Characterization of serum proteomic and inflammatory profiling at early stage of iron deficiency in weaned piglets.

The objective of this study was to examine the early serum proteomic and inflammatory profiles of weaned piglets subjected to iron deficiency. Twelve healthy piglets (Duroc × Landrace × Large Yorkshire, body weight: 4.96 ± 0.05 kg) were weaned at 21 days of age. Subsequently, these animals were randomly allocated to one of two groups, with six replicates in each group (maintaining a male-to-female ratio of 1:1), the control group (administered 100 mg/kg Fe as FeSO4·H2O) and L-Fe group (no additional Fe supplementation). The results showed that 42 days after initiating, compared with control group, routine blood analysis revealed a reduction in serum iron content, red blood cell (RBC) count, hemoglobin (HGB) content, hematocrit (HCT), and mean corpuscular volume (MCV) (P < 0.05). Subsequent sample analysis indicated a noteworthy decrease in iron deposition in the liver, spleen, and kidneys of piglets fed the L-Fe diet compared with control group (P < 0.05). However, final body weight, average daily gain (ADG), average daily feed intake (ADFI), feed conversion ratio, and tissue coefficients were similar between the two groups (P > 0.05). During the early stages of iron deficiency, piglets exhibited increased villus height (VH) and the ratio of VH to crypt depth (CD) in the duodenum (P < 0.05) and increased expression levels of iron transporters, including duodenal cytochrome (Cybrd), divalent metal transport 1 (DMT1), and ferritin light chain (FTL) (P < 0.05). Subsequently, isobaric tags for relative and absolute quantitation (iTRAQ) were used to identify serum proteins. Gene Ontology (GO) analysis of the differentially abundant proteins (DAP) revealed that 24 of the 30 DAP were involved in platelet function, immune response, cellular metabolism, transcription, and protein synthesis. Notably, prothrombin, asporin (ASPN), and Rac family small GTPase 3 (RAC3) expression was induced, whereas glycoprotein Ib platelet subunit alpha (GPIbA) expression was decreased. This was accompanied by a substantial reduction in serum complement 3 (C3) and complement 4 (C4) contents (P < 0.05), with elevated the contents of interleukin-1ß (IL-1ß), interleukin-4 (IL-4), interleukin-6 (IL-6), transforming growth factor-ß1 (TGF-ß1), and tumor necrosis factor-α (TNF-α) (P < 0.05). Our findings underscore the essential role of dietary iron supplementation in maintaining iron homeostasis and modulating inflammatory responses in piglets.

Determination of optimal dietary calcium levels under different sources of zinc in Jing tint 6 layer chicks from 15 to 42 d of age.

An experiment was conducted to investigate the optimal dietary calcium (Ca) levels in Jing Tint 6 layer chicks fed different sources of zinc (Zn). The diets were formulated using 2 different Zn sources: organic Zn (80 mg/kg Zn as HMZn) and inorganic Zn (80 mg/kg Zn as sulfate). For each Zn source, 5 diets were formulated to contain Ca levels of 0.80, 0.90, 1.03, 1.10, and 1.20%. Results showed that dietary Ca levels had a significant effect on body weight gain (BWG) and feed conversion ratio (FCR) (P < 0.05). In addition, BWG was significantly enhanced by the organic Zn diets (P < 0.05). Dietary Ca levels significantly affected tibia length (P < 0.05) and serum Ca and P contents (P < 0.05) but did not affect serum total protein (TP), albumin (ALB), or alkaline phosphatase (ALP) levels (P > 0.05). The apparent total tract retention coefficients (ATTRC) of Ca showed a quadratic trend (P < 0.05) with increasing Ca levels. Furthermore, organic Zn diets reduced excreta Ca output and enhanced the ATTRC of Ca in birds on d 42 compared with inorganic Zn diets. The optimal dietary Ca levels were estimated as 0.93, 0.94, and 0.96% for birds fed organic diets and 1.07, 0.99 and 0.94% for birds fed inorganic diets using nonlinear models based on the criteria of BWG, tibial length, and serum P, respectively. In general, organic Zn supplementation improved growth performance and reduced the calcium requirements of birds on d 42.

Assessment of Non-Phytate Phosphorus Requirements of Chinese Jing Tint 6 Layer Chicks from Hatch to Day 42.

We aimed to estimate the non-phytate phosphorus (NPP) requirements of Chinese Jing Tint 6 layer chicks. We randomly allocated 720 birds to five treatments with six cages of 24 birds each, feeding them a corn-soybean diet containing 0.36%, 0.41%, 0.46%, 0.51%, and 0.56% NNP. The results showed that the body weight gain (BWG), tibial length, and apparent total tract digestibility coefficients (ATTDC) of P were affected (p < 0.05) by dietary NPP level. A quadratic broken-line analysis (p < 0.05) of BWG indicated that the optimal NPP for birds aged 1-14 d was 0.411%. Similarly, 0.409% of NPP met tibial growth needs. However, 0.394% of NPP was optimal for P utilization according to the ATTDC criterion. For 15-42 d birds, 0.466% NPP, as estimated by the BWG criterion, was sufficient for optimal growth without decreasing P utilization. Using the factorial method, NPP requirements were calculated as 0.367% and 0.439%, based on the maintenance factors and BWG for 1-14 and 15-42 d birds, respectively, to maintain normal growth. Combining the non-linear model with the factorial method, this study recommends dietary NPP levels of 0.367% and 0.439% for 1-14 and 15-42 d birds, respectively, to optimize P utilization without affecting performance.

Arsenic effectively improves the degradation of fluorene by Rhodococcus sp. 2021 under the combined pollution of arsenic and fluorene.

The performance of bacterial strains in executing degradative functions under the coexistence of heavy metals/heavy metal-like elements and organic contaminants is understudied. In this study, we isolated a fluorene-degrading bacterium, highly arsenic-resistant, designated as strain 2021, from contaminated soil at the abandoned site of an old coking plant. It was identified as a member of the genus Rhodococcus sp. strain 2021 exhibited efficient fluorene-degrading ability under optimal conditions of 400 mg/L fluorene, 30 °C, pH 7.0, and 250 mg/L trivalent arsenic. It was noted that the addition of arsenic could promote the growth of strain 2021 and improve the degradation of fluorene - a phenomenon that has not been described yet. The results further indicated that strain 2021 can oxidize As3+ to As5+; here, approximately 13.1% of As3+ was converted to As5+ after aerobic cultivation for 8 days at 30 °C. The addition of arsenic could greatly up-regulate the expression of arsR/A/B/C/D and pcaG/H gene clusters involved in arsenic resistance and aromatic hydrocarbon degradation; it also aided in maintaining the continuously high expression of cstA that codes for carbon starvation protein and prmA/B that codes for monooxygenase. These results suggest that strain 2021 holds great potential for the bioremediation of environments contaminated by a combination of arsenic and polycyclic aromatic hydrocarbons. This study provides new insights into the interactions among microbes, as well as inorganic and organic pollutants.

Effects of Different Yeast Selenium Levels on Rumen Fermentation Parameters, Digestive Enzyme Activity and Gastrointestinal Microflora of Sika Deer during Antler Growth.

The aim of this experiment was to study the effects of different selenium supplemental levels on rumen fermentation microflora of sika deer at the velvet antler growth stage. A total of 20 5-year-old, healthy sika deer at the velvet antler growth stage with an average body weight of (98.08 ± 4.93) kg were randomly divided into 4 groups, and each group was fed in a single house. The SY1 group was the control group, and the SY2 group, SY3 group and SY4 group were fed a basal diet supplemented with 0.3, 1.2 and 4.8 mg/kg selenium, respectively. The pretest lasted for 7 days, and the formal trial period lasted for 110 days. The results show that: At the velvet antler growth stage, the digestibility of neutral detergent fiber and acid detergent fiber of sika deer in the SY2 group was significantly higher than that in the control group (p < 0.01). The digestibility of cellulose and crude fiber of sika deer in the SY2 group was significantly higher than those in the SY3 and SY4 groups (p < 0.01) and significantly higher than that in the control group (p < 0.05). The contents of acetic acid and propionic acid in the rumen fluid of sika deer in the SY2 group were significantly higher than those in the SY1 group (p < 0.05). Digestive enzyme analysis of rumen fluid at the velvet antler growth stage showed that the activity of protease in rumen fluid in the SY2 group was significantly lower than those in the SY1 group and SY4 group (p < 0.05). The relative abundance of Fibrobacter succinogenes in the SY2 group was significantly higher than that in the SY1 group (p < 0.05) and extremely significantly higher than those in the SY3 and SY4 groups (p < 0.01). Correlation analysis between yeast selenium level and bacterial abundance showed that the yeast selenium content in rumen fluid was significantly positively correlated with Butyrivibrio and Succiniclasticum (p < 0.01). Further verification of bacterial flora functioning showed that the SY2 group was more inclined to the degradation and utilization of fiber. In conclusion, 0.3 mg/kg selenium supplementation can increase the abundance of Prevotella ruminicola and Fibrobacter succinogenes in the rumen of sika deer and improve the degradation of fibrous substances by mediating the catabolite repression process.

Dietary iron regulates intestinal goblet cell function and alleviates Salmonella typhimurium invasion in mice.

Iron is an important micronutrient that plays a vital role in host defenses and bacterial pathogenicity. As iron treatments increase the risk of infection by stimulating the growth and virulence of bacterial pathogens, their roles in anti-infection immunity have frequently been underestimated. To estimate whether adequate dietary iron intake would help defend against pathogenic bacterial infection, mice were fed iron-deficient (2 mg kg-1 feed), iron-sufficient (35 mg kg-1 feed), or iron-enriched diet (350 mg kg-1 feed) for 12 weeks, followed by oral infection with Salmonella typhimurium. Our results revealed that dietary iron intake improved mucus layer function and decelerated the invasion of the pathogenic bacteria, Salmonella typhimurium. Positive correlations between serum iron and the number of goblet cells and mucin2 were found in response to total iron intake in mice. Unabsorbed iron in the intestinal tract affected the gut microbiota composition, and the abundance of Bacteroidales, family Muribaculaceae, was positively correlated with their mucin2 expression. However, the results from antibiotic-treated mice showed that the dietary iron-regulated mucin layer function was not microbial-dependent. Furthermore, in vitro studies revealed that ferric citrate directly induced mucin2 expression and promoted the proliferation of goblet cells in both ileal and colonic organoids. Thus, dietary iron intake improves serum iron levels, regulates goblet cell regeneration and mucin layer function, and plays a positive role in the prevention of pathogenic bacteria.

Comparison of Growth Characteristics and Genomics of Two Canine Distemper Virus Strains Isolated From Minks in China.

Canine distemper (CD), caused by the CDV variant strain with HI542N/Y549H, has become an epidemic in fur-bearing animals in China since 2012. To well understand the genomic and replicated characteristics of the CDV variants, we determined the viral growth kinetics and completed the genome sequences of two CDV strains, namely SDZC(17)M2 and LNDL(17)M4, isolated from CDV-infected minks from Shandong and Liaoning province in China, in 2017. SDZC(17)M2 showed higher viral titers and extensive syncytia in BHK-minkSLAM (BMS) cells than LNDL(17)M4. Although both two strains belong to the Asia-1 genotype and clustered an independent clade in the phylogenetic tree, SDZC(17)M2, harboring I542N/Y549H substitutions in the H protein, shared high identity (99.3-99.6% nt) with the other variant strains, whereas LNDL(17)M4, with the only Y549H substitution, shared a lower identity (97.7%-97.9% nt) with the other variant strains. Furthermore, a novel R223K substitution was identified in the conserved cleavage site (RRQRR → RRQKR) of the F protein in the SDZC(17)M2 strain. However, it which did not significantly affect the cell to cell fusion activity when combined with the CDV H/minkSLAM in BHK-21 cells. The key variations in the genome contributed to the virulence and the evolutionary trend need to be determined in the future.

Mink SLAM V-Region V74I Substitutions Contribute to the Formation of Syncytia Induced by Canine Distemper Virus.

The Signal lymphatic activation molecule (SLAM, also known as CD150) as the cellular receptor of canine distemper virus (CDV) plays an important role in the virus-host interaction. However, it is still unknown whether amino acid differences in the SLAM variable (V) region affect the formation of syncytia. Here, using raccoon dog SLAM (rSLAM) and mink SLAM (mSLAM), we performed SLAM-V homologous modeling, site-directed mutagenesis, and surface expression analysis, as well as a cell fusion assay, to study the interaction between SLAM and CDV. More specifically, our investigation focused on two amino acid residues (74 and 129) of SLAM, previously predicted to play a relevant role in receptor-ligand interaction. Our results indicated that only residues at position 60, 74, and 129 were different between rSLAM and mSLAM among the 29 amino acids that might interact with CDV H, and residues 74 and 129 were located in the interface region interacting with CDV H. The amino acid substitution at the positions of 74 have a significant effect on the expression of mSLAM. The SLAM-V74I mutation in mink significantly improved the cell fusion efficiency of CDV. In contrast, the SLAM-I74V mutation in the raccoon dog significantly decreased cell fusion efficiency. We conclude that residue 74 of SLAM plays an important role during the the formation of syncytia. Only when implementing CDV infection analysis, the rSLAM-Q129R can significantly decreased the mean number of syncytia, but the mSLAM-R129Q can't. Additionally, residue 60 show variability between rSLAM and mSLAM. We believe that our study makes a significant contribution to the literature because we provide molecular data, partially accounting for the differences in host membrane and virus interaction laying the foundation for further molecular work.