Veterinarska stanica, Vol. 48 No. 1, 2017.
Original scientific paper
Determination of Physiological Particularities of the Sexual Cycle and Breeding Season of Pramenka Breed
Silvijo Vince
orcid.org/0000-0002-1883-3225
; Veterinarski fakultet Sveučilišta u Zagrebu, Hrvatska
Juraj Grizelj
; Veterinarski fakultet Sveučilišta u Zagrebu, Hrvatska
Branimira Špoljarić
; Veterinarski fakultet Sveučilišta u Zagrebu, Hrvatska
Hrvoje Valpotić
; Veterinarski fakultet Sveučilišta u Zagrebu, Hrvatska
Maja Platiša
; Guernsey Islands, Velika Britanija
Dražen Đuričić
; Veterinarska stanica Đurđevac, Hrvatska
Foteini Samartzi
; Hellenic Agriculture Organization-Demeter, Solun, Grčka
Velimir Berta
; Veterinarska stanica Varaždin, Hrvatska
Nikola Rošić
; Veterinarska stanica Jastrebarsko, Hrvatska
Boris Stojanov
; Veterinarski centar Strumica, Makedonija
Marko Samardžija
; Faculty of Veterinary Medicine University of Zagreb, Croatia
Abstract
The objective of this study was to determine the physiological characteristics and particularities of the sexual cycle and breeding season of the Pramenka sheep breed - Lika strain. For this purpose, during the period from 10 June 2011 to 05 September 2012, blood was sampled from sheep and one ram and orchidometry performed on the ram to determine reproductive seasonality. In the period from 10-31 October 2012, sheep blood was sampled to determine the duration of sexual cycle, in which oestrus was previously synchronized with i.m. application (in a 12-day interval) of a synthetic analogue of prostaglandin F2α (Estrumate®, cloprostenol) in a dose of 75 mg. Concentrations of progesterone and testosterone were analyzed using the automatic system Immulite® One. Analysis of the LH was performed using ELISA (ELISA). Statistical analysis was conducting using the software package SAS (Statistical Analysis Software) 9.1.3. The results of progesterone concentrations indicated that the sexual activity season begins in late July. Most sheep in the study entered the season in late August and in September, and continued with sexual activity until December. Concentrations of testosterone and ram orchidometry recorded a significant increase during August and September and a sharp decline in December, while the girth of the scrotum increased beginning in June, and gradually declined in late winter and spring. As a consequence of increased feeding with complete feed three months before the start of the season in 2012, the physical condition of sheep was improved and the season started on average 19 days earlier than in 2011. The average duration of oestrus in sheep was 17.2 days. The average length of the luteal phase in the Pramenka breed - Lika strain was 13.8 days, and the follicular phase 3.4 days. The average duration of the LH wave was 12.4 hours, with a range of 8 to 16 hours, and therefore, adequate blood sampling every eight hours is sufficient for its detection.
Keywords
Pramenka breed - Lika strain; Seasonality; Sexual cycle; LH; Progesterone
Hrčak ID:
221486
URI
Publication date:
21.2.2017.
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