Root architecture, which determines the water and nutrient uptake ability of crops, is highly plastic in response to soil environmental changes and different cultivation patterns.  Root phenotyping for field-grown crops, especially topological trait extraction, is rarely performed.  In this study, an image-based semi-automatic root phenotyping method for field-grown crops was developed.  The method consisted of image acquisition, image denoising and segmentation, trait extraction and data analysis.  Five global traits and 40 local traits were extracted with this method.  A good consistency in 1st-order lateral root branching was observed between the visually counted values and the values extracted using the developed method, with R²=0.97.  Using the method, we found that the interspecific advantages for maize mainly occurred within 5 cm from the root base in the nodal roots of the 5th–7th nodes, and that the obvious inhibition of soybean was mostly reflected within 20 cm from the root base.  Our study provides a novel approach with high-throughput and high-accuracy for field research on root morphology and branching features.  It could be applied to the 3D reconstruction of field-grown root system architecture to improve the inputs to data-driven models (e.g., OpenSimRoot) that simulate root growth, solute transport and water uptake.

This study evaluated the effects of the dietary starch amylose/amylopectin ratio on growth performance, rumen fermentation and blood parameters, carcass characteristics and marbling score, and meat fatty acid profiles and transcriptional changes in the genes involved in the gluconeogenesis pathway in Chinese Qinchuan cattle.  Forty-five cattle were randomly divided into three groups.  The bulls were fed a control diet (middle amylose/amylopectin ratio=0.47) or diets with either waxy corn starch (WS) inclusion (low amylose/amylopectin ratio=0.23) or pea starch (PS) inclusion (high amylose/amylopectin ratio=0.60) for 90 days.  The bulls were individually allowed to receive the diets at the daily amount of at least 2.1% of their individual BW twice daily.  The bulls were weighed at 45-day intervals, and blood and rumen fluid samples were also collected at 45-day intervals.  The bulls were slaughtered and longissimus thoracis (LT) samples were collected for meat quality measurements.  Compared with PS, the average daily gain (ADG) and feed efficiency in control and WS were increased (P<0.05) during d 0 to 45.  However, the feed efficiency in PS was increased (P<0.05) compared with the control and WS during d 46 to 90.  During the whole feeding trial, the ADG in control and WS showed trends that were higher (0.05<P<0.1) than that of PS, while other growth performance measures and feed intake did not differ (P>0.05) among the three groups.  Compared with PS, the serum insulin concentration in WS was increased (P<0.05) at d 45, but not at d 90.  Compared with control and WS, the serum SOD and T-AOC concentrations in PS were increased (P<0.05) at d 45, but not at d 90.  Compared with control, the rumen microbial crude protein contents in WS and PS were increased (P<0.05) at d 0, while those of control and WS were higher (P<0.05) than that of PS at d 45, but not at d 90.  Compared with PS, the backfat thickness in control and WS were increased (P<0.05), however, the marbling score and expression of genes related to the gluconeogenesis pathway in liver of the three groups did not differ (P>0.05).  Chemical and physio-chemical compositions of LT did not differ (P>0.05) among the three groups.  In conclusion, diets with low or middle amylose/amylopectin ratios increased the backfat thickness, and tended to improve ADG, but had no effect on other carcass characteristics, fat content in the LT, or the expression of hepatic genes related to the gluconeogenesis pathway in Chinese Qinchuan cattle. 

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Recombinant virus-vectored vaccines are novel agents that can effectively activate specific and nonspecific immunity, are multivalent and multieffective, and have high safety ratings.  Animal alphaherpesviruses have a large genome, contain multiple nonessential regions that do not affect viral replication and are capable of accepting the insertion of an exogenous gene and expressing the antigen protein.  Furthermore, animal alphaherpesviruses have a wide host spectrum, can replicate in the host and continuously stimulate the animal to produce immunity to the corresponding pathogen, thus making them ideal carriers for recombinant virus-vectored vaccines.  With the development of gene-editing technology, recombinant viruses capable of expressing foreign genes can be constructed by various methods.  Currently, studies on recombinant virus-vectored vaccines constructed based on animal alphaherpesviruses have involved poultry, pigs, cattle, sheep, and companion animals.  Studies have shown that the construction of recombinant animal alphaherpesviruses enables the acquisition of immunity to multiple diseases.  This article mainly summarizes the current progress on animal alphaherpesvirus-vectored vaccines, aiming to provide reference for the development of new animal alphaherpesvirus-vectored vaccines.

 

As a new feed additive, chitosan has been shown in recent years to have a certain role in reducing methane emissions from the gastrointestinal tracts of ruminants.  However, the effects of chitosan with different molecular weights on rumen fermentation, methane production and bacterial community structure are not yet clear.  A basal diet without chitosan served as the control (CTL), and the treatment diets were supplemented with chitosan with different molecular weights: 1 000 (1K), 3 000 (3K), 5 000 (5K), 50 000 (5W) and 200 000 (20W) dry matter (DM).  Six fermentation units per treatment were established.  Gas chromatography was used to measure the concentrations of methane, H₂ and volatile fatty acids (VFAs).  The bacterial 16S rRNA genes were sequenced with an Illumina MiSeq platform and analysed to reveal the relative abundances of bacterial community taxa.  The results showed that the propionate proportion was significantly increased by the addition of chitosan with different molecular weights (P<0.05), while methane production and the acetate proportion were significantly decreased (P<0.05).  The relative abundances of Rikenellaceae_RC9_gut_group and Prevotellaceae_UCG_003 were significantly increased in the 3K chitosan group compared with the CTL group, whereas the relative abundance of Ruminococcaceae_NK4A214_group was significantly decreased (P<0.05).  Correlation analyses of the relative abundances of the bacterial genera showed that Prevotella was positively related to propionate production (P<0.05).  In conclusion, 3K chitosan could reduce methane production by replacing fibrolytic bacteria (Firmicutes and Fibrobacteres) with amylolytic bacteria (Bacteroidetes and Proteobacteria) in the bacterial community structure.