INVESTIGATIONS ON THE POSSIBILITIES OF
REINDEER BREEDING 11.

Mikko Varo

Department ofAnimal Breeding, University ofHelsinki

Received October 13, 1972

Abstract. The net increase in the weight of the reindeer calves has been during the first
summer 35 and 40 kg and the second 17 and 25 kg for the females and males, respectively.
There are genetic differences in the development of the weights and measures of the
young reindeer. These differences can be utilized in improving the productivity by breeding.
Also the change in weight during the winter season seems to be an inheritable feature. The
sum of the body length and the chest girth, or the combined measure, looks like being the
most useful basis for selection.

Introduction

These results are from experiments initiated in 1962 at Askankangas. The preliminary
results have been reported earlier (Varo 1964). Here are reported chiefly the first two-

year weights and measures of the calves born in 1963. The experimental material consists
of the calves of a reindeer herd of six bucks and 120 dams. Originally there were 76 calves
but in 1965 there were only 64 calves left for various reasons. Thus the material is rather
small for any far-reaching conclusions. The group was planned as the first part of a larger
experimental program. Since the experimental conditions are extremely severe, an ex-
tension of the experiments has so far not come off and we have to present results, the
statistical significance of which is not always as good as one could hope for. However,
even these results give some indications regarding breeding, the aim of which is the im-
provement of the productivity of reindeer. The basis for all breeding is the heritability of
the economically important quantitative features. In the following this is studied by
estimating the heritability coefficients for the progeny of the bucks according to the half-
sibcorrelation. Since the level of the weights and measures in different sex groups is quite
different, the above correlations have been calculated within the sex groups.

Means and variations of the progeny

In Tables I—31 —3 the studied properties have been presented in the order of their ap-
pearance with age. Weighings have been made both in fall and in spring, while measure-
ments have been made only in spring. For practical reasons the weighings and measure-

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235

Table 1. Means (x) and standard deviations (s) of weight and condition. (Grades of condition: 4 = good,
O =bad).

Time and property Average Females
age, days Total x

number

Males Signifi-
s cance of

difference
s Total x

number

Birth weight 38 5.720 0.502 26 6.000 0.600 *

Kail 1963: 125 38 26
Weight 40.500 4.549 45.462 4.438 ***

Condition 3.4 0.6 3.7 0.5 *

Spring 1964:<! 344 38 26
Weight 40.526 4.279 46.115 4.607 ***

Condition 3.1 0.7 3.0 1.0

Fall 1964: 483 38 26
Weight 57.947 5.357 70.346 5.946 ***

Condition 3.5 0.6 3.5 0.5

Spring 1965: 692 38 26
Weight 59.000 6.431 66.700 6.757 ***

Condition 3.2 0.7 2.7 0.6 **

Fall 1965: 842 25 22
Weight 59.860 4.375 84.041 6.915 ***

Condition 3.2 0.5 3.5 0.6

Spring 1966: 1052 29 21
Weight 61.690 2.944 81.143 7.199 ***

Condition 2.8 1.1 3.0 0.9

ments of the whole sample have been carried out simultaneously. This is why there are
some variations in the individual ages at the time of the measurements. However, the
size of the sample did not allow the levelling out of the variation caused by the differ-
ences in ages. Neither is there any reason for a correction as far as the heritability study is
concerned, since the average time ofbirth of the progeny groups from different fathers did
not vary. Moreover correction is out of question in practical breeding since the times of
birth cannot be foreseen. The variation in times of birth of the calves will increase the
error variation and cannot increase the differences between fathers, the presented herit-
abilities (see later) give therefore the role of genetic factors in the total variation more or

less as a cautious estimate. It should be pointed out that the influence of the time ofbirth
(= age) on the results was relatively speaking quite small as is pointed out later. Like-
wise, the average age of both sexes was very uniform; the males were born, on an average,
one day later than the females.

From Table 1 it can be seen that the males are already in the first fall distinctly heavier
than the females and the difference in weight seems to be increasing with age. However,



236

Table 2. Means (x) and standard deviations (s) of measures.

Average Females Males Signifi-
Time and property age, days Total Total cance of

number x s number x s difference
(3-9)

Spring 1964: 344 38 26
Height 81.7 3.1 84.6 3.9 **

Length of trunk1) 80.4 3.0 83.0 3.1 **

Total length 2) 138.2 5.2 143.0 4.8 ***

Chest girth 88.0 4.6 91.9 4.0 ***

Chest depth 31.5 1.4 32.4 0.9 **

Chest width 18.9 1.3 19.9 1.1 **

Hip depth3) 29.9 1.9 31.7 1.8 *»*

Hip width 20.2 1.2 20.8 1.3

Spring 1965: 692 38 26
Height 90.3 3.3 94.2 3.1 ***

Length of trunk 89.6 3.1 92.8 4.0 ***

Total length 154.3 6.7 162.7 5.5 ***

Chest girth 98.8 4.8 103.2 3.8 ***

Chest depth 36.4 2.0 37.8 2.9 *

Chest width 21.8 1.2 22.4 1.2 *

Hip depth 34.1 1.9 34.8 1.7
Hip width 21.8 1.3 22.7 1.0 **

1) From the top of Shoulder blade to back.
2 ) From muzzle to back.
3 ) In front of hip.

in the third spring the difference in weights is relatively smaller than in the previous fall,
which, at least in part, is due to the pregnancy of the females. Somewhat surprising is
that the general condition of the females in the spring under consideration was distinctly
better than that of the males. The great decrease in the weight and condition of the males
that took place during the second winter might be due to the strenuous mating period
in the fall.

The increase in weight from birth to the first fall weighing has been 34.8 kg for females
and 39.5 kg for males. It corresponds to the average increase of 278 g per day for females
and 316 g per day for males. From the above figures it may also be calculated that the
weight increase of the females and the males has been 6.1- and 6.6-fold, respectively,
when compared to the weight at birth. Until the following fall weighing during 358
days the additional growth has been no more than 17.4 kg for the females and 24.9 kg
for the males or from half to two thirds of the growth in the first summer. The additional
growths correspond to a 3.1- and 4.1-fold birthweight, respectively. The average daily
growth for the whole period has been only 49 g for females and 70 g for males. But, as
can be seen from the spring weights, the weights have not increased at all during the first
winter, over a period of more than seven months. During the summer period, into which
the growth seems exclusively to concentrate, the daily weight increase must have been



237

Table 3. Means (x ) and standard deviations (s) of some qualitative properties.

Females Males Males Significance
Time and property Total Total of difference

number x s number x s (<J $)

Spring 1964:
Regularity of antlers 34 3.6 0.8 25 4.0 0.0
Branchcount of antlers 34 2.1 0.8 25 2.2 1.2
Height of antlers 34 14.9 6.1 25 22.5 8.0 *•*

Number of larvae of gadflies 38 9.3 7.8 26 11.9 9.8

Spring 1965:
Regularity of antlers 35 3.7 0.6 26 4.0 2.0 *

Branchcount of antlers 35 5.0 2.8 26 6.8 2.3 *•

Height of antlers 35 27.6 8.0 26 35.6 8.3 ***

Shade 38 3.2 0.5 26 3.0 0.7
Quality of hair 38 2.2 0.7 26 1.9 0.8

Basis for evaluation: Regularity of antlers; regular = 4, irregular = 0.
Shade; fair = 1, dark = 5.
Quality of hair; good = 1, bad = 3.

much greater than the average value. In the period of 140 days between spring and fall
weighings the average daily growth was as much as 124 g for females and 178 g for males.
The rate of growth of the first summer was not reached, however. During the second
winter season (the interval between the weighings was again about seven months),
there has also been a discontinuity in the weight increase and slight decreases have been
observed in the weights of the males. The condition of the animals has been clearly worse
in spring than in the fall.

It is evident from Table 2 that the males are also bigger than the females except for
the hip width. That the changes in the differences ofchest and hip depths, and also possibly
of chest width at the age of two, are more insignificant than earlier, may be due to the
fact that 78 % of the females have been pregnant.

Table 3 shows that the growth of the antlers of the males is already in the first year
distinctly faster than with the females. The figures in the table are means and variations
of individuals with antlers. In addition to their bigger size the antlers of the males are also
more branched and more regular. In the first year there were four polled females and
one polled male. Of these the male and one female grew antlers during the second year
and two females during the third year. The lack of antlers in adolescence seems to be at
least in part, only due to a delay in the growth of antlers. The number of branches has
been given in the table as a sum of the branches in both antlers. In the first year the antlers
have been almost exclusively unbranched spikes. In the second year the antlers of the
females have mostly had two and those of the males three points.

It can be seen from all the tables that most of the properties of the females have more
variation than those of the males. Relatively speaking this is the case also with weights,



Table 4. Heritabilities (h2 ).

h 2! h%

0.55 0.60

0.45 0.68
0.00 0.00

h 2 2 Significance of differ-Time and property
ences between fathers

Birth weight

Fall 1963:
Weight
Condition

Change in weight winter 1963/64
Change in condition winter 1963/64

0.96 0.96
0.000.00

Spring 1964:
Weight
Condition
Height
Length of trunk
Total length
Chest girth
Chest depth
Chest width
Hip depth
Hip width
Regularity of antlers
Branchcount of antlers
Height of antlers

0.04 0.06
0.45 0.44
0.00 0.00
0.56 0.73

0.120.08
0.00 0.00
0.00 0.00
0.00 0.00
0.17 0.23
0.00 0.00
0.24 0.26

0.160.16
0.08 0.12

Fall 1964:
Weight
Condition

0.39 1.00
0.55 0.52

Change in weight winter 1964/65
Change in condition winter 1964/65

0.15 0.23
0.56 0.68 *

Spring 1965;
Weight
Condition
Height
Length of trunk
Total length
Chest girth
Chest depth
Chest width
Hip depth
Hip width
Regularity of antlers
Branchcount of antlers
Height of antlers
Quality of hair

0.24 0.39
0.00 0.00
0.15 0.25
0.15 0.21
0.39 0.70 »

0.34 0.49
0.61 0.69
0.33 0.36
0.14 0.15
0.43 0.51
0.27 0.30
0.87 1.00 »*

0.18 0.27
0.78 0.79

238



239

although the variation in kilograms has generally been lower with females than with
males. In the second and third year the variation coefficients have been 8.3 and 9.2 %

in the fall weights and 10.0 and 10.9% in the spring weights, respectively. The wider
relative variation in the spring weights suggests that the ability to manage in the winter
is an individual characteristic. The results, given later, support this view, since according
to them also the genes may have something to do with the changes in weight during the
winter season.

Heritability of the characteristics

As pointed out above, the heritability coefficients have been calculated within the
sex groups. Of course it might be useful to study the heritability independently in ex-

perimental samples of both sexes since differences are possible. The small size of the
sample does not allow, this however, if dependable results are to be obtained. Moreover, in
the present stage of reindeer breeding it may be sufficient to have, as a foundation for
further plans, the knowledge which shows the average heritability in a sample of both
sexes. The heritability coefficients appear in Table 4. The coefficients h2 x have been
calculated so that the total variation includes the variation between the sex groups. On
the other hand, when calculating the coefficients h2

2 the variation between sexes has been
subtracted from the total variation.

The heritability of the weight at birth has been estimated from a somewhat smaller
material than in the earlier investigation (Varo 1964). However, the value of the coefficient
has remained practically unchanged. The fall weight is one of the few features where the
difference between fathers turned out to be significant. The estimates of the heritabilities
of the weights in the first and second fall do not differ greatly from each other and the
general mean is about h 2 = 0.6.

The heritabilities of the ratings regarding condition are quite contradictory in different
years. The big differences can partly be explained, however. Thus it is possible that the
differences between fathers as far as the condition of the progeny is concerned remain
small in the first fall, since the mothers’ care of their calves and other maternal influences
determine the condition of the offspring. The high correlations between the size of the
motherand the weight development of the calves found in the later investigations (M. Varo
and H. Varo 1971) suggest a powerful maternal influence, although the significance of
the nursing ability of the mother remains obscure. However, the condition estimated the
following spring may be influenced by individual features, and also by the inclinations
inherited from the fathers. This is even more true with regard to the condition in the
second fall, which can be influenced directly by the individual ability of the animal to
seek and utilize fodder. The causes that lower the heritabilities of the spring weights
compared to fall weights may have a similar influence on the condition. Thus the condition
of the progeny as well as their weights may, after the severe winter 1964—65, have been
due mainly to the unfavourable circumstances. The condition of the progeny in the spring
at the age of one has been highly dependent on the father, while at the age of two the
influence of the father has no longer been discernible. Possibly the very big differences
between the fodder conditions during the winters in question have been one effective
factor. Also the earlier mentioned strenuous heat period of the males may prove a con-
tributing factor when the condition in the spring is estimated.



240

Table 5. Connection between changes in condition and weight in winter.

Change in Change in weight (kg)
condition as winter 1963/64 winter 1964/65
grade points females males all females males all

+ 2 +5.0 +5.0 +13.0 +13.0
+ 1 —1.3 +7.0 +2.3 + 3.6 + 3.6

0 +l.B +0.5 +1.4 + 2.1 —0.6 + 1.3
—1 —2.4 +O.l —1.3 1.3 —4.7 3.0
—2 —2.5 —1.4 —1.7 3.0 —5.3 4.5
—3 —2.0 —2.0

The significance of the spring weight as an indicator of the hereditary inclination seems
to be very much smaller than that of the fall weight. At a higher age the significance
seems to be increasing, however. It may by natural that the individual inclinations in
the weight increase show up better after a far more favorable summer as far as the fodder
is concerned than after a strenuous winter. Since the weights of these age groups will be
of crucial importance when planning the breeding, these results suggest that weighings
or the compensating measurements have to be made in the fall, preferably before the
animals go on heat.

Here it may advisable to discuss in greater detail also the changes of weight and con-
dition during the winter season. It is clear that these properties are interconnected, as

far as the estimation of the condition visually and manually is correct. The connection of
the measures is visualized by the numerical series given in Table 5. The fact that the
changes in weight follow closely the estimates of condition shows that the estimation has
succeeded reasonably well. These herilabilities have also been given in Table 4. The
estimate of the heritability in the changes of weight from the variations between fathers
inside the sex groups suggested that in the first winter the genetic factors had a definite
influence on the change. The differences between the fathers were very significant (P <

0.01) and the value of the coefficient was h 2 = 0.96. The sex groups showed no differences
at the time. In the second winter the sexes were very significantly different from each
other, and the heritability of the change in weight had values between 0.15 and 0.23,
depending on whether the calculation had been made as a fraction of the total variation or
of the variation within the sex groups. The differencesbetween fathers were not significant
in this case. In any case, it is possible, according to the results, that the magnitude of the
change in weight during the winter season is dependent also on the inherited properties.

The change in condition during the first winter seemed to be fully independent of
genetic factors. This is a logical consequence from the fact that also in the first fall the
condition was dependent on other than genetic factors. On the other hand, the change
in condition during the second winter had a fairly good value of the heritability coefficient,
h 2 = 0.56—0.68, which was due to the significant (P < 0.05) differences between the
fathers. The genetic correlation of the changes in weight and condition inside the sex

groups was in the first winter r = 0.19 and in the second winter r = 0.52. The correlations
in phenotypes were r = 0.42 and r = 0.52, respectively.



241

The problem of the changes in weight and condition during the winter season has
not been fully investigated as yet. The main reason for the differences in genetic inclinations
may be either the differences in ability to deposit nutrients in summertime and reach the
corresponding condition in fall or the differences in ability toget fodder in winter. In the
former case big changes in weight and condition reflect great adaptability to the variable
circumstances in different seasons, while in the latter case the ability to maintain weight
and condition as constant as possible, or even to increase them constantly, could indicate
an ability to satisfy the need of nourishment also in winter season. These features would
be most valuable in reindeer breeding if they could be proved to be genetic in origin.
More extensive experiments are, however, necessary to work out this problem satisfactorily.
The survival of young reindeer in winter season is in any case one of the fundamental
problems in reindeer economy.

A general estimate of the heritabilities of the measures shows that the significance of
measures as indicators of genetic inclinations increases with age. This trend is especially
clear in the total length and the width of chest and hip. The lower values of the herita-
bilities of hip depth at older age may again be due to the fact that among females there
have been many pregnant individuals. This makes it difficult to obtain comparable
measures. It is hard to explain, however, why there are such big differences in the estimates
for the length in different years. Here occasional interferences must be accounted for as
their influence can be quite substantial in a small sample like this. The heritability of
height has stayed fairly low, but this is no doubt mainly due to the fact that it is difficult
to measure a half-wild and restless animal often in deep snow.

It is evident that selection resting directly upon weight would offer the best starting
point for breeding work aiming at increased weight or body size. In the circumstances
prevailing in Lapland, the carrying out of a weighing program on a large scale is extremely
difficult in practice, however. This is why the weighings have to be replaced in breeding
work extensively with measures which seem to be more reliable and are, simultaneously,
easily obtainable. Thus the weight is preferably estimated from the values of body length
and chest girth.

Table 4 presents heritability coefficients also for some other properties. The herita-
bilities of different features in antlers would have been different from those given, had
the polled individuals been tabulated here. The animals polled in the first year showed
an unusually weak growth of antlers also later. Thus the antlers of the male that was
polled in the first year were only 20 cm high in the second year, while the average size
for the other males was 36.2 cm. The figures for the females were 2.5 and 28.1 cm, respec-
tively. Reindeer that had antler buds, however small, in the first year, had antlers ofnormal
size in the second year. A very high heritability degree was obtained for the quality of
hair. A buck that has passed on his exceptionally thick, even and shiny hair to all his
offspring, has greatly influenced these results.

Correlation coefficients
The correlations in phenotypes between different features were calculated separately

for both sexes. In spite of the small size of the sample, the result was in both cases uniform



Table 6. Correlations (r x 100) in phenotypes of the progeny.
(P < 0.05, r > 0.25; P < 00.1, r > 0.33; P < 0.001, r > 0.41).

I 2 3 4 5 6 7 8 9 10 II 12 13 14

Birth date 1 -06 -47 -28
Birth weight 2 -06 46 25
Fall 196 3: Weight 3 -47 46 58
Condition 4 -28 25 58
Spring 1964: Weight... 5 -28 57 50 33
Condition 6 -22 14 23 17
Height 7 -23 40 38 24
Length of trunk 8 —27 40 58 32
Total length 9 -18 33 42 26
Chest girth 10 -26 42 42 25
Chest depth 11 -16 40 48 21
Chest width 12 -27 38 44 29
Hip depth 13 -09 19 39 17
Hip width 14 -30 24 39 31
Regularity of antlers 15 —ll 20 28 18
Branchcount of antlers 16 -18 25 29 25
Height of antlers 17 —35 31 48 31
Number of larvae of gadflies 18 25 26 02 -03
Fall 1 964; Weight 19 -23 45 57 35
Condition 20 10 01 17 02
Spring 196 5: Weight... 21 -25 35 41 24
Condition 22 —O2 03 -02 -11
Height 23 -25 38 48 31
Length of trunk 24 —l2 31 43 34
Total length 25 —l4 30 38 26
Chest girth 26 -25 29 44 23
Chest depth 27 -40 19 43 28
Chest width 28 -48 27 37 19
Hip depth 29 -19 29 38 09
Hip width 30 -42 15 26 22
Regularity of antlers 31 05 -07 15 12
Branchcount of antlers 32 —2l 13 15 25
Height of antlers 33 02 06 -02 02
Shade 34 -04 02 06 11
Quality of hair 35 24 —2l —3B —29

-28 -22 -23 -27 -18 -25 -16 -27 -09 -30
57 14 40 40 33 42 40 38 19 24
50 23 38 58 42 42 48 44 39 39
33 17 24 32 26 25 21 29 17 31

47 41 53 50 68 67 68 54 64
47 42 37 29 55 23 46 30 17
41 42 52 36 45 37 33 18 12
53 37 52 44 59 41 45 33 15
50 29 36 44 44 48 37 52 28
68 55 45 59 44 64 60 38 31
67 23 37 41 48 64 53 43 41
68 46 33 45 37 60 53 29 62
54 30 18 33 52 38 43 29 40
64 17 12 15 28 31 41 62 40
07 05 28 17 24 12 16 10 06 03
13 10 34 18 25 12 13 14 23 11
33 34 26 20 20 20 23 31 13 17
07 08 20 25 -04 19 08 12 03 -11
71 27 36 53 60 41 50 46 54 45

-12 -10 -17 05 -07 -13 -12 -11 08 00
62 23 27 41 61 50 52 46 38 44
05 05 -15 -11 11 07 05 06 05 18
59 33 57 48 60 48 55 37 49 33
46 32 25 45 46 40 31 30 37 34
49 27 23 43 47 32 33 31 36 35
63 21 18 38 53 59 56 49 50 42
51 20 16 30 32 44 53 33 40 35
55 33 25 33 47 36 46 50 26 46
46 27 21 34 47 38 41 25 48 33
39 39 11 18 25 33 24 38 19 39
11 12 -14 -06 -04 -00 23 16 17 18

25 19 24 08 16 17 21 08 10 09
21 28 11 -05 05 12 26 03 16 00

-03 22 18 14 13 02 -01 00 09 -07
-35 -09 -17 -25 -30 -03 -27 -30 -12 -46

enough to give the weighed means of the coefficients in Table 6. This was done to

reduce the numerical information since the differences with a few exceptions were not
significant. The first line of the correlation matrix shows that the time of birth seems to
have influenced weights and measures, although seldom with any significance. The
influence has been definite in the first fall only as regards weight and in the following
spring as regards height. In the spring 1965, at the age of two, the time of birth seemed
still to have a big influence on the depth and width of chest, and the width of hip.
The influence of the time of birth does not deserve very much attention since it seems

242



15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

11 -18 -35 25 -23 10 -25 -02 -25 -12 -14 -25 -40 -48 -19 -42 05 -21 02 -04 24
20 25 31 26 45 01 35 03 38 31 30 29 19 27 29 15 -07 13 06 02 -21
28 29 48 02 57 17 41 -02 48 43 38 44 43 37 38 26 15 15 -02 06 -38
18 25 31 -03 35 02 24 -11 31 34 26 23 28 19 09 22 12 25 02 11 -29

13 33 07 71 -12 62 05 59 46 49 63 51 55 46 39 11 25 21 -03 -35
O. 10 34 08 27 -10 23 05 33 32 27 21 20 33 27 39 12 19 28 22 -09
28 34 26 20 36 -17 27 -15 57 25 23 18 16 25 21 11 -14 24 11 18 -17
17 18 20 25 53 05 41 -11 48 45 43 38 30 33 34 18 -06 08 -05 14 -25
2* 25 20 -04 60 -07 61 11 60 46 47 53 32 47 47 25 -04 16 05 13 -30
12 12 20 19 41 -13 50 07 48 40 32 59 44 36 38 33 -00 17 12 02 -03
15 13 23 08 50 -12 52 05 55 31 33 56 53 46 41 24 23 21 26 -01 -27
1) 14 31 12 46 -11 46 06 37 30 31 49 33 50 25 38 16 08 03 00 -30

405 23 13 03 54 08 38 05 49 37 36 50 40 26 48 19 17 10 16 09 -12
03 11 17 -11 45 00 44 18 33 34 35 42 35 46 33 39 18 09 00 -07 -46

28 34 07 17 00 19 03 28 04 08 16 13 09 16 05 -03 15 -08 10 -02
2 3 55 -03 20 -07 20 03 32 16 07 22 20 20 26 15 12 25 30 09 -18
b 4 55 -11 29 -13 22 00 36 27 26 23 25 27 22 29 29 41 32 -01 -33
07 -03 -11 05 08 -01 04 05 -01 09 02 -20 -12 -01 02 -13 13 -02 -24 04

20 29 05 24 76 18 67 58 61 70 53 55 51 40 -01 18 20 02 -38
010 07 -13 08 24 07 21 06 14 22 16 24 -04 25 03 01 -04 -00 02 02
19 20 22 -01 76 07 46 58 65 63 83 54 61 59 50 12 17 12 04 -37

OB 03 00 04 18 21 46 05 22 08 32 25 30 38 28 16 12 11 -06 -17
28 32 36 05 67 06 58 05 47 50 53 46 49 44 32 04 24 22 06 -26
04 16 27 -01 58 14 65 22 47 58 53 37 46 53 38 17 21 05 19 -43
08 07 26 09 61 22 63 08 50 58 49 38 42 49 50 03 22 24 04 -34
16 22 23 02 70 16 83 32 53 53 49 67 48 56 40 04 18 17 -05 -26
13 20 25 -20 53 24 54 25 46 37 38 67 46 60 36 09 24 37 06 -12
■ 20 27 -12 55 -04 61 30 49 46 42 48 46 42 65 06 23 22 11 -50
16 26 22 -01 51 25 59 38 44 53 49 56 60 42 35 11 17 19 10 -24

O5 15 29 02 40 03 50 28 32 38 50 40 36 65 35 01 29 25 02 -27

!0312 29 -13 -01 01 12 16 04 17 03 04 09 06 11 01 13 10 11 -22
15 25 41 13 18 -04 17 12 24 21 22 18 24 23 17 29 13 42 -09 -19

■o|B 30 32 -02 20 -00 12 11 22 05 24 17 37 22 19 25 10 42 12 -06
iO 09 -01 -24 02 02 04 -06 06 19 04 -05 06 11 10 02 11 -09 12 -24
02 -18 -33 04 -38 02 -37 -17 -26 -43 -34 -26 -12 -50 -24 -27 -22 -19 -06 -24

to be mainly due to a few individuals that were born quite late and did not keep pace
with the general progress. It appears that the calves born in the last week of May or
especially in the beginning ofJune, in the cirsumstances of Aska, were weaker than the
others and remained below average during the whole experimental period. The reason
for giving up the correction practice of the weighings and measurements, as mentioned
above, was the fact that the apparently big influence of the birth time was really restricted
to a few exceptions.

It is not possible or even necessary to discuss the figures in the correlation matrix in

243



244

detail. It should be emphasized, however, that the future progress of a reindeer can be
predicted, with good reliability already from the birth weight. Since the correlations be-
tween this and later weights are fairly stable and statistically significant, the correlations
between weights are also generally speaking adequately high and give pointers to succesful
breeding. It can be argued further that the connection between several measures and
weights is quite stable, and this possibly allows the replacement of weights with suitable
measures when making selections in practice. The cest girth and both measures of length
seem to be most suitable for the purpose. The usual body length taken from the withers
to the back, which primarily indicates the length of the trunk, is probably more suitable
than the total length, since the latter includes the less valuableneck and head.

Since the basis for the selection of reindeer has to be made as simple as possible, chest
girth and body length have been combined to a sum variable. The sum of the two measures
in question has simply been computed without accent. The correlations of this combined
measure and the different weights were as follows:

Combined measure, spring 1964:
weight, fall 1963 0.55
weight, spring 1964 0.66
weight, fall 1964 0.54
weight, spring 1965 0.54

Combined measure, spring 1965:
weight, fall 1963 0.51
weight, spring 1964 0.62
weight, fall 1964 0.73
weight, spring 1965 0.85

It can be seen that compared to the coefficient between the weights in the correlation
matrix, these correlations prove the combined measure to be a very satisfactory estimate
of the weight.

It must be remembered, in the case of the correlations of hair quality, that the lowest
mark in the scale has been given for the highest quality. Thus the negative correlations
give the connection of the good quality hair with a feature, the value of which increases
with the measure. According to this good quality hair seems to indicate generally also
good condition and growing ability. It should be mentioned moreover that late born
calves seem to have been pestered by gadflies more than the others, which could be one
reason for their continuous poor condition.

Other observations

The influence of the parent on weight. The dependence of the
weight of the progeny on the weight and measures of the parent was studied also with an
illustrative selection experiment in which the parents were divided into -f- and groups
according to their weights and combined measures. The progeny were divided after their
parents into four groups: +S +D, +S —D, ■—S +D, and -— S —D. The average differ-
ences in weight between the groups +S +D and —S —D appear in Table 7. In order
to eliminate the influence of the sex, the differences in the calves have been computed
separately for both sexes and the figures in the table are the means of these values.



245

Table 7. Differences in weights of the progeny of plus and minus parents.

Difference (kg) in weights of progeny
Time as the parents have been graded by

weight measures

Birth date 0.41 0.67
Fall 1963 2.75 3.05
Spring 1964 3.52 5.40
Fall 1964 3.90 6.40
Spring 1964 4.06 5.15

The results suggest that the selection of parents according to the measures or the
weights leads at least to an equally favorable change in weights of the offspring. More-
over, the significance of the measurements is emphasized by the fact that the parents
have been measured only once, but the weights are the means of four different weighings.
Without giving more results it can be added that the selection according to one parent
was of course on an average only half as effective as according to both parents. The differ-
ences in the spring weights of the calves were influenced much more by the mothers than
the fathers, and also here the measures of the mothers proved to be a distinctly better
basis for selection than the weights. Vostrjakov (1971) has also indicated the big influence
of the weight of the mother on thebirth weights of the calves as well as on the later weights.
These observations suggest, as do the results on the above heritabilities, that the own

genetic inclinations of the progeny are of less importance in the development of spring
weights than are the fall weights, while the ability of mothers to take care of their calves
shows up strongly in the spring. The offspring of good size mothers seem to fare best in
the winter.

Somewhat differentresults were obtained from the investigations where the correlation
between the calf and the mother was computed inside the sex groups. Accordingly, the
value of the correlation coefficient between the measures of the mothers and the weights
of the progeny in the second fall was r = 0.32*, while the weights of the mothers gave
r = 0.41**. Keeping in mind the big number of the weighings of the mothers and also
what has been said above of the spring and fall weights of the offspring, it is evident that
the difference between the coefficients is actually quite small, which points to the use-
fulness of the measures in practice.

Table 8. Dates and weights of birth of the calves by the year and area.

Date of birth in May (d)
Year Number females males

fmx s x s

Weight of birth (kg)
females maleArea males

x s X

Aska 1963 42 30 13.9 0.9 14.7 1.1 5.694 0.078 6.027 0.123
Aska 1964 35 37 12.2 0.8 13.0 0.6 4.609 0.112 5.191 0.159
Kielajoki 1964 28 23 22.7 0.8 20.9 1.1 4.446 0.169 4.878 0.162
Aska 1965 16 10 15.6 1.7 14.6 2.0 4.713 0.207 5.100 0.245



246

Figure 1. Experimental sites in northern Finland (Pudasjärvi = Aska).



247

In addition to the results from the experimental area ofAska at Pudasjärvi, information
has also been obtained about the times and birth weights of calves from the experimental
group of Kielajoki at Inari (see enclosed map, Figure 1) in 1964 and 1965. This group
dispersed later, but the results are seen in Table 8. They show that the male calves have
always been heavier than the females. It is also evident that birth weights may have a
very big yearly variation. This is evident especially in the results of Aska in 1963 and
1964. The calves came both years from the same herd, even if not exclusively from the
same parents. Thus they are mainly either half or full sisters. In spite of this, the calves
of both sexes were very significantly heavier in 1963 than in 1964. The differences were
1.085 kg for females and 0.836 kg for males. The former year was quite good for grazing

while the latter was very poor. The calves born in Aska in 1965 are offspring of the dams
born in 1963. The lower weights of these calves may be mainly due to the young age of
the mothers.

The calves born in Kielajoki are distinctly, although not significantly lighter than
those born in Aska. On an average in 1963, the parents in Kielajoki and in Aska were of
the same age.

Times ofbirth in Aska have been practically the same every year. The calves of 1964
were born 9 days later in Kielajoki than in Aska, on the average. The difference is very
significant. It should be mentioned that the experimental animals were moved later to
Kaamanen.

The order of superiority of the bucks. The question ofthe breeding
efficiency became quite interesting when the bucks were arranged according to the means
of their 1963 progeny separately for both sexes. They were graded from 1 to 6 for altogether
25 properties including all weights, measures and estimates ofcondition. Grade 6 indicates
the most favorable property. When the correlation within groups was computed from
these ratings it was o.49*** and o.46*** according to female and male offspring, respec-
tively. These coefficients show that the list of superiority of the bucks is fairly uniform
according to all the above values. This may be explained as a reflection of size, the herita-
bility of which apparently is very high, both in measures and in weights. Moreover, size
plays a considerable role in the maintenance of individual condition. Differences of this
type between the bucks are of considerable practical significance. In fact the selection of
qucks is of crucial importance in the reindeer breeding initiated so far (Varo 1971).

REFERENCES

Varo, R. M. 1964. Tutkimuksia poron jalostusmahdollisuuksista. Summary: Investigations on the possi-
bilities of reindeer breeding. Ann. Agric. Fenn. 3: 296—310.

Varo, R. M. 1969. Längsiktiga renavelsfrägor. Samnordisk renforskningskonferens Gällivare 1969. Kungl.
Lantbruksstyrelsen, Medd. B 88: 31 —40 1971.

Varo, R. M. 1971. Poronjalostuksen käytännöllinen toteuttaminen. Poromies 3:9—-11.
Varo, R. M. & Varo, H. 1971.The milk production ofreindeer cows and the share ofmilk in the growth

of reindeer calves. Maatal.tiet. Aikak. 43: I—lo.
Votsrjakov, P. N. 1971. Poronhoito ja jalostustyö Neuvostoliitossa. Esitelmä Porosymposiumissa Rova-

niemellä 26.—27. 5.1971. Poromies 5: 4—ll.



248

SELOSTUS

TUTKIMUKSIA PORON JALOSTUSMAHDOLLISUUKSISTA IL

Mikko Varo

Kotieläinten jalostustieteen laitos, Helsingin yliopisto, Viikki

Tässä tutkimuksessa esitettävät tulokset on saatu pääasiassa samasta eläinaineistosta, josta saadut
ensimmäiset koetulokset on julkaistu samannimisessä suomenkielisessä julkaisussa (Varo 1964).

Painon ja kunnon kehitys kolmen ensimmäisen elinvuoden aikana osoittaa (taulukko 1), että kasvu
on talvikauden ajan lähes pysähdyksissä; uroksilla havaitaan painojen jopa laskeneen. Urokset ovat kui-
tenkin sekä painoltaan että useimmilta mitoiltaan (taulukko 2) naaraita selvästi kookkaampia.

Painojen periytymisasteet (taulukko 4) ovat tyydyttävän suuret, joskin pienestä aineistosta johtuen
epävarmat. Painon muutos talvella —joko lisääntyminen tai väheneminen —, näyttää olevan perinnöl-
lisiin taipumuksiin perustuva piirre. Kevätpainot ovat kasvutaipumuksen osoittajina syyspainoja epä-
varmempia ilmeisesti juuri siksi, että eri yksilöiden kyky selviytyä talvesta on erilainen. Kunnon huono-
neminen eräillä yksilöillä ilmenee myös painon laskuna (taulukko 5).

Eri ominaisuuksien väliset yhteydet on esitetty taulukossa 6 korrelaatiokertoimin. Merkityksellisimpiä
ovat eri painojen samoin kuin myös mittojen väliset korrelaatiokertoimet, jotka osoittavat alkukehitykses-
sään hyvin edistyneiden yksilöiden yleensä säilyttävän asemansa myös myöhemmin. Muutamat hyvin
myöhään syntyneet yksilöt jäävät yleensä pysyvästi jälkeen normaaliaikaan syntyneistä. Painavilla, hyvin
kasvaneilla yksilöillä on yleensä muita parempi karvan laatu. Vanhempien valinnalla voidaan jälkeläis-
ten painonkehitystä parantaa (taulukko 7). Käytännön jalostustyössä näyttää ns. yhteismitta, eli rinnan-
ympäryksen ja pituuden summa, sopivimmalta mitalta suoritettaessa valintaa kasvunopeuden paranta-
miseksi.