NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
REVIEW
Züchtung, Ernährung und Haltung der landwirschaftlichen Haustiere Allgemeiner
Teil. By SCHMIDT, J., PATOW, C. V. AND KLIESCH, J. (1956E) (Breeding, feeding
and keeping of farm animals—General part) Berlin ; Verlag Paul Parey. viii 366
pp. 125 Figs. Price : DM. 28
This is the seventh revised edition of the first volume of a two-volume standard
German text-book on animal breeding, feeding and keeping of farm animals. The
volume discusses the general principles involved in animal husbandry. The subject
matter is divided into six major headings; (a) German cattle position, fodder resources
and production, (b) Concept of "breeding" and the material of breeders, (c) Reproduc-
tion and heredity as basis for breeding, (d) Breeding procedures, (e) Measures for
promoting animal breeding and (f) Feeding and keeping of livestock of economic
importance. The subject under heading (a) covering 13 pages may be taken as
introduction. The portion devoted to breeding covers about 200 pages and the
rest of the pages deal with nutrition and animal keeping. There is an index also.
After reviewing the cattle position in Germany today in comparison to what it
was prior to war and earlier, with reference to livestock and production statistics,
the reader is introduced to the subject of breeding procedures, by first discussing the
place and time of origin of the domesticated animals, followed by a formal presenta-
tion of the principles of reproduction and genetics explained through examples
taken exclusively from animal material. In considering the breeding procedures,
the place and aim of breeding, the relative importance of breeding and type, pure
breeding, cross breeding and inbreeding are first discussed; then follows a chapter
on selection: selection according to breed and species, according to conformation
and performance, according to constitution, pedigree and progeny; how selection
can improve health, resistence, longevity, fertility, development, production and
thriftiness. The portion dealing with constitution would be of special interest to
Indian readers. Production covers milk, work and wool and combination of more
than one economic trait. Among measures aiding breeding operations, the role of
co-operatives and breeders associations are described.
The chapters on nutrition follow the formal pattern of presentation. After
describing the various feeding stuffs, the wastes from the different industrial estab-
lishments, the nutrive value and requirements of various classes and kinds of ani-
mals are given. Detailed ration schedule tables for feeding work horses, brood
mares, foals, milch cows, 1-2 year old heifers, 1 year old calves, suckling calves,
breed sows, suckling pigs, market pigs and poultry are given. This is a special
feature of the book which combines the sound exposition of the theoretical principles
with the practical suggestions that are useful for both the students and the
practical animal husbandrymen.
147
12 AR/56
13
148
REVIEW
[ Vol. XXVI, Part III
In the chapters on keeping livestock, after discussing the basic principles,
specific suggestions, illustrated by neat diagrams and photographs of buildings
and sheds to house the different kinds of livestock are presented.
The book has excellent getup. Though the practical suggestions are based
chiefly on conditions met with in Germany, the book as a whole should prove useful
to Indian students also. It is a pity that a book of this type that gives at one place
all relevant information on theoretical and practical aspects of animal husbandry
and breeding is yet to be written in India, for use of Indian students of the subject.
(S. S. P)
MG1PC-M—12AR/56—26-11-56—1,000.
ERRATA
Read page numbers in the Indian Journal of Veterinary Science and Animal
Husbandry of March 1956 as commencing from 52.
HERBAGE ABSTRACTS
AND
FIELD CROP ABSTRACTS
These two quarterly journals, prepared by the Commonwealth Bureau of
Pastured and Field Crops, Hurley, England, are composed of abstracts from the
world's current scientific literature. Herbage Abstracts deals with grass-
lands, fodder crops and their management and Field Crop Abstracts
with
annual field crops, including rice. Both Journals include a review article with
each number as well as abstracts dealing with crop husbandry, varieties, crop
botany, control of diseases, pests and weeds, and a section devoted to book
reviews and notices.
For those engaged in agricultural research or in the giving of agricultural
advice or information, the reading of these two journals offers a ready means
of keeping abreast of current developments without recourse to the labour of
scrutinizing the mass of agricultural publications now appearing in many languages.
The annual subject and author indexes, dating from 1930 and 1948, respectively,
from a valuable source of reference to past work.
The price of each Journal (with index) is 36/- per annum, post free, in the
British Commonwealth and 45/- in other Countries. Orders should be sent to
Commonwealth, Agricultural Bureaux, Central Sales Branch, Farnham Royal,
Bucks, England.
A NEW SIRE INDEX FOR MILK PRODUCTION
BY K. S. KRISHNAN, Indian Council of Agricultural Research, New Delhi
(Received for publication on April 3, 1956)
A N important aspect of the breeding programmes for dairy cattle is the evalua-
tion of the breeding worth of the different bulls. Two methods are in common
use for this purpose. One is the daughter average index which is the simple average
of the milk yield of all daughters of a sire. The other is the commercial Mount
Hope Index, also known as the Intermediate Index, obtained as:
I=2D—M
where D and M are the average milk yields of daughters of the sire and his mates
(mothers of daughters) respectively. Both these methods, however, suffer from
certain shortcomings.
Any method of sire evaluation is likely to be affected by the culling of female
calves and heifers. No satisfactory procedure is available for overcoming this
defect in the estimation of the sire index. Retention of all female progenies till the
completion of their first lactation, except for reasons of disease or confirmed infer-
tility, is, therefore, essential for proper sire evaluation. Apart from this common
limitation, the simple daughter average index does not take into account the possible
assortive matings resulting in unequal average production levels of the dams sired
by different bulls. One limitation of the intermediate index is that it overcorrects
for the differential level of production of dams mated to different sires, that is, is
the set of cows mated to a sire is inferior to the average, the index overestimates
the sire's breeding worth, whereas if the dams are above average, the index under
estimates its worth. Secondly, the intermediate index has a high sampling error
with the consequence that many a times it fails to discriminate between even the
best and the worst bulls among about a dozen bulls that may be used on a herd.
For the last few years extensive studies on breeding data for dairy cattle herds
maintained at different Government farms have been undertaken by the Statistical
Wing of the Indian Council of Agricultural Research. An important aspect of the
analysis has been the examination of the relative merits of the sires used. In the
149
31 AR/56
2
150 NEW SIRE INDEX FOR MILK PRODUCTION [Vol. XXVI, Part IV,
course of this work the above limitation of the two common-sire indices became
increasingly clear and this led to the development of a new index which has been
found to be superior to both. This new index is described in the present article
and the method of calculating it is explained. The superiority of the new index
over the other two is also illustrated by comparing the three indices in respect
of 69 sires from six herds.
The new index
The proposed index is obtained from the formula:
S=D—b (M—A)
where D is the average for the daughters of the sire, M is the average for the dams
of these daughters, b is the intra sire regression of the daughters' performance on
that of its dam, and A is the herd average.
This index is the ordinary regression estimate familiar in sampling theory, where-
in dam's performance is treated as the auxilary variable. It may be termed as
the corrected daughter average index or corrected index for short.
The superiority of the corrected index over other two is partly due to its lower
sampling error and to the more appropriate allowance it makes for the inequality
in the production levels of the dams mated to different bulls. From theoretical
considerations it has been deduced that for a heritability of 50 per cent or less—
and actual analysis of breeding data shows that for most of the quantitative charac-
ters of interest this is true—the corrected index will on an average be more than
four times as efficient as the intermediate index, the standard error for the former
being less than one half of the latter. In other words, about four times as many
daughter-dam pairs of records will be necessary for estimating the worth of the
sire with a given precision if the intermediate index is used, as are required with the
corrected daughter average index. The corrected index will also be more precise
than the simple daughter average index, the extent of superiority depending on the
value of the heritability coefficient, provided that the number of daughter-dam
pairs is not too few. The derivation of these results is given in the Appendix I.
The appropriateness of the correction made for the unequal production levels
of dams mated to different bulls, made in the corrected index can be seen from the
following considerations.
The phynotypic superiority of a selected group of individuals from a lot should
be considered as made up of two parts; one part ascribable to better genetic make-
up and the other to environment. The fraction due to better genetic make-up is
December, 1956]
K.
S.
KRISHNAN
151
equal to the heritability coefficient for the herd. One half of the additively genetic
superiority or otherwise of each parent over the average of the whole lot can be
expected on an average, to be transmitted to the offspring. Thus if a dam is selec-
ted on the basis of its milk yield which is higher than the herd average by x lb. and is
mated to a bull of average merit, the. resulting progeny, if daughter, may be ex-
pected to yield h 2 /2 x lb. more milk than the herd average, where h 2 is the heritability
coefficient. This implies that, even under the assumption of equal contribution
from both the parents, the appropriate correction to be applied for the daughters'
average in order to eliminate the influence of differential production levels of the
dams mated to different bulls is h 2 /2 times the average phynotypic superiority of the
dams mated to the bull concerned, over the herd average. This quantity should
be algebraically subtracted from the daughters' average, i.e. numerically subtrac-
ted or added according as the average production of the dams mated to the bull
concerned is higher or lower than the herd average.
It has been shown by Lush [1945] and others that twice the intra-sire regression
of daughter's yield on that of its dam usually provides the best estimate of the herita-
bility coefficient for a herd. This has been seen to be the case in respect of the Indian
herds so far studied. The intra sire regression accordingly provides the best esti-
mate for the factor h 2 /2 in the correction term. Using this estimate the correction
may be seen to be the one given in the formula for S given earlier.
Computational procedure
The computation of the new index from actual data will be illustrated with the
help of the records pertaining to the Hariana herd maintained at the Government
Cattle Farm, Hissar. The first lactation yields over 300 days or less, measured in
units of 10 lb., are analysed. These yields in respect of each of the 10 sires tested
are given in Table I.
The quantities that are required to be calculated are (a) the herd average, (b)
the intra-sire regression coefficient,(c) the corrected index and (d) the standard error
of the index.
The herd average required for the calculation of the corrected index is obtained
as the average of the dam's yields without repeating the dams having more than
one daughter. This average worked out to 130.8 units in the present case. The
average for the herd will be taken as 1300 lb. in the nearest round figure.
The steps in the calculation of intra-sire regression are shown in columns (3)
to (13) in Table II. As an illustration, the procedure for obtaining these figures
152
NEW SIRE INDEX FOR MILK PRODUCTION [Vol. XXVI, Part IV,
TABLE I
First lactation yields (in 10 lb. in 300 days or less) of the dams mated to different sires and their daughters
(Hariana herd, Government Cattle Farm, Hissar)
Sire I
Dam's
yield
176
222
222
82
32
66
66
201
..
..
..
Daugh-
ter's
yield
134
118
174
136
66
110
131
194
..
..
..
Sire II
Dam's
yield
127
231
207
109
154
154
154
142
..
..
..
Daugh-
ter's
yield
121
142
196
139
85
162
84
74
..
..
..
Sire III
Dam's
yield
108
177
177
228
105
204
204
204
203
203
..
Daugh-
ter's
yield
261
219
135
211
119
190
199
120
176
43
..
Sire IV
Dam's
yield
200
108
91
107
179
57
56
164
78
..
..
Daugh-
ter's
yield
141
82
156
158
86
152
176
184
79
..
..
Sire V
Dam's
yield
68
74
87
232
141
141
123
50
..
..
..
Daugh-
ter's
yield
93
99
151
183
164
171
121
168
..
..
..
Sire VI
Dam's
yield
186
67
208
208
68
73
25
..
..
..
..
Daugh-
ter's
yield
129
158
283
160
190
151
131
..
..
..
..
Sire VII
Dam's
yield
235
28
73
73
268
26
..
..
..
..
..
Daugh-
ter's
yield
202
77
117
125
227
93
..
..
..
..
..
Sire VIII
Dam's
yield
43
168
168
219
219
238
161
..
..
..
..
Daugh-
ter's
yield
128
161
107
230
139
272
130
..
..
..
..
Sire IX
Dam's
yield
47
152
229
62
62
187
187
19
209
88
273
Daugh-
ter's
yield
123
92
220
60
172
202
223
178
94
135
142
Sire X
Dam's
yield
94
188
138
87
54
..
..
..
..
..
..
Daugh-
ter's
yield
114
116
177
166
71
..
..
..
..
..
..
December, 1956]
K.
S.
KRISHNAN
153
TABLE II
Calculation of corrected daughter average indices and their standard errrors (10 lb. unit)
(Hariana herd, Government Cattle Farm, Hissar)
Sire
No.
(1)
I
II
III
IV
V
VI
VII
VIII
IX
X
Total
Daughter
dam
pairs
(2)
8
8
10
9
8
7
6
7
11
5
79
Total
for
dams
(3)
1067
1278
1813
1040
916
835
703
1216
1515
561
10944
Total
for
daughters
(4)
1063
1003
1673
1214
1150
1202
841
1167
1641
644
11598
Sum of squares for dams
Crude
(5)
186405
215532
344597
142800
128884
136191
139167
236784
281695
73709
1885764
C.T.
(6)
142311
204160
328697
120178
104882
99604
82368
211236
208657
62944
1565037
Corrected
(7)
44094
11372
15900
22622
24002
36587
56799
25548
73038
10765
320727
Sum of squares for daughters
Crude
(8)
151905
138543
315915
177478
173742
223356
136225
216859
274619
90378
1899020
C.T.
(9)
141246
125751
279893
163755
165312
206401
117880
194556
244807
82947
1722548
Corrected
(10)
10659
12792
36022
13723
8430
16955
18345
22303
29812
7431
176472
Sum of products
Crude
(11)
156572
165374
299742
138410
139761
153942
130546
217005
237678
75226
1714256
C.T.
(12)
141778
160229
303315
140284
131675
143381
98537
202725
226010
72257
1620191
Corrected
(13)
14794
5145
—3573
—1874
8086
10561
32009
14280
11668
2969
94065
154
NEW SIRE INDEX FOR MILK PRODUCTION [Vol. XXVI, Part IV,
TABLE II—contd.
Calculation of corrected daughter average indices and their standard errors (10 lb.unit)
(Hariana herd, Government Cattle Farm, Hissar)
Sire
No.
I
II
III
IV
V
VI
VII
VIII
IX
X
Av. for
dams
(3)÷(2)
(14)
133.4
159.8
181.3
115.6
114.5
119.3
117.2
173.7
137.7
112.2
'Dam's Av'
—Herd Av.
(14)—130
(15)
+3.4
+29.8
+51.3
—14.4
—15.5
—10.7
—12.8
+43.7
+ 7.7
—17.8
(15) × b
(16)
+1.0
+8.7
+15.0
—4.2
—4.5
—3.1
—3.8
+12.8
+2.2
—5.2
Av. for
daughters
(4)÷(2)
(17)
132.9
125.4
167.3
134.99
143.8
171.7
140.2
166.7
149.2
128.8
Corrected
Index
(17)—(16)
(18)
131.9
116.7
152.3
139.1
148.3
174.8
144.0
153.9
147.0
134.0
(7) × b 3
(19)
3793
978
1368
1946
2065
3147
4886
2198
6283
926
(13) × 2b
(20)
8678
3018
—2096
—1099
4743
6195
18776
8377
6844
1742
Residual
S.S.
(10) + (19)
—(20)
(21)
5774
10752
39486
16768
5752
13907
4455
16124
29251
6615
n(n-1)
(22)
56
56
90
72
56
42
30
42
110
20
Variance
of
Index
(21)÷(22)
(23)
103
192
439
233
103
331
148
384
266
331
S. E. of
Index
√(23)
(24)
10.1
13.9
21.0
15.3
10.1
18.2
12.2
20.0
16.3
18.2
December, 1956]
K.
S.
KRISHNAN
155
for one bull, viz. Sire I, is explained, below :
Total for dams mated, repeating each dam's record as many times as the number
of daughters from the same sire
=176+222+222+82+32+66+66+201
=1067
(Col. 3)
Total for daughters
=134+118+174+136+66+110+131+194
=1063
(Col. 4)
Crude sum of squares for dams, repeating each dam's record
=(176) 2 +(222) 2 +(222) 2 +(82) 2 +(32) 2 +(66) 2 +(66) 2 +(201) 2
=186405
(Col. 5)
Correction term for sum of squares for dams
= (Total for dams) 2 / Number of pairs = (1067) 2 / 8
=142311
(Col. 6)
Corrected sum of squares for dams
=Crude S.S.—Correction term
=186405—142311
=44094
(Col. 7)
The corrected sum of squares for daughters is obtained in the same manner:
Crude sum of squares for daughters
=(134) 2 +(118) 2 +(174) 2 +(136) 2 +(66) 2 +(110) 2 +(131) 2 +(194) 2
=151905
(Col. 8)
Correction term
(1063) 2 / 8
=141246
(Col. 9)
Corrected sum of squares for daughters
=151905—141246
=10659
(Col. 10)
The corrected sum of product is calculated next using the product of the yields
for each pair.
Crude sum of products
=(176 × 134)+(222 × 118)+(222 × 174)+(82 × 136)+(32 × 66)+(66 × 110)+
(66 × 131)+(201 × 194)
=156572.
(Col. 11)
156
NEW SIRE INDEX FOR MILK PRODUCTION [Vol. XXVI, Part IV,
Correction term for the sum of products
(Total for dams) (Total for daughters)
Number of pairs
= (1067) × (1063) / 8
=141778
(Col. 12)
Corrected sum of products
=156572—141778
=14794
(Col. 13)
If the records are available for only one sire and the number of daughter-dam
pairs is large, say 50 or more, the intra-sire regression may be estimated as the quo-
tient obtained by dividing the corrected sum of products by the corrected sum of
squares for dams. But such a large number of pairs from a single sire is hardly
likely to be available, the common situation being a number of sires from the same
herd with much fewer daughter-dam pairs each. In such cases the corrected sums
of products and the sums of squares for dams may be pooled over all sires. The
intra-sire regression coefficient may then be obtained as ratio of the pooled sums of
products to that for the pooled sums of squares for the dams. For the Hariana
herd taken for illustration here, data in respect of ten sires were available. Com-
putations made for these sires in the manner explained above are presented in Table
II. The estimate of the intra-sire regression coefficient obtained from the pooled
data is
= 94065 / 320726
=0.2933
The corrected daughter average index for Sire I is now obtained as below :
Average for dams
=1067 / 8
=133.4
(Col. 14)
Deviation of the average for dams from the herd average
=133.4—130
=+3.4
(Col. 15)
Correction for the effect of dams
=(Dams' av.—herd av.) × regression coefficient
=+3.4 × 0.2933
=+1.0
(Col. 16)
December, 1956]
K.
S.
KRISHNAN
157
Average for daughters
=1063 / 8
=132.9
(Col. 17)
Corrected Index
=Daughter av.—correction
=132.9—1.0
=131.9
(Col. 18)
The following are the steps for computing the standard error of the index :—
Residual sum of squares
=(corrected S.S. for daughters)+(corrected S.S. for dams) × (b) 2 —(cor-
rected S.P.) × 2b
where S.S. and S. P. denote the sum of squares and products, respectively.
=10659+(44094) × (0.2933) 2 —14794 × 2 × 0.2933
=5774
(Col. 21)
The divisor for the residual sum of squares
= n × (n.1)
= 8 × 7
= 56
(Col. 22)
Variance of the Sire Index
= Residual sum of squares / Divisor in Col. (22)
=5774 / 56
=103
(Col. 23)
Standard error of the index
= √Variance = √103 = 10.1
(Col. 24)
It may be noted that in calculating the regression and the sire index the dam's
record is repeated with that of each of her daughters when the number of daughters
is more than one. This procedure is a close approximation to the exact but elaborate
technique suggested by Kempthorne and Tandon [1953]. This method is satisfactory
when the correlation between the daughters of the same dam is low and the number
of full sibs is few, which is normally the case.
The method given for the calculation of the standard errors of the indices is a
simplified approximation to the exact procedure, as the component term in the
sampling variance due to the sampling nature of the regression estimate is neglected.
The extent of under-estimation in the standard errors of the indices will, however
decrease with an increase in the volume of data on which the regression coefficient
31 AR/56
2
158
NEW SIRE INDEX FOR MILK PRODUCTION [Vol. XXVI, Part IV,
is based. Experience in the analysis of breeding data at the Indian Council of
Agricultural Research suggests that the bias involved in using the simplified method
being of an order of less than one per cent is negligible, unless the data available for
estimating the intra-sire regression is very scanty. The component of the sampling
variance of the regression coefficient is
Residual S.S. / n-1 × (Dams' average—Herds' average) / Corrected S.S. for dams from total lin
and should be added to column (23) in Table II in order to obtain the exact
variance of the regression coefficient. For example, the correction needed for
the estimate of variance 103, corresponding to Sire I in column (23), Table II is
5774 / 7 × (+3.4) 2 / 320727 which is less than 0.5.
A frequent limitation of the estimates of the intra-sire regression coefficients
obtained from the data available for a set of contemporary bulls is that they are of
low precision owing to the inadequacy of the data. In these circumstances it is
desirable to make use of the data for sires that may have been tested in the past
from the same herd in order to obtain an estimate of the regression coefficient with
a higher precision. This can be done easily by adding to the numerator and the
denominator (i.e. to the corrected sum of products and the sum of squares for dams
respectively) the corresponding quantities for the previous sires. The regression
coefficient may then be obtained as the ratio of these two quantities. This procedure
is justified since the change in the. proportion of heritable variation is not likely
to be appreciable in the course of a few generations with the moderate selection
that is possible in small herds. In case, however, the earlier data pertain to a period
in the distant past—say more than 20 or 25 years before—and a substantial change
in the herd average has occurred during the intervening period, it would not be
advisable to use such data.
Comparison of indices
In order to see how far the expectations of the superiority of the corrected index
over the other two indices, viz. the simple daughter average index and the inter-
mediate index is realised in practice, data relating to as many as 69 bulls for six
herds were analysed. The three indices with their standard errors are given in
Tables III to VIII. It will be seen from columns 7 and 9 of the Tables that the
standard errors for the corrected and the intermediate indices are, generally speak-
ing, in the ratio of 1 : 2 as expected. A comparison of the standard errors for
the corrected and the simple average indices indicates that the gain achieved due
to the reduction in the standard errors is negligible. This is not surprising as it
can be seen from the results given in the Appendix I that the expected reduction in
the standard errors is less than 2.5 per cent for a heritability coefficient of 50 per
cent or less.