eloci y (cm/s)
Mean (95% CI) 12.9 (9.9–16.0) 14.9 (13.7–16.2) 12.8 (11.9–13.8) 8.83 (7.98–9.69) 9.27 (8.33–10.2)
Median (min–max) 11.7 (7.4–21.7) 13.7 (7.4–26.8) 12.5 (7.4–19.4) 8.55 (5.1–17.1) 9.4 (5.7–13.9)
Figu e 6.
Dopple spec a o he caudal ena ca a (
A
) and a hepa ic ein (
B
). A ypical lamina enous
low can be obse ed in bo h cases.
Table 5.
Resul s o ul asonog aphy examina ion o he caudal ena ca a exp essed as mean (95% CI) and
median (minimum–maximum). Values ob ained in he mos equen loca ion a e highligh ed in bold.
Loca ion Flank 12 ICS 11 ICS 10 ICS 9 ICS
No. o obse a ions (no. cows)
Gene al 56 (11) 29 (8) 16 (4) NA NA
Re e se maximum eloci y 12 (3) 0 (0) 0 (0) NA NA
Mean eloci y (cm/s)
Mean (95% CI) 19.9 (17.9–21.8) 18.1 (16.6–19.7) 16.5 (13.7–19.2) NA NA
Median (min–max) 18.6 (6.8–42.2) 18.2 (9.1–24.4) 15 (10–27) NA NA
Maximum eloci y (cm/s)
Mean (95% CI) 50.3 (45.8–54.9) 42.6 (39.3–46) 39 (33.4–44.6) NA NA
Median (min–max) 49 (18–110) 43 (17–57) 37 (23–61) NA NA
Re e se maximum eloci y (cm/s)
Mean (95% CI) 17.9 (13.1–22.7) * * NA NA
Median (min–max) 14.5 (8–30) * * NA NA
Blood low (F)
L/min Mean (95% CI) 4.58 (3.83–5.33) 6.09 (5.24–6.93) 3.94 (2.76–5.12) NA NA
Median (min–max) 4.33 (0.47–12.40) 5.51 (1.77–10.40) 3.04 (1.60–8.81) NA NA
ml/min/kg Mean (95% CI) 9.17 (7.51–10.80) 11.30 (9.71– 12.80) 7.17 (4.93– 9.41) NA NA
Median (min–max) 8.38 (1.08–30.10) 10.90 (3.05– 19.20)
5.52 (2.85– 16.90)
NA NA
ICS: in e cos al space; NA: no accessible. * No e e se eloci y obse ed.
Hepa ic eins a e mainly ound be ween he 12
h
(11/16) and he 10
h
ICS (12/16), bu a e also
ound be ween he lank (4/16) and he 9 h ICS (8/16) in some indi iduals (Table 6).
Table 6.
Resul s o ul asonog aphy examina ion o he hepa ic eins exp essed as mean (95% CI) and
median (minimum–maximum). Values ob ained in he mos equen loca ion a e highligh ed in bold.
Loca ion Flank 12 ICS 11 ICS 10 ICS 9 ICS
No. o obse a ions (no. cows)
Gene al 12 (4) 52 (11) 43 (12) 42 (11) 26 (8)
Re e se maximum eloci y 3 (1) 2 (1) 4 (1) 2 (1) 4 (1)
Mean eloci y (cm/s)
Mean (95% CI) 12.9 (9.9–16.0) 14.9 (13.7–16.2) 12.8 (11.9–13.8) 8.83 (7.98–9.69) 9.27 (8.33–10.2)
Median (min–max) 11.7 (7.4–21.7) 13.7 (7.4–26.8) 12.5 (7.4–19.4) 8.55 (5.1–17.1) 9.4 (5.7–13.9)
Maximum eloci y (cm/s)
Mean (95% CI) 31.4 (24.0–38.8) 35.2 (32.1–38.2) 31.1 (28.7–33.5) 21.9 (19.8–24) 23.3 (20.9–25.6)
Median (min–max) 35 (18–53) 33 (19–71) 31 (18–52) 21 (11–38) 23 (15–36)
Re e se maximum eloci y (cm/s)
Mean (95% CI) 17.7 (8.94–26.4) 25.5 (19.1–31.8) 19 (8.69–29.3) 11 (–1.7–23.7) 7 (4.75–9.25)
Median (min–max) 18 (14–21) 26 (25–26) 21 (10–25) 11 (10–12) 7 (5–8)
Blood low (F)
L/min Mean (95% CI) 1.84 (0.77–2.92) 2.28 (1.86–2.7) 1.35 (1.03–1.67) 0.76 (0.63–0.9) 0.95 (0.69–1.22)
Median (min–max) 1.03 (0.19–4.92) 1.73 (0.32–5.38) 0.81 (0.3–3.71) 0.62 (0.19–1.61) 0.8 (0.09–2.72)
ml/min/kg Mean (95% CI) 4.13 (1.51–6.74) 4.43 (3.58–5.28) 2.65 (1.94–3.35) 1.47 (1.2–1.73) 1.86 (1.27–2.45)
Median (min–max) 2.2 (0.32–11.9) 3.61 (0.55–10.8) 1.6 (0.56–8.98) 1.21 (0.35–3.68) 1.47 (0.14–6.22)
ICS: in e cos al space; NA: no accessible.
