A comparative study of the effects of intramuscular administration of gonadorelin, mating and intrauterine infusion of either raw seminal plasma or seminal plasma purified β‐NGF on luteal development in llamas

• Published in: Reproduction in domestic animals 2017-08, Vol.52 (4), p.625-631
• Main Authors: Silva, M, Urra, F, Ulloa‐Leal, C, Ratto, MH
• Format: Article
• Language: English
• Subjects: Animals; Camelids, New World - physiology; Copulation - physiology; corpus luteum; Corpus Luteum - drug effects; Drug Administration Routes - veterinary; Female; Gonadotropin-Releasing Hormone - administration & dosage; llamas; Luteinizing Hormone - blood; Male; Nerve Growth Factor - administration & dosage; Ovary - drug effects; ovulation; Ovulation - drug effects; Progesterone - blood; Semen; seminal plasma; Ultrasonography; β‐NGF
• ISSN: 0936-6768; 1439-0531
• DOI: 10.1111/rda.12958

Contents The aim of this study was to compare the effect of the intramuscular administration of 50 μg of gonadorelin acetate versus natural mating, intrauterine infusion (i.u.) of a physiological relevant dose of either raw llama seminal plasma (SP) or purified beta‐nerve growth factor from seminal origin (spβ‐NGF) on ovulation rate and corpus luteum (CL) development and function in llamas. Females with a follicle (≥8 mm) were assigned to groups: (i) i.m. administration of 50 μg of gonadorelin acetate (GnRH; positive control; n = 4); (ii) single mating (mating; n = 6); (iii) i.u. infusion of 4 ml of llama SP (SP; n = 4); or (iv) i.u. infusion of 10 mg of spβ‐NGF contained in 4 ml of PBS (phosphate‐buffered saline) (spβ‐NGF; n = 6). Ovaries were examined by power Doppler ultrasonography at 0, 1, 3, 6, 12 and 24 hr after treatment to determine preovulatory follicle vascularization area (VA), and additionally every 12 hr until Day 2 (Day of treatment = Day 0) to determine ovulation. Afterwards, ovaries were examined every other day until Day 8 to evaluate CL diameter and VA. Blood samples were collected on Days 0, 2, 4, 6 and 8 to determine plasma progesterone (P4) concentration. Ovulation rate did not differ (p = .7) among groups, but treatment affected (p