title: Effects of varying doses of β-nerve growth factor on the timing of ovulation, plasma progesterone concentration and corpus luteum size in female alpacas (Vicugna pacos).
abstract: Ovulation in camelids is induced by the seminal plasma protein ovulation-inducing factor (OIF), recently identified as β-nerve growth factor (β-NGF). The present study measured the total protein concentration in alpaca seminal plasma using a bicinchoninic acid (BCA) protein quantification assay and found it to be 22.2±2.0mgmL(-1). To measure the effects of varying doses of β-NGF on the incidence and timing of ovulation, corpus luteum (CL) size and plasma progesterone concentration, 24 female alpacas were synchronised and treated with either: (1) 1mL 0.9% saline (n=5); (2) 4µg buserelin (n=5); (3) 1mg β-NGF protein (n=5); (4) 0.1mg β-NGF (n=5); or (5) 0.01mg β-NGF (n=4). Females were examined by transrectal ultrasonography at 1-2-h intervals between 20 and 45h after treatment or until ovulation occurred, as well as on Day 8 to observe the size of the CL, at which time blood was collected to measure plasma progesterone concentrations. Ovulation was detected in 0/5, 5/5, 5/5, 3/5 and 0/4 female alpacas treated with saline, buserelin, 1, 0.1 and 0.01mg β-NGF, respectively. Mean ovulation interval (P=0.76), CL diameter (P=0.96) and plasma progesterone concentration (P=0.96) did not differ between treatments. Mean ovulation interval overall was 26.2±1.0h. In conclusion, buserelin and 1mg β-NGF are equally effective at inducing ovulation in female alpacas, but at doses ≤0.1mg, β-NGF is not a reliable method for the induction of ovulation.
authors: Faculty of Veterinary Science, The University of Sydney, Camperdown, NSW 2006, Australia.
authors: C C
authors: CC
authors: Stuart
authors: Cria Genesis, PO Box 406, Ocean Grove, Vic. 3226, Australia.
authors: J L
authors: JL
authors: Vaughan
authors: Faculty of Veterinary Science, The University of Sydney, Camperdown, NSW 2006, Australia.
authors: C M
authors: CM
authors: Kershaw-Young
authors: Baarrooka Alpacas, PO Box 20, Strathbogie, Vic. 3666, Australia.
authors: J
authors: J
authors: Wilkinson
authors: Faculty of Veterinary Science, The University of Sydney, Camperdown, NSW 2006, Australia.
authors: R
authors: R
authors: Bathgate
authors: Faculty of Veterinary Science, The University of Sydney, Camperdown, NSW 2006, Australia.
authors: S P
authors: SP
authors: de Graaf
mesh_terms: D000818:Animals; D002064:Buserelin / Q000494:pharmacology; D002161:Camelids, New World; D003008:Cloprostenol / Q000494:pharmacology; D003338:Corpus Luteum / Q000187:drug effects*; D005260:Female; D008297:Male; D020932:Nerve Growth Factor / Q000008:administration & dosage*; D010060:Ovulation / Q000187:drug effects*; D010062:Ovulation Induction / Q000379:methods; D011374:Progesterone / Q000097:blood*
chemical_list: D003008:Cloprostenol; D011374:Progesterone; D020932:Nerve Growth Factor; D002064:Buserelin