To investigate the impact of Isalo scorpion cytotoxic peptide (IsCT) on the immune function of immune organ (head kidney, spleen, and skin) of grass carp (Ctenopharyngodon idella), 540 fish (136.88 ± 0.72 g) were supplied with a different amount of IsCT (0, 0.6, 1.2, 1.8, 2.4, and 3.0 mg/kg diet) through a period of 60 days. Afterward, 24 fish were randomly selected from each group and were inoculated with Aeromonas hydrophila for a period of 6 days. Our findings suggested that appropriate IsCT complementation: (1) attenuated skin morbidity and histopathological structural changes in the head kidney and spleen (p < 0.05), which ensured the structural integrity of the immune organs; (2) increased the activity and expression of immune substances (p < 0.05), which in turn increased the function of the immune organs, promoting immune responses; (3) through the regulation of the Janus kinase/signal transducers and activators of transcription (JAKs/STATs) signaling pathway, the mRNA expression of anti-inflammatory cytokines increased and the mRNA expression of pro-inflammatory cytokines decreased, which in turn increased the function of the immune organs, reducing the inflammatory response (p < 0.05). However, the addition of IsCT did not affect the expression of IL-12p35, STAT2, and STAT3a in the immune organ. Ultimately, this study provided evidence that IsCT enhanced immune function via the JAKs/STATs signaling pathway in the immune organ in grass carp after challenged with Aeromonas hydrophila.
Fish health assessment is essential for maintaining sustainable aquatic ecosystems and ensuring the well-being of wild and farmed fish populations. Hematological parameters are crucial indicators of fish health, with poikilocytosis emerging as a fundamental marker with significant diagnostic value. Poikilocytosis refers to abnormally shaped erythrocytes in bloodstream, reflecting underlying physiological and pathological conditions. Poikilocytosis can occur in various fish species and can be influenced by environmental stressors, infectious agents, nutritional deficiencies, and exposure to pollutants. Morphological alterations in erythrocytes, such as acanthocytes, echinocytes, dacrocytes, schistocytes, spherocytes, and codocytes are common poikilocytes in fish. Understanding the relationship between poikilocytosis and fish health has important implications for disease diagnosis, monitoring, surveillance, and management. By quantifying poikilocytic changes, researchers and veterinarians can differentiate normal variations from pathological conditions, facilitating targeted interventions and treatment strategies. While most studies have focused on heavy metal toxicity, stressors, nutritional deficiencies, pollutants, and therapeutics, the etiological induction of poikilocytosis in fish health has been overlooked. Nonetheless, poikilocytosis remains a valuable biomarker for assessing fish health and their environment. This review highlights piscine poikilocytosis as a significant fish hematological biomarker and its importance in understanding their health and culture conditions.
Nutrition modulates the vulnerability of animals to xenobiotics insults including antibiotics in cultured fish. However, studies exploring the role of low-fat diet (LFD) in modulating adverse effects of antibiotics are currently limited. This study explored the physiological effects of feeding LFD supplemented with oxytetracycline (OTC) in Nile tilapia (Oreochromis niloticus) fingerlings. Thirty Nile tilapia (8.64 ± 0.44 g) were tagged and randomly stocked into three tanks and fed on a control diet (CD, 70 g/kg lipid), LFD (20 g/kg lipid) and the LFD supplemented with 2.00 g/kg diet of OTC (80 mg/ kg body weight/day), hereafter LFD + OTC for 9 weeks. The results indicated that the Nile tilapia fed on LFD + OTC reduced growth performance and feed utilization efficiency than those fed on CD and LFD. Moreover, the fish fed on LFD + OTC had lower body composition, nutrients digestibility and mesenteric fat index than those fed on CD and LFD. Feeding the fish with LFD + OTC decreased antioxidant capacity in the liver than those fed on CD and LFD. The Nile tilapia fed on LFD + OTC increased hepatotoxicity than those fed on CD and LFD. Feeding the Nile tilapia on LFD + OTC decreased immunity response in the kidney and liver than those fed on CD and LFD. The LFD + OTC affected nutrients metabolism in the liver and serum than other diets. Taken together, feeding LFD with OTC impairs physiological functions of Nile tilapia by inhibiting growth performance, antioxidant capacity, immunity response and nutrient metabolism.
Pseudomonas plecoglossicida (P. plecoglossicida) is a pathogen in aquaculture that causes considerable economic loss. According to artificial infection experiments, the fish were classified into control group, moribund group, and survival group. Compared to the control group, both the moribund group and the survival group of fish had fewer red blood cells (RBCs) and lower oxygen saturation (SaO2). Furthermore, the fish in the survival group has more RBCs and SaO2 compared to the moribund group. The concentrations of total iron, ferrous iron, ferric iron, and mineralized iron in the fish spleen of the moribund and survival groups were lower compared to those of the control group. Additionally, the concentrations of these iron components in the fish spleen of the survival group were higher than those of the moribund group. The results demonstrated that iron mineralization is involved in the survival of fish challenged with P. plecoglossicida. Compared to the control and survival groups, the fish spleen had several distinguishing features in the moribund group, including less reduced glutathione (GSH), higher mitochondrial complex V activity, more lipid peroxidation, and reactive oxygen species, as well as reduced glutathione peroxidase 4 (gpx4) expression. Moreover, there were intact cell membranes, a normal nucleus size, no chromatin concentration, and disappearance of cristae in the mitochondria of the spleens of the moribund group. The characteristics of spleen cells in the moribund group were consistent with ferroptosis, suggesting that ferroptosis was involved in the death of fish challenged with P. plecoglossicida.
Zimbabwe is currently rated as one of the top 10 fish producers in Sub- Saharan Africa. Fish farming in Zimbabwe is dominated by the culture of Nile tilapia (Oreochromis niloticus) followed by rainbow trout (Oncorhynchus mykiss). Over 90% of the cultured fish is O. niloticus, which comes from Lake Kariba. Since the first decade of the 21st century, there has been a significant increase in fish production from two tons to eight tons annually. The increase in fish production has been attributed to the government and donor-funded fishery programs. In this review, current practices, opportunities, and challenges for aquaculture in Zimbabwe are highlighted. The current practices include intensive, semi-intensive, and extensive aquaculture systems. Consistent high market demand for fish and numerous water bodies with potential for cage culture are some of the drivers for aquaculture. Despite the industry’s significant growth, there are still a number of management and production issues that need to be resolved. Weaknesses in structural issues and operational frameworks in Non- Governmental Organizations, lack of credit facilities, subsidies, limited technology, obfuscated governance, weak fish disease surveillance mechanisms and legal frameworks, and constrained human resources capacity are some of the challenges plaguing fish culture in Zimbabwe. Cogent aquaculture policies, sustainable subsidies, intensive training of human resources and fisheries experts, strengthened disease surveillance, cheaper alternative fish feeds, reliable viable fingerling production, concerted value chain efforts, and exploration of lucrative export markets is a panacea for the fledgling aquaculture industry in Zimbabwe.
The objective of this study was to evaluate the impact of the determination methods (free feeding [FF] and tube feeding [TF]) on the available energy of ingredients (wheat, paddy, and brown rice). A total of 101 adult Hy-Line Brown roosters (35 weeks old) with an initial body weight of 2.72 ± 0.21 kg were used, in which 96 roosters were randomly assigned to the FF group and TF group, and the remaining five birds were selected to determine the endogenous energy loss. Each group consisted of 12 dietary treatments. In the FF group, each diet treatment comprised 2 replicates with 2 birds per replicate and 4 replicates with 1 bird per replicate for each diet in the TF group. The 12 dietary treatments included a basal diet (BD) and 11 test diets, in which wheat, paddy, and brown rice replaced 30% corn, soybean meal, and wheat bran in the BD. The experiment was performed three times. There was a significant effect of source on apparent metabolizable energy (AME) and true metabolizable energy (TME) in paddy (p < 0.05). Results showed that AME in wheat, paddy, and brown rice measured by the FF method were greater than those values gained by the TF method (p < 0.05). The average AME and TME values were 3537, 3140, and 3893 kcal/kg dry matter (DM) and 3555, 3163, and 3933 kcal/kg DM for wheat, paddy, and brown rice, respectively, measured by the FF method. The means of AME and TME evaluated by the TF method were 3270, 2988, and 3764 kcal/kg DM and 3642, 3357, and 4135 kcal/kg DM for wheat, paddy, and brown rice, respectively. In conclusion, the determination method has a considerable effect on available energy, and the TF method underestimates the AME of ingredients.
Large-scale genotyping at a low cost is crucial for molecular breeding of livestock. In this study, the Cattle110K capture chip was developed, based on the genotyping by target sequencing system. The chip panel included 112,180 single necleotide polymorphisms (SNPs), from potential functional regions screened by genome-wide associated study, BayesB, expression quantitative trait loci-mapping, ATAC-seq, and reported functional markers. All the SNPs on the panel were distributed evenly on the cattle genome, with more than 99% of the markers having a minor allele frequency greater than 0.05. Assessment results indicated that a total of 1.2 M high-quality SNPs were identified in the 110 K regions, averaging approximately 10 SNPs per target sequence. The genotype consistency for the repetitive samples using the Cattle110K liquid chip was 99.21% while the concordance between the Illumina BovineHD BeadChip and this chip averaged 98.17%. A significant association signal for slaughter weight and carcass length was identified on 37.3–41.5 Mb of chromosome 6, pinpointing the NCAPG-LCORL locus. This locus has previously been associated with meat and carcass traits in cattle. Additionally, novel candidate regions were identified around 3.4 Mb of chromosome 13 and 73.5 Mb of chromosome 8, significantly correlated with hip height and marbling score, respectively. We compared the accuracy of genomic estimated breeding values between the Illumina BovineHD BeadChip and this chip. The results demonstrated that the Cattle110K capture chip had a comparable ability in genomic prediction to the Illumina BovineHD BeadChip. Advances in using the cost-effective liquid capture chip are expected to accelerate the genetic progress of cattle in the coming years.
As a model of regenerative medicine, hair follicle stem cell (HFSC) plays a determining role in the hair cycle. Emerging evidences showed that long noncoding RNAs regulated the biological function of HFSC. In this current study, we found that lncRNA-000552, standing for “goat secondary HFSC Associated SYNE3 Regulator of HF Cycle” (HFSCARC) expressed higher in anagen than that in telogen of cashmere goat. Through experiments involving nucleocytoplasmic separation and RNA-FISH, we determined that HFSCARC was primarily located in the nucleus of HFSC. To understand the function of HFSCARC, the study performed various assays, including crystal violet staining, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, EdU, and flow cytometry analysis, which collectively revealed that HFSCARC inhibited HFSC proliferation. Additionally, HFSCARC promoted the differentiation of HFSC by investigating the expression of marker genes specific to stem cells and keratinocytes. RNA sequencing analysis was conducted to investigate the global gene expression changes associated with HFSCARC expression. The results showed that HFSCARC altered the expression of genes involved in cell proliferation, hair follicle development, and regulation of bone morphogenetic proteins (BMP) signaling. Furthermore, the study revealed that HFSCARC activated the BMP signaling pathway. Intriguingly, the study found a decreased expression of SYNE3, which was a neighboring gene of HFSCARC. The altered expression of genes associated with transmethylase and demethylase further suggested that HFSCARC might play an important role in regulating the SYNE3 expression. Overall, this study provides valuable insights into the regulatory role of HFSCARC in the biological function of HFSC. These findings contribute to a better understanding of the involvement of noncoding RNAs in the regulation of hair cycle.
There is an increasing amount of scientific research into animal sentience. Many scientists are studying the cognitive, emotional, and communicative capacities of a range of animals. The results of this research have led to a number of legal recognitions of the sentience of a range of animals. In 1997, the European Union (EU) gave legal recognition to the sentience of animals and updated and elevated this recognition in the Treaty of Lisbon. Other countries and states as well as the World Organization for Animal Health (WOAH, formerly OIE) have followed it. Scientists are increasingly acknowledging that sentience and emotion have arisen in a wide range of species. Research now emphasizes that there is an extraordinary variation in how different animal species (such as mammals, birds, fish, or insects) perceive the world and their environment. This paper looks at the sentience of the main farmed land and aquatic animals and the implications of this for how such animals are bred and housed. The paper concludes that intensive farming systems deprive animals of opportunities for positive emotions, such as play, exploration, social interaction, and feeding to satiation, and stops them from satisfying naturally motivated behaviors. To truly respect animal sentience, production systems should be designed with the animal's characteristics and needs in mind. The authors conclude that regenerative, agroecological, or organic farming systems better protect and respect the sentience of animals leading to less suffering and more opportunities for positive experiences.