[Research progress on the establishment and application of the hypoxia cell model in varicocele-associated male infertility].

Varicocele (VC) is considered as one of the primary causes of male infertility, and the pathogenesis and treatment measures for VC-associated male infertility (VMI) are being explored continuously. The construction of an appropriate in vitro model for VMI is of significant importance for the study of this disease. And the model of testis cell hypoxia, with its relatively stable experimental conditions, short cycle, good repeatability and few influencing factors, has been primarily applied in cellular experimental researches on VMI. This article reviews the selection of cell lines, use of modeling methods, and evaluation of cell models in recent VMI-related cellular experiments, aiming to provide some reference for scholars in their studies of the pathogenesis and treatment of VMI using the in vitro experimental model.

Lactation performance and rumen fermentation in dairy cows fed a diet with alfalfa hay replaced by corn stover and supplemented with molasses.

OBJECTIVE: The objective of current study was to investigate the lactation performance and rumen fermentation characteristics of dairy cows fed a diet with alfalfa hay replaced by corn stover but supplemented with molasses. METHODS: Sixteen Holstein cows in mid-lactation were randomly assigned to 1 of 2 dietary treatments: i) alfalfa based diet (AH), and ii) corn stover based diet supplemented with molasses (CSM). The experiment was conducted according to a 2×2 crossover design with 22-d each period, consisting of 17 d for adaptation and 5 d for data and samples collection. RESULTS: Dry matter intake and milk yield were higher for cows fed AH than CSM (p<0.01). Milk protein content and nitrogen conversion were higher (p<0.05), while milk urea nitrogen was lower (p<0.01) for cows fed AH than CSM-fed cows. Contents of milk total solids, fat and lactose were not different between two groups (p>0.10). Total rumen volatile fatty acid concentration tended to be higher (p = 0.06) for cows fed AH than CSM-fed cows. Molar proportion of acetate was lower (p = 0.04), but valerate was higher (p = 0.02) in cows fed AH than CSM-fed cows. Rumen concentration of propionate, and isobutyrate, and ratio of acetate to propionate tended to be different (p<0.10) between two groups. The feed cost per kilogram of milk was lower in CSM than AH (p<0.01). No differences were found in feed efficiency and most plasma parameters tested (p>0.10). CONCLUSION: In comparison with AH diet, CSM diet could be fed to dairy cows without negative effect on feed efficiency, ruminal fermentation, but economically beneficial, indicating that CSM could be an alternative choice for dairy farms instead of AH to feed mid-lactation dairy cows.