Until a computer service evolved to
embrace all milk-recorded ewes in Israel and replaced registration in the flock
book, the flock book (kept jointly by the Sheep Breeders' Association and the
Department of Sheep Husbandry of the Israeli Ministry of Agriculture) formed
the basis for selection in Awassi flocks.
The flock book
registered only milk-recorded flocks with mean lactation yields exceeding 250
kg, and from such flocks only those ewes whose breeding standard yield exceeded
350 kg, the breeding standard or maximum lactation yield in any one year being
then regarded as the optimal genetic capacity of a ewe under the conditions of
feeding and maintenance prevailing in her flock.
The flock book was
established in 1943 with an initial registration of 362 ewes from 14
milk-recorded flocks. The ewes of these flocks had an average milk yield of 160
kg and above, while the registered ewes had a breeding standard yield of not
less than 250 kg. In 1948/49 the minimum requirement for individual
registration was raised to 275 kg, and in 1955/56 to 350 kg. The flock standard
was increased to 200 kg in 1955/56, and to 250 kg a
few years later.
The increase in
flock book and individual requirements for registration affected the number of
flocks and ewes eligible. Thus, in 1955/56 seven flocks that did not come up to
the 200 kg standard were excluded from the flock book, with the result that the
average breeding standard yield of all registered ewes rose from 258 to 280 kg
of milk. On the other hand, a large increase in the number of flocks and
milk-recorded ewes, such as occurred in 1949/50, reduced the average breeding
standard milk yield for four consecutive years (see Table 4-3).
Flock rams are
registered in the ram register of the flock book or computer administration on
condition that they are sired by selected stud rams out of dams that are
attested for ram breeding. Only such ewes are eligible for this purpose that
have yielded not less than 900 kg of milk in their first two lactations, or 1
600 kg in three lactations, with a fat content of milk of not less than 6
percent.
Stud rams may be
registered in the stud ram register of the flock book or computer
administration on condition that they are sired by selected stud rams and that
their dams have produced not less than 1 200 kg of milk with not less than 6
percent butterfat in the course of their first two lactations, or 1 900 kg
during their first three lactations. Only progeny-tested rams of strong
constitution and characteristic Awassi type are
eligible.
The flock book or
computer administration issues registration certificates for ewes and rams. A
ewe's certificate furnishes information with regard to the breeder, owner, date
of birth, ear number, colour of head and fleece,
flock book or computer number, date of registration, pedigree chart with
particulars on milk yields and conformation, body measurements and weight, a
score card (milk, wool, conformation, fertility, health), photograph, lambings and progeny record.
A ram's
certificate gives the names of the breeder and owner, the name and number of
the ram, date of birth, grading in different years, colour,
special features, score points for conformation, total score, pedigree chart
over three generations with milk yields and score for conformation of
ancestors, photograph and history of the ram.
Another ram
certificate of the flock book or computer administration contains the numbers
of the certificate and the ram, date of birth, breeder (farm), and pedigree
chart over three ancestral generations,
with the milk yields of the female ancestors, specifying the year, lactation,
days, and maximum annual and daily yields (Fig. 7-1).
Special pedigree
certificates in English and Hebrew for stud rams and ewes are issued by the
secretary of the Sheep Breeders' Association and the flock book or computer
manager for export purposes. These contain the number of the ram or ewe, date
of birth, name of breeder, and the pedigree of the animal for two ancestral
generations, including the milk yields of the dam and grandams
(Figs 7-2 and 7-3).
At one time the
flock book management issued annual reports on all registered flocks. These
were arranged according to the mean breeding standard milk yields of the flocks
and, in addition, supplied information on the number of ewes in each flock, the
record yield, the number and percentage of ewes classed according to milk
yields (above 400 kg, 350-400 kg, 300-350 kg, 250-300 kg, 200-250 kg, 150-200
kg, and below 150 kg), and the mean annual milk yield of the ewes of each
flock. Some annual reports also gave information on the quantity of milk
marketed for each ewe and flock.
Since 1968/69 the
flock book records have been replaced with computer records. The reports have
since provided every flock account in the list with a mark indicating the
distinction between flocks of pure-bred Awassi or
cross-bred East Friesian-Awassi ewes, and also of the
milking system practised in each of these two groups,
namely, single milking or primary milking followed by secondary milking. This
enables breeders not only to compare the absolute yields of their flocks with
those of other flocks irrespective of breed and milking system, but also with
the yields of ewes similar to their own in breed composition and milking
arrangement. The computer reports do not include the mean breeding standard
milk yields as did the flock book reports in the past.
Auxiliary
registers, in Hebrew, are issued by the Sheep Breeders' Association in different
sizes for records of large flocks, most of which belong to communal
settlements, and of smaller flocks belonging to village farmers. The auxiliary
registers comprise lists for rams, ewes, yearlings, and female lambs for
retention by the breeder or for disposal through the Sheep Breeders'
Association; variations in annual milk yields between ewes; variations in
maximum milk yields; and for sheep that left the flock during the year.
Further, lists of mating or insemination, hormone applications, lambings, milk control records, and shed books are kept.
At the end of the
year the information on the rams and ewes of a flock is transferred to two
lists for the computer service, one for rams and the other one for ewes. At the
head of the list for rams the flock number, year, and name of owner (farm) are
stated. All data are inserted in figures specified for the computer. One line
in the list is devoted to each ram, with space for the following data:
| 1) current number, 1-20 | 8) name of breeder (farm) |
| 2) ram's number | 9-11) sickness or exit from flock: |
| 3) breed | 9) cause |
| 4) date of birth | 10) sickness |
| 5) number of sire | 11) month |
| 6) number of dam | 12) kind of change |
| 7) date of introduction to flock | 13) type of list |
At the head of the
list for ewes the year, name of owner (farm), flock number, total quantity of
marketed milk, quantity of milk used otherwise, and
the monthly milk production from October to September are given. As in the list
for rams, all data are inserted in figures specified for the computer. One line
in the list is devoted to each ewe, with space for the following data:
| 1) current number, 1-20 | 13) lamb no. 1: history, sickness, month |
| 2) ear number of ewe | 14) lamb no. 2: history, sickness, month |
| 3) breed | 15) lamb no. 3: history, sickness, month |
| 4) date of birth | 16) first month of lactation |
| 5) number of sire | 17) monthly milk records, October to September |
| 6) number of dam | 18) date of end of lactation |
| 7) month of introduction to flock | 19-21) sickness or exit from flock: |
| 8) name of breeder (farm) | 19) cause |
| 9) date of lambing | 20) sickness |
| 10) number of lambings | 21) month |
| 11) number of lamb's sire | 22) kind of change |
| 12) number of lambs-male, female | 23) type of list |
Figure 7-2. Certificate of pedigree of the Israeli Awassi
ram
Each year the
flock book or computer administration sends the flock-master the last
computerized reports on the state of his flock with particulars for every ram
and ewe. Hence there is no need for the flock-master to repeat the different
items concerning the animals included in previous reports. He has merely to add
the last year's breeding history, milk records and other changes with the
respective computer symbols in the empty spaces provided for every ram and ewe,
and return the completed sheets to the flock book or computer administration.
Figure 7-3. Certificate of pedigree of the Israeli Awassi
ewe
Bedouin and fellahin select flock
rams mainly based on size and development of the male lambs kept for breeding
and their dams' milk yields. The latter criterion, in the course of centuries,
has brought about a high genetic potential for Awassi
milk, while the former has operated against twinning, for single lambs have an
advantage over twins in birth weights and growth during the suckling period.
From the beginning
of improvement of the Awassi sheep by Jewish
shepherds in Palestine, selection of breeding stock has been based mainly on
milk production. Type, conformation and colour were
additional criteria, more especially in flocks producing stud rams. Owing to
the insignificant part of the income derived from wool in the economy of
improved Awassi breeding in Palestine and
subsequently in Israel, the quantity and quality of the wool has been generally
neglected, save for a single flock in which selection for a heavier fleece was practised at one time. In Iraq, however, wool is of major
importance in the selection of Awassi breeding stock.
As regards type,
shepherds have a particular image of the ideal Awassi
in view and endeavour to select their breeding stock
in conformity with this standard.
Conformation has
played a considerable role in the selection of stud animals in Palestine, and
all ewes and rams previously entered in the flock book had to be judged by a
commission for conformation. Under computer administration in Israel, the
maximum score for ewes continues to be 25 points, including height (4), length
of body (4), heart girth (4), shank girth (3), udder (5), and general
impression (5). Of the remaining 75 points in the 100-point-maximum score
system for ewes, 50 are designated for milk production, 10 for health and
fertility, and only 10 for pedigree and 5 for wool. For rams the maximum score
of 25 points for body conformation includes 6 for height, 5 for length of body,
6 for heart girth, 3 for shank girth, and 5 for general impression.
In 'general
impression' the shape of the head, horns and ears, which have no bearing on
production but only on type, are included. The conformation of the fat tail is
important because this has an influence on the facility of milking and the
cleanliness of the milk. The strength and position of the legs are a major
consideration in the scoring of the Awassi which has
to obtain part of its feed from pasture.
The selection of
flock ewes in Israel is left to the discretion of the breeders who may be
guided by instructors of the Department of Agriculture or by officers appointed
by the Sheep Breeders' Association.
Generally,
breeders decide in autumn on how many ewes to replace by yearlings; commonly
this is around 25 percent. In an experimental flock, over a period of five
years, 23.2 percent of the number of ewes at the time of
service were culled during the following year, in addition to an average
annual mortality rate of 2.2 percent (Goot, 1966).
Ewes with impaired or abnormal udders are culled first, to be followed by aged
animals and those with milk records well below the average of the flock. Barren
ewes are disposed of earlier in the year. If still breeding regularly, old ewes
of high breeding value with regard to milk production and twinning are
sometimes left in the flock for another year or two even if their milk yields
have decreased. Lambs for replacement of the culls are selected in accordance
with their dams' milk yields and their individual conformation and development.
The culled ewes are sold for slaughter and the female lambs not required for
replacement in their own flocks — about one-half of the total number reared —
are sold to flocks that are in a stage of new establishment or enlargement. The
majority of sales and purchases of breeding stock are arranged by the Sheep
Breeders' Association.
For three decades,
the selection for milk in the Awassi breed in Israel
was based on the maximum or standard lactation record of ewes in any one year,
a record that is markedly influenced by year-to-year changes in environmental
conditions and the age of the animals. Contemporary comparisons are relatively
free of these sources of error and show a higher heritability than the maximum lacatation records. Soller etal. (1966)
examined four selection criteria, one based on the maximum lactation yield and
three on contemporary differences, in 20 rams and 731 dam-daughter pairs of
three large Awassi flocks. The contemporary
comparison criteria included: 1) first-lactation contemporary differences,
which are of particular importance, as the end of the first lactation is the
most efficient time for selection in Awassi flocks;
2) average contemporary differences in milk yields, defined as the average of
the contemporary comparison values of the various total lactation records of
ewes. Estimates of the heritability of this selection criterion are of
particular importance in the pedigree selection of rams; 3) maximum contemporary
comparison, defined as the highest of the contemporary comparison values
obtained for the various total lactation records of a ewe. All ewes born in the
same year and flock were considered to form a contemporary group, provided that
this included at least 20 ewes. The average total lactation record of the
contemporary group for each year, excluding very late lambings,
was computed. The contemporary difference of each ewe for each of her total
lactation records was computed by subtracting the average of her contemporary
group for that year, including herself, from her own record for that year. The
heritability estimates for these four selection criteria were used to compare
relative efficiencies for selection and the annual genetic improvement that
might be expected from breeding programmes based on
the estimates (Table 7-1).
Most conspicuous
is the extreme inefficiency of the maximum or standard lactation
yield as a criterion
of selection. Maximum production on a contemporary difference basis is less
efficient than either first-lactation or average-lactation records, but the
difference is not great. Although average records are slightly superior to
first-lactation contemporary comparisons, the authors hold that the use of the
latter is justified for all breeding purposes. This would imply that, as far as
selection is concerned, milk recording and testing could be limited to first
lactations.
To ascertain the
annual genetic improvement that may be expected from different breeding programmes, Soller etal. (1966) examined four possibilities, one
based on selection without the progeny testing of rams, and three others based
on progeny testing. The latter included a flock test, in which four rams are
tested annually in a single flock on the basis of 20 daughters each; a 'master breeder'test, in which two groups of six rams each are
tested in two cooperating flocks for two years, each ram on 30 daughters; an
'AI centre' test, in which eight rams are tested yearly on the basis of 40
daughters each. In each of the three progeny-testing plans, the best or the two
best rams are to be retained for breeding (Table 7-2).
The expected
annual genetic improvement for the four programmes
ranges from 3.2 to 5.5 kg or 1.1-1.8 percent. The master breeder and AI centre programmes promise about the same rate of annual
improvement, which is considerably larger than that based on the selection of
ewes only on progeny testing within a single flock.
In view of the
inefficiency of the standard or maximum lactation yield for genetic improvement
of milk yields, this system was discarded in Awassi
flocks in Israel toward the end of the 1960s and replaced by the country-wide
progeny testing of all stud and flock rams employed in milk-recorded Awassi flocks. All farms under milk control are required to
use only such rams for breeding as are approved and distributed by the Sheep
Breeders' Association.
Male lambs may be
reared for service as future flock rams if each of their parents has a score
for conformation of not less than 16 points and if their dams are eligible for
flock ram breeding by virtue of their milk and butterfat yields (see p. 226).
The dams must also be approved for flock ram breeding by a commission composed
of the flock book manager, the head of the breeding committee and a geneticist.
The milk and butterfat tests of such ewes must have been carried out by a
special milk tester appointed by the flock book administration. Flock rams must
be replaced every three years.
In the case of
lambs from very high-yielding dams, an exception is sometimes made with regard
to the latters' conformation score. Lambs from such
dams may be reared as reserve rams even if their dams have scored less than 16
points. The sire of such lambs, however, must be a selected stud ram.
Stud rams must be
the progeny of stud rams and selected dams and be approved by a commission
similar in composition to that required for the approval of flock rams. A stud
ram's dam must be distinguished by a very high milk yield (see p. 226) and his
sire have a high score for conformation, show strength and true type, and have
been progeny tested. The progeny test for stud rams comprises four times the
number of daughters required for the progeny testing of flock rams, and of the
total
number of
rams tested for stud ram approval only the best 25 percent are eligible .Stud
rams must be replaced every two years in the flock in which they are stationed.
Since the
introduction of the computer service by the flock book or computer
administration, the progeny testing of rams used in milk-recorded flocks
includes all of their milk-recorded daughters in three separate groups, namely,
after their first lambing as yearlings or as two-year-olds, and their second
lambing at the age of two years. It gives information on their mean milk yields
during the current year and the total mean of the current and previous years, and
further, on the number of daughters tested, the number of lambings
or abortions, the percentage of pregnancies, the age of lambing, the number of
lambs, the percentage of mortality, the mean number of milking days a year, the
mean milk yield a year, the number of full lactations (minimum 150 days), the
mean length of lactation, the mean milk yield for each lactation, the plus or
minus deviation from the mean, the number of daughters culled from the flock,
and the total percentage and causes of culling (such as low milk yield or udder
trouble).
During the last
few years the vast majority of the stud and flock rams employed in the Awassi flocks of Israel has been supplied by the 'Eyn Harod flock. This flock
comprises approximately 1 000 breeding ewes, including yearlings. In the
breeding of rams it is self-contained. One ram was brought in in 1964, and another one in 1955. Twice new blood was
introduced into the flock through the female line. In 1945/46 ten ewes were
purchased from a bedouin flock and were mated with 'Eyn Harod rams. Of their progeny,
two male lambs were retained in the flock for stud breeding. Again,
in 1956/57,200 female lambs, the majority of which had been sired by 'Eyn Harod rams, were introduced
into 'Eyn Harod from other
improved Awassi flocks. During
the years 1970-75 one ram, sired by a ram from 'Eyn Harod, was obtained from another well-bred Awassi flock. In 1977, a large, highly improved Awassi flock, situated in the northern part of Israel, was
disbanded, and the pick of the flock, consisting of one yearling ram and 35
young ewes, was taken over by 'Eyn Harod, which for many years had provided the stud rams for
the flock.
So far close
inbreeding has been avoided. In none of the pedigrees of the 25 stud rams
employed at 'Eyn Harod for natural
service in 1973/74 does a ram or a ewe appear twice in the parental,
grandparental and great-grandparental generations, and only in one pedigree are
the great-grandsire on the dam'side and the
great-great-grandsire on the sire's side of the stud ram identical.
The 25 stud rams
have 13 different sires. In their pedigrees two rams appear twice each, two
other rams three times each, and one ram four times as sires. Two ewes appear
twice each as dams in the pedigrees of the 25 stud rams, but in every pair the
sires differ, showing that the breeder has avoided having full brothers among
the stud rams of his flock.
