|
|
Assessment of effect of different methods of hormonal induction ovulation in females of common carp
BORŮVKA, Vít
By hormonally induced artificial propagation of general carp (Cyprinus carpio), originally from pond breeding, were 3 groups of stripped eggs to broodstock weighted 3829 +- 729 kg intramuscularly injected in interval of 12 hours. They were intramuscularly injected in two different doses by diffrent preparations: 1.extract of carp hypophysis (CPE) in dose 0.5 + 2,5 mg×kg-1, 2. Ovopel containing GnRHa and dopamine antagonist (DA) in doses 0.5 + 2 mg×kg-1, 3. Dagin containing GnRHa and DA in doses 5 + 20 mg×kg-1. Single groups of stripped eggs (n = 17 to 19 pcs) were placed into separated ponds. The avarage temperature of flowing water was 20.9 +- 0.9 °C. The highest ratio of stripped eggs to broodstock was observed following injection of Dagin (89.5 %) and by Ovopel (82.4 %). The highest mortality of stripped eggs to broodstock was observed by using CPE (76.5 %). The highest values of gonadosomatic index (pGSi) propagated stripped eggs were observed in groups injected by Dagin (18.4 +- 5.2 %) and Ovopel (17.6 +- 5.9 %), the lowest values were observed by using CPE (16.3 +- 6.5 %). The relative labour fertility of stripped eggs was very stable ( Ovopel 117000 +- 39000 pcs×pcs-1, Dagin 116000 +- 32000 pcs×pcs-1, CPE 115000 +- 45000 pcs×pcs-1). The highest average wet weight of one egg was 1.42 mg (CPE) and 1.59 mg (Dagin), only this variation was statically provable ( = 0.05). The period of latence from the second hormonally injection to the artificial propagation (after ovulation) was 15.5 +- 1.2 h (resp. 324 +- 25 h°) with Ovopel, with CPE 16.4 +- 1.0 h (so 341 +- 22 h°) and with Dagin 16.5 +- 0.4 h (so 345 +- 7.6 h°). The statistically important difference ( = 0.05) was observed only in period of latence between groups of fish injected by Ovopel and Dagin. The highest propagation of stripped eggs in incubation bottles was observed by using extract of Ovopel (80.9 +- 14.9 %), then by using CPE (75.0 +- 17.1 %) and Dagin (74.8 +- 9.6%). By comparing cumulate parameter,which is given by number of fertilized eggs in one kilo after hormonally injection and after 24 hours of incubation in incubation bottles (including all followed aspects: % of stripped eggs, the relative labour fertility of stripped eggs and number of fertilized eggs), were observed synthetic preparations GnRHa like more effective than CPE, which contains natural carp gonadotropin. The highest values of this parameter were found out in Ovopel groups (78000 pcs×kg-1) and Dagin groups (77000 pcs×kg-1). The lowest value was observed in CPE group (66000 pcs×kg-1).
|
guest ::
