MORPHOLOGY AND VIABILITY OF

BOVINE EMBRYOS FROZEN IN MEDIACONTAINING BSA AND PROP ANEDIOL

ByK. RAMACHANDRAN

'r THESISSubmitted in partial fulfilment of the

requirement for the degree of

Boctorof 'hilosophyFaculty of Veterinary and Animal Sciences

Kerala Agricultural University

Department of Animal ReproductionCOLLEGE OF VETERINARY AND ANIMAL SCIENCES

MANNUTHY, THRISSUR -680651KERALA

2000

'l-

CERTIFICATE

Certified that the thesis, entitled "MORPHOLOGY AND VIA.BILTTY OF

BOVINE EMBRYOS FROZEN IN MEDIA. CONTAINING BSA AND

PROPANEDIOL" is a record of research work done independently by

Dr. K. Ramachandran, under my guidance and superVISIon and that it has not

previously formed the basis for the award of any degree, fellowship or associateship

to him.

Thiruvananthapuram

\b . \0- 2000

Dr. S.p. Siresan Nair(Chairman, Adviso Committee)

Associate Pro ssor & Head

Department of Animal HusbandryCollege of Agriculture, Vellayani

Thiruvananthapuram

ABSTKACT

The observation of the study was to compare the effect of Bovine Serum

Albumin (BSA) and i,2 Propanediol on the morphology and viability of bovine

embryos frozen under two freezing and thawing protocols.

A total of sixteen crossbred cows, kept under identical conditions, maintained in

the Network Project on Embryo Transfer attached to the Department of Animal

Reproduction, College of Veterinary and Animal Sciences, Thrissur.

The animals were superovulated by FoHtropin-V and Prosolvin, starting on the

day 11 of the cycle. Of the 16 cows superovulated i 3 showed good response. While

two cows did not show any response, there were multiple follicles in both the ovaries

without any evidence of ovulation in the third animal. A total of 85 (76 transferable

and 9 non transferable) embryos were recovered from a total of 24 Bushings from i 3

cows, non-surgically on day 7. A total of 56 embryos (mean 3.50 :i: 0.822) were

recovered in the first treatment;. from i 3 Bushings. In one cow, though, there was 80

per cent Bushing, no embryos could be recovered. While 22 embryos (mean 2.75 :i:

0.861) were recovered in the second treatment from 8 Bushings, only 7 (mean i.4 :i:

0.4) embryos were recovered in the third treatment, from 5 Bushings.

A total of 72 transferable (60 morulae and i2 blastocysts) were sleeted for the

freezing trials. The embryos were divided into three groups with 24 (20 morulae and 4

blastocysts) embryos and assigned to three media. The fIrst medium was FBS with 10

per cent glycerol, second PBS containing 10 per cent glycerol and 1 per cent BSA; the

third medium was with a composition of 10% glycerol and 20% 1,2 propanediol in

PBS. Two freezing protocols were used for freezing of the embryos. In the fIrst

protocol, with 12 embryos (10 morulae and 2 blastocysts), the initial cooling was at a

rate of I°C/min from room temperature to _OCand then at a rate of 0.3°C/min to

-35°C, while in the second protocol the initial rate of cooling was at 5°C/min to -7°C

and then at O.3°C/min to -30°C before transferring to liquid nitrogen. Thawing was

carried out at 37°C for 20 sec after 30 days of preservation. Cryoprotectants were

removed by two methods, a four step-wise using decreasing concentrations of

cryoprotectants in the fIrst method and one step using 1M sucrose phosphate buffered

saline in the second. Thirty four embryos (26 morulae and 8 blastocysts) found

normal after freezing and thawing were subjected to culture for 24 h in PBS enriched

with 4 per cent BSA at 37°C and 5 per cent CO2 tension. Sixteen embryos (13 morulae

and 3 blastocysts) were transferred to 15 recipient cows. While one cow was confIrmed

pregnant on examination 60 days after transfer, eleven cows returned to heat

subsequently, two cows came to oestrus on days 34 and 35 respectively, after the

transfer. The third showed oestrum on 45th day of transfer. The glucose, acid

. phosphatase and alkaline phosphatase values showed a normal range of 86.2 to 195.2

mgjlOO ml; 14.17 KA to 22.3 KA and 119.02 to .129.00 KA (mean 128.075 :f: 9.019,

18.675 :f: 0.667 and 122.67 :f: 0.788) respectively in the luminal fluid of the recipient

animals. The average serum progesterone levels on day 0, 14 and 28 days after oestrus

in 11 cows which showed subsequent heat after the transfer were 0.357 :f: 2.140, 3.053

:f: 0.420 and 2.572 :f: 0.627 ng/ml and that of the animals which failed to show oestrum

were 0.157:f: 0.166,3.793:f: 0.406 and 3.867:f: 0.362 ng/ml respectively.

While significant difference was seen between the freezing media I and II and II

and III respectively on the morphology of embryo after the freezing and thawing, no

significant differences were seen between the media I and III, between the freezing

protocols and cryoprotectant removal procedures on the morphology of embryos

frozen. No significant differences were noticed on the effect of the freezing medi~

freezing protocols and the cryoprotectant removal procedure after the culture on the

morphology of the embryos.

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