MATERIALS AND METHODS
Experimental protocol was approved by the Amhara Agricultural Research center (ARARI), Bahir Dar, Ethiopia. This
experiment was conducted on on-station, called Debre Birhan Agricultural research Center (DBARC), Debre Birhan,
Location of study area
DBARC is located 120 km North-east of Addis Ababa at an altitude of 2,765 m.a.s.l. and at a latitude of 09°36′23′′N
and longitude of 39°39′10′′E. Debre Birhan is characterized by a bi-modal rainfall pattern, where the main rainy season is
from June–September accounting for 75% of the total rainfall, an erratic unreliable short rainy season is February,
March–April, May and a dry season October–January. Based on the meteorological data obtained from DBARC, the
average annual rainfall is 923 mm. The mean annual maximum temperature is 19.87°C occurs between March and June,
while the mean annual minimum temperature is 6.59°C occurs between October and January.
Experimental animals and their management
A total of 32 Washera ewes were used for AI experiment. Ewe’s age ranges from 4 to 6 years and that gave at least
one birth, which their body condition score (BCS) are 2.5 and above and ewes not suckling were used in this trial.
Whereas, in natural controlled mating system all ewes were sired by pure Awassi in a group of 26-30 ewes per ram and
mating were lasted on average between 51 and 90 days. All experimental ewes were housed in the night and allowed to
graze during the day on natural pasture daily for 6 hrs. In addition, the experimental animals were supplemented with
200g head/day mixed commercial concentrate consists of 33% noug (Guizotia abyssinica) cake, 65.5% wheat bran, 1%
limestone and 0.5% salt. The animals had free access to fresh water twice a day. As a routine flock health management
practice of the research center the experimental animals were drenched against internal parasites (Rafoxanide at
1ml/4kg body weight, Chanelle pharmaceuticals manufacturing Ltd., Ireland and Tetraclozash-900® at 1 bolus/30kg
body weight, Ashish life Science Pvt. Ltd., India) and were vaccinated against Ovine Pasteurellosis, Peste des Petitis
Ruminants (PPR), Sheep and Goat Pox, Blackleg and Anthrax (National veterinary institute, Debrezeit, Ethiopia) in the
different seasons of the year before the beginning of the experiment. Moreover, the experimental animals were sprayed
against ectoparasites (Diazinol 60% E.C at 1ml/1Lit. of clean water, Kafr EL Zayat pestisides and chemicals CO., Egypt) in
All experimental ewes received single injection of 5 mg of the PGF2α analogue dinoprost (1 ml Enzaprost®; CEVA
laboratories, Libourne, France) intramuscularly at unknown stage of estrous cycle. Then ewes were subdivided into two
groups randomly by blocking the animals for BCS and allocated to Awassi and Dorper fresh semen cervical insemination.
Ewes were observed for oestrous at 4 hrs intervals for a period of 48 hrs. Ewes were kept indoor the whole days during
oestrous identification. Ewes at heat were identified using proven ram fitted with an apron. Standing to be mounted was
the key sign used to determine oestrous response.
Semen collection and artificial insemination
Semen was collected from Awassi and Dorper rams trained to serve an artificial vagina (AV), after allowing the rams
to mount in estrus ewes. Collected semen was immediately evaluated for volume, appearance (color and contamination),
sperm cell concentration and mass motility. The volume of semen was measured with a calibrated collection glass and
sperm cell concentration was evaluated using AccuRead IMV Technologies SA, 232 Spectrophotometer. Sperm mass
motility was estimated subjectively by using phase contrast microscope (Scope Technology Scope Photo 3.0.12). The
qualified semen to be used for AI was diluted with OviXcell extender (preservation medium for ovine semen, IMV
Technologies, France). Fixed time cervical AI was performed in estrus ewes 48-51 hrs following 1 ml Enzaprost®
administration with 0.25 ml diluted fresh semen (approximately 150×106 sperm/straw and its mass motility score 3 and
above) using a speculum equipped with a light source and an insemination gun, slowly releasing the semen into the first
fold of the cervix.
The data were analyzed using Statistical Package for the Social Sciences (IBM SPSS version 20). Effects were
considered to be significant when the level of probability was 5% or less.
Oestrous response, pregnancy, lambing, and fecundity rate were calculated by using the following formula:-
Citation: Besufkad Sh, Bisrat A, Demis Ch, Abebe A, Abebe A, Goshime Sh, Zewude T (2020). Comparative advantages of cervical insemination over natural mating on