The purpose of the experiment was to analyze the influencing factors of bovine superovulation-in vivo embryo production, and to provide basis for improving in vivo embryo production efficiency and optimizing in vivo embryo production process. Holstein and Simmental cattle young cows with normal reproductive performance at 14~15 months of age were subjected to superovulation treatment, and different breeds and types of Follitropin beta, the superovulation effect of repeated supersteak was compared with that of different operators. The mean number of recovered embryos and the mean number of effective embryos in the Simmental cattle were higher than those in the Holstein, with significant difference (P<0.05) and no significant difference (P>0.05), respectively. The effective embryo rate of Holstein was higher than that of Simmental cattle, but the difference was not significant (P> 0.05) The average embryo, effective embryo and effective embryo rate of the imported Follitropin beta treated Simmental cattle were significantly higher than those of the domestic Follitropin injection group (P<0.05) . There was no significant difference in the average number of embryos obtained from Follitropin beta imported from different countries (P>0.05) , and no significant difference in the average number of embryos obtained by technicians from different countries (P>0.05) , there was no significant difference in the number of effective embryos and effective embryo rate between technician No. 1 and technician No. 2(P>0.05) , but it was significantly higher than that of technician No. 3(P<0.05) The average number of embryos obtained by superovulation was 7.0 and 7.7, the average number of effective embryos was 2.7 and 3.2, the effective embryo rate was 38% and 41% , respectively, the effect of the second superovulation was better than that of the first, but there was no significant difference between the two superovulation (P>0.05) .Superovulation and in vivo embryo production are affected by various factors such as donor breed, superovulation frequency, source of Follitropin beta, technical level of operators, etc. , the optimal superovulation scheme is found by integrating various factors.

A survey was conducted on the egg-laying interval of 2160 nests and 465 pairs of producting pigeons with different purposes and different physical stages in 4 pigeon farms. The result showed that the egg laying of all kinds of producting pigeons showed a high regularity. The egg-laying interval was 24 to 48 hours in the same nest (97.68%). The regularity was more obvious in commercial-egg-producting pigeons, which had 99.58%. The average egg-laying interval was 34.38 days in commercial-squab-producting pigeons during hatching and nursing. The average egg-laying interval was 12.73 days in the empty-nest pigeons. It was 21.65 days shorter than that of the pigeons during hatching and feeding and 2.14 days shorter than that of the commercial producting pigeons respectively. For the pigeons duting hatching and nursing, the data had a high dispersion and great differences between different pigeon farms. It was significantly lower in the empty-nest pigeons. The commercial egg-laying pigeons had the lowest dispersion and an abvious peak of egg production.

Objective In order to explore the effects of different disinfection methods on the microorganisms eradication on the eggshell surface and hatching effect of pigeon eggs. Method This experiment established five disinfection methods. Using the same incubator and hatching program, 15000 pigeon hatching eggs were selected and randomly divided into five groups, with 3 replicates per group and 1,000 eggs per replicate. Each group was disinfected with the corresponding method before incubation. The specific groups were designed as follows: formaldehyde + potassium permanganate fumigation (Group A), bromogeramine solution immersion (Group B), bromogeramine solution spraying (Group C), potassium permanganate solution immersion (Group D), and trichloroisocyanuric acid fumigation (Group E). The surface Salmonella, Escherichia coli (E.coli), and total bacterial counts on the eggshells before and after disinfection were measured, and the sterilization rates were calculated. Hatching-related parameters including infertile eggs, dead embryos, healthy squabs,weak squabs and dead squabs were recorded. Result The results showed that Salmonella was not detected in the experiment, and no E. coli colonies were found in all groups after disinfection. For total bacterial sterilization rate, Group B and C were significantly greater than the other groups (P < 0.05), and Group A and E were significantly greater than Group D (P < 0.05). In terms of hatching performance, Group C had the significantly highest dead embryo rate and the significantly lowest hatching rate of fertile eggs (P < 0.05), while Group E had the significantly lowest dead embryo rate (P < 0.05). The hatching rates of fertile eggs in Group A and E were significantly greater than those other groups C and D (P < 0.05). For chick performance, Group C had the significantly lowest healthy chick rate and the significantly highest dead chick rate (P < 0.05), whereas Group A and E had the significantly highest healthy chick rate (P < 0.05). The dead chick rate of Group B was significantly greater than that of Group A, D and E (P < 0.05). Conclusion In conclusion, Group B and C showed better sterilization effects, while Group A and E exhibited better hatching and chick performance. Group C presented the poorest overall effect. Group A achieved a balance between sterilization efficiency and hatching performance, representing the optimal comprehensive treatment.

Porcine embryo cryopreservation technology serves as a key approach for the conservation and efficient utilization of pig germplasm resources, as well as for the creation of new gene-edited pig breeds. However, due to the high lipid content in porcine embryos and their extreme sensitivity to low temperatures, the post-thaw survival rate and subsequent developmental potential of cryopreserved embryos still lag significantly behind those of fresh embryos. A technical system capable of supporting large-scale applications has yet to be established. This article systematically introduces the importance of porcine embryo cryopreservation and the limitations of conventional slow-freezing methods. It focuses on discussing the current research status and main directions of vitrification cryopreservation technology, elaborating on recent advances in improving cryoprotectants and optimizing freezing protocols for porcine vitrification. Furthermore, it highlights the latest breakthroughs in using high-throughput sequencing technologies to elucidate the molecular mechanisms of cryo-induced damage in porcine embryos at the transcriptomic and proteomic levels. Finally, it proposes that future efforts should integrate artificial intelligence models, metabolic reprogramming, and automated loading devices to further enhance the developmental potential of cryopreserved embryos, thereby laying a solid foundation for the long-term preservation and industrial application of local pig genetic resources.