Animal Science Journal最新文献

The takin is an endangered animal native to Asia, uniquely distinguished by its combined bovine and caprine physiognomy. Due to human activities like hunting and habitat loss, takin populations have significantly decreased, making conservation efforts crucial. Mesenchymal stem cells (MSCs) are multilineage cells with self-renewal capabilities and can differentiate into various cell types, making them useful for conservation efforts. This study aimed to isolate and characterize MSCs from the takin. MSCs were obtained from the bone marrow of the femur. Karyotype analysis was conducted to assess the chromosomes of the MSCs. MSC-specific surface markers were detected by flow cytometry. Multilineage differentiation was performed and osteo-, adipo-, as well as chondrogenesis-related gene expression was assessed by qRT-PCR. The results showed that MSCs exhibited a spindle-shaped morphology, along with notable proliferative capacity. Karyotype analysis determined that MSCs of the takin were diploid with 52 chromosomes. Flow cytometry demonstrates that MSCs from the takin exhibited cell surface marker expression consistent with other MSCs. MSCs from the takin were differentiated into osteoblasts, adipocytes, and chondrocytes, with increased expression of genes associated with osteoblasts, adipocytes, and chondrocytes. In conclusion, MSCs were successfully isolated from the takin, helping preserve the endangered animal resources.

Concerns over antibiotic resistance from the use of ionophore antibiotics in the treatment of metabolic disorders in cattle have led to investigations into alternative antimicrobial compounds. This is the first study to evaluate the effects of betulin, a natural compound found in birch tree bark, on in vitro rumen fermentation and its bacterial composition. Treatment with betulin decreased the relative abundance of Streptococcus and increased the relative abundance of Rikenellaceae RC9 gut group and Pseudobutyrivibrio without affecting short-chain fatty acid (SCFA) production. Additionally, we found betulin had a minimum inhibitory concentration (MIC) of 18.75 μg/mL on Streptococcus equinus ATCC33317 and a MIC of 75 μg/mL on Pseudobutyrivibrio xylanivorans BAA-455. Furthermore, we found a reduction in gas production in the betulin treatment group in batch culture and decreased viscosity of the culture medium incubated with S. equinus ATCC33317. These results suggest betulin's potential as a natural alternative to ionophore antibiotics to prevent metabolic disorders caused by Streptococcus.

This study was conducted to evaluate the effects of maternal intake of naturally mycotoxin-contaminated corn (MMC) on offspring chicks challenged with lipopolysaccharide (LPS). A total of 378 healthy 80-week-old Hy-line brown breeder hens were divided into three groups with 126 hens per group, and fed corn–soybean meal basal diet formulated by replacing uncontaminated corn with 0%, 50%, and 100% MMC for 6 weeks, respectively. After artificial insemination and hatching of breeding eggs, 48 healthy offspring chicks at 15 days of age with average weight from each breeder hen group (a total of 144 chicks, half male and half female) were selected and divided into two groups with six replicates and four chicks in each replicate and injected intraperitoneally either with sterile saline or with equal LPS solution at 17 and 19 days of age. Chicks were fed the same basal diet until 21 days of age. The results showed that maternal MMC diet and LPS challenge decreased body weight, increased alanine aminotransferase and aspartate aminotransferase activities, and induced oxidative damage in offspring chicks. In conclusion, low levels of mycotoxins from breeder hens negatively affected the growth performance, induced liver damage, and reduced stress resistance ability in offspring chicks.

The effective control of genetic disorders is essential for animal welfare and sustainable production. Since 1996, 10 causative mutations in autosomal recessive genetic disorders have been identified in Japanese Black cattle, leading to the development of DNA-based genetic diagnostic tests. The government has published profile sheets detailing genetic disorders and designated seven of these disorders as having a significant economic impact, prompting a response policy using DNA-based genetic diagnostic tests to reduce their occurrence. However, the effects of these tests on the frequency of risk alleles have not yet been evaluated. In this study, we analyzed the risk allele frequency trends over two decades using a large-scale dataset from central slaughterhouses. We found that following the publication of the profile sheet, the frequencies of the risk alleles rapidly declined, reaching very low levels. For such a rapid decline to occur within three generations, a significant proportion of asymptomatic heterozygous carriers would need to have been eliminated from the breeding system. This level of removal is considered unattainable through natural selection alone, indicating the need for DNA-based genetic diagnostic tests. These results showed that DNA-based genetic diagnostic tests were effective in suppressing the frequency of risk alleles in the population.

This study investigated the combined effect of branched-chain amino acids (BCAAs), valine (Val), leucine (Leu), and isoleucine (Ile) on chick myoblast proliferation and associated gene expression within a three-component system. Isolated myoblasts were incubated in 22 different culture media, designed using a {3, 5} simplex lattice design to cover the entire range of compositions for each BCAA. The proliferation was estimated based on cell quantities after 72 h of incubation. The proliferation data under different BCAA combinations were fitted using Scheffé's seven-term special cubic model for three components. The response surfaces of proliferation showed a convex configuration, with increases in Ile leading to a decrease in proliferation. The maximal proliferation was observed at Leu and Val proportions of 3:7 and 1:1 in an Ile-free medium, as measured by the DNA assay and water-soluble tetrazolium salt (WST-8) assay, respectively. These findings suggest that Val has a greater influence than Leu on myoblast proliferation, particularly in DNA content. The responses of myoblast proliferation-associated factors, Pax7 and p21, corresponded to the proliferation evaluated with DNA and WST-8 assays, respectively. These results indicate that the growth of chick myoblast cells is affected by the combination of BCAAs in a three-component system.

To illustrate the effects of chitosan oligosaccharide (COS) supplementation on abdominal fat deposition (AFD), lipid metabolism, cecal microbiota composition, and short-chain fatty acids (SCFA) content in the ceca of broilers. Totally, 144 one-day-old male Arbor Acres broilers were randomly allocated into two groups with six replicates and 12 broilers per replicate. The control group (CON) was fed the basal diet; the treatment group was fed the basal diet with 200-mg/kg COS (COS₂₀₀). COS supplementation led to a reduction (p < 0.05) in AFD, serum triglyceride, hepatic high-density lipoprotein cholesterol content, hepatic fatty acid synthase, acetyl-coenzyme A carboxylase gene expression level, and peroxisome proliferator-activated receptor γ gene expression level in abdominal fat (AF). Furthermore, COS supplementation resulted in higher (p < 0.05) relative abundance of cecal Bacteroidetes and Alistipes but lower (p < 0.05) relative abundance of Desulfobacterota, Patescibacteria, Campilobacterota, Deferribacterota, Shuttleworthia, and Erysipelatoclostridium, accompanied by increasing acetic acid, propionic acid, isobutyric acid, caproic acid, and total acid content. The AF weight inversely (p < 0.05) correlated with the relative abundance of Bacteroidota and isobutyric acid content. Overall, COS supplementation reduced AF deposition by inhibiting hepatic fatty acid synthesis, abdominal adipocyte differentiation, and proliferation-related gene expression, which was associated with the changes in cecal microbiota composition and SCFA content.

The aims of this study were to investigate the effects of re-vitrification at the pronuclear (PN) stage of porcine embryos generated from vitrified oocytes on subsequent development and to clarify if re-vitrification is more feasible at the PN stage or at the blastocyst stage. Immature porcine oocytes at the germinal vesicle (GV) stage were vitrified/warmed and subjected to in vitro maturation, parthenogenetic activation (PA), and embryo culture. Subsequent parthenotes were either cultured without re-vitrification for 6 days (GV-vit group) or were re-vitrified 8 h after PA at the PN stage (GV-vit/PN-revit group), and after warming, cultured for 6 days. Embryo development to the blastocyst stage was compared with a control group processed without vitrification at any stage. Then, blastocysts obtained in each group were vitrified/warmed and their survival was assessed. Blastocyst formation in the GV-vit/PN-revit group decreased dramatically (p < 0.05) compared with the GV-vit and control groups (3.4% vs. 10.2% and 22.4%, respectively). However, 80.0% of the blastocysts in the GV-vit group survived re-vitrification. Hence, after blastocyst re-vitrification, 8.2% of the vitrified oocytes re-expanded to transferable embryos. In conclusion, re-vitrification at the PN stage was detrimental for subsequent development, whereas that at the blastocyst stage was more advantageous.

This study investigates the effects of L-carnitine on nuclear maturation and fertilization in cattle and goat oocytes. Ovaries were collected from females with poor reproductive efficiency in the tropical climate, and cumulus-oocyte complexes (COCs) were retrieved from large antral follicles. COCs were cultured with varying concentrations of L-carnitine (0, 0.5, 1, and 1.5 mg/mL for goats; 0, 0.25, 0.375, and 0.5 mg/mL for cattle). Cumulus expansion and nuclear maturation were assessed, while bovine oocytes underwent in vitro fertilization. Here, L-carnitine enhanced cumulus expansion and nuclear maturation, with the highest maturation rates at 1 mg/mL in goats and 0.375 and 0.5 mg/mL in cattle. Fertilization rates in cattle improved with L-carnitine supplementation, particularly at 0.375 and 0.5 mg/mL. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that L-carnitine modulates pathways related to oxidative stress reduction, glucose metabolism, and mitochondrial function. Protein–protein interaction network analysis identified key regulatory genes, including SOD2, SIRT3, IGFBP3, PRL, NOS2, NOX4, SOD1, HMOX1, LEP, and AKT1, which may mediate L-carnitine's effects on oocyte maturation and fertilization. In conclusion, L-carnitine supplementation enhances oocyte competence possibly by improving cellular metabolism and reducing oxidative stress, providing valuable insights for optimizing assisted reproductive technologies in ruminants.