الفهرس 
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Abstract
Milk production reccrds of the Friesian herd,
located at Sakha Expe]CtalStation, Animal
Production Research Ins~itute, Ministry of Agricu1-
ture were used. These records included data tor
imported cowa from the Netherlands between 1960 and
1961, in addition to heir descendents up till
1979.
l~~tation records (1794 and 1389
records, respectively) oGtained through the period
from 1l)bU to 11)7Y Wl\8 une u to inveat1gate the nongenetic
factors that nced 305-day mUle production
and to evaluate phenot envirDDDl8ntal aDd genetic
trends of change in 05-day milk yield. The least
squares procedures were :ollowed •.
Results obtained are eriZed as fol101J8:
Non-genetic factors:
’lhe overall mean
29.67 months. It ShOWf
the age at first calving was
on-signi:ficant effect on
305-day milk yield.
Autumncalvers recorded the highest milk prod..u.c’tion
compared with calvers of the other seasons of
the yea:r. The differences due to season of oalving
in 305-day milk yield were non-significant.
Year or calving citituted U considerable
highly significant (P 0.01) source of variation
in 305-day milk product i”’ll of either the III or the
2-nd lactations.
Trends of change:
~oDltive phenotypic change was observed in )05-d~
milk yield of both tbe III and 2nd lactations. The
average annual phenotypic change ranged between 22.C17
and 44.05 Kg.
Bnvironmental change in J05-day milk yield of
either the 1-st or the 2.-rU laotation was indioated to
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be positive. The averu.L. amount of this change, obtained
by the 2 methods used, ranged between 45.09 and
65.75 Kg per year.
Genetic change in the 305-day milk yield of the
1ll and 2Ee, lactatiorj.~ was found to have a negatiTe
diroct ion. The overage annual genetlo ohange, oaloulated
by the three methods of analysis used, ranged between
_ 1.03 and _ 36.17Kg. The average genetic change per
generation ranged betw$en - 31.25 and - 49.68 Kg.
5- SU1J1liiARY Arw CONCLlfS IO.N
l’;gyptdepends on importing farm machinery to
implement its own ”a g.r Lcu Lt uraL Develop!I1ental Flan”.
mechanizution of irrigation has become of national
priority to rationalize the water use, enable,traffic
of farm machinery, cutdown in areae lost in levees
and distribution ditches, end reduce unnec~ssary e.xpenses
apent in land levelling and gradation used in _
conventional irrigation methods.
In this direction, it is of interest to have a
sprinkler system that ia appropriate to irrigation in
both of the reclaimed and pereD-~ial landa. And since
mOB~ of the economical holdings in the ~gyptian agriculture
lie in the range of 5 to 10 reddens (2.1 10
4.2 hal, it haa become pertinent to develop 8 por1able
sprinkler unit that fulfils tbe following requiremen1s:
(1) easy to use in the local conditions, (2) economically
feasible, (J) can be locally manufactured, maintained
and repaired, and (4) does not require big
capital investment.
This paper deala withtbe following objectives:
.,
1- ~valuation of localll eDllfac1ured sprinkler he:ads
and determinat1onof tbe optimum operating
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conditions. A testing set-up was used to detect
varia t ions in a prinkler performance. lJiffer encea
in the order of 20% re~ulted.
2- A prototype of the sprinkler unit was constructed
in local workshops, and was tested in lentil planted
in clayey 80il as means of supplementary irrigation
and proved successful.
J- the optimum distribution efficiencies ”Cu, P
eCf
.’
and {)”JOu were found to be at a rectangular sp8.,lng
of 12x16 m at a J>ressure of 0.25 Afra for ’tbe sprinkler
heads ”Rain bird JO” and 18x18 m or ..18x24 til
for ”Rain Bird 10 Btl at a pressUX’e of 0.3 MPa.
4- ’fhe unit was hydraulicalll tested. It was founel
that the lel.1gthsof lUU IB, and 1)0 m are SUitable
for a hose of about 4 em diameter, wben using 8
”Rain 13ird JO” bead at a spacillg of 12 •• on the
line, where the total p~e88ure head or rate o~
discharge varia’tlODS were within 20~ or lO~ respec’tively.
_’hen wRaiD Bird 10” was used with the
4-cm diameter hoss, tbelpr8a8ure and discharge
varia tiona were beyond tho•• tolerated, as sta1eli
above. A hose of ) em. diameter gave a better
match with ”h a i.n J:lird 70 Btl at 18 m-a pa cdng (6
heads along lUO-m.line, .or 8 heads along 150 m,
line) •
5- A graphical relationship was deduced between 1he
precipitation rate, spriI:.kler head spacing, sprinkler
rate of discharge, pump rate of discharge,
and 1 he required pump power. The rela t ion can g:Lve
clues to the designer of the system or its opera1tor.
b- A linear relationship 1s devised to describe the
rate of performance of the machine, in the follol,ing
form:
A = K (T. 11d) ,
Where;
A = area served dlUillg a whole irrigation c)”cle,
K ; a constant that depends on daily operatl~~
hours, spacing, un.ber of sprinklers; field
efficiency (K = 5(81 x Sm) . t. 7 ),
4200 f
T = period between irrigations: day,
1= rate of water application amV’br,
d = water requirement:: DIl,
1~= number of sprinkler. on the line,
Sl =
Sm =
t =
7r =
sprinkler spacing; on 11ne: m,
lateral spacing: m
daily operating ,houra, and
field e ffic ieney de pend Lng on time loa t
in 1ine moving.
7- Rates of performance and operation coats were eetimated
in two cases:
(a) Using the system in supplementary irrigation
of some sensitive crops auch as lentil in clayey
8cil under a l,-day irrigation cycle.
(b) In irrigation of sandy Boil under a 4-day cycle.
the moat economical operation in sandy soil was
found to coincide with using a 150-m long hose with
8 sprinklers ”Rain vird 10 En with an expense of 4.6
~.h/fed.1 irrigation (about’ lO/ba/irrigation) according
to the hgyptian conditions of 1985.
The M.ost economical operation for supplementarJf
irrigation of clayey soil .1th·sensitlve crops was at
an expense of 7.33 1.E/fed./irri~ when using l50-m
long hose, 12 ”HaLn Bird JOIl sprinkler, at a a pacIng
of lixlb m to give an application rate of ’7 mm/h t o
Bui\ clayey 80ila with a Ij-days cycl~,and with a
water.requirement or’ ~5 mmiirrig. (IOU mJ/fed./irr.ig.).
The specific equation of performance for the above
set of conditions waB:
A = 3.51 (T. lId)
1.Linimumirriga t Lon expenses in sandy 8oil resulted
from a wat ez requirement of JO m..rnlirl’ig. every 4 da,’s
(lib mJ/fed./irrig.) at 4.6 LE/fed./1rrig., ”A’henusIng
l,u-m hose, 5-cm diameter, fIlth eightltuftain .Bird 7013”
sprinklers and a t a spacing of 18x24 m, The reeul\:ing
performance equation took ”he following specific fo:t’m:
A = ,.21 (T. lid).