Superovulation of beef heifers with folltropin or FSH-P

THERIOGENOLOGY

SUPEROVULATION

OF BEEF R.J. Mapletoft,

HEIFERS

WITH

FOLLTROPIN

OR FSH-P

A. Gonzalez, J.G. Lussier, B.D. Murphy and T.D. Carruthers Western College of Veterinary Medicine University of Saskatchewan Saskatoon, Saskatchewan, Canada S7N OWO Two experiments were designed to determine the dose response for Folltropin on superovulatory response in beef heifers and to compare results with that of a standard dose of FSH-P. All heifers were treated in a decreasing dose schedule over 4 days starting on days 8-10 of the cycle. Cloprostenol was administered 48 hours after initiation of treatment and heifers were inseminated 12 and 24 hours after onset of heat. In the first experiment, 37 beef heifers were treated with FSH-P (28 mg) or 10, 20, 30 or 40 mg Folltropin. Embryos were collected nonsurgically on Day 7 and corpora lutea (CL) were counted by rectal palpation. No significant differences were observed among groups (Table 1). Table

1.

Superovulatory response Folltropin (Experiment I) FSH-P Group I 28 mg 7 10.9 5.7 3.3 (59)

:L Total embryos Fertilized (%) Transferable (0~)

of

Group II 10 mg 7 11.9 8.6

beef

heifers

treated

Folltropin Group III 20 mg 8 12.1 7.0 5.1 (73)

(1008j6 (867j4

with

FSH-P

Group IV 30 mg

Group V 40 mg

8 12.1 8.9 7.1 (81) 2.9 (32)

7 11.3 4.5 3.0 (67) 2.0 (44)

In the second experiment, 44 beef heifers were assigned at random of four doses of Folltropin (5, 10, 20 or 40 mg). Heifers were slaughtered morning of day 7 for ovarian and ova/embryo data collection (Table 2). Table 2.

Superovulatory response of Folltropin (Experiment II)

Folltropin

n

CL

5 mg 10 mg 20 mg 40 mg

11 11 11 11

3.6a 10.7b 20.3bC 22.9c

a,b& - column

means

without

beef

heifers

treated

Total

Ova/Embrvos Fert (%)

0.8a 4.8b 6.8b 6.3b

0.4a(50) 3.6b(75) 5.lb(75) 4.Ob(75)

common

superscripts

differ

or

with

Trans

four

to one on the

doses

of

(%)

0.3(38) 1.1(23) 2.6(38) 2.2(35) (P
Folltropin would appear equally efficacious to FSH-P in inducing In addition, supramaximal doses of Folltropin superovulation in the beef heifer. did not cause a reduction in numbers or percentage of fertilized ova or transferable embryos.

274

JANUARY

1988 VOL. 29 NO. 1