Effect of immunization of ewes against prostaglandin F-2  on the life-span of corpora lutea and oestrous behaviour during two breeding seasons

Abstract

Two adjuvants, Freund's complete adjuvant (FCA) and GNE (proprietary product; Intervet Ltd, The Netherlands), were used to immunize cyclic Finnish Landrace ewes (4-6/treatment) against a prostaglandin F-2 alpha-human serum albumin (PGF-HSA) conjugate. Ewes were randomized to the following treatments: (a) control-untreated, (b) control-5 mg HSA in FCA (control-HSA), (c) 5 mg PGF-HSA in FCA (FCA-5 mg), (d) 15 mg PGF-HSA in FCA (FCA-15 mg), (e) 5 mg PGF-HSA in GNE (GNE-5 mg) and (f) 15 mg PGF-HSA in GNE (GNE-15 mg). Ewes were monitored for oestrus (twice daily) and ovarian activity (progesterone concentrations in blood samples taken twice weekly) for 2 consecutive breeding seasons. In the first breeding season, the mean number of oestrous periods detected was 6.0, 5.7, 0.0, 0.2, 1.8 and 0.5 in control, control-HSA, FCA-5 mg, FCA-15 mg, GNE-5 mg and GNE-15 mg-assigned ewes, respectively [pooled standard error of difference (s.e.d.) = 1.2]. A persistent CL formed, on average, 10.0, 10.0, 29.8 and 32.5 days after primary immunization (pooled s.e.d. = 14.6) in 6/6 FCA-5 mg, 6/6 FCA-15 mg, 5/6 GNE-5 mg and 4/4 GNE-15 mg-assigned ewes, respectively; these CL were maintained for, on average, 138.7, 139.0, 127.8 and 129.0 days, respectively (pooled s.e.d. = 15.9).(ABSTRACT TRUNCATED AT 250 WORDS)

Aetiology and Endocrinology of Pseudopregnancy in the Goat

“…Because PGFza is known to play a final role in the luteolytic mechanism of the goat's oestrous cycle (Homeida and Cooke 1982), active immunization against PGFza appeared to be an obvious method. A similar approach has been followed by others to control ovarian hnction in sheep (Scaramuzzi and Baird 1976;Ronayne et al 1990;Bettencourt et al 1993).…”

Basic aspects of immunomodulation through active immunization

“…The first efforts to study the effects of active immunization against hormones were done with luteinizing hormone (LH) (Wakabayashi and Tamaoki, 1966;Quadri et al, 1966;Pineda et al, 1968). Subsequently, a vast array of protein-, peptide-and steroid hormones have been tried, including follicle-stimulating hormone (FSH) (Torjesen and Sand, 1975;Wickings and Nieschlag, 1980;Al-Obaidi et al, 1986)) human chorionic gonadotrophn (hCG) (Talwar et al, 1976;) thyroid-stimulating hormone (TSH) (Melmed et al, 1980)) inhibin (Henderson et al, 1984;Scanlon et al, 1993)) growth hormone (GH) (Beattie et al, 1992), luteinizing hormone-releasing hormone (LHRH) (Fraser and Gunn, 1973;Ladd et al, 1990;Adams and Adams, 1992;Thau, 1992;Hoskinson et al, 1990)) vasopressin (Kamoi et al, 1977)) somatostatin (Varner et al, 1980)) testosterone (Thomson et al, 1985;Hillier et al, 1973)) progesterone (Kaushansky et al, 1977) and many others (Ohlson et al, 1981;Yamada et al, 1978;Bettencourt et al, 1993;Ronayne et al, 1990;Skinner et al, 1984;Mettler and Czuppon, 1985;Travis, 1993).…”