A rumen simulation technique (RUSITEC) apparatus with eight 800 ml fermenters was used to investigate the effects of replacing dietary starch with neutral detergent-soluble fibre (NDSF) by inclusion of sugar beet pulp in diets on ruminal fermentation, microbial synthesis and populations of ruminal cellulolytic bacteria. Experimental diets contained 12.7, 16.4, 20.1 or 23.8% NDSF substituted for starch on a dry matter basis. The experiment was conducted over two independent 15-day incubation periods with the last 8 days used for data collection. There was a tendency that 16.4% NDSF in the diet increased the apparent disappearance of organic matter (OM) and neutral detergent fibre (NDF). Increasing dietary NDSF level increased carboxymethylcellulase and xylanase activity in the solid fraction and apparent disappearance of acid detergent fibre (ADF) but reduced the 16S rDNA copy numbers of Ruminococcus albus in both liquid and solid fractions and R. flavefaciens in the solid fraction. The apparent disappearance of dietary nitrogen (N) was reduced by 29.6% with increased dietary NDSF. Substituting NDSF for starch appeared to increase the ratios of acetate/propionate and methane/volatile fatty acids (VFA) (mol/mol). Replacing dietary starch with NDSF reduced the daily production of ammonia-N and increased the growth of the solid-associated microbial pellets (SAM). Total microbial N flow and efficiency of microbial synthesis (EMS), expressed as g microbial N/kg OM fermented, tended to increase with increased dietary NDSF, but the numerical increase did not continue as dietary NDSF exceeded 20.1% of diet DM. Results suggested that substituting NDSF for starch up to 16.4% of diet DM increased digestion of nutrients (except for N) and microbial synthesis, and further increases (from 16.4% to 23.8%) in dietary NDSF did not repress microbial synthesis but did significantly reduce digestion of dietary N.

There is a lack of studies that have investigated grain yield, its components and photosynthesis in late stages of wheat growth, giving us insufficient understanding of how these factors interact to contribute to yield during this period. As a result, three field experiments were carried out examining 20 winter wheat genotypes of diverse origins under irrigated, terminal drought and dryland conditions in the southern Idaho. Our objective was to evaluate the interaction between post-anthesis physiological traits, especially leaf-level photosynthetic capacity, senescence and yield components on grain yield in different moisture regimes. Genotype differences were found in leaf-level photosynthesis and senescence, canopy temperature depression, grain yield and yield components in each water regime. Grain yield was closely associated with traits related to grain numbers. In all three moisture regimes, positive correlations were observed between grain yield and photosynthesis that were dependent on the timing or physiological growth stage of the photosynthetic measurement: highly significant correlations were found in the mid-and late grain filling stages, but no correlations at anthesis. Consistent with these findings, flag leaf senescence at the late grain filling stage was negatively correlated with grain yield and photosynthetic rate (under terminal drought and dryland conditions). These findings provided evidence that grain yield was sink-limited until the final stages of growth, at which time sustained photosynthesis and delayed senescence were critical in filling grain. Because the trends were consistent in moisture sufficient and deficient conditions, the results suggest that late-season photosynthesis and delayed leaf senescence are driven by the size of the reproductive carbon sink, which was largely governed by factors affecting grain numbers.

Four Holstein heifers (215 ± 7 kg; means ± SD), fitted with one pancreatic pouch, duodenal re-entrant cannulas, and duodenal infusion catheters, were used in this experiment. In phase 1, the 24-h profile of pancreatic fluid was determined. Pancreatic fluid flow peaked 1h after feeding, but peaks of similar magnitude also occurred before the morning feed, necessitating 24-h collection of pancreatic fluid to estimate daily excretion. In phase 2, the effects of duodenal infusions of 0, 10, 20, or 30 g of leucine on pancreatic fluid flow were determined in a 4 × 4 Latin square design. The leucine was infused for 12h in 2,500 mL of the infusate, and samples of pancreatic fluid and jugular blood were collected in 1-h intervals from the beginning of the infusion for 36 h. The results showed that the secretion rate of pancreatic fluid (mL/h) was significantly higher in 10-g leucine group than the other groups (mL/h). Protein concentration (mg/mL) in pancreatic fluid was elevated proportional to the amount of leucine infused. Leucine infusions increased both the concentration (U/mL) and secretion rate (U/h) of α-amylase. Infusion of 10 g of leucine also increased the secretion rates (U/h) of trypsin, chymotrypsin, and lipase, but did not change their concentrations. No significant effects of leucine infusions on plasma glucose and insulin concentrations were found. The results indicate that leucine could act as a nutrient signal to stimulate α-amylase production and pancreatic exocrine function in dairy heifers.

Immune stress is the loss of immune homeostasis caused by external forces. The purpose of this experiment was to investigate the effects of immune stress on the growth performance, small intestinal enzymes and peristalsis rate, and mRNA expression of nutrient transporters in broiler chickens. Four hundred and thirty-two 1-d-old broilers (Cobb500) were randomly assigned to four groups for treatment; each group included nine cages with 12 birds per cage. Group 1 = no vaccine (NV); Group 2 = conventional vaccine (CV); group 3 = lipopolysaccharide (LPS)+conventional vaccine (LPS); group 4 = cyclophosphamide (CYP)+conventional vaccine (CYP). The results demonstrated that immune stress by LPS and CYP reduced body weight gain (BWG), feed intake (FI), small intestine peristalsis rate and sIgA content in small intestinal digesta (p<0.05). However, the feed conversion ratio (FCR) remained unchanged during the feeding period. LPS and CYP increased intestinal enzyme activity, relative expression of SGLT-1, CaBP-D28k and L-FABP mRNAs (p<0.05). LPS and CYP injection had a negative effect on the growth performance of healthy broiler chickens. The present study demonstrated that NV and CV could improve growth performance while enzyme activity in small intestine and relative expression of nutrient transporter mRNA of NV and CV were decreased in the conditions of a controlled rational feeding environment. It is generally recommended that broilers only need to be vaccinated for the diseases to which they might be exposed.

Molecular marker-assisted selection is a better way to satisfy the growing customer requirement with the development of beef cattle growth and breeding research. For now, quantitative trait locus (QTL) for cattle growth and carcass traits, just like body height, body length and carcass weight have been detected on bovine chromosome 6. In this study, ligand-dependent nuclear receptor corepressor-like (LCORL) was selected as the potential positional candidate gene located in chromosome 6 which is closely connected with the bovine growth and carcass traits. A total of 450 Qinchuan beef cattle were used to detect mutations in exon and its neighbouring region, and the promoter region of the bovine LCORL gene. The methods for SNPs detection were polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and created restriction site PCR (CRSPCR), and the results of this study show that there were two variations in intron regions, the other four variations were located in the promoter region. Linkage disequilibrium analysis and haplotype analysis indicated that L78-Q4 had strong linkage disequilibrium, A T G C G C (16.2%) and G C G C A T (16.7%) had higher haplotype frequencies, G C A C A C (0.8%) and G T A C A T (0.7%) had lower haplotype frequencies. Correlation analysis indicated that SNP g. INT+52098A>G was significantly associated with slaughter weight and carcass weight. Based on the research, we selected LCORL as the candidate gene that can contribute to improved marker-assisted selection for the meat performance of Qinchuan beef cattle.

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ABSTRACT. The insulin-induced gene 1 (Insig-1) is a regulator of lipid metabolism and plays an important role in the sterol-mediated regulation of SREBP, SCAP and HMG-CoA reductase. We used PCR-RFLP and DNA sequencing to detect polymorphisms of the Insig-1 gene in 215 individuals of the Qinchuan cattle breed. Four SNPs [4366(A>G), 4534(T>C), 5001(T>C), and 5235(G>A)] were indentified. The association of the genetic viariation with growth and carcass traits (body length, withers height, hip width, slaughter weight, and carcass weight) was analyzed. The individuals with better performance had the GG genotype at locus A4366G, and CC genotypes at locus T4534C and locus T5001C. These could be used for beef cattle breeding improvement in China. Additionally, linkage disequilibrium analysis reflected that all mutations were in low linkage disequilibrium with each other. We concluded that polymorphisms in the Insig-1 gene are associated with growth and carcass traits and could be used for marker-assisted selection and management in beef cattle breeding programs.

Valsa mali (V. mali), the causal agent of apple tree Valsa canker, severely damages apple production, a major economic crop in China. To date, our understanding of the molecular mechanisms associated with the pathogenicity of V. mali is still limited. RNA interference participates in various biological processes in multicellular organisms. The Argonaute proteins (AGOs), which are a core component of the RNA interference system, play key roles in vegetable growth, environmental responses and fungal pathogenicity. Previously, transcriptome analysis revealed that the AGO2 gene (VMAGO2) was up-regulated during V. mali infection, suggesting that VMAGO2 plays a potential role in pathogenicity. In this study, we investigated the potential roles of VMAGO2 in the growth, stress responses and pathogenicity of V. mali. VMAGO2 was isolated and found to be orthologous to AGO2 of Neurospora crassa and Fusarium graminearum.Real-time quantitative PCR analysis showed that VMAGO2 expression was 3.4-fold higher than that of the control (mycelium) at 24 hr post-inoculation (hpi). Six positive VMAGO2 mutants were generated using double-joint PCR and PEG-mediated transformation. Deletion of VMAGO2 did not result in any obvious phenotypic change when compared with that of wild-type strain 03-8. Furthermore, the colonial morphology was not obviously affected when the mutants were subjected to osmotic and pH stress treatments. However, the knockout mutants did not grow on PDA with 0.05% H 2 O 2 . More importantly, infection assays showed that the average lesion diameter/ length resulting from mutant infections was 34.8% and 19.8% smaller on apple leaves and twigs, respectively, than those resulting from wild-type infections. All six positive mutants showed a consistent phenotype, and the defects of the mutants were fully complemented by re-introducing the WT VMAGO2 allele. Our results demonstrated that VMAGO2 plays an important role in H 2 O 2 tolerance and the pathogenicity of V. mali.