In vitro evaluation of the ovistatic and ovicidal effect of the cosmopolitan filamentous fungi isolated from soil on Ascaris suum eggs

The ovicidal activity of seven fungal strains: Acremonium alabamense, Alternaria chlamydospora, Cladosporium herbarum, Fusarium solani, Paecilomyces variotii, Paecilomyces viridis and Penicillium verruculosum isolated from urban soil samples from Poland was determined in vitro. The fungal mycelium was co-cultured with Ascaris suum eggs on plates with 2% water–agar for 28 days. Eggs exposed and unexposed (control) to fungal mycelium were observed weekly by light microscopy and the percentage of malformed eggs were determined. The eggs were classified according to following parameters: type 1 – biochemical and physiological effect without morphological damage to the eggshell; type 2 – lytic effect with morphological alteration of the eggshell and embryo; type 3 – lytic effect with morphological alteration of eggshell and embryo with hyphal penetration and internal egg colonization. All examined species of fungi extended embryogenesis, but the retardation of embryonic development was varied and depended on the species. A. alabamense, A. chlamydospora and P. verruculosum exhibited very high inhibitory activity on A. suum egg development. The fungus-exposed eggs revealed morphological alternations in all stages of embryogenesis. Isolates of F. solani, P. variotii and P. viridis showed hyphal penetration and internal colonization of A. suum eggs (type 3 effect). No appressoria were produced and simple hyphal penetrations were most commonly observed. A. alabamense and P. verruculosum demonstrated morphological destruction, with eggshell destruction. The remaining fungi showed type 1 effect. The results demonstrated that examined strains of F. solani, P. variotii and P. viridis may be considered to be potential limiting factors of parasitic geohelminth populations.     

Enterobacteriaceae andSalmonella recovered from nonsanitized and sanitized broiler hatching eggs

Sanitizing hatching eggs may reduce the chances that a broiler flock will become colonized withSalmonella and reduce the numbers of other microorganisms, such asEnterobacteriaceae, that can depress hatchability. An experiment was conducted to determine if a quaternary-biguanide sanitizer applied as foam or spray would reduceEnterobacteriaceae orSalmonella naturally occurring on broiler hatching eggs. The sanitizer was applied to buggies of 5,040 eggs the day before set (one buggy/treatment at each of 2 settings). Treated eggs were compared with untreated controls. Foam application loweredEnterobacteriaceae prevalence at set (0 vs. 18%) and transfer (5 vs. 28%); spraying was effective only when eggs were set (2.5 vs. 11%). At transfer spray, treated and control eggs were 19%Enterobacteriaceae-positive. FiveSalmonella-positives were recorded during the study. No indication that the sanitizer was effective in reducingSalmonella prevalence when applied as foam was observed (3/120 vs. 1/120). NoSalmonella were recovered from spray-treated eggs. No statistically significant difference forSalmonella prevalence was noted, but with such a low rate of recovery it is difficult to draw a firm conclusion. However, the sanitizer applied as foam was effective at decreasing the prevalence ofEnterobacteriaceae (a family of bacteria that includesSalmonella andEscherichia coli), and is present more often and in higher numbers thanSalmonella.     

Chemical treatment of lobster eggs against epibiotic bacteria

Eggs of the European lobster, Homarus gammarus (L.), were exposed to malachite green (5, 10, 15 mg 1^–1: 10 min), glutaraldehyde (50, 100, 150 mg 1^–1: 3 min) and iodine as Buffodine^TM (50, 100, 150 mg 1^–1: 10 min). The efficiency of the treatments was tested by incubating eggs individually in wells of multiwell dishes with TSB agar for 14 days after exposure. In order to find any effect on viability, batches of 30 eggs from each of three females were incubated artificially in a recirculation system for 19 days and repeatedly exposed to the disinfectants. Iodine as Buffodine (150 mg 1^–1) was the only treatment that resulted in a significant decrease of the bacterial growth on lobster eggs, but the treatment also resulted in inhibited hatching compared with the control group. Thus, our results indicate that treatment with 150mg^–1 iodine as Buffodine could be a strategy for reducing bacterial growth on lobster eggs when massive egg mortality due to bacteria is otherwise unavoidable. The treatment could, however, lead to decreased viability of larvae due to inhibited hatching.     

Egg quality determinants in cod (Gadus morhua L.): egg performance and lipids in eggs from farmed and wild broodstock

Lipids and essential fatty acids, particularly the highly unsaturated fatty acids, 20:5n‐3 (eicosapentaenoic acid; EPA), 22:6n‐3 (docosahexaenoic acid; DHA) and 20:4n‐6 (arachidonic acid, AA) have been shown to be crucial determinants of marine fish reproduction directly affecting fecundity, egg quality, hatching success, larval malformation and pigmentation. In Atlantic cod (Gadus morhua L.) culture, eggs from farmed broodstock can have much lower fertilization and hatching rates than eggs from wild broodstock. The present study aimed to test the hypothesis that potential quality and performance differences between eggs from different cod broodstock would be reflected in differences in lipid and fatty acid composition. Thus eggs were obtained from three broodstock, farmed, wild/fed and wild/unfed, and lipid content, lipid class composition, fatty acid composition and pigment content were determined and related to performance parameters including fertilization rate, symmetry of cell division and survival to hatching. Eggs from farmed broodstock showed significantly lower fertilization rates, cell symmetry and survival to hatching rates than eggs from wild broodstock. There were no differences in total lipid content or the proportions of the major lipid classes between eggs from the different broodstock. However, eggs from farmed broodstock were characterized by having significantly lower levels of some quantitatively minor phospholipid classes, particularly phosphatidylinositol. There were no differences between eggs from farmed and wild broodstock in the proportions of saturated, monounsaturated and total polyunsaturated fatty acids. The DHA content was also similar. However, eggs from farmed broodstock had significantly lower levels of AA, and consequently significantly higher EPA/AA ratios than eggs from wild broodstock. Total pigment and astaxanthin levels were significantly higher in eggs from wild broodstock. Therefore, the levels of AA and phosphatidylinositol, the predominant AA‐containing lipid class, and egg pigment content were positively related to egg quality or performance parameters such as fertilization and hatching success rates, and cell symmetry.     

几种轮虫需精卵休眠时间的初步研究↑（*）

本文报道了角突臂尾轮虫，萼花臂尾轮虫，褶皱臂尾轮虫部分新产需精卵的自然休眠期分别为９天，６－７天，大于１２天，晶囊轮虫部分需精卵的休眠显８－１１ｈ。光照是轮虫新产需精卵萌发的必要条件。     

2014—2023年中国禽蛋市场展望

近年来中国禽蛋生产稳步增长,满足了日益增长的禽蛋消费需求,成为不可或缺的畜禽养殖产业。未来10年,受养殖风险高和比较效益低等因素影响,中国禽蛋生产增速放缓;消费需求继续平稳上涨,且以国内消费为主;进出口贸易量基本稳定,贸易顺差明显的格局将持续。     

Olive leaves (Olea europea L.) and α‐tocopheryl acetate as feed antioxidants for improving the oxidative stability of α‐linolenic acid‐enriched eggs

Ninety‐six brown Lohmann laying hens were equally assigned into four groups with six replicates. Hens within the control group were fed a corn–soybean‐based diet supplemented with 4% linseed oil. Two other groups were given the same diet further supplemented with 5 or 10 g ground olive leaves/kg feed, while the diet of the fourth group was further supplemented with 200 mg α‐tocopheryl acetate/kg. Supplementing diets with olive leaves had no effect on egg production, feed intake and egg traits. Eggs collected 28 days after feeding the experimental diets were analysed for lipid hydroperoxides and malondialdehyde (MDA) content, fatty acid profile, α‐tocopherol concentrations and susceptibility to iron‐induced lipid oxidation. Olive leaves were also analysed for total and individual phenolics, and total flavonoids, whereas their antioxidant capacity was determined using both the DPPH (1,1‐diphenyl‐2‐picrylhydrazyl) and ABTS (2,2‐azinobis3‐ethylbenzothiazoline‐6‐sulphonic acid) radical scavenging activity assays. Results showed that neither α‐tocopheryl acetate nor olive leaves supplementation exerted (p > 0.05) any effect on the fatty acid composition of n‐3 eggs. Supplementing the diet with 5 g olive leaves/kg had no (p > 0.05) effect on the hydroperoxide levels of n‐3 eggs, while supplementing with 10 g olive leaves/kg or 200 mg α‐tocopheryl acetate/kg, the lipid hydroperoxide levels were reduced (p ≤ 0.05) compared to control. However, although hydroperoxides were reduced, MDA, a secondary lipid oxidation product, was not affected (p > 0.05). Iron‐induced lipid oxidation increased MDA values in eggs from all groups, the increase being higher (p ≤ 0.05) in the control group and the group supplemented with 5 g olive leaves/kg. The group supplemented with 10 g olive leaves/kg presented MDA values lower (p ≤ 0.05) than the control but higher (p ≤ 0.05) than the α‐tocopheryl acetate group, which presented MDA concentrations lower (p ≤ 0.05) than all other experimental diets at all incubation time points.     

Egg tanning improves the efficiency of CRISPR/Cas9-mediated mutant locust production by enhancing defense ability after microinjection

The mutant efficiency and hatching ratio are two key factors that significantly affect the construction of genome-modified mutant insects. In the construction of CRISPR/Cas9-mediated dsLmRNase2~(–/–) mutant locusts, we found that the tanned eggs which experienced a 20-min contact with the oocyst exhibited a higher success rate compared to fresh newlylaid eggs that were less tanned. However, the heritable efficiency of the dsLmRNase2 deletion to the next generation G_1 progeny was similar between adults derived from the tanned or less tanned engineered eggs. Further, the similar effective mutant ratios in the normally developed eggs and G_0 adults of tanned and less tanned eggs also indicated that tanning did not reduce the absolute mutation efficiency induced by CRISPR/Cas9. Moreover, we found that the syncytial division period, which was longer than the time for tanning, conferred a window period for microinjection treatment with efficient mutation in both tanned and less tanned eggs. We further found that tanned eggs exhibited a higher hatching rate due to a reduced infection rate following microinjection. Both the anti-pressure and ultrastructure analyses indicated that the tanned eggs contained compressed eggshells to withstand increased external pressure. In summary, tanned eggs possess stronger defense responses and higher efficiency of genome editing, providing an improved model for developing Cas9-mediated gene editing procedures in locusts.     

室内人工饲养4代花绒寄甲的繁殖生物学

为了解决人工大量繁育花绒寄甲(Dastarcus helophoroides)的技术问题,选用麻天牛(Thyestilla gebleri)作为花绒寄甲1龄幼虫的替代寄主,利用人工饲料饲喂成虫,在实验室中连续饲养4代花绒寄甲,统计分析每一代花绒寄甲成虫产卵量、产卵前期、雌雄性比、体长、体宽、体质量、卵的孵化率以及下一代幼虫寄生率等指标,分析人工饲料和替代寄主对室内多代饲养花绒寄甲的影响。结果表明:花绒寄甲成虫的体长、体宽、体质量随着室内饲养代数的增加而减小;花绒寄甲成虫的产卵前期也随着饲养代数的增加而延长;随着室内饲养代数增加和时间的延长,平均每头雌虫的产卵量增加;使用替代寄主繁殖4代后出现成虫雌雄性比不符合1∶1的情况;室内饲养4代对花绒寄甲卵的孵化率和初孵幼虫的室内寄生率几乎没有影响。通过各个繁殖生物学特性指标的比较发现,人工合成饲料A的产卵前期明显延长,以麻天牛为替代寄主时,繁育出的后代雄虫数量明显多于雌虫。综上可见,室内饲养多代后对花绒寄甲的繁殖生物学特性有影响,虽然能完成室内人工大量繁育花绒寄甲的需求,但会出现一些体征下降的趋势,平均产卵量会升高。     

鸡种蛋孵化率低的原因与对策研究

根据调查结果分析，在我国，即便是一些集体孵化厂和个体孵化厂，孵化温度、孵化湿度、通风换气、种蛋质量等条件基本符合鸡胚生长发育的要求。这表明，我国这几方面的孵化条件已得到了很好的解决，不是当前影响孵化率的主要原因。但我国种鸡蛋的孵化率与先进国家（如日本等）相比有相当大的差距，调查结果分析，主要原因有：①日翻蛋次数不足且不合理；②孵化方式落后；③孵化设备陈旧；④技术管理跟不上。针对这些原因提出了相应的