NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
212 GENETIC CORRELATIONS IN AUSTRALIAN MERINO SHEEP [Vol. XXVIII, Pt. IV,
ewe lambs born in the spring of 1951 (group 'A') and 273 born in the autumn of
1952 (group 'W'). Each of these groups was further divided into "selection groups"
containing animals selected for or against individual wool characteristics.
(a) Characters observed
(i) Body measurements. All measurements were made on live animals. Body
length, depth and width, and fore cannon length were measured according to the
procedure of Turner et al. [1953]. Fore cannon length was used as an index of
mutton quality, while to assess conformation, body length, depth and width were
measured.
(ii) Mutton score. Scores for "mutton type" were based on the shape of the
hind quarters of living animals viewed from the rear. Sheep with "good fill" in the
hind quarters giving the impression of an inverted U were scored high, while those
with "poor fill" looking more or less like an inverted V were scored low [McMahon,
1943]. Only three grades (2, 1 and 0 in the descending order of merit) were used.
Assessments were made two or three days after crutching. Each sheep was graded
by four observers, each recording his score independently. The score used in the
final analysis was the sum of the scores of the four observers [Taneja, 1955 c].
(iii) Skin fold score. Photographic standards similar to those described by
Carter [1943] were used for the Trangie sheep and the scoring was done at weaning.
The total of individual scores for neck, trunk and breech region was used in the
analysis.
(iv) Body weights. Sheep were weighed at five and eleven months of age.
The standard procedure for weighing the sheep has been to hold them over-night
without food and water so that the differences due to the contents of the digestive
tract are minimised. Sheep of all groups are mixed before weighing so that they
are weighed in random order.
(b) Analysis
Hazel [1943] and Hazel et al., [1943] described several methods for estimating
genetic correlations. These methods involve measuring the relationship between
two different characters either of related individuals or of the same individual.
In this study the correlations between various traits of the same individuals have
been estimated.
Sums of squares and sums of cross products were obtained separately for each
group. The variances and co-variances between sires for the two groups were
combined together and divided by (n 1 —1) + (n 2 —1) to obtain estimated variances
and co-variances, where n 1 and n 2 represent the number of sires in each group.
Similarly, the appropriate residual sums of squares and sums of cross products
for the two groups were combined together and divided by (N 1 —n 1 ) + (N 2 —n 2 )
to obtain the residual variances and co-variances, where N 1 and N 2 represent the
total number of individuals in each group.
December, 1958]
G.
C.
TANEJA
213
The expected composition of mean squares and cross products are given in
Table I.
TABLE I
Expected composition of variances and co-variances
Source
Between sires
Residual
d.f.
n—1
N—n
M.S. (i)
σG 2
i +KσS 2
i
σG 2
i
Cross product (i.j)
Cov G i G j +k Cov S i S j
Cov G i G j
M.S. (j)
σG 2
j +KσS 2
j
σG 2
j
The genetic variances and co-variances were obtained by subtracting residual
variances and co-variances from that of between sires (Table I).
r G i G j =Cov S i S j /σS 2 . i σS 2
j
G i is the genic value for the trait i and G j is the genic value for the trait j.
For estimation of genetic correlations, the variances and co-variances between
groups have not been deducted from that of between sires. This procedure will not
affect the values of genetic correlations.
RESULTS
The estimates of genetic correlations are presented in Table II. The results
can be summarised as below :—
(a) Positive correlations between :
(i) various body measurements,
(ii) body measurements, body weights and mutton score,
(iii) body weights at different ages.
(b) Negative correlations between fold score and all other characters studied.
TABLE II
Genetic correlations among body characters
d
1
w
c
f
m
b 1
b 2
d
—
—
—
—
—
—
—
—
1
0.52
—
—
—
—
—
—
—
w
0.20
0.43
—
—
—
—
—
—
c
0.28
0.91
0.57
—
—
—
—
—
f
—0.48
—0.45
—0.34
—0.61
—
—
—
—
m
0.55
0.51
0.31
0.27
—0.73
—
—
—
b 1
0.57
0.26
0.25
0.29
—0.52
0.85
—
—
b 2
0.81
0.61
0.28
0.34
—0.11
0.38
0.26
—
d=depth, 1=length, w=width, c=cannon length, f=skin fold score, m=mutton score, b 1 =body
weight at 5 months, b 2 = body weight at 11 months.
December, 1958]
G.
C.
TANEJA
215
Mather [1949] found that continuous selection for chaeta number in Droso-
phila resulted in correlated responses to selection. He found that higher chaeta
number was associated with loss of fertility and under relaxed conditions, the fertility
was regained. This he postulated as due to recombination of genes within chromo-
somes by a suitable cross-over. Mather concluded that genes responsible for
chaeta number are linked with fertility genes. He believes that pleiotropic effects of
genes are not to be expected.
Results obtained in Drosophila cannot be expected to be wholly applicable to
the domestic animals, because Drosophila has few segregating units (chromosomes)
compared with large animals. It is quite possible to achieve intense selection in
Drosophila and the effect of linkage may then be important. In sheep, on the
other hand, there are several times as large a number of segregating units and linkage
cannot be expected to be important to the same extent. Moreover, in sheep and
other livestock, selection for any linked combination must be weak, especially where
a large number of genes influence the character in question.
SUMMARY
Measurements of body length, depth and width, fore cannon length, mutton
score, skin fold score, and body weights at 5 and 11 months were recorded
for Peppin Merino ewe lambs. Observations were made on two groups of lambs—
284, born in the spring of 1951 and 273, born in the autumn of 1952—at the Trangie
Agricultural Experiment Station of the New South Wales Department of Agriculture.
Genetic correlations amongst the characters studied indicate:
1. Positive correlation between :
(i) various body measurements,
(ii) body measurements, body weights, and mutton score and
(iii) body weights at different ages.
2. Negative correlation between fold score and all other characters studied.
ACKNOWLEDGEMENTS
The author expresses his thanks to Professor P. R. McMahon, New South
Wales University of Technology, Sydney, for his advice and criticism. Thanks are
also due to the New South Wales Department of Agriculture, for permission to
use their material and facilities at the Trangie Agricultural Experiment Station.
78 AR/58
10
216 GENETIC CORRELATIONS IN AUSTRALIAN MERINO SHEEP [Vol. XXVIII, Pt. IV,
REFERENCES
Belschner, H. G. (1937).—Sci. Bull. Dep. Agric. N.S.W. No. 54
Carter, H.B. (1941).—J. Aust. Inst. Agric. Sci. 2 : 101
——(1943).—Coun. Sci. Indust. Res. Aust. Bull. No. 164
Hazel, L. N. (1943).—Genetics. 28 : 476
——Baker, M. L. and Reinmiller, C.E. (1943).—J. Anim. Sci. 2 : 118
Lush, J. L. (1948). The Genetics of Populations, Ames, Iowa, (Mimeo)
Mather, K. (1949). Proc. 8 th Int. Cong. Genetics. (Hereditas Suppl. Vol.) 376
McMahon, P. R. (1943).—Proc. N.Z. Soc. Anim. Prod. (mimeo)
Nichols, J. E. (1945).—Livestock Improvement (Oliver and Boyd : London)
Taneja, G. C. (1955 a).—Aust. J. Agric. Res. 6 : 343
—— (1955 b).—J. Aust. Inst. Agric. Sci. 21: 26
—— (1955 c).—Aust. J. Agric. Res. 6 : 882
—— (1958) J. Genetics. (In press)
Turner, Helen N., Hayman, R. H., Riches, J. H., Roberts, N.F., and Wilson, L.T. (1953).—C.S.I.R.O.
Aust. Div. Anim. Hlth. & Production, Rep. No. 4 (ser. S.W.—2)
ABSTRACTS
Experiments and observations leading to development of the California Mastitis Test.
SCHALM, O.W. and NOORLANDER, D.O. (1957).—J. Amer. Vet. Med. Assoc.
130, (5), 199—204
T HE authors have given details of a quick and reliable test developed by them
for the detection of abnormal milk at the side of the cow. This test has been
designated as the California mastitis test (C.M.T.).
The test consisted in drawing milk directly from the respective teat into milk
receptors or cups fitted to a plastic paddle and adding the test solution (dry form
of detergent 0.5 per cent, Na OH, 1.5 per cent and bromocresol purple in final con-
centration of 1 : 10,000) to an estimated equal quantity of milk in each cup by
squirting the reagent from a prolyethylene wash bottle and mixing them by gentle
circular motion of the paddle. The reactions were graded on the basis of the amount
of shredding or clumping of the particulate material formed.
On comparing the C.M.T. score with mean total cell-count per ml. of milk and
percentage of polymorphonuclear cells of 573 samples of fore-milk, 136 of stripping
milk, 234 bucket and 154 bulk samples, there was noted, in general, a good correla-
tion. The test, therefore, in addition to its use in testing fore-milk and strippings of
individual glands, was also found useful in testing the bucket milk for rapid screening
of herds for mastitic cows, and for testing bulk milk for the detection of herds having
a high degree of udder inflammation. [R.L.].
The relative immunity to brucellosis of calves vaccinated intradermally compared to
those vaccinated subcutaneously. GILMAN, H.L. and HUGHES, D.E. (1957).
Cornell Veterinarian, XLVII, 291—301
T HE authors have given an excellent review of the comparative value of sub-
cutaneous, intradermal and intracaudal methods of calfhood vaccination with
strain 19 Br. abortus vaccine ; according to different workers the intradermal and in-
tracaudal methods of inoculation were as effective as the subcutaneous method.
Experiments were conducted by the authors to determine the relative immu-
nity to brucellosis of a group of calves (13) vaccinated intradermally with 0.2 ml.
of the vaccine at eight months' age compared to a group of calves (13) vaccinated
subcutaneously with 5 ml. of the vaccine at the same age. Four calves were kept as
unvaccinated controls to test the virulence of the infecting organisms. Of the 13
animals in group A (vaccinated intradermally) eight calved at term and showed
no evidence of infection either in blood reaction or presence of the organisms. Five
aborted, and in each case B. abortus was recovered. Of the 13 animals vaccinated
subcutaneously, one aborted with recovery of organisms, ten calved at term and
217
78 AR/58
11
218
ABSTRACTS
[Vol. XXVIII, Pt. IV,
showed no evidence of having acquired the infection, and the remaining two calved
at term but acquired infection as shown by the recovery of B. abortus. Of the four
controls, three showed high and persistent blood reactions and aborted ; B. abortus
was recovered from each of them. One control showed a slight post-exposure rise
in blood titre, calved normally and did not become infected.
According to the authors, the subcutaneous administration of the vaccine
conferred a somewhat higher level of immunity than the intradermal method. The
number of animals was small, and the exposure was relatively severe. [C.L.S.]
A preliminary trial with three new drugs as prophylactics against Trypanosoma congo-
lense in Zebu cattle. J.ROBSON and A. H. MILNE. (1957). Vet. Rec. 69, (22),
564-566.
E NCOURAGED by the favourable report of Watkins and Woolfe [1956] on the
prophylactic action of the compounds RD 2787, RD 2801 and RD 2902 (all com-
bining in part structure of dimidium and antrycide) in mice against Trypanosoma
congolense, the authors undertook trials with these compounds in the experimentally
produced infection of cattle.
In a preliminary experiment designed to judge the apparent toxicity, the three
compounds were given subcutaneously, one to each of three healthy oxen respecti-
vely, as 2 per cent solution at the rate of 3 mg./kg. body weight. All the drugs
caused local swellings, which however disappeared within a month ; at the end of
a week, a loss of 12 to 16 lb. in body weight was noticed, but it was regained in two
weeks. However, the drugs given as 2 per cent solution by the intramuscular
route in the main experiment caused neither lameness nor any local reaction.
The drugs were given at the dose of 2 mg./kg. to 3 groups of 18 cattle each
and at half this dose rate to another 3 groups of 8 cattle each, respectively. A
seventh group of 12 cattle served as control. Experimentals with no histories
of trypanosome infection were selected and maintained in fly-proof sheds
to avoid extraneous infection.
All the drugs at both the dosage levels gave complete protection against
heavy challenges of T. congolense of proven virulence by needle to cattle (6
and 2 cattle from each of the first three and the next three groups respectively
on each challenge) when tested at 2 and 4 months of dosing respectively, except
that one of the 2 cattle injected with RD 2902 at 1 mg./kg. rate developed the
infection 45 days after challenge. The 3 challenged controls developed infection
in 7 to 12 days. The remainder were challenged six months after dosing. All
the cattle given RD 2801 at 2 mg./kg. dose rate were still refractory to the infec-
tion, though 2 of the 4 animals which had received the drug at the 1 mg./kg.
rate dose showed trypanosomes in the blood. Similarly, trypanosomes broke
through the protection in 2 each of the 6 and 4 animals of the groups protected
with RD 2787 at the 2 and 1 mg./kg. dose levels respectively ; in 3 of the 6
cattle given RD 2902 at 2 mg./kg. rate and in all the 4 given the drug at the
lower dosage level—though the prepotent periods in a majority of cases of break-
downs were longer.
December, 1958]
ABSTRACTS
219
Seven months after dosing, half of the cattle challenged at 2 and 4 months
were rechallenged. RD 2801 at the higher dose rate still protected 5 of the
6 cattle and one out of 2 cattle at the lower dose level ; RD 2787 protected 4
out of 6 cattle at the higher dose rate, and RD 2902 protected only 2 of the 6
and one out of 2 cattle at the higher and lower dosage levels respectively.
Thus the authors conclude that one injection of the compound RD 2801
(now designated prothidium) appeared to protect the cattle against T. congolense
for a period of six months, while the compounds RD 2787 and RD 2902 proved
less effective, in the order written. Trypanosomes developed no resistance to
any of these compounds, as cases where breakdown occurred were successfully
treated with ethidium. [B.S.G.]
An empirical test of part record selection for egg production. I.M. LERNER and E.R.
DEMPSTER (1956). Poult. Sci. 35, (6), 1349—55.
E XPERIMENTS were carried out to test whether the combined family
and individual selection for egg-production based on breeding from pullets is
a more efficient procedure than one based on breeding from hens. In the former
case, females were mated when they were about a year old, while in the second
instance the minimum interval between the hatching dates of dam and daughter
was approximately two years. The flock was divided into two sub-populations,
designated respectively as the pullet and the hen lines. The first selection
of sires was made from the same base in the two sub-populations. Thereafter,
the male-selection schemes were identical in both lines, cockerels being chosen
on the basis of part-record indexes of their full-sister families. The females in
the pullet line were selected on the basis of production to nine months of age.
In the hen line, the birds were selected with respect to production to 18 months
of age.
The results of reproductive performance based on a hatching season of four
weeks' duration showed relatively higher reproductive efficiency of the pullet
line. Over the. three years of the test, the average number of breeding birds
needed to replace the flock was of the order of 20 per cent lower in the pullet than
in the hen line. In the former case, breeding females produced six daughters
surviving to 3½ months of age, as compared to five in the hen line. In egg
production results, the pullet line exceeded the hen line in the average hen-
housed and survivors' production. On the other hand, with respect to viability,
the hen line was superior. The higher mortality of the pullet line might be
associated with its higher inbreeding, for, in the hen line the sires came from a
later generation than did the dams, while in the pullet line, the males and
females mated were contemporary and hence somewhat more closely related.
In general, the results showed that pullet breeding is a practical and desirable
procedure in programmes of combined family and individual selection for egg
production. [S.B.]
220
ABSTRACTS
[Vol. XXVIII, Pt. IV,
The control of molds on shell-treated eggs. PATRICIA CLEMENTS and A.R. WINTER
(1956). Poult. Sci. 35, (5), 1116-20.
T HE aim of the experiment was to find out the fungicidal and bactericidal
properties of six chemical compounds. These compounds were tested at 0.25
per cent level in water, for dipping before shell-treatment and for use in Foamrex
and oil dipping solutions. The oil used had a viscosity of 64 to 75 Saybolt points
at 100°F, Pour point 25°F and specific gravity 0.845 to 0.858. Foamrex is an
alkaline wettable wax solution containing small (1 to 2 micron) particles of wax
dispersed in water by means of an emulsifying agent. The eggs for experiment,
except the controls, were kept at 55°F for a day before testing, and after cleaning
with warm water were dried before a fan. The eggs were then candled for 'A'
grade. They were then dipped in the testing solutions, immediately removed
and after drying before a fan, stored for 15 days at room temperature (65°F
to 95°F) with a relative humidity of 95 to 100 per cent.
At the end of the preservation period, these eggs were washed with a solu-
tion containing 500 ml. of sterile water, and emulsifying agents, 0.1 percent
between 80 and 0.15 per cent G-2800. These washings were used for mold and
bacterial count by the dilution plate method.
The fungicides tested were (1) Alkyl trimethyl ammonium chloride, (2)
Di-duodecnyl dimethyl ammonium chloride, (3) Cetyl pyridinium chloride,
(4) Cetyl trimethyl ammonium bromide, (5) Duomeen T mono acetate and (6)
Salicylanilide.
It was found that clean, soiled and washed eggs had about the same micro-
bial growth at the end of 15 days at room temperature, due perhaps to the bio-
logical saturation point being reached during the holding period. Also, mere
dipping in oil or Foamrex had no effect on visible mold growth on the shells,
mold and bacterial count of shell washings and rots.
Cetyl trimethyl ammonium bromide was found to be an effective fungicide
when used alone or with oil, having some germicidal value at 0.25 per cent level.
It was not effective when used with Foamrex.
Di-duodecnyl dimethyl ammonium chloride was an effective fungicide and had
some bactericidal properties when used alone or in combination with oil or Foamrex
at 0.25 per cent concentration.
Duomeen T mono acetate reduced mold growth on shells by about 55 per cent
and bacterial growth by about 27 per cent.
Cetyl pyridinium chloride at 0.25 per cent concentration reduced both mold and
bacterial growth when used alone or in combination with oil; but was ineffective as
a fungicide and germicide when used with Foamrex.
Alkyl trimethyl ammonium chloride reduced mold count by about 50 per cent
and was more effective when used with oil than Foamrex. It had little bactericidal
action.
December, 1958]
ABSTRACTS
221
Salicylanilide was effective in most trials.
Summarising, according to the authors, cetyl trimethyl ammonium bromide,
cetyl pyridinium chloride and salicylanilide were effective fungicides when used
with oil for treating eggs shell. Di-duodecnyl dimethyl ammonium chloride on the
other hand was an effective fungicide in oil as well as Foamrex. [T.D.M.]
The value of faecal nitrogen and crude fibre in estimating intake of four sub-
tropical grasses. R. MILFORD 1957. Aust. J. Agri. Res. 8, (4), 359
T HIS paper examines the correlation between nitrogen and crude fibre composi-
tion of the faeces, and the dry matter intake.
All studies were conducted with mature Border Leicester Merino wethers by
feeding four sub-tropical grasses viz. (1) Paspalum commersonii (2) Urochloa pullulans
(3) Chloris gayana (4) Panicum maximum.
Sheep were fed daily from pasture samples which were freshly cut and coarsely
chaffed.
It was found that correlation between the percentage of faecal crude fibre and
digestibility of dry matter was not significant for P. commersonnii, U. pullulans,
and C. gayana, but there was significant correlation in the case of P. maximum.
The correlation between percentage faecal nitrogen and digestibility of day
matter was also not significant for C. gayana and U. pullulans, but negatively signi-
ficant in the case of P. maximum and positively in the case of P. commersonii.
From the above observations, it is clear that relationship between per cent
nitrogen and crude fibre in faeces and dry matter digestibility does not show much
promise as a method of estimating pasture intake under sub-tropical conditions.
In this respect, sub-tropical grass species differ from temperate grass species.
However, a highly significant positive correlation between dry matter intake
and total nitrogen in faeces was found for all the four species of grasses. The correla-
tion between total faecal nitrogen and dry matter intake could be expressed by a
common regression equation for three grasses, except P. maximum which had a
different regression equation.
Value for total nitrogen in faeces in grams per 100 gm. dry matter intake varied
primarily because high intake of dry matter was associated with high protein grasses
and low intake with low protein grasses.
According to the author, the relationship between total faecal nitrogen and
dry matter intake can be used to measure intake of free grazing animals on mono-
specific swards or on mixed swards of species with similar relationship. [B. S. G.]
78 AR/58
12
222
ABSTRACTS
[Vol. XXVIII, Pt. IV,
Fertilization and embryonic mortality rates of bulls histories of either low or high
fertility in artificial breeding. H. J. BEARDON, W.H. HANSEL and R.W. BRAT-
ton. (1956). J. Dairy Sci. XXXIX, (3), 312-318
A COMPARATIVE study of the effect of high fertility and low fertility bulls used
in artificial breeding has revealed that the rate of fertilization and the number of
normal embryos are greater in the high fertility group of bulls than those of low
fertility. The rate of fertilisation, based on three day post-oestrus slaughter, was
76.9 per cent for 26 heifers bred to bulls with histories of "low" fertility and 26.6
per cent for 29 heifers bred to bulls with histories of "high" fertility in artificial
breeding. The percentages of normal embryos determined by slaughtering 33-days
post-oestrus animals, in the above experiment, were 57.7 per cent and 86.1 per cent
respectively. The percentage of heifers which did not conceive was 19.6 for
those bred to low-fertility bulls and 10.5 for those of high fertility ones. The
difference between the two groups of bulls is statistically non-significant.
Further, the repeat breeding in cows bred to high fertility bulls is always due
to embryonic mortality, whereas in animals bred to low fertility bulls both non-
fertilisation and early embryonic mortality may be the cause. [G.C.B.]
MGIPC—M—78 AR/58—27 5.69—1300.
Vol. XXIX, Part I
March, 1959
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