Comparison of active dry yeast (Saccharomyces cerevisiae) and yeast culture for growth performance, carcass traits, meat quality and blood indexes in finishing bulls.

This study was conducted to compare the effect of active dry yeasts (ADY) and yeast cultures (YC), two typical products of yeast preparations, on growth performance, carcass characteristics, meat quality and blood indexes in finishing bulls fed a high-concentrate diet. Forty-five finishing bulls (mean body weight (BW) ± standard deviation: 505 ± 29 kg BW) were allocated to three groups of 15 bulls and assigned randomly to one of three diets which were CON diet (basal diet), ADY diet (basal diet + Levucell SC) and YC diet (basal diet + Diamond V XP), respectively. After 98 days of trial, all bulls were slaughtered. The result showed that ADY rather than YC improved growth performance and carcass traits of bulls compared to CON. Moreover, both ADY and YC improved beef tenderness and changed blood indexes related to fat metabolism. In conclusion, ADY had more pronounced effect on growth performance of bulls fed high-concentrate diet, and both ADY and YC improved the beef quality by intensive fat metabolism.

[Anaerobic Biodegradability of Perfluorooctanoic Acid (PFOA)].

Perfluorooctanoic acid (PFOA), one of the most typical representatives of perfluoroalkyl surfactants (PASs), has relatively high detection rate and level of pollution, and the accumulation of PFOA in the environment has been a serious threat to human health and security of the whole ecological environment. Therefore, studies on anaerobic biodegradability of PFOA are very important for elucidation of its environmental fate. This study used anaerobic sludge from municipal sewage treatment plant (WWTP) and 5.0 mg·L-1 vitamin B12 (VB12) as catalysts for the degradation of PFOA in the anaerobic environment. The anaerobic biodegradability of PFOA was examined by liquid chromatography tandem mass spectrometry (LC-MS/MS) and ion chromatography while some indictors, such as molar recoveries of PFOA as well as concentrations of fluoride, acetate, 2H-PFOA (F(CF2)6CHFCOOH), and shorter chain (

[Effects of algae and kaolinite particles on the survival of bacteriophage MS2].

In this study, Bacteriophage MS2, Kaolinite and Microcystis aeruginosa were selected as model materials for human enteric viruses, inorganic and organic particles, respectively. The influence of the inorganic (Kaolinite) or organic (Microcystis aeruginosa) particles on the survival of MS2 at different conditions, such as particles concentration, pH, ion concentration and natural organic matter (NOM) were studied. The results showed that Kaolinite had no effect on the survival of phage MS2 except that apparent survival of MS2 increased 1 logarithm in higher hardness water. Microcystis aeruginosa addition reduced 1 logarithm of MS2 survival. However, when the pH value was greater than 4.0 or the concentration of Microcystis aeruginosa was less than 1.0 x 10(6) cells x L(-1), Microcystis aeruginosa addition had no influence on the survival of MS2. In higher hardness water, Microcystis aeruginosa protected MS2 viruses and then increased the survival of MS2. In drinking water, resource containing higher concentration of particles, the survival ability of virus would be enhanced with the increase of the hardness and then elevated the risks of drinking water safety.

[Rapid evaluation of beef quality by NIRS technology].

The aim of the present study was to develop a near-infrared reflectance (NIR) spectroscopy rapid method for evaluation of beef quality. Partial least squares (PLS) prediction model for the physic-chemical characteristics such as moisture, fat, protein, pH, color and WBSF in beef was established with good veracity. One hundred fourteen samples from five different parts of beef carcass (tenderloin, ribeye, topside, shin, striploin) were collected from meat packer after 48 h aging. Spectra were obtained by scanning sample from 950 to 1 650 nm and pretreated the model by MSC, SNV and first derivative. Predictive correlation coefficients of physic-chemical parameters in beef were 0.947 2 (moisture), 0.924 5 (fat), 0.934 6 (protein), 0.620 2 (pH), 0.820 3 (L), 0.864 6 (a*), 0.753 0 (b*) and 0.475 9 (WBSF) respectively. Root mean square errors of calibration (RMSEC) were 0.313 3 (moisture), 0.221 0 (fat), 1.243 2 (protein), 0.744 6 (pH), 1.778 3 (L*), 1.394 2 (a*), 1.763 9 (b*) and 1.0743 (WBSF). They were externally validated with additional 30 beef samples. Statistics showed that there was no significant difference between predicted value and those obtained with conventional laboratory methods. The results showed that NIRS is a rapid, effective technique for evaluating beef quality. The predictions for chemical characteristics gave higher accuracy than prediction for physical characteristics.

[Interaction of ctDNA and EGCG-Cu(II) complex].

The fluorescence spectra, absorption spectra and resonance light scattering (RLS) spectra of EGCG-Cu((II) complex with nucleic acid were studied. Compared with the spectrum of EGCG-Cu(II), the spectrum of EGCG-Cu(II)-DNA system showed the following features: (1) in the fluorescence spectra, the peak did not shift, but the fluorescence intensity was enhanced and was proportional to the concentration of DNA. Under suitable conditions, EGCG-Cu(II) promised to be a probe for detecting DNA; (2) Absorption spectra of EGCG-Cu(II)-DNA system showed hyperchromicity; and (3) RLS of EGCG-Cu(II)-DNA system was enhanced also. A mechanism was suggested that the combination of nucleic acid and EGCG-Cu(II) complex was caused by intercalation and electrostatic force. An intercalation interaction between EGCG-Cu(II) and DNA enhanced the fluorescence intensity. Hyperchromicity of absorption spectra and RLS occurred because of electrostatic force. The effects of acid and ionic strength on fluorescence intensity were also discussed.

Blastocysts produced by nuclear transfer between chicken blastodermal cells and rabbit oocytes.

Interspecies nuclear transfer (INT) has been used as an invaluable tool for studying nucleus-cytoplasm interactions; and it may also be a method for rescuing endangered species whose oocytes are difficult to obtain. In the present study, we investigated interaction of the chicken genome with the rabbit oocyte cytoplasm. When chicken blastodermal cells were transferred into the perivitelline space of rabbit oocytes, 79.3% of the couplets were fused and 9.7% of the fused embryos developed to the blastocyst stage. Both M199 and SOF medium were used for culturing chicken-rabbit cloned embryos; embryo development was arrested at the 8-cell stage obtained in SOF medium, while the rates of morulae and blastocysts were 12.1 and 9.7%, respectively, in M199 medium. Polymerase chain reaction (PCR) amplification of nuclear DNA and karyotype analyses confirmed that genetic material of morulae and blastocysts was derived from the chicken donor cells. Analysis mitochondrial constitution of the chicken-rabbit cloned embryos found that mitochondria, from both donor cells and enucleated oocytes, co-existed. Our results suggest that: (1) chicken genome can coordinate with rabbit oocyte cytoplasm in early embryo development; (2) there may be an 8- to 16-cell stage block for the chicken-rabbit cloned embryos when cultured in vitro; (3) mitochondrial DNA from the chicken donor cells was not eliminated until the blastocyst stage in the chicken-rabbit cloned embryos; (4) factors existing in ooplasm for somatic nucleus reprogramming may be highly conservative.