Effects of Ovarian Preservation Time on in vitro Maturation and in vitro Fertilization of Oocytes from Slaughtered Sheep

[Objectives] The aim was to study the effects of ovarian preservation time on in vitro fertilization of oocytes from slaughtered sheep. [Methods] The collected ovaries were randomly and evenly divided into four groups. They were preserved in physiological saline containing penicillin（ 100 IU/ml） and streptomycin（ 100 μg/ml） at 15-20 ℃ for 0（ Control）,6,12 and 18 h,respectively. Then,the oocytes were subjected to in vitro fertilization. [Results]The maturation rates,cleavage rates and blastocyst rates of the oocytes preserved for 6 and 12 h showed no significant differences compared with those of the oocytes preserved for0 h（ 72. 03%,70. 87% vs. 73. 68%; 74. 12%,72. 60% vs. 74. 49%; 22. 22%,20. 75% vs. 23. 29%）（ P 〉 0. 05）. There were also no significant differences in maturation rate,cleavage rate or blastocyst rate between the oocytes preserved for 18 and 0 h（ P 〉 0. 05）. [Conclusions] Within a certain rage（ 0-18 h）,storage time of ovary at 15-20 ℃ does not affect the continued development of oocytes from slaughtered sheep.

Effects of Medium on in Vitro Maturation of Pig Oocytes and in Vitro Early Development of Parthenogenetic Embryos

[ Objective] To improve quality of oocytes maturing in vitro and to optimize in vitro culture system of porcine early embryos. [ Method ] Oocytes were cultured in the improved TCM199 and NCSU-23 basic media, which were added pig follicular fluid （PFF） or high-quality fetal bovine serum （FBS） both at a proportion of 10% （V/V）. After in vitro maturation and development, effects of medium on maturation of pig oocytes and development of eady parthenogenetic embryos were investigated using maturing rate of pig oocytes and development rate of parthenogenetic embryos as indicators. [ Result] After 42 h culture, the maturing rates of pig oocytes respectively cultured in the TCM199, TCM199 added FBS, TCM199 added PFF, NCSU-23, NCSU-23 added FBS and NCSU-23 added PFF were （54.2 ±3.5）%, （68.5 ±3.2）%, （69.3 ±3.7）%, （51.6 ±3.3）%, （63.2 ±3.1 ）% and （65.5 ±3.5）%, respectively. The pig oocytes cultured in the TCM199 or NCSU-23 that was added FBS or PFF had significantly higher maturing rate （P 〈 0.05）. The development rates of parthenogenetic embryos were not significantly different between these six experimental media. However, the parthenogenetic embryos which developed in the TCM199 added PFF （36.5 ±4.8） had significantly more blastomeres than those developed in the TCM199 or NCSU-23 （ 18.7 ± 3.2 and 15.5 ± 2.4, respectively） （ P 〈 0.05）. [ Conclusion ] The improved TCM199 and NCSU-23 added PFF or FBS can largely promote in vitro maturation of pig oocytes and in vitro development of early parthenogenetic embryos.

Variety Comparison between Domestic Alfalfa and Introduced Alfalfa

[ Objective] To explore the growth characteristics of domestic and introduced alfalfa varieties and provide scientific guidance for the intro- duction of superior alfalfa varieties. [Method] A total of 17 domestic and introduced alfalfa varieties were selected. Through a three-year compari- son of varieties, their biological characters, plant height, branch density, fresh forage yield, leaf stem ratio and other traits were detected and ana- lyzed. [ Result] All the tested alfalfa went through the cold winter between 2006 and 2008 and could finish the reproductive cycle. The forage yield per plant and the plant height of the domestic alfalfa varieties were the highest, but their branching ability and the leaf stem ratio were lower. The European alfalfa varieties had strong branching capability, and the leaf yield of the American alfalfa varieties was the highest. [ Conclusion] The do- mestic alfalfa varieties have suoerior oerformances, while the introduced alfalfa varieties have better aualities.

Molecular Markers of Fat and Inosinic Acid Content in Sheep Muscle and Application

This study was conducted to speed up the process of improving the quality of lamb breeds in China,and to solve the problems that restrict the development of lamb breeds in China,such as low quality of lamb breeds,low meat production rate,and poor meat quality.By studying molecular markers of fat content in sheep muscles,we searched for polymorphic loci related to fat content in sheep muscles on the ANGPTL4 gene.Among the 9 polymorphic loci retrieved,ANGPTL4 was found.Two polymorphic sites,C724 A and A601 G,were significantly associated with intramuscular fat in mutton.In summary,these two molecular markers can be used as a molecular marker reference when breeding high-quality meat or hair and meat using German Merino sheep breeds.

Study on the Relationship Between CAPN Gene Peptide and Fat Content in Sheep Muscle

[Objectives] This study was conducted to speed up the process of improving the quality of lamb breeds in China,and to solve the problems that restrict the development of lamb breeds in China,such as low quality of lamb breeds,low meat production rate,and poor meat quality. [Methods]By studying molecular markers of fat content in sheep muscle,the CAPN gene was used to find polymorphic sites related to fat content in sheep muscle,and the correlation between two polymorphic sites C724 A and A601G on CAPN1 and CAPN2 and fat content in sheep muscle was analyzed. [Results] The two polymorphic sites,C724 A on CAPN1 and A601G on CAPN2 were significantly related to intramuscular fat in mutton. [Conclusions] These two molecular markers can be used as a molecular marker reference when breeding high-quality meat or hair and meat using German Merino sheep breeds.