Animal Husbandry and Veterinary Medicine
This experiment was designed to explore the relationship between the musk-producing ability and fertility of male musk deer, which would provide a theoretical basis for germplasm resource breeding. The musk production of 224 forest musk deer was recorded, of which 57 had fecundity data. The influencing factors of musk yield and fecundity, and the correlation between them were statistically analyzed. The results showed that there was no significant difference in musk production among different age groups and different musk-extracting time groups in captive forest musk deer (P>0.05), but the musk production tended to decrease with age. The average production of adult musk deer was significantly higher than that of juvenile musk deer, with a difference of 3.51g per deer (P<0.05). There was no significant difference in the fecundity of male musk deer among different age groups (P>0.05). There was no significant difference in the fecundity of male musk deer at different musk-extracting times (P>0.05). The correlation study showed that there was a significant correlation among the fecundity indicators of male musk deer (P<0.05).The musk production of male musk deer was positively correlated with the twin birth rate and the average number of offspring per litter. With the increase in the musk production of male musk deer, the twin birth rate and the average number of offspring per litter also increased, but the correlation was not significant (P>0.05). Correct musk extraction could not affect the fecundity of male musk deer. The higher the musk production of male musk deer, the better the trend of fecundity indicators. Combined with the physical condition, age, musk production, and previous reproductive experience of male musk deer, breeding male musk deer can be preliminarily screened. This study provides theoretical guidance for improving the reproductive efficiency of forest musk deer and optimizing the feeding and management.
To obtain the 14-3-3 protein of Trichinella spiralis (T1) and to identify and evaluate its biological characteristics, the biological information of 14-3-3(Ts14-3-3) protein of Trichinella spiralis was analyzed and predicted using relevant websites and software. Ts14-3-3 was recombined with pET-28a using gene cloning and prokaryotic expression techniques, and the recombinant Ts14-3-3(rTs14-3-3) protein was obtained. After the antigenicity was identified by Western blot, the rTs14-3-3 protein immune serum was prepared. qPCR and indirect immunofluorescence were used to identify its expression in different insect stages and its localization in muscle larvae. The effect of rTs14-3-3 protein on larvae in the muscle of mice infected with Trichinella spiralis was evaluated by animal experiments. Soluble rTs14-3-3 protein was successfully prepared, with a size of about 33 kDa, and it could specifically recognize the positive serum of porcine Trichinella spiralis. The titer of the prepared immune serum was as high as 1:52000. The protein was highly expressed in the muscle larvae of Trichinella spiralis, and the gene was transcribed in the larvae, adults, and muscle larvae during the intestinal infection stage of Trichinella spiralis. The pest reduction rate of mouse muscle larvae was 55.2%. rTs14-3-3 protein has good reactivity and immunogenicity, can reduce the number of muscle larvae in mouse tissues infected by Trichinella spiralis, and has potential as a serological diagnosis and candidate vaccine molecular antigen.
This article aims to explore the comprehensive application of natural medicines, microbiota, and multienzymes in the prevention and treatment of piglet diarrhea to improve the efficiency and benefits of pig farming. The healthy growth and development of piglets are crucial for the sustainable development of the pig industry. The combination of comprehensive prevention and treatment strategies, including the antiviral and antibacterial effects of natural medicines, the regulatory role of microbiota, and the digestive assistance provided by multienzymes, plays an important role in the sustainable development of pig farming. To effectively implement comprehensive prevention and treatment strategies, further research and practical application are needed to optimize the effectiveness of medicines, microbiota, and multienzymes.
The aim of this study is to establish a rapid indirect CLIA antibody detection method for porcine pseudorabies virus gB protein, in order to provide technical support for the prevention and control of porcine pseudorabies disease and the evaluation of vaccine immunization level in large-scale pig herds. In this study, carboxylated magnetic beads were coupled with recombinant gB protein to form immunomagnetic beads, and the reaction conditions were optimized by using a fully automated chemiluminescence instrument; six different concentrations of standards were used to draw the standard curves; the negative and positive determination criteria were determined by drawing ROC curves; and the specificity, sensitivity, reproducibility, and compliance were evaluated after the preliminary establishment of the method. The results showed that the optimal pH for magnetic bead coupling was 6.0, the optimal concentration for protein coupling was 40 μg/mL, 10% BSA was the optimal sealant, the optimal dilution of enzyme-labeled secondary antibody was 1:20000, the serum reaction time was 5 min, the enzyme-labeled antibody reaction time was 10 min, and the pre-stimulation solution reaction time was 5 min. Finally, a standard curve with R2=0.9987 was drawn, and at the same time the judgment criteria were set as follows: ≥16.78 U was judged as positive, and <16.78 U was judged as negative. In the methodological evaluation, there was no cross-reactivity with the positive sera of 7 porcine pathogens, and the sensitivity was slightly higher than that of the commercial kits, with intra-batch and inter-batch coefficients of less than 10%, and the total compliance rate with the commercial ELISA kits was 98.9%. The indirect chemiluminescent antibody detection method for porcine pseudorabies virus gB protein established in this study can be used for epidemiological investigation of PR and assessment of vaccine immunization level, and provides theoretical reference for the development of subsequent kits.
The microorganism has the strong material decomposition and the transformation ability, may produce the rich secondary metabolite, the fermentation Chinese traditional medicine is an important processing technology of Chinese traditional medicine processing. Probiotics can regulate the balance of animal gastrointestinal flora, produce many kinds of active enzymes and other metabolites, promote the development of animal immune system organs, participate in many physiological functions of the body, such as substances synthesis of sugar, nitrogen, lipids, inorganic salt metabolism and vitamin, and enhance the body’s disease resistance. The technology of probiotics fermenting traditional Chinese medicine has many advantages, such as improving drug effect, degrading macromolecular active substance, reducing toxic and side effects, promoting animal growth and improving immunity, etc., which is an ideal feed additive after end prohibition. In this paper, the kinds of probiotics, technological types, mechanism and efficacy of probiotics fermenting traditional Chinese medicine and its application in animal breeding are described respectively; it provides a theoretical reference for the development of new anti-feed additives.
On the basis of quantitative analysis of China's formula feed standards, this article summarizes the evolution of China's formula feed standards in order to provide feasible suggestions for the development of the feed industry. This article applies quantitative analysis methods and selects national and non-national standard systems for formula feed of 39 years in China from 1984 to 2023 as research samples. ROST CM6 software is used to quantitatively analyze the evolution characteristics of formula feed standards in China. Research has found that China's feed standards have gone through four peak periods of standard formulation and publication, with a focus on feed standard testing, experimental animal formula feed, formula feed nutrition standards, and formula feed hygiene standards. Non national standards have a certain degree of advancement or lag compared to national standards. At different stages, China's formulated feed standards have been continuously revised and improved from promulgation to development into the current feed standard system with Chinese characteristics.
This study aims to delve into the current research status and application potential of ultra-high temperature composting technology in the field of livestock and poultry manure treatment. By analyzing pilot studies on ultra-high temperature composting, engineering cases of ultra-high temperature composting, and the quality and application effects of ultra-high temperature compost products, the results show that exogenous heating and the addition of hyperthermophilic bacterial agents are key factors in achieving ultra-high temperature composting, with the addition of hyperthermophilic bacterial agents being particularly crucial. The study indicates that ultra-high temperature composting is suitable for treating livestock and poultry manure of different scales and types, demonstrating economic feasibility. Moreover, the products of ultra-high temperature composting meet the standards for organic fertilizers in China and have shown good effects in cultivation, indicating broad prospects for promotion and application. However, there is still work to be done in exploring and utilizing microbial strain resources for ultra-high temperature composting and demonstrating the field application of ultra-high temperature compost products.
In the study, using a novel duck reovirus (NDRV) to actively infect commercial ducklings with different maternal antibody levels, and the ducklings' cloacal viral shedding, body weight, spleen index, liver and spleen tissue lesions, and pathological indicators were tested and observed. The goal was to discover the protective effect of maternal antibodies on early NDRV infection in ducklings, laying the foundation for disease prevention and control. A total of 58 one-day-old commercial ducklings were tested for NDRV maternal antibodies. They were grouped according to maternal antibody levels and challenged at 3 days of age. Cloacal swabs were collected on days 3, 5, and 7 post-challenge to test for shedding, and weights were recorded on days 2, 8, and 10. Ducklings were euthanized 7 days post-challenge for necropsy to observe liver and spleen lesions, calculate spleen index, and prepare liver and spleen pathological sections. The results showed that all challenged ducks shed the virus, and high maternal antibody groups were unable to prevent shedding. Weight gain in challenged ducks was significantly lower than the control group (P < 0.01). Necrosis was observed in the spleens, and scattered hemorrhagic foci with necrosis were found in the livers of challenged ducks. The spleen index of challenged ducks was significantly higher than the control group (P< 0.01). There were no significant differences in spleen index and body weight among ducklings with different maternal antibody levels post-challenge (P> 0.05). Liver and spleen cells showed varying degrees of pathological damage. This experiment demonstrates that high maternal antibodies cannot provide effective protection against this NDRV isolate in ducklings. The method of using immune breeder ducks to protect ducklings from infection requires further consideration.
Long-term addition of antibiotics in feed can cause the problems such as drug residues and bacterial resistance, leading to a decline in the quality of livestock and poultry products, threats to human health, and damage to the ecological environment. In 2020, Announcement No. 194 of the Ministry of Agriculture and Rural Affairs officially implemented, and the use of growth promoting antibiotic additives in feed was completely prohibited, marking the arrival of the era of "anti antibiotic" in the livestock and poultry industry. Non antibiotic breeding has become a major trend in the development of the livestock and poultry industry. Antibiotic substitutes can improve the growth performance of animals, improve intestinal health, and regulate the host immune system. They have the advantages of safety, efficiency, low residue, and low pollution, and have great prospects in the application of feed additives. Therefore, this article reviews the research progress in the application and action mechanism of green additives such as antibiotic substitutes, microecological agents, organic acids, plant extracts, Chinese herbal medicines, antimicrobial peptides, etc., in order to provide reference for healthy livestock breeding and promote the green and healthy development of livestock and poultry breeding in China.
In order to screen suitable pollinators for Glycyrrhiza uralensis and improve the seed yield of G. uralensis, the flower-visiting behavior and pollination effects of Bombus terrestris and Apis mellifera ligustica were compared. In the licorice field, during the flowering period of licorice, the inflorescences that were about to bloom under different pollination treatments were tagged and then the mature seeds of different treatments were harvested, and the number of pods per mature inflorescence, the number of seeds per pod, and the weight of 1000 grains, and other licorice yield-related traits were counted by conventional seed examination after pollination. The results showed that there were significant differences between A. mellifera ligustica and B. terrestris in flower visits to licorice. B. terrestris opened the keel flap more easily, and the single visit time [(2.98±0.05) s] was faster than that of A. mellifera ligustica [(8.19±0.21) s], and the frequency of visits to flowers [(12.98±0.29) flowers/min] was significantly higher than that of A. mellifera ligustica [(9.21±0.15) flowers/min]. Its peak emerging period (10:00) and peak homing period (14:00) were the same as those of A. mellifera ligustica. The number of colonies of A. mellifera ligustica was significantly higher than that of B. terrestris, but the seed setting rate of B. terrestris (52.92%) was higher than that of A. mellifera ligustica (43.33%), both of which were significantly higher than that of self-pollination (13.75%) and wind-borne pollination (22.19%). The pod numbers of single inflorescence pollinated by B. terrestris and A. mellifera ligustica were 20.67 and 19.41, respectively, which were 34.6 and 32.5 times higher than self-pollination, and 25.2 and 22.6 times higher than wind-borne pollination, respectively. The seed number of single inflorescence pollinated by B. terrestris and A. mellifera ligustica were 91.46 and 74.75, respectively, which were 33.0 times and 26.8 times higher than self-pollination, 28.5 times and 23.1 times higher than wind-borne pollination. The effective release distance of B. terrestris was about 210 m, which was significantly greater than that of A. mellifera ligustica (90 m). In conclusion, B. terrestris and A. mellifera ligustica are excellent pollinators for licorice, and B. terrestris shows better pollination effect on licorice, which can effectively solve the problem for insufficient vector insects in large-scale licorice seed production.
In order to explore the effective way to realize the protection of livestock and poultry genetic resources in China, the current situation of the protection of livestock and poultry genetic resources was systematically sorted out, and the realistic difficulties faced by the protection were deeply analyzed. The results show that, at present, the number of protected varieties has been increasing, regulations and policies have been improved, protected areas, seed conservation farms and gene banks have begun to take shape, and the quality of the workforce has been improved. However, it is also faced with the dilemma of not digging deep into the characteristics of resources, and the disconnection between protection and exploitation; the weak support of regulations and policies, and the lack of linkage in the management system; the obsolete facilities in the protected areas, conservation farms and gene banks, and the outdated protection technology; the insufficient financial support, and the single channel of investment. Based on this, the following countermeasures and suggestions are put forward: strengthen the depth mining of resources, improve the level of development and utilization; establish and improve laws and regulations, integrate departmental management resources; strengthen the guidance of fiscal funds and establish a diversified investment and financing system; continue to promote the development and construction of seed conservation farms, protected areas and gene banks.
This study aims to investigate a strain of pathogenic bacteria, isolated from the organs of dead pigs on a Jinzhou pig farm. The research encompasses bacterial isolation and identification, drug sensitivity tests, and clinical diagnosis and treatment implications. Gram staining was conducted using LB agar culture, followed by BP special medium culture. Drug sensitivity testing, 16S rDNA sequencing, and mouse pathogenicity testing were also performed. Pathological tissue sections were prepared for microscopic observation. Gram staining microscopy results indicated that the bacterium was Gram-positive cocci. The BP Petri dish revealed black colony growth with a transparent ring around it. Drug sensitivity tests demonstrated high sensitivity to enrofloxacin, ofloxacin, amikacin, and kanamycin. 16S rDNA sequencing revealed a high similarity between the 16S rDNA fragments of this bacterium and Staphylococcus aureus. Microscopic examination of pathological sections revealed significant pathological damage in various tissues and organs. The causative organism on this pig farm was identified as Staphylococcus aureus, which exhibited resistance to certain antibiotics and demonstrated some pathogenicity in the mouse attack test.
The aim is to obtain the fermentation strains with remarkable ability to produce enzyme and antibacterial property, and provide reference for the conversion of new feed resources and the search for antibiotic substitutes. Using strain H14 as the starting point, its enzymatic property and antibacterial ability were analyzed. The feed addition and fermentation time of fermented rapeseed meal were optimized by single factor experiments. A strain of Bacillus cereus H14 that produces cellulase, protease, amylase, and xylanase was screened and identified. The optimal reaction conditions for cellulase production were 60℃ and pH 9, and the activity of cellulase, protease, amylase and xylanase was 11.51 U/mL, 73.68 U/mL, 5.96 U/mL and 14.02 U/mL respectively. The maximum inhibitory diameters against Escherichia coli and Staphylococcus aureus were 18.200±0.200 mm and 17.567±0.493 mm, respectively. The optimal conditions for fermenting rapeseed meal to produce cellulase were adding 25% rapeseed, incubating for 48 h, enzyme activity reached 12.608 U/mL, and the optimal antibacterial effects on Escherichia coli and Staphylococcus aureus were adding 25% rapeseed meal and incubating for 48 h, the antibacterial diameter (mm) was 24.933±0.204; and adding 25% rapeseed meal and incubating for 72 h, the antibacterial diameter (mm) was 27.400±0.529, respectively. The fermentation products contain sucrose, xylose, and glucose. This experiment screened out a good fermentation strain, which could provide some reference for the development of fermented feed.
Currently, Varroa destructor is acknowledged as a harmful parasite of honeybee colonies in the bee industry, leading to significant economic losses and ecological issues worldwide. In recent years, effective control of Varroa destructor in honeybee colonies has been elusive. While traditional physical, chemical, and biological control methods have been crucial in preventing and managing Varroa destructor, each approach has its own advantages and drawbacks, and persistent issues and limitations remain. This study reviews the latest research progress on the biological characteristics, pathogenicity, diagnosis, and control methods of Varroa destructor, offering valuable insights for future research and the prevention of Varroa destructor in honeybee colonies.
Porcine epidemic diarrhea virus (PEDV), which causes porcine epidemic diarrhea, was used as the research target in this study. The live vector strain LP1522-PEDS of Lactobacillus plantarum containing PEDV S gene was used to immunize mice orally. The content of SIgA in feces and the contents of IgG, IL-4, IL-2 and IFN-γ in serum of immunized mice were detected by ELISA, and the immune effect of Lactobacillus recombinant strain LP1522-PEDS on mice was evaluated. The results showed that after the first immunization, the contents of SIgA in feces and IgG, IL-4, IL-2 and IFN-γ in serum of the commercial inactivated vaccine group and the engineered strain immunization group were significantly higher than those of the control group (P<0.05). The antibody levels of the inactivated vaccine group and the recombinant strain group reached the maximum after 42-56 days of immunization. The levels of antibodies and immune factors were as follows: commercial inactivated vaccine group > LP1522-PEDS group > empty vector group ≈ control group. Subsequently, the antibody levels in the inactivated vaccine group and LP1522-PEDS group gradually decreased. After 70 days of immunization, the antibody level of the commercial inactivated vaccine group decreased with small amplitude and the antibody level of the engineered strain immunization group decreased greatly. The results showed that the genetic engineering Lactobacillus plantarum LP1522-PEDS carrying PEDV S gene could induce PEDV immune response in mice via oral administration.
The aim is to screen for more efficient cryopreservation schemes for bovine in vitro embryos by comparing the effects of different vitrification and programmed cryopreservation schemes. The 2-hour recovery rate, 24-hour hatching rate, and 45 day initial pregnancy rate between instrument vitrification and manual vitrification frozen bovine embryos in vitro were compared; the 2-hour recovery rate, 24-hour hatching rate, and 48-hour hatching rate of frozen bovine in vitro embryos between two programmed freezing schemes were compared; and the pregnancy rates of 45 day transplantation of fresh embryos in vitro, frozen embryos in vitro, and frozen embryos in vitro in cattle were compared. There was no significant difference in the 2-hour recovery rate (72.91%±5.52% vs.70.91%±6.75%) and 24-hour hatching rate (60.42%±6.33% vs. 58.18%±5.62%) between the instrument vitrification freezing scheme and the programmed freezing scheme for thawed embryos (P>0.05). The 24-hour hatching rate of frozen thawed embryos with sucrose scheme in programmed freezing was significantly higher than that of the freezing scheme without sucrose (44.23%±3.33% vs. 37.50%±3.58%) (P<0.05). The 45 days examination pregnancy rates of fresh bovine embryos in vitro, frozen bovine embryos in vitro, and frozen bovine embryos in vivo were 56.81%±6.27%, 45.00%±6.13%, and 49.41%±7.55%, respectively. In practical applications, there is still a certain gap in the freezing effect of bovine embryos produced in vitro compared to in vivo embryos. There is no significant difference in the effect between instrument vitrification freezing and manual vitrification freezing. The use of sucrose in the programmed freezing scheme can significantly improve the freezing effect.
To clarify the effect of returning manure and water from large-scale dairy farms on the growth of alfalfa and the physical and chemical properties of soil, 5 amounts of cow manure water of 0, 150, 300, 450 and 600 m3/hm2 returning to the field after solid-liquid separation and fermentation were set in this experiment. By measuring the changes in alfalfa yield, quality, soil nutrient content and heavy metal content under different treatments, the results showed that returning manure to the field could significantly increase the hay yield of alfalfa. With the increasing in the amount returned to the field, the yield increased significantly, under the treatment of 600 m3/hm2, the annual hay yield of alfalfa reached 19369.0 kg/hm2; the application of manure water could not reduce the crude protein and relative feeding value of alfalfa; the return of manure water to the field could significantly increase the pH and salt content of the soil, and it could increase the soil organic matter content. Under the condition of no fertilization throughout the year, the available nitrogen, available phosphorus and available potassium in the treated soil all showed a decline. Returning manure water to the field could not meet the annual growth needs of alfalfa, and it should be combined with fertilization for better results. The return of manure water to the field would increase the content of heavy metals such as copper, cadmium, arsenic, lead, and chromium in the soil, and the content of each heavy metal would increase the most at the level of 600 m3/hm2. In general, the amount of cow manure water returning to the field should be controlled within the range of 300-450 m3/hm2 to achieve double improvement of alfalfa yield and soil quality.
Anthocyanin, as a natural bioactive substance, is widely used in the livestock and poultry breeding industry. This article reviews the current research progress on anthocyanins and discusses their application in livestock and poultry breeding from the perspective of green breeding and their important role in improving breeding benefits. The promotion of feed additives such as anthocyanins will become an important trend in the future livestock and poultry breeding industry, contributing to the industry's sustainable development.
Embryo transfer technology is a modern reproductive technology that can accelerate the expansion and reproduction rate of domestic animal populations. It has been widely applied in the promotion and rapid expansion of excellent animal breeds such as cattle, sheep, and horses. This article reviews the superovulation technology, synchronous estrus technology and factors affecting embryo transfer involved in sheep embryo transfer, so as to provide ideas for the improvement of sheep embryo transfer technology and its application in the sheep industry, and lay a foundation for subsequent technological progress.
The aim of this experiment was to study the effects of Chinese herbal extracts on performance, blood immune function and antioxidant properties of Highland brown laying hens. A total of 360 healthy 42-week-old Highland brown laying hens were randomly divided into 4 groups with 3 replicates per group and 30 laying hens per replicate. Samples in groups A, B and C were fed with 0.4% Chinese herbal extract compound Coptis Jiedu Powder HLJDS, Pulsatilla Pulsatilla Powder BTWS and Qingwen Decoction QWT on the basis of commercially available normal full price feed, and control group D was fed with the commercially available normal full price feed. The pre-test lasted for 7 days and the experiment lasted for 28 days. The results showed as follows. In terms of production performance, the laying rate of laying hens in group C was extremely significantly higher than that of control group D (P<0.01), and the laying rate of laying hens in group A was significantly higher than that of control group D (P<0.05). The feed to egg ratio of laying hens in groups A and C was significantly lower than that of control group D (P<0.01). There was no significant difference in average egg weight among all groups (P>0.05). The defective egg rate of laying hens in groups A and C was extremely significantly lower than that of control group D (P<0.01), and the defective egg rate of laying hens in group B was significantly lower than that of control group D (P<0.05). There was no dead culling chicken in group A and Group C during the whole experiment period, while the dead culling rate in control group D was 2.22%. In terms of egg quality, there were no significant differences in egg shape index, protein concentration index and yolk index in groups A, B, C and D (P>0.05), but the number of defective eggs in fecal eggs, bloodstained eggs, malformed eggs and soft preserved eggs in control group D was significantly higher than that of the other three groups, and there was a phenomenon of uneven egg color. In terms of immune function, the activity of lysozyme in blood of groups A and C was extremely significantly higher than that of control group D (P<0.01). Serum globulin of laying hens in group C was extremely significantly higher than that of control group D (P<0.01), and serum globulin of laying hens in group A was significantly higher than that of control group D (P<0.05). In terms of antioxidant performance, the T-SOD activity in blood of laying hens in groups A and C was significantly higher than that of control group D (P<0.01). The content of MDA in blood of laying hens in groups A and C was significantly lower than that of control group D (P<0.01). Dietary addition of HLJDS and QWT can improve the production performance of laying hens, reduce the defective egg rate and dead chickens to a certain extent, and improve the immune function and antioxidant properties of laying hens, which is conducive to improving the economic benefits of laying hens.
Animal Husbandry and Veterinary Medicine
