Suckling Behaviour of Piglets Affected by Body Weight and Sex
35
Suckling Behaviour of Piglets Affected  
by Body Weight and Sex
Martina DOBAJ GOMBOC1, Janko SKOK2, Dejan ŠKORJANC2, Maja PREVOLNIK POVŠE2* 
1Agricultural and Forestry Institute Murska Sobota, Ulica Štefana Kovača 40, 9000 Murska Sobota, Slovenia 
2University of Maribor, Faculty of Agriculture and Life Sciences, Pivola 10, 2311 Hoče, Slovenia
ABSTRACT
Piglet suckling behaviour has been extensively studied, but surprisingly, there are not many studies that specifically consider 
body weight and sex in this context. These two basic individual characteristics have been considered more as supporting data 
but not as main factors. Therefore, the objective of the present research was to examine the effect body weight on suckling 
behaviour of piglets during lactation separately by sex. The study comprised 14 litters with a total of 158 piglets (85 male, 73 
female, litter size 6−15 piglets). Suckling behaviour was described in terms of suckling position (the teat at which the piglet 
suckled during suckling), suckling territory (the range two outermost suckling positions of the piglet encompasses) and suckling 
stability (the tendency to suckle successively at the same position), and was observed in six periods: 0−3, 4−7, 8−10, 11−14, 15−21 
and 22−32 days of age. In each period, piglets were also weighed. The udder was divided into three areas: anterior (1st-2nd teat 
pair), middle (3rd-5th teat pair) and posterior (6th-8th teat pair). Body weight affected suckling behaviour differently in male 
and female piglets (i.e., all traits in females, suckling stability only in males). The relative body weight of females decreased 
significantly from the anterior towards the posterior part. Heavy females (but not males) suckled considerably more frequently 
on the anterior area. Heavier piglets (male and female) established more stable suckling order. Suckling territory of males 
was quite large, but did not differ among body weight classes. Interestingly, light females visited significantly larger suckling 
territory than heavy females. The present results fill a gap in the otherwise broad knowledge of pig suckling behaviour, which 
is of great importance for litter management during lactation, especially when cross-fostering is implemented. In this context, 
knowledge of the detailed role of sex and body weight is of particular importance because breeders rely mainly on basic body 
traits when managing litters.
Key words: pig, lactation, body weight, sex, suckling position, suckling stability, suckling territory
Agricultura Scientia 20: No 1: 35-42(2023)
https://doi.org/10.18690/agricsci.20.1.4
INTRODUCTION
The process of suckling in the pig, the only truly polytocous 
ungulate, is complex but has been extensively studied and 
is thus relatively well explained (McBride, 1963; Fraser, 1973; 
Fraser and Jones, 1975; Ewbank, 1976; Skok, 2015). In general, 
previous studies have shown that neonatal piglets begin to 
form suckling order immediately after birth, with a relatively 
stable teat order established as early as in the first few days 
of lactation (fully in the second week). The suckling order 
reduces conflicts between littermates and consequently 
increases the growth and survival rate of piglets (Fraser and 
Jones, 1975; Puppe and Tuchscrerer, 1999; Skok and Škorjanc, 
2014a). Further, it was generally found, that the anterior teat 
pairs are considered the most attractive to piglets (De Passille 
et al., 1988; Fraser, 1975; Fraser, 1984), however, the middle part 
of the udder was found to be most crowded, competitive 
and stressful environment with the highest frequency of 
fights/aggressive interactions (Skok and Škorjanc, 2013, 
2014a). Consequently, the stability of suckling order is lower 
in the middle of the udder and higher on both the anterior 
and posterior teat pairs (De Passille et al., 1988; Puppe and 
Tuchscrerer, 1999; Skok and Škorjanc, 2014a). According to the 
literature, several factors could affect teat selection mutually 
or in interaction such as the amount of milk produced in 
different parts of the udder (Jeppersen, 1982a), the specific 
smell and taste of the teats (Jeppersen, 1982b), the proximity of 
the sow’s head and vocalisation (Castren in sod., 1989; Kasanen 
*Correspondence to: 
E-mail: maja.prevolnik@um.si
Suckling Behaviour of Piglets Affected by Body Weight and Sex
36
in Algers, 2002), potential recognition of littermates (Ewbank 
in sod., 1974; McLeman in sod., 2005), aggression/fighting ability 
(Skok and Škorjanc, 2014b), morphological characteristics of 
the teats such as teat length and space between teats (English, 
1973; Jeppersen et al., 1982b), ancestral suckling preferences 
(Skok in Gerken, 2016) etc. 
Yet, suckling behaviour is also affected by several pig-
let-related factors such as the basic ones, body weight and 
sex. However, previous studies, although numerous, did not 
clearly explain the effect of body weight and sex of piglets on 
suckling behaviour. Such studies were rare, and body weight 
and sex appeared to be supporting information rather than 
influencing factors subjected to comprehensive analysis. 
First, body weight may play an important role in the selection 
of suckling position. However, the studies indicated only a 
tendency, if any, for heavier/larger piglets with higher dom-
inance rank in the social structure to occupy the anterior 
(and middle) teat pairs (Fraser and Jones, 1975; Orihuela in 
Solano, 1995; Puppe and Tuchschrerer, 1999; Skok et al., 2007, 
Skok & Škorjanc, 2013). Further, the effect of body weight 
on the suckling stability is even less clear. De Passille et al. 
(1988), for instance, showed a significant positive correlation 
between body weight and suckling stability after the fourth 
day of lactation. This is not entirely consistent with several 
other studies which showed higher suckling stability at both 
ends of the udder than at the middle teat pairs (Fraser, 1975; 
Puppe and Tuchscherer, 1999), as heavier piglets suckle at 
the front and lighter at the last teat pairs. Indirectly, the 
relationship between body weight and suckling stability was 
also studied through litter growth rate and litter size (faster 
growing litters and smaller litters showed more stable teat 
order; Winfield et al., 1974) or litter body weight variability 
(there was little evidence that higher variation in birth body 
weight allowed faster establishment of dominance; Milligan 
et al., 2001a). As for piglet sex, there is an even greater lack of 
studies directly addressing this issue. Rosillon-Warnier and 
Paquay (1984) found, for instance, that sex (in addition to 
birth weight and order) had no effect on teat order. Further, 
differences between the sexes were mainly related to dif-
ferences in body weight and aggressiveness (Milligan et al., 
2001b; Bonisoli-Alquati et al., 2010), which may implicitly be 
related also to suckling behaviour. 
A considerable gap in the understanding the complex 
relationship between body weight and sex of piglets and its 
effect on suckling behaviour was a motive for the present 
research. Our objective was to study the effect of piglet body 
weight on suckling behaviour in terms of suckling order 
stability, suckling position and the size of suckling territory 
(range) separately in male and female piglets. We hypothe-
sised that heavier piglets would establish a stable suckling 
order earlier, occupy the anterior and middle teat pairs more 
frequently and have a smaller suckling range. As for the sex 
of the piglets, similar behavioural patterns were expected in 
case of male and female piglets of different weights.
MATERIAL AND METHODS
Animals and housing
Data was collected at the Pig Research Centre of the Faculty 
of Agriculture and Life Sciences, University of Maribor in 
accordance with Animal Protection Act (Ur. 1. RS, No. 38/2013). 
The data set comprised 14 litters with a total of 158 piglets 
(85 male piglets and 73 female piglets). The size of the litters 
ranged from 6 to 15 piglets with a median of 10.5 piglets. 
Sows were of different breeds/crossings and were in different 
parities. During lactation, the sows with their litters were 
housed in conventional pens with farrowing crates. From the 
14th day of age, piglets were additionally offered solid feed. All 
piglets were individually marked on the back within 24 hours 
after birth. These markings were maintained until the end of 
lactation. Piglets were given ear numbers at the first weighing.
Performance of measurements
Measurements were carried out during lactation (from birth 
to weaning). Data comprised piglet characteristics (body 
weight and sex) and suckling behaviour parameters (suckling 
position, suckling territory and suckling stability). Sex of piglets 
was determined at birth. Piglets were weighed 6-times during 
lactation, always after observation of suckling behaviour. Body 
weight was further converted to relative body weight within 
each litter using the formula: relative body weight = (body 
weight – mean) / standard deviation. The values of relative 
body weight ranged from −2.75 to 2.29. Based on relative body 
weight, piglets were divided into three classes: light, medium 
and heavy piglets, with values of −0.5 and +0.5 as cut-off values 
between classes.
Behaviour observation
To determine the order of suckling, each piglet was observed 
individually. Therefore, data were collected by direct 
observation of sows and litters. Behavioural observations were 
carried out in six periods of lactation: 0−3, 4−7, 8−10, 11−14, 15−21 
and 22−32 days of age. At least two consecutive suckling sessions 
were considered on each observation day. The following was 
recorded: piglet identification and teat(s) visited throughout 
the suckling session (visited teats) including pre- and post-
massage phase and milk outflow with special attention 
given to the latter (teats selected during milk outflow, i.e. 
preferential teats). 
Suckling Behaviour of Piglets Affected by Body Weight and Sex
37
Suckling position
Suckling position of each piglet was determined based on 
preferential teats (selected during milk outflow). Preferential 
teats were divided into three suckling areas: anterior (1st and 
2nd teat pair), middle (3rd, 4th and 5th teat pair) and posterior 
(6th, 7th and 8th teat pair). Final results were expressed as the 
number of sucklings per teat pair in each suckling area.
Suckling territory
Suckling territory (or range) was calculated based on the area 
of the udder encompassed by the teats that the piglet suckled, 
with a ‘teat pair’ as the unit of measurement. Particularly, 
it is the number of teat pairs in the range of the outermost 
teat pairs that are also included in the count; for example, 
the suckling territory of the piglet that visited the 2nd, 4th, and 
7th teat pair in a given period was 6. Suckling territory in our 
case, with sows having up to 8 teat pairs, could therefore range 
from 1 to 8.
Suckling stability 
Suckling stability was calculated using an equation derived 
from basic probability theory as described in Skok (2015). 
Suckling order stability ranges from 0 to 1, with 0 indicating 
complete instability (no piglet in the litter sucked more than 
once on a given teat) and a value of 1 indicating complete 
stability (a given suckling pair was used only for one piglet; 
Skok and Škorjanc, 2013). The value n represents the number 
of sucklings on a particular suckling pair that a given piglet 
performs, and N represents the total number of sucklings 
observed on a specific suckling pair.
Statistical analysis
Statistical analysis was performed in the IMB SPSS Statistics 
program (Version 28.0). First, we analysed the relationship 
between body weight and sex. Independent samples t-test was 
used to test the differences in relative body weight between 
sexes. Additionally, the distribution of male and female piglets 
was calculated according to relative body weight classes 
and the differences checked using Chi squared test. Results 
indicated somewhat higher relative body weight of female 
compared to male piglets (Fig. 1a) as well as the tendency 
of different distributions of male and female piglets among 
relative body weight classes (Fig. 1b). All further analyses on 
the effect of body weight of piglets on behavioural traits were 
carried out by sexes.
Analysis of suckling position included calculation of 
frequencies of male and female piglets of different weights 
across suckling areas (anterior, middle, posterior). The dif-
ferences in distributions were tested using the Chi squared 
test. Additionally, means with standard errors for relative 
body weight were calculated for each suckling area (anterior, 
middle, posterior) and the differences among them tested 
using analysis of variance and Tukey’s post-hoc test (sep-
arately by sexes). In case of suckling stability and suckling 
territory, the effect of body weight (light, medium and 
heavy) was calculated using Kruskal-Wallis test separately 
for male and female piglets. Non-parametric test was used 
as both behavioural traits were not normally distributed 
(tested with Shapiro-Wilk test of normality). 
RESULTS 
Suckling position
The frequency of suckling in male piglets (castrates) and 
female piglets (gilts) on different suckling areas showed 
different distribution (Fig. 2). Female piglets most frequently 
occupied the anterior teat pairs (45%), followed by middle teat 
pairs (39%) and vice versa in male piglets who suckled most 
often on the middle (46%) followed by anterior teat pairs (34%). 
Posterior teat pairs were used much less frequently in both 
sexes (16% and 20% for female and male piglets, respectively).
The results further showed different distributions of 
male and female piglets of different body weight classes 
across suckling areas (Fig. 2) whereby the difference between 
sexes mainly concerned anterior part of udder (significant 
difference, p<0.001 – not shown). Body weight of piglets sig-
nificantly affected suckling position in females and only 
tended to affect it in males (Fig. 2b). The distributions of 
heavy, medium and light females differed significantly 
among suckling areas (p<0.001), especially in the anterior 
suckling area. Heavy females predominate on anterior area 
and rarely used posterior teat pairs. Medium weight females 
occupied equally often anterior and middle teat pairs. Light 
females most often suckled on middle teat pairs, followed 
by posterior and anterior teat pairs. The distributions of 
male piglets of different weight classes differed to a lesser 
-0.08
0.08
-0.5
-0.4
-0.3
-0.2
-0.1
0.0
0.1
0.2
0.3
0.4
0.5
Male Female
rB
W
Sex
p=0.018
a)
0
5
10
15
20
25
30
35
40
45
50
Heavy Medium Light
Fr
eq
ue
nc
y,
 %
rBW class
Male
Female
b)
Chi squared=5.20
p=0.074
rBW – relative body weight calculated within each litter as rBW=(body 
weight–mean)/standard deviation
Figure 1: Relationship between relative body weight and sex 
of piglets
Suckling Behaviour of Piglets Affected by Body Weight and Sex
38
extent across suckling areas compared to females. Male 
piglets of all three body weight classes suckled most often 
on middle area, followed by anterior and finally posterior 
area. Additional analysis on body weight effect (Fig. 3) con-
firmed pronounced differences among suckling areas in case 
of females only (p<0.001) with relative body weight decreas-
ing significantly from the anterior to the posterior area (Fig. 
3b). In male piglets, relative body weight was similar across 
suckling areas (p=108; Fig. 3a) 
Suckling stability
According to the results, body weight significantly affected 
suckling stability (Fig. 4). The effect of interaction between 
body weight and sex was not significant as the same pattern 
of suckling stability could be seen for male and female piglets. 
In both sexes, suckling stability significantly increased with 
piglet body weight. Medians for light, medium and heavy 
males were 0.35, 0.43 and 0.60, respectively (p<0.001). In females, 
medians were 0.40, 0.42 and 0.48 for light, medium and heavy 
piglets, respectively (p=0.038). 
Suckling territory 
The effect of body weight of piglets on suckling territory is 
presented in Fig. 5. There was no significant effect of body 
weight on suckling territory in male piglets (p=0.934) where 
median value for suckling territory of all three body weight 
classes amounted to 2. In females, body weight significantly 
affected suckling territory (p=0.047). The results indicated that 
light females selected teats to suckle on broader suckling 
territory compared to heavy females, with medium weight 
females having intermediate position. 
DISCUSSION
A noteworthy result of present study is that male and female 
piglets showed different patterns of suckling behaviour. Thus, 
the results to a certain extent complement published data 
where a large majority of studies treated suckling behaviour 
of all piglets together not paying attention to possible sex 
differences. Moreover, general patterns of udder occupation 
during suckling – with the highest crowd on middle area, 
similar or somewhat lower occupancy in the anterior area 
and considerably lower in posterior area – that was shown in 
many studies (Puppe and Tuchscherer, 1999; Skok & Škorjanc, 
2013; Skok et al., 2014), was in our study confirmed in case 
of male piglets only. Females, namely, most often occupied 
anterior positions, but in accordance with literature, posterior 
teat pairs were generally seldom visited in all piglets. During 
0
5
10
15
20
25
30
35
40
45
50
Anterior Middle Posterior
N
um
be
r o
f s
uc
kl
in
gs
Suckling area
Heavy
Medium
Light
All (%)
Chi squared=9.44; 
p=0.051
a)
0
5
10
15
20
25
30
35
40
45
50
Anterior Middle Posterior
N
um
be
r o
f s
uc
kl
in
gs
Suckling area
Heavy
Medium
Light
All (%)
Chi squared=33.15
p<0.001
b)
Figure 2: Suckling position according to body weight in male 
(a) and female piglets (b)
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
rB
W
Suckling areaa)
p=0.363
Anterior Middle
Posterior
-0.6
-0.4
-0.2
0.0
0.2
0.4
0.6
rB
W
Suckling areab)
c
b a
p<0.001
Anterior
Middle
Posterior
rBW – relative body weight calculated within each litter as rBW=(body 
weight–mean)/standard deviation 
Figure 3: Relative body weight of male (a) and female piglets 
(b) suckling on different suckling areas
p<0.001
a)
aa
b
Heavy Medium Light
p=0.038
b)
a
ab
b
Heavy Medium Light               
Suckling stability – the tendency to suckle successively at the same 
position 
Figure 4: Suckling order stability according to body weight in 
male (a) and female piglets (b)
Heavy               Medium Light
p=0.934
a) Heavy Medium Light
p=0.047              
b)
b
ab
a
Suckling territory – the range two outermost suckling positions of the 
piglet encompasses
Figure 5: Suckling territory according to body weight in male 
(a) and female piglets (b)
Suckling Behaviour of Piglets Affected by Body Weight and Sex
39
lactation, the front teat pairs were found as being the most 
often occupied by heavier piglets with higher dominance rank 
in the social structure as these teats are supposed to be more 
attractive (Fraser, 1975; Orihuela & Solano, 1995; Puppe and 
Tuchscherer, 1999). The reasons for higher affinity of piglets for 
the front teats have still not been unambiguously explained. 
Several interacting factors are probably involved such as milk 
productivity in relation to higher intensity of stimulation in 
this part of udder due to higher crowd (review in Skok and 
Škorjanc, 2014b), higher degree of safety (lower risk of being 
trampled the anterior area; Scheel et al., 1977), morphological 
characteristics of teats (e. g. shape and length; Fraser, 1984) or 
proximity of the mother's head and sow vocalisation (Castren 
in sod., 1989; Kasanen in Algers, 2002). However, it should be 
emphasised that only the tendency or very weak effect of body 
weight on suckling position was mainly reported. Our results 
conversely showed strong effect of body weight on suckling 
position, but was not uniform in both sexes, as it had highly 
significant effect in females but not in males. This difference 
between sexes that was found in our research could explain 
weak correlations of suckling position with body weight 
reported in literature when considering both sexes together. 
According to the results, females were more successful 
in acquiring the positions in the anterior part of the udder, 
where presumably suckle the piglets with the highest 
position in the dominance rank (Fraser, 1975; Orihuela 
& Solano, 1995; Puppe and Tuchscherer, 1999). It is known 
from some other contexts (e. g. weaning), that females may 
participate more in aggressive interactions which are oth-
erwise a core tool in the establishment of the dominance 
hierarchy (Mesarec et al., 2021). Higher dominance rank is 
associated with higher body weight (Ewbank, 1976; Puppe 
and Tuchscherer, 1999). Indeed, females in our study proved 
to be heavier than males (Fig. 1). Although literature data 
are not consistent in this regard; some studies showed one 
sex (mainly males) as heavier, while no differences in weight 
were observed between the sexes in other studies (Milligan, 
2001b; Škorjanc et al., 2007). When studying the effect of sex 
on suckling behaviour during lactation, it is worth men-
tioning possible consequences of castration of male piglets. 
Castration is usually carried out in the first few days after 
birth, at the time of the most intensive establishment of 
the teat order. It is a stressful and painful procedure, which 
can hinder growth and cause changes in behaviour of male 
piglets (e.g., reduced participation in teat fights, altered 
suckling behaviour; Prunier at al., 2006). 
In our research, piglet body weight turned out to be 
an important influential factor affecting suckling stability 
in the same direction (positive correlation) in both sexes. 
Opposite, previously published papers showed no important 
impact of body weight on suckling stability, e.g., only a weak 
correlation with suckling stability/teat fidelity (De Passillé 
et al., 1988; see also Skok and Škorjanc, 2013). Regarding the 
effect of sex, only one study (Rosillon-Warnier and Paquay, 
1984) found comparable results showing no effect of the sex 
of piglets on teat order stability.
Interestingly, male piglets occupied a similar and rel-
atively broad suckling territory regardless of body weight, 
and the same was true for lower body weight females. Heavy 
females, on the other hand, were clearly more territorial 
and, according to the results on suckling position (anterior) 
and stability, also more dominant. To our knowledge, there 
are no studies that directly address suckling territory or 
range in pigs in relation to sex and/or body weight. However, 
one is tempted to suspect that the pattern observed here for 
suckling territory mirrors to some extent the situation of 
territorial/home range dynamics in the wild counterpart of 
the domestic pig. Firstly, the male wild boar is a dispersing, 
mostly solitary sex and therefore has an innate tendency 
to occupy a larger territory/home range than the female, 
which has been demonstrated in numerous studies (Massei 
et al., 1997; Dexter, 1999; Saïd et al., 2012; Podgórski et al., 2014; 
but see also Russo et al., 1997). In addition, the pig/wild boar 
has a matrilineal social system in which sows and their 
offspring live in family groups, with some females dispers-
ing after weaning but the others remaining in the natal 
group (Kaminski et al., 2005; Podgórski et al., 2014). In social 
species, subordinate females suffer from competition with 
more dominant group members. Therefore, the tendency 
to disperse may allow subordinate females to escape from 
groups or territories where there is intense competition 
for resources or reproductive opportunities (Clutton-Brock 
and Lukas, 2012). Following this analogy, it can be hypoth-
esised that female piglets, which are lighter and thus sub-
ordinate, show dispersal tendencies early in life (excavating 
wide suckling territories), while heavier and thus dominant 
females show a tendency towards greater territorial behav-
iour (speaking in a later temporal context, show a tendency 
to remain in the natal group/territory). Although no simple 
parallels can be drawn between domestic animals and their 
wild counterparts (e.g. Price, 1984), it can be assumed that 
domesticated forms of animals retain a large proportion of 
the traits that were 'programmed' during the evolutionary 
time of the species, as divergence has occurred relatively 
recently, with the random genome sequences of wild boars 
and domestic pigs being very similar and indistinguishable 
(Rubin et al., 2012).
CONCLUSIONS
As oppose to the hypothesis, body weight affected suckling 
behaviour differently in male and female piglets. Although 
considerably stronger effect of piglet body weight on suckling 
behaviour was observed than has been demonstrated in 
previous studies, this effect was found only in female piglets 
with the exception of suckling stability. Heavier male piglets 
Suckling Behaviour of Piglets Affected by Body Weight and Sex
40
had higher suckling stability, but did not differ from lighter 
piglets in suckling position and territory. Heavier female 
piglets selected more frequently anterior teat pairs, established 
a more stable suckling order, and consequently had a smaller 
suckling territory compared to lighter females. The present 
findings complement understanding of the detailed role of 
piglet body weight and sex in suckling behaviour, which was 
lacking in the otherwise well-explained behaviour of piglets 
during lactation.
ACKNOWLEDGEMENT
This research was financed by the Slovenian Research Agency 
under the research program P-0164.
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Vpliv telesne mase in spola pujskov na sesno obnašanje
IZVLEČEK
Sesno obnašanje pujskov je bilo v preteklosti sicer obsežno raziskano, pa vendar presenetljivo ni prav veliko raziskav, ki bi posebej 
obravnavale vpliv telesne mase in spola na sesno obnašanje. Ti dve osnovni lastnosti pujskov sta bili v raziskavah vključeni kot 
podporni podatki, ne pa kot glavni dejavniki preučevanja. Iz tega razloga je bil cilj naše raziskave preučiti vpliv telesne mase na 
sesno obnašanje pujskov v času laktacije ločeno po spolu. V raziskavo je bilo vključenih 14 gnezd s skupno 158 pujski (85 pujskov 
moškega spola, 73 pujskov ženskega spola, velikost gnezda 6–15 pujskov). Sesno obnašanje smo opisali kot sesni položaj (sesek, ki 
ga je pujsek sesal med sesanjem), območje sesanja (razpon, ki sta ga zavzemala dva najbolj oddaljena seska, ki jih je pujsek sesal 
med sesanjem) in stabilnost sesanja (nagnjenost k zaporednemu sesanju na istem sesku). Opazovanja so bila izvedena v šestih 
obdobjih laktacije: 0−3, 4−7, 8−10, 11−14, 15−21 in 22−32 dni starosti. V vsakem obdobju smo pujske tudi stehtali. Vime svinje smo 
razdelili na tri dele: sprednji ali anteriorni (sesni par 1 in 2), srednji (sesni par 3 in 4) in zadnji ali posteriorni (sesni pari 6, 7 in 
8). Rezultati so pokazali, da ima telesna masa različen vpliv na sesno obnašanje pri pujskih ženskega in moškega spola in sicer 
vpliva na vse preučevane lastnosti pri ženskih pujskih, pri moških pujskih pa le na stabilnost sesanja. Telesna masa pujskov 
ženskega spola je bila na sprednjem delu vimena v primerjavi z zadnjim delom značilno večja. Pri ženskem spolu se je izkazalo, 
da težji pujski precej pogosteje sesajo na prednjem delu vimena. Težki pujski obeh spolov so vzpostavili stabilnejši sesni red v 
primerjavi z lahkimi pujski. Območje sesanja je bilo pri moških pujskih precej obsežno, vendar se ni razlikovalo glede na telesno 
maso pujskov. Zanimivo pa so lahki pujski ženskega spola sesali na značilno večjem območju sesanja kot težki pujski ženskega 
spola. Dobljeni rezultati zapolnjujejo vrzel v sicer dobrem poznavanju sesnega obnašanja pujskov, kar je pomembno za rejsko 
delo v času laktacije, še zlasti pri izvajanju navzkrižnega premeščanja pujskov. V tem kontekstu je poznavanje podrobne vloge 
spola in telesne mase še posebej pomembno, saj se rejci pri delu pogosto odločajo predvsem na osnovni telesne lastnosti pujskov. 
Ključne besede: prašič, laktacija, telesna masa, spol, položaj sesanja, stabilnost sesanja, območje sesanja