(1) This in vivo trial was conducted to study the effects of polysaccharide extracts of two mushrooms, Lentinus edodes (LenE) and Tremella fuciformis (TreE), and a herb, Astragalus membranaceus (AstE) on growth performance, and the weights of organs and the gastrointestinal tract (GIT) of broiler chickens. (2) Three extracts (LenE, TreE and AstE) were supplemented at inclusion rates of 0.5, 1, 2, 3 and 4 g/kg from 7 to 14 d of age and compared with an antibiotic treatment group (20 mg/kg, virginiamycin (VRG) as well as a group of non-supplemented birds. (3) Body weight (BW) gain, feed intake and feed conversion ratio (FCR) of the extract-supplemented groups were not significantly different from those of the antibiotic group. Significant effects of type of extract and concentration on growth performance were found from 7 to 28 d of age. Generally, birds fed with LenE showed higher BW gain and lower FCR from 7 to 28 d of age than those fed with TreE and AstE and 2 g/kg LenE was considered the optimal inclusion rate for enhanced broiler growth. However, the extracts had no significant effect on the relative weights of organs and GIT compared with the antibiotic group. (4) The birds fed the extracts showed better growth performance than the non-supplemented birds, but were not significantly different from those fed VRG. Of the three extracts, LenE appeared to be a potential growth promoter. Future studies are needed to investigate whether the extracts can be used as alternatives for antibiotic growth promoters in challenged birds, and to elucidate the mechanisms for potentially enhanced growth performance in poultry.

The aim of this study was to evaluate the influences of season, parity, lactation, udder area, milk yield, and clinical symptoms on bacterial intramammary infection (IMI) in dairy cows. A total of 2,106 mastitis pathogens in 12 species were isolated from 125 dairy farms distributed in 30 different cities in China, and the information about these factors was recorded at the same time. Mastitis pathogens were isolated from 63.43% of the milk samples, whereas Streptococcus agalactiae accounted for 38.61% of all pathogens, followed by Str. dysgalactiae (28.16%), Staphylococcus aureus (19.10%), Escherichia coli (6.90%), and other pathogens (7.23%). According to our investigation, IMI was more common in spring with the isolation rate of pathogens at 81.04%, and lowest in winter (52.34%). Cows were more likely to be infected by environmental pathogens (E. coli or Str. uberis) in summer, in rear quarters and in cows with higher daily milk yield or lower somatic cell count. In addition, Str. dysgalactiae exhibited a higher prevalence with increased parity. Different clinical symptoms of quarters with bacterial IMI were seen in this study, and mastitis pathogens were isolated from healthy quarters.

The aim of this study was to investigate the effects of N-acetylcysteine (NAC) on antibiotic susceptibility of bovine mastitis pathogens including Staphylococcus aureus, Streptococcus dysgalactiae, Escherichia coli, and Streptococcus agalactiae. Minimum inhibitory concentrations (MIC) were tested by the agar-based E-test method. The presence of 10mM NAC reduced the MIC of penicillin and ampicillin but enhanced the MIC of erythromycin and ciprofloxacin for all of the strains. In addition, NAC-mediated modulation of MIC of kanamycin, tetracycline, and vancomycin was diverse, depending on the target bacterial pathogen and antibiotic being used. The results suggest that NAC is an important modulator of antibiotic activity against the major bovine mastitis pathogens.