A comparison of semen diluents on the in vitro and in vivo fertility of liquid bull semen

The aim of this study was to assess the effect of semen diluent on calving rate (CR) following artificial insemination with liquid bull semen stored for up to 3 d postcollection. In experiment 1, the effect of storing liquid semen maintained at a constant ambient temperature in 1 of 7 different diluents [Caprogen (homemade), OptiXcell, BioXcell, BullXcell, INRA96, NutriXcell, or AndroMed (all commercially available)] on total and progressive motility was assessed on d 0, 1, 2, and 3 postcollection. In experiment 2, the field fertility of liquid semen diluted in Caprogen, BioXcell, or INRA96 and inseminated on d 1, 2, or 3 postcollection was assessed in comparison to frozen-thawed semen (total of n = 19,126 inseminations). In experiment 3, the effect of storage temperature fluctuations (4 and 18°C) on total and progressive motility following dilution in Caprogen, BioXcell, and INRA96 was assessed on d 0, 1, 2, and 3 postcollection. In experiment 1, semen stored in Caprogen, BioXcell, and INRA96 resulted in the highest total and progressive motility on d 1, 2, and 3 of storage compared with OptiXcell, BullXcell, NutriXcell, and AndroMed. In experiment 2, an effect of diluent on CR was found as semen diluted in BioXcell had a lower CR on d 1, 2, and 3 of storage (46.3, 35.4, and 34.0%, respectively) in comparison with Caprogen (55.8, 52.0, and 51.9%, respectively), INRA96 (55.0, 55.1, and 52.2%, respectively), and frozen-thawed semen (59.7%). Effects were found of parity, cow fertility sub-index, as well as the number of days in milk on CR. In experiment 3, when the storage temperature of diluted semen fluctuated between 4 and 18°C, to mimic what occurs in the field (nighttime vs. daytime), BioXcell had the lowest total and progressive motility in comparison to Caprogen and INRA96. In conclusion, diluent significantly affected sperm motility when stored for up to 3 d. Semen diluted in INRA96 resulted in a similar CR to semen diluted in Caprogen and to frozen-thawed semen, whereas that diluted in BioXcell resulted in a decreased CR. Consistent with this finding, semen diluted in BioXcell was less tolerant of temperature fluctuations than that stored in Caprogen or INRA96. Given that it can be used directly off the shelf, INRA96 may be a suitable alternative to Caprogen for the storage of liquid bull semen.     

The cost-benefit of genomic testing of heifers and using sexed semen in pasture-based dairy herds

Recent improvements in dairy cow fertility and female reproductive technologies offer an opportunity to apply greater selection pressure to females. This means there may be greater incentive to obtain genomic breeding values for females. We modeled the impact of changes to key parameters on the net benefit from genomic testing of heifer calves with and without usage of sexed semen. This paper builds on earlier cost-benefit studies but uses parameters relevant to pasture-based systems. A deterministic model was used to evaluate the effect on net benefit due to changes in (1) reproduction rate, (2) genomic test costs, (3) availability of parent-derived breeding values (EBV_PA), and (4) replacement rate. When the use of sexed semen was included, we also considered (1) the proportion of heifers and cows mated to sexed semen, (2) decreases in conception rate in inseminations with sexed semen, and (3) the marginal return for surplus heifers. Scenarios with lower replacement rates and no availability of EBV_PA had the largest net benefits. Under current Australian parameters, the net benefit of genomic testing realized over the lifetime of genotyped heifers is expected to range from A$204 to A$1,124 per 100 cows for a herd with median reproductive performance. The cost of a genomic test, a perceived barrier to many farmers, had only a small effect on net benefit. Genomic testing alone was always more profitable than using sexed semen and genomic testing together if the only benefit considered was increased genetic gain in heifer replacements. When other benefits (i.e., the higher sale price of a surplus heifer compared with a male calf) were considered, there were combinations of parameters where net benefit from using sexed semen and genomic testing was higher than the equivalent scenario with genomic testing only. Using sexed semen alongside genomic testing is most likely to be profitable when (1) used in heifers, (2) the marginal return for selling surplus heifers (sale price minus rearing costs) is greater than A$400, and (3) conception rates of no more than 10 percentage points lower than those achieved using conventional semen can be realized. Net benefit was highly dependent on the marginal return. Demonstrating that the initial investment in genomic testing can be recouped within the lifetime of the heifers tested may assist in the development of extension messages to explain the value of genomic testing females at the herd level.     

香辛料精油在油炸牛肉加工中的抗氧化性研究

以黄牛肉为研究对象,应用正交试验设计和理化分析方法研究丁香油和肉桂油在油炸牛肉加工中的抗氧化性,比较不同加工参数对其抗氧化性的影响。研究发现,在牛肉油炸过程中,肉桂油和丁香油具有显著的抗氧化性,明显好于不添加抗氧化剂的空白对照组。随肉桂油添加量增加,油炸牛肉过氧化值(PV)呈下降趋势,在添加量为50μl时,PV最小,而A532nm随肉桂油添加量增加先下降,在添加量为0.012%(30μl/250ml)时达到最低后又逐渐上升到未添加肉桂油水平。丁香油与肉桂油对油炸牛肉的抗氧化性的影响趋势基本相同,随丁香油添加量增加,PV也呈下降趋势,在添加量为0.02%(50μl/250ml)时,PV最小,突然上升后又逐渐下降,而A532nm随丁香油添加量增加先下降,在50μl达到最低后又逐渐上升到未添加丁香油水平。     

中国肉桂油掺杂鉴定

本文介绍用GC／MS鉴定天然中国肉桂油中掺杂合成中物的分析方法。测定掺杂合成物中特征副产品的色谱保留指数，通过单离子检测方式（SIM）检测该副产品的质谱离子，从而判断掺杂化合物的存在，方法简捷有效。     

相转移催化条件下从桂叶油制备天然苯甲醛的研究

在相转移催化条件下 ,从桂叶油出发通过碱性水解制备天然苯甲醛。分别讨论了反应时间、反应温度、催化剂种类、催化剂浓度和碱浓度等因素对反应的影响。确定出最佳反应条件为 :反应时间 2 .5 h、反应温度为 70°C、Na OH和催化剂聚乙二醇 - 1 5 0 0的用量为油质量的 1 5 %,此时苯甲醛收率为 5 2 .0 %     

酸枣仁多组分鼻用温敏凝胶的制备、评价及其联合释放研究

以泊洛沙姆P407和泊洛沙姆P188为凝胶材料,甘油或聚乙二醇为保湿剂,制备了复方添加酸枣仁中主要有效成分酸枣仁皂苷a、酸枣仁皂苷b、斯皮诺素的复方多组分鼻用温敏凝胶。以无膜溶出法进行了凝胶体外释放评价,以渗透膜法考察了其活性成分的联合释放规律,通过f2检验法证实凝胶活性成为的体外释放行为具有协同性。     

Genetic impacts of using female-sorted semen in commercial and nucleus herds

This study was designed to investigate the genetic effects of using sorted semen in a dairy cattle population. Progress was monitored in elite and commercial animals over 20 yr of selection. To study the genetic impact of using sorted semen in commercial herds, a scenario was evaluated in which female-sorted semen was available to commercial herds. Second, to study the genetic impact of using sorted semen in nucleus herds, scenarios were simulated in which female-sorted semen was used only in a centralized nucleus herd, in which multiple ovulation and embryo transfer (MOET) took place. Because of the additional advantage of marker-assisted selection when sorted semen was used in nucleus herds, a second scenario was simulated in which both sorted semen and marker-assisted selection were implemented. In the scenario in which female-sorted semen was used in commercial herds, a large genetic advantage was observed early in commercial cows. The average superiority in first-lactation cows exceeded 30% in yr 11, relative to a base scheme with regular semen, but continued to decrease until it reached 9% in yr 20. The increased selection intensity in commercial cows contributed to the genetic merit of future cows (cow-to-cow contribution), but the contribution of the nucleus grew over time and gradually marginalized the cow-to-cow contribution. The genetic advantage of gender control in MOET schemes was minimal except when marker-assisted selection was also available. Two factors that affected the contribution of marker-assisted selection were studied: 1) within- vs. across-family selection of donors, and 2) the number of loci in the quantitative trait locus component. Schemes that selected donors regardless of their family structure were superior, and the quantitative trait locus component with more loci increased the effectiveness of sorted semen. Finally, we studied a reduced MOET scheme in which the number of harvested females was reduced from 42 to 25/yr. The reduced scheme in combination with female-sorted semen was not found to be genetically inferior to the large scheme in combination with regular semen.     

天麻酸枣仁胶囊毒理学安全性研究

目的 研究天麻和酸枣仁复合胶囊毒理学特性, 为其进一步研究开发奠定基础。方法 首先进行小鼠极性经口毒性试验, 采用最大给药量实验法(maximum tolerated dose, MTD), 然后进行遗传毒性试验, 包括Ames试验、小鼠骨髓细胞微核试验(间隔24 h两次经口灌胃法)和小鼠精子畸形试验, 最后进行大鼠30 d喂养试验来评价其毒理学安全性, 剂量分别为334、500、667 mg/kg×bw, 观察大鼠体重、增重量、进食量、食物利用率、血常规等指标的变化。结果 以最大给药量(30000 mg/kg)的样品灌胃后, 未见中毒症状, 无动物死亡; Ames试验、小鼠骨髓细胞微核试验和小鼠精子畸形试验3项遗传毒性试验结果均为阴性; 30 d喂养试验发现, 与对照组相比, 各剂量组大鼠的各项指标差异没统计学意义(P>0.05)。结论 天麻酸枣仁胶囊在本实验范围内尾无毒、无遗传毒性的产品, 可进一步进行开发研究。     

Sex-sorted semen for dairy heifers: Effects on reproductive and lactational performances

The objectives of this study were to evaluate the effects of using sex-sorted semen for first AI of heifers on health and productivity during first lactation. Holstein heifers (herd A = 227 and herd B = 1,144) received first artificial insemination (AI) with sex-sorted semen (SX; n = 343) or conventional semen (CS; n = 1,028), and all heifers that displayed estrus after first AI were reinseminated with conventional semen up to 11 times before being culled. Age at first AI was 13.1 ± 0.1 and 13.8 ± 0.1 mo for SX and CS heifers, respectively, in herd A and 12.9 ± 0.1 mo for both SX and CS heifers in herd B. Pregnancy per AI after first AI was greater for CS heifers than for SX heifers (51.8 vs. 40.2%). From heifers initially enrolled, 70.2% calved in herds A (n = 188) or B (n = 774) and first-lactation data were collected. Interval from first AI to calving was greater for SX heifers than for CS heifers (10.2 ± 0.1 vs. 9.9 ± 0.1 mo). Among heifers conceiving to first AI, SX heifers were more likely than CS heifers to deliver a female calf (85.7 vs. 47.7%), but because SX heifers were more likely to deliver a dead calf (8.8 vs. 3.4%), the difference in proportion of SX and CS heifers delivering a live female calf was smaller than expected (SX = 79.1%; CS = 47.2%). Rearing cost from first AI to calving was greater for SX heifers than for CS heifers ($775.3 ± 6.7 vs. $750.0 ± 5.9), but calf revenue tended to be greater for SX heifers ($142.0 ± 7.2 vs. $126.7 ± 6.4) and cost per female calf produced was smaller for SX heifers than for CS heifers ($−809.4 ± 10.8 vs. $−1,249.7 ± 10.9). Treatment did not affect calving difficulty, proportion of heifers needing assistance, and incidence of retained fetal membranes or metritis. Among heifers that conceived to first AI, however, SX heifers were more likely to be culled within 30 DIM (3.3 vs. 1.6%) and tended to be more likely to be culled within 60 DIM (5.5 vs. 3.4%) than CS heifers, but overall replacement cost was not different ($136.8 ± 13.4). Total milk yield (9,245.5 ± 84.7 kg) and income over feed cost ($554.7 ± 5.1) were not different. Overall economic return was greater for SX heifers than CS heifers ($−83.7 ± 36.7 vs. −175.3 ± 33.4). Use of sex-sorted semen for first insemination of virgin heifers reduced the cost per female calf produced and increased the economic return during the first lactation.