Effects of Body Measurements and Weight on Calf Size
and Calving Difficulty of Holsteins I
M. SIEBER,2 A. E. FREEMAN? and D. H. KELLEY
Animal Science Department
Iowa State University
Body measurements (heart and paunch Dystocia is an important problem of dairy
girths, wither height, chest depth, pelvic cattle. In 1976, Philipsson (17, 18 19) re-
length and width, and body length), body searched calving difficulty, stillbirth, and asso-
weight, and calving evaluation data (calf ciated factors and related body measurements
birth weight, calf sex, calf presentation, to dystocia for Swedish dairy cattle breeds. At
and calving assistance needed) were col- the same time, Pollak and Freeman (20) were
lected from 1974 parities of 762 Holstein conducting the first large research study of
cows between 1968 and 1986. Degree of dystocia for US dairy cattle. Djemali et al. (10)
calving assistance was scored continu- reported an additional 14 d open and 465 kg
ously from 1 (no assistance) to 10 (hard less milk for cows with extreme calving diffi-
mechanical assistance). Phenotypic corre- culty than for cows with no calving difficulty.
lations of dam body traits with calf birth McDaniel (13) demonstrated decreased milk
weight were all significantly positive yield in the lactation following a difficult birth
when combined for all parities and and estimated in 1981 that minimum cost for
each assisted birth was $50 to $60 for heifers.
ranged from .23 for paunch girth to .27
Dystocia is affected by several nongenetic
for body weight and heart girth. Correla-
and genetic factors, including age and parity of
tions of dam body traits with calving
dam (2, 7, 8, 12, 17, 20), sex of calf (4, 7, 8, 12
assistance scores were all significantly
,20), year-season (8, 18, 20), size of calf (20),
negative across parities and ranged from
and evaiuator of birth difficulty (11). Pheno-
-.24 to -.30. Correlations of calf birth typic correlations between calving difficulty
weight with calving assistance were and calf birth weight range from. 17 to .54 (3, 7
higher for first parity (.37) than for all ,21). Most studies (2, 4, 8, 20, 24, 25, 26) have
parities (.20). Least squares analysis found low heritability (approximately t 0%) for
showed that cows with shorter wither calving difficulty.
height and shorter pelvises tended to re- Differences among dairy bulls have been
quire more calving assistance. Heavier reported if dystocia is measured as a direct
calves, winter calvings, and earlier parity effect of the sire (4, 6, 20). For beef breeds,
all were related to increased dystocia. some researchers have shown significant sire
Male calves were heavier than female differences (8, 26). However, Sagebiel et al.
calves and also were associated with (22) found that sire effects within breeds were
greater calving difficulty. not significant for beef breeds; they reported
that sire and cow breeds had significant effects
on dystocia scores if the calf was male. Thomp-
son et al. (24) found no relationship between
sire transmitting ability for production and dys-
AcceptedFebruary27, 1989. tocia but a negative correlation (-.28) between
1journal Paper Number J-12933, Iowa Agriculture and transmitting ability for type and dystocia. They
HomeEconomicsExperimentStation, Ames; ProjectNum- also found that size of the cow had a major
ber 1053. effect on the type-dystocia relationship; for
2present address: Animal ImprovementProgramsLabo-
rato_ry,ARS, USDA,Beltsville,MD 20705. daughters, large size was associated with both
3Reprintrequests. high type scores and increased dystocia, Ali et
1989 J Dairy Sci 72:2402-2410 2402
BODY MEASUREMENTS AND CALVING DIFFICULTY 2403
al. (1), however, found that daughters that were or posterior), and calving assistance needed
large with wide pins, long sloping rumps, and (type and degree). Calving assistance needed
little slope from thurl to pin bone were more was classed as none, manual, manual with ob-
likely to have easier calvings. Boldman and stetrical chains, or mechanical; difficulty of
Famula (6) studied relationship of sire transmit- calving was evaluated by an observer as easy,
ting ability for dystocia with progeny linear intermediate, or hard for each calving assis-
type traits. They reported little correlated re- tance class. Only three caesareans and three
sponse in linear type traits among bulls whose embryotomies occurred; these were excluded
progeny were born with the least difficulty. from analyses. Of 33 twin births (66 calves),
Since 1978, the National Association of Ani- none were assisted mechanically. Distribution
mal Breeders has evaluated Holstein sires na- of calving assistance scores was similar to that
tionally for dystocia. The original linear proce- for nontwin births. A preliminary analysis
dure of Berger and Freeman (4) was modified showed that differences in calf birth weight
to a categorical method for July 1988 evalua- between twins and nontwins was slight; there-
tions (9). The goal of this program is to identify fore, twin births were not excluded from analy-
sires that might be preferred for mating to ses. Only records without an abortion were
heifers and small cows because less assistance included. Each evaluator scored more than 30
is needed during birth of these sire's progeny.
The objectives of this study were to deter- Body measurement and weight data were
mine 1) relationships between cow body mea-
combined with calving evaluation data. All
surements and weight with calf birth weight
fifth and greater parities were grouped together.
and 2) relationships of cow body measurements
The final data included 1794 parities from 762
with calving difficulty by parity.
The model for analyzing calf weight was:
MATERIALS AND METHODS
Body measurement and body weight data Yijklmo = kt + (YS)i + Pj + gk + Vl
were obtained from the Iowa State University 8
research herd at Ankeny. Seven body measure- +sin + Z bn(mijklmno- ~ n )
ments (heart girth, paunch girth, wither height, n= l
chest depth, pelvic length, pelvic width, and + eijklmo 
body length) and body weight were recorded
between 30 and 55 d postpartum. Data were
collected between 1968 and 1986 as described where:
by Sieber et al. (23).
The Ankeny research farm is operated under Yijklmo = calf birth weight measured by
typical to above average Iowa conditions and is evaluator 1 for calf o of sex m
used primarily for long-term dairy cattle breed- born in year-season i from par-
ing research. In this herd, foundation females ity j of a cow resulting from
were selected for low and high milk yield based mating to a sire in sire group k;
on pedigree estimates and were mated to sires kt = overall mean;
selected for high and breed average PD milk in (ys)i = effect of year-season i (within
a 2 x 2 factorial design. Based on average PD year, season 1 = May through
milk of active AI sires each year, progeny of October and season 2 = No-
high PD sires are mated to high PD simms, and vember through April);
progeny of average PD sires are mated to aver- pj = effect of parity j (j =
age PD sires for all generations. This breeding 1,2,3,4,>5);
strategy causes the genetic difference between gk = effect of sire group k [k = I
the two cow populations to approach the differ- (high PD), 2 (breed average
ence in breeding value (twice their difference in PD)];
PD) between the two sire groups after several Vl = effect of calving weight evalua-
generations. tor 1 (1 = 1..... 5);
Calving evaluation data were calf birth Sm = effect of calf sex m [m = 1
weight, sex of calf, calf presentation (anterior (male), 2 (female)];
Journal of Dairy Science Vol. 72, No. 9, 1989
2404 SIEBER El" AL.
mijklmno = cow body measurement for TABLE 1. Overall distribution of records across all parities
trait n (n = 1..... 8); by type and degree of calving assistance (number of re-
cords = 179~,).
Nn = mean for body measurement
trait n for all cows; Calving assistance
bn = regression coefficient for body Type Degree Score Number Percentage
measurement trait n; and None 1 1222 68.1
eijklmo = random residual. Manual Easy 2 54 3.0
Intermediate 3 15 .8
All effects except residual were fixed. A cow Hard 4 1 ,1
effect was not included in the model even Manual with Easy 5 99 5.5
though cows produced more than one calf. If obstetrical Intermediate 6 217 12.1
chains Hard 7 147 8.2
the data were perfectly balanced, all cow ef-
Mechanical Easy 8 2 .1
fects would be in the residual; lacking balance, Intermediate 9 15 .8
some cow effects might be included in other Hard 10 22 1.2
effects in the model. Cows can be considered as
random variables; thus, the expected effects on
other variables in the model are zero if there is
no selection on cows across parities for the The model for analyzing difficulty was:
traits of interest or correlated traits. Voluntary
culling before 1977 was extremely limited (5);
Yijldmo = I.t + (ys) i + Pj + gk
therefore, no selection on cows relative to the
traits analyzed or to correlated traits was as- +v 1 +s m
sumed. Residual variance would be larger with 8
some cow effect included, and tests of signifi- + ~ bn(mijklmno-Nn)
cance are conservative. Data were analyzed
across parities. Submodels that included fewer + bw:~'ffijklmo - w---)
than eight covariables were not investigated. + eijklmo 
Calving assistance data were assigned scores
based on the degree of actual assistance given where:
(Table 1). The descriptions related to how as-
sistance was given so that assistance could be Yijklmo = calving assistance score for
recorded more objectively. Three herdsman did dam of calf o;
all the evaluations and assigned scores as de- Wijklmo = fixed effect of birth weight of
scribed. Obstetrical chains were always avail- calf o;
able, and if they were used, the degree of = mean birth weight of all calves;
assistance needed was generally greater than if bw = regression coefficient for birth
assistance was manual. Scores ranged from 1 weight of calves;
(no assistance) to 10 (hard mechanical assis-
tance). Scores could have been assigned based and all other effects are as in Model [1 ]. As
on frequency, but this was not done for this with Model [I], Model  was used for analy-
analysis. Even if scores 4 (hard manual assis- sis on an overall parity basis.
tance) and 5 (easy manual assistance with ob- Quadratic effects of body measurements and
stetrical chains) had been reversed, the conclu- weight were not significant under either model
and, therefore, were not included in final analy-
sions would have been the same. No
misclassification occurred at the ends of the
range of scores. Analyses of calving difficulty
(as assistance was actually given) were con- RESULTS AND DISCUSSION
ducted with the assumption of continuity for Means and SD of dam body measurements
calving assistance scores, similar to the method and weights and calf birth weights are in Table
used by Meyer and Burnside (16) for subjective 2 by and across parities. All body traits and calf
milking speed scores. weight increased with parity. Pelvic length and
Journal of Dairy Science Vol. 72, No. 9, 1989
BODY MEASUREMENTS AND CALVING DIFFICULTY 2405
TABLE 2. Means and SD for dam body lxaits (measurements and weights) and calf birth weights by and across parities.
Trait 1 2 3 4 ->5 All
Number of calves 739 442 294 169 150 1794
Heart girth, cm 187.5 195.6 201A 202.8 205.2 194.6
Paunch girth, cm 219.9 232.0 238.6 241.9 245.4 230.1
Wither height, cm 131.1 135.5 137.0 137.3 138.3 134.3
Chest depth, cm 71.7 74.8 76.7 77.4 78.2 74.4
Pelvic length, cm 51.9 54.2 55.3 55.5 55.6 53.7
Pelvic width, cm 51.1 54.9 56.9 57.5 58.1 54.1
Body length, cm 153.2 159.5 163.2 163.8 164.2 158.3
Body weight, kg 489.4 553.1 595.2 610.7 629.7 545.6
Calf weight, kg 37.9 39.7 41.1 41.1 41.6 39.5
Heart girth, cm 7.3 6.7 7.8 7.8 7.4 9.8
Paunch girth, cm 10.1 10.0 10.8 10.7 10.8 13.9
Wither height, cm 3.6 3.6 3.8 3.8 4.0 4.7
Chest depth, cm 2.6 2.4 2.6 2.5 2.6 3.5
Pelvic length, cm 2.2 2.1 2.4 2.5 2.3 2.7
Pelvic width, cm 2.4 2.3 2.5 2.4 2.5 3.7
Body length, cm 5.7 5.9 6.0 5.8 5.4 7.4
Body weight, kg 49.4 53.2 60.8 59.3 62.1 75.3
Calf weight, kg 4.4 5.8 5.3 6.2 5.4 5.8
width, chest depth, and wither height had but were significant only for body weight
smaller SD than did other body traits. (P<.01) and heart and paunch girths and wither
Distribution of calvings by calving difficulty height (P<.05). No traits had significant
is in Table 3 by parity. For first parity, over (P<.05) correlations for third parity. For fourth
50% of births received some degree of assis- parity, correlation for pelvic length was slightly
tance. As parity increased, percentage of cows significant (P<.05) and positive (.t6). For fifth
receiving assistance decreased: 52% dystocia parity and greater, correlations for body length
for first parity, 20% for second, 17% for third and weight were significant (P<_.05) and posi-
and fourth, and 14% for fifth and greater. As tive (.20). Across all individual parities, all
reported by Bar-Anan et al. (2), dystocia was correlations were highly significant (P<.001)
two to three times greater at first calving than and positive. Correlations across parity ranged
at later calvings. Philipsson (17) found similar from .23 for paunch girth to .27 for heart girth
results with 15.7% dystocia for heifers versus and body weight. In general, calves from
4.8% for cows. In a more recent study with a heavier and larger cows were heavier than those
large number of Holstein records, Djemali et al. of smaller and lighter cows.
(10) found 28 to 36% dystocia for first-calf Phenotypic correlations of dam body traits
heifers and I0 to 16% dystocia for older cows. and calf birth weight with calving assistance
Phenotypic correlations computed as Pear- are in Table 5 by and across individual parities.
son product-moment correlations of dam body For individual parities, none of the dam body
measurements and weights with calf birth measurements had significant (P<.05) correla-
weights are in Table 4 by and across individual tions. Correlation of dam body weight with
parities. For first parity, all dam body traits had calving assistance score was significant (P___.05)
positive, highly significant (P<.001) correla- and positive (.18) for fourth parity. Across all
tions with calf birth weight except for paunch individual parities, however, correlations for
girth, which was less significant (P<.01). Cor- dam body traits were all highly significant
relations were lowest (.10) for paunch girth and (P<.001) and negative; correlations ranged
highest (.21) for heart girth and chest depth. from - . 2 4 (heart and paunch girths, body
For second parity, all correlations were positive length, and body weight) to - . 3 0 (pelvic width).
Journal of Dairy Science Vol. 72, No. 9, 1989
2406 SlEBER ET AL.
TABLE 3. Distribution of records by type of calving assistance and parity.
1 2 3 4 >5 All
CMves 739 442 294 169 150 1794
Type of cMving assistance
None 357 353 243 140 129 1222
Manu~ 29 15 14 8 4 70
Manu~ with obstetric~ chains 317 73 37 20 16 463
Mechanical 36 1 0 1 1 39
Type of calving assistance
None 48.3 79.9 82.7 82.8 86.0 68.1
Manual 3.9 3.4 4.8 4.7 2.7 3.9
Manual with obstetrical chains 42.9 16.5 12.6 11.8 10.7 25.8
Mechanical 4.9 .2 0 .6 .7 2.2
Correlations became significant across all pari- ties are in Table 6. All regression coefficients
ties because of the general increase in body size for dam body measurements and weight gener-
as a cow aged, which increased the range of ally were small and nonsignificant (P<.05), Al-
measurements. In general, heavier and larger though many phenotypic correlations in Table 4
cows had easier calvings and needed less assis- were significant, they had not been adjusted for
tance than did smaller cows. Correlations of other effects, which explains why correspond-
calf birth weight with calving assistance were ing regression coefficients in Table 6 were
highly significant (P<.001) and positive regard- nonsignificant. Average LS means for summer
less o f parity and ranged from .20 to .39. and winter seasons were significantly (P_<.001)
BreDahl (7) found similar correlations between different with calves .60 kg heavier for winter
birth weight and calving assistance o f . 17 to .27 than for summer calvings. Parity did not have a
for four breeds as did Rice and Wiltbank (21) significant (P<.05) effect on calf birth weight.
for Angus (.36) and Herefords (.44). Significant (P_<.05) difference was found be-
Results from least squares (LS) analysis of tween sire groups; calves from high PD bulls
Model  for calf birth weight across all pari- were .64 kg heavier than those from breed-av-
TABLE 4. Phenotypic correlations1 of dam body traits (measurements and weights) with calf birth weights by and across
Trait 1 2 3 4 >-5 All
Heart girth .21"** .10" .04 .I1 .13 .27***
Paunch girth .10"* .12" .02 .08 A0 .23***
Wither height .20*** .10" .04 .06 .11 .25***
Chest depth .21"** .02 -.01 .05 .06 .24***
Pelvic length .18'** .08 .04 .16" .07 .24***
Pelvic width .16"** .07 .03 .11 .14 .26***
Body length .15"** .08 .01 .13 .20* .24***
Body weight .18"** .15"* .05 .11 .20* .27***
1pearson product-moment correlation.
Journal of Dairy Science Vol. 72, No. 9, 1989
BODY MEASUREMENTS AND CALVING DIFFICULTY 2407
TABLE 5. Phenotypic correlations 1 of dam body traits (measurements and weights) and calf birth weights with calving
assistance by and across individual parities.
Trait 1 2 3 4 _>5 All
Heart girth .05 -.06 .00 .12 -.16 -.24"**
Paunch girth .02 .01 -.05 .14 -.I0 -.24"**
Wither height -.02 -.04 -.05 .02 -.07 -.25***
Chest depth .01 -.08 -.08 .01 -.10 -.27***
Pelvic length -.04 -.06 -.08 .11 -. 15 -.25***
Pelvic width -.03 -.05 -.04 .11 -.01 -.30***
Body length -.01 .01 -.03 .02 -.10 -.24***
Body weight .05 -.01 -.01 .18" -.14 -.24***
Calf weight .37*** •25*** •38*** •39*** .29*** •20***
1Pearson product-moment correlation.
erage bulls. D i f f e r e n c e s a m o n g evaluators also at birth. E f f e c t o f calf sex on calf birth w e i g h t
were significant (P<.01). Largest significant agrees with results o f Philipsson (19), w h o
(P_.001) difference was for calf sex; m a l e s f o u n d that m a l e calves usually had larger b o d y
calves w e i g h e d 2.1 kg more than f e m a l e calves d i m e n s i o n s than did females, and M e i j e r i n g
TABLE 6. Least squares (LS) analysis of calf birth weight on dam body traits (measurements and weight) over all parities
(number of records = 1794).
Source df coefficient MS LS X LS SE
Heart girth 1 .05 45.95
Paunch girth 1 ~,04 65.73
Wither height 1 .08 82.61
Chest depth 1 -.05 9.79
Pelvic length 1 -.01 .50
Pelvic width 1 .03 2.99
Body length 1 .04 46.32
Body weight 1 .01 89.57
Year-season 29 99.24***
Summer 39.26 :8"1
Winter 39.83 .82
Sire group 1 174.66"
High 9.87 32"
Average 39.23 .32
Calf sex 1897.13"**
Male id./o 132
Female 38.51 .32
Residual 1746 27.33
Journal of Dairy Science Vol, 72, No, 9, 1989
2408 SIEBER ET AL.
TABLE 7. Least squares (LS) analysis of calving assistance score on dam body traits (measurements and weight) and calf
birth weight over all parities (number of records = 1794).
Source df coefficient MS LS ~ LS SE
Heart girth 1 .01 .95
Paunch girth 1 .00 .34
Wither height 1 -.04" 19.72
Chest depth 1 .03 2.64
Pelvic length 1 -.12"** 51.90"**
Pelvic width 1 -.03 3.18
Body length 1 .02 6.62
Body weight 1 .00 .42
Calf birth weight 1 .13"** 793.78***
Year-season 29 7.07*
Summer i.;9 .33
Winter 2•10 .33
2 1.75 .14
3 1.43 .17
4 1.41 .21
->5 1.35 .22
Sire group • "9155
Calf sex 46.54**
Male i.io 113
Female 1.73 ,13
Residual 1745 4.42
lCalving assistance score coded 1 (no assistance) to 10 (hard mechanical assistance).
(14), who reported that male calves were 1 to 3 sociated with greater calving difficulty. Differ-
kg heavier than females at birth. ence between average LS means for summer
Results from LS analysis of Model  for and winter seasons was significant (P_<.05) with
calving assistance score across all parities are less calving difficulty associated with summer
in Table 7. Wither height had a small negative than winter calving. Pollak and Freeman (20)
coefficient (-.04, P<.05), which indicates that found similar results and reported that winter
shorter cows have more calving problems than births (October to March) were more difficult
do taller cows• The coefficient for pelvic length than summer births. Parity had a highly signifi-
had a higher level of significance (P<_.001) and cant (P<.001) effect on calving assistance score
was larger in magnitude (-.12). Cows with with more assistance needed for first parity
shorter pelvises had more difficulty giving birth than for later parities. This result agrees with
and needed more assistance than did cows with findings of previous studies (2, 15, 17, 20)• No
longer pelvises. Philipsson (19) and Menissier significant (P<.05) difference was found be-
et al. (15) have reported that dystocia seems to tween sire groups, but differences between
be caused mainly by feto-pelvic incompatibili- evaluators were significant (/'<.05). A signifi-
ty. Regression coefficients for calf birth weight cant (P<.01) difference was found between
were highly significant (P<.001) and positive. male and female calves in their effect on dam's
As expected, heavier calves generally were as- need for calving assistance; dystocia was asso-
Journal of Dairy Science Vol• 72, No. 9, 1989
BODY MEASUREMENTS AND CALVING DIFFICULTY 2409
ciated more often with births o f male calves cultural Research and Development Project
than with those o f females as reported in pre- N u m b e r 1-629-83-RE.
vious studies (2, 4, 19, 20). In a separate analy-
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Journal of Dairy Science Vol. 72, No. 9, 1989