Nicolae Pacala

Improving performance of Zackel sheep through cross-breeding with prolific Bluefaced Leicester under semi-intensive and extensive production systems

The aim of the current research was to evaluate the effects of cross-breeding Romanian indigenous Turcana (TA) ewes belonging to the Zackel breed group with prolific Bluefaced Leicester (BL) rams on the performance and reproduction rates of F1 cross-bred descendants under semi-intensive and extensive production systems. The UK stratified sheep production system was applied for the development of the cross-breeding scheme. F1 Bluefaced Leicester×Turcana (F1BL×TA) cross-bred ewes proved to be highly precocious and registered an average fertility rate of 94.7% when mated as ewe lambs, compared with 9.52% (p ≤0.001) of the pure-bred TA. F1BL×TA cross females registered an average prolificacy of 159 and 202% when mated at the ages of 8 and 18 months, respectively, while the TA ewes produced on average 112 and 127% (p ≤ 0.01 and p ≤ 0.001, respectively). 3W: Dorper×(F1BL×TA) cross-breds had different (p ≤ 0.001) weaning weights at the age of 90 days when reared semi-intensively (31.0 kg) and extensively (27.6 kg). Introducing the stratified sheep production system into Central, Eastern and Southern Europe could prove valuable for improving meat performance on farms that keep Zackel sheep under semi-intensive and extensive production systems.

Possibilities to Improve the Quality of the Embryos Obtained from Donor Cows

The aim of this paper was to add gestagene hormones in superovulatory treatments of the embryo donor cows, in order to obtain a higher number of viable embryos. Experiments were performed on 5 Friesian breed cows. As gestagene hormones, were used Synchro MateB (SMB) implants, containing 3 mg Norgestomet. The implants were inserted subcutaneously, on the external part of the ear, additionally 2 ml injection solution of SMB containing 3 mg Norgestomet and 5 mg Estradiol valeriate, were administrated (0 day). The superovulation inducing treatments, started in the 5 day, by administrating 400 mg Folltropin –V (FSH), divided in 8 doses of 50 mg each, administrated of 12 hours intervals. Together with the last dose of FSH, 25 mg Lutalyse (PgF2α) were administrated. The SMB implant was removed in the 9 day, on the same time with the last FSH dose administration. The embryos were non-surgical recovered in the 7 day from the estrus. Embryo quality was evaluated after morphological criteria described by IETS manual (1998). Embryos were classified in the fallowing quality codes: code 1 (very good quality), code 2 (good quality), code 3 (satisfying quality), code 4 (nonviable embryos). From 5 cows that reacted well to the superovulation treatment 38 embryos ( x =9.5 embryos/donor female) were obtained. The majority of the embryos (60.5%) were in blastocyst stage, and 13.2% were in morula stage. The results obtained at embryo classification into quality codes are listed in table 1. Tab. 1 Quality of the recovered embryos Quality codes Very good (code 1) Good (code 2) Satisfying (code 3) Nonviable (code 4) Recovered embryos (n) n % n % n % n % 38 15 39.5 6 15.8 7 18.4 10 26.3