In order to explore the relationship between the yield of qualified frozen semen and serum biochemical indexes of bulls at different ages, as well as the effect of aging on the physiological indexes of bulls at different ages. Eventually, the stud bulls were screened more accurately by serum biochemical indicators. Blood samples were collected from 10 Simmental bulls in spring for two consecutive years, some serum biochemical indicators were detected, and the results of frozen semen production were compared and analyzed. The results showed that semen density, qualified frozen sperm yield, serum aspartate aminotransferase and abdominal insulin levels decreased significantly with age (P<0.01). Serum androstenedione, dehydroepiandrosterone, testosterone, and serum γ-glutamyltransferase were significantly increased in both high-yield and low-yield groups, while serum zinc and serum alkaline phosphatase were significantly increased in low-yield group (P<0.01). The serum levels of copper and magnesium in the high and low yield groups increased significantly (P<0.05). The levels of serum total protein and serum uric acid decreased significantly (P<0.05). Therefore, it is necessary to pay attention to the daily health management of breed bulls, timely supply the necessary trace elements, and reasonably arrange the service age of breed bulls to give full play to the breeding potential of breed bulls.

In modern pig farming, semen quality is an important indicator for testing the production performance of breeding boars, including parameters such as sperm density, vitality, morphology, and DNA fragments. Semen quality is influenced by various factors such as the internal and external environment of male animals, and there are certain differences among pig populations in different regions. At present,many problems, such as large errors, long cycles, and low efficiency in evaluating the quality of boar semen through conventional methods, seriously restrict the development of the pig industry. In order to further analyze the mechanism of spermatogenesis of local pigs and improve their semen quality, weconducted in-depth research from the perspective of molecular genetics. In this article, the research progress of AKAP3, HSF-1, WIP1, SPATA6, and MTHFR genes in the semen quality of local pigs was reviewed, which provides reference materials for the subsequent breeding of high-quality boars.

In this experiment, 2kg Epimedium was used as raw material, and Epimedium polysaccharide was extracted by water extraction and alcohol precipitation method, sevage method and anion exchange column. The semen of 10 Simmental cattle was weighed and measured. Each semen was divided into 5 equal parts by a pipette. The Epimedium polysaccharide solution was diluted with ultrapure water to dilute the finished bovine frozen semen diluent. The polysaccharide concentrations were 8, 4, and 2 mg / mL, respectively. The control group did not add Epimedium polysaccharide, and the frozen semen vitality and deformity rate were detected after encapsulation and freezing. Bovine frozen semen containing Epimedium polysaccharide diluent was prepared for artificial insemination, and the difference of conception rate between polysaccharide frozen semen and ordinary frozen semen was compared. The results showed that 255.9134 g of crude polysaccharide with a sugar content of 58.86 % was obtained by water extraction and alcohol precipitation, and 51.2411 g of polysaccharide with a sugar content of 94.8 % was obtained by sevage method and anion exchange column after removing protein. When the concentration of Epimedium polysaccharide was 2 mg/mL, the thawing activity of frozen semen was (51 ± 3.7) %, the deformity rate was (21.15 ± 9.34) %, and the conception rate was 80.00 %, which was better than other groups. Conclusion : When the concentration of 94.8 % Epimedium polysaccharide is 2 mg / mL, the reproductive function of bovine sperm can be preserved to the maximum extent, and the conception rate of artificial insemination is the highest.

Objective By investigating the effects of season and insemination protocol on the efficacy of estrus synchronization in Hanshan white cashmere goats, this study aims to provide data support and a reference for the large-scale application of estrus synchronization technology in this breed. Method In this experiment, during both the non-breeding and breeding seasons, Hanshan white cashmere goats were randomly divided into two groups: the timely artificial insemination group and the timed artificial insemination group. Both groups received the P4-eCG protocol, in which a progesterone (P4) sponge was intravaginally implanted for 14 days, and equine chorionic gonadotropin (eCG) was intramuscularly injected at the time of sponge removal. In the timely artificial insemination group, estrus was detected using teaser rams, and artificial insemination was performed at 12 and 24 hours after estrus detection. In the timed artificial insemination group, two timed artificial inseminations were directly performed at 48 and 60 hours after sponge removal. Result The results indicated that there was no significant difference in the estrus synchronization rate between the breeding and non-breeding seasons following the estrus synchronization protocol (P>0.05). However, both the pregnancy rate and lambing rate were significantly higher during the breeding season compared to the non-breeding season (P<0.05). Both during the non-breeding season and the breeding season, there were no significant differences (P>0.05) in pregnancy rate and lambing rate between the timely artificial insemination group and the timed artificial insemination group. Conclusion In conclusion, the P4-eCG protocol achieved satisfactory estrus synchronization outcomes in Hanshan white cashmere goats, although pregnancy and lambing rates were significantly greater during the breeding season than in the non-breeding season. Considering operational convenience, the timed artificial insemination program is recommended.

Objective Oula sheep are an important meat-purpose breed of Tibetan sheep on the Qinghai–Tibet Plateau. However, due to pasture shortages during the long cold season and their seasonal estrus pattern, the estrus rate of grazing Oula sheep during the non-estrus season is extremely low, which severely limits batch production and farming efficiency. This study therefore sought to identify a cost-effective and easy-to-apply estrus synchronization protocol for grazing Oula sheep at the end of the cold season that would provide technical support for batch reproduction. Methods The study was conducted at a hornless Oula sheep cooperative in Henan Mongolian Autonomous County, Huangnan Prefecture, Qinghai Province. A total of 160 healthy, multiparous, 2.5-year-old hornless Oula ewes with similar body weights were randomly assigned to 16 groups of 10 animals each. Four nutritional levels were compared: natural grazing alone, and natural grazing supplemented with concentrates containing 16%, 18% or 20% crude protein. Three estrus synchronization protocols were also applied: two injections of cloprostenol (PG); insertion of a flurogestone acetate sponge (Progesterone-releasing intravaginal device, PRID) combined with a PG injection; and an injection of gonadorelin (Gonadotropin-releasing hormone, GnRH) combined with a PG injection. The experiment lasted 10 days. Blood samples were collected at the beginning and end of the experiment, and serum concentrations of estradiol (E2), progesterone (P), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured using enzyme-linked immunosorbent assay. Estrus rates were determined at the end of the experiment by teasing with a ram. Results Under natural grazing conditions during the non-estrus season, Oula sheep did not show estrus (0% estrus rate). After concentrate supplementation, natural estrus began to appear. Supplementation with 18% or higher protein concentrate increased the natural estrus rate to 30%. Treatment with exogenous hormones alone under natural grazing conditions produced estrus rates of 30%–40%. Combining nutritional supplementation with estrus synchronization treatment further increased estrus rates, with the highest rate (60%) observed in the group that received 18% protein supplementation combined with the GnRH+PG protocol. Hormone measurements revealed no significant differences in serum E2 or LH concentrations among the groups (P > 0.05). The GnRH+PG group had significantly higher serum FSH concentrations than the other groups (P < 0.05), while the PRID+PG group had significantly higher serum P concentrations than the other groups (P < 0.05). Conclusion At the end of the cold season on the Qinghai–Tibet Plateau, short-term supplementation with 18% or higher protein concentrate effectively induces natural estrus in Oula sheep during the non-estrus season, but the resulting estrus rate remains modest. Adding exogenous hormone treatment to nutritional supplementation improves the estrus rate further. The combination of short-term 18% protein supplementation with the GnRH+PG protocol achieves approximately 60% estrus synchronization at a manageable cost and is recommended for batch reproduction of grazing Oula sheep during the non-estrus season.