Meta-analysis of selenium effects on the meat quality of broilers.

The effects of sodium selenite or selenium yeast on the meat quality of broilers were searched in the literature published in the Chinese National Knowledge Infrastructure (CNKI), Wanfang Database, China Science and Technology Journal Database (VIP), PubMed, Web of Science, and Science Direct databases from January 1, 2010 to December 31, 2022. Meta-analysis was performed with Stata software (StataCorp. 2011), and the standardized mean difference (SMD) and its 95% confidence interval (CI) were calculated using a random effects model. Twenty of the identified 846 literature sources, which included 791 broilers, were screened. The meat quality indices considered were shear force, drip loss, cooking loss, water holding capacity (WHC), pH, and color. The source of heterogeneity was studied using sensitivity and subgroup analyses, and publication bias was evaluated using funnel plots. The results showed that the supplementation of selenium in the broiler diet significantly reduced the shear force (SMD = -0.67, 95% CI [-1.12, -0.22], P < 0.05) and drip loss (SMD = -0.84, 95% CI [-1.39, -0.30], P < 0.05) and increased the pH (SMD = 0.38, 95% CI [0.01, 0.75], P < 0.05) of broiler breast muscle; however, it had no significant effects on other indices. Funnel plots revealed a slight publication bias in the shear force and pH of breast muscle but none in the drip loss of breast muscle. The sensitivity analysis showed that the results were stable and reliable. In conclusion, selenium supplementation in broiler feed can improve some indices of broiler meat quality, and its inclusion in broiler diets is recommended, in conjunction with other minerals, which is of great significance to improve the quality, preservation time and economic benefits of chicken products.

Meta-Analysis of the Effects of Organic Chromium Supplementation on the Growth Performance and Carcass Quality of Weaned and Growing-Finishing Pigs.

Many factors influence the effects of exogenous organic chromium (EO-Cr) on the growth performance and carcass qualities of weaned and growing-finishing pigs, such as pig growth stages, types of EO-Cr, period of supplementation, and farm management. However, it is challenging to comprehensively consider all factors in one study. To solve this problem, we searched all relative literature published from 1 January 2000 to 1 January 2023, to systematically analyze and review the effects of EO-Cr on pig growth performance and carcass qualities via meta-analysis. Thirty-five papers were filtered and analyzed, which involved 4366 pigs. The results showed that, for weaned piglets, EO-Cr diets significantly increased the average daily gain (ADG, p < 0.001) and average daily feed intake (ADFI, p = 0.022) but reduced the feed-gain ratio (p = 0.004). In addition, for growing-finishing pigs, EO-Cr supplementation significantly increased the ADG (p < 0.001), carcass lean ratio (p = 0.020), and loin muscle area (p < 0.001), but had no significant effect on the ADFI (p = 0.071), feed-gain ratio (p = 0.692), dressing percent (p = 0.989), or back fat thickness (p = 0.142). Moreover, the effect of EO-Cr was greater in weaned piglets than in growing-finishing pigs. In terms of the dose effect of the supplement, chromium nicotinate is the most suitable EO-Cr type for weaned piglets with an optimal dosage range of 0.125-0.150 mg/kg. On the other hand, chromium picolinate is the most suitable EO-Cr type for growing-finishing pigs with an optimal dosage range of 0.250-0.300 mg/kg. In conclusion, EO-Cr supplementation is beneficial for enhancing the growth performance and carcass qualities of both weaned and growing-finishing pigs.

Vitamin K2 supplementation improves impaired glycemic homeostasis and insulin sensitivity for type 2 diabetes through gut microbiome and fecal metabolites.

BACKGROUND: There is insufficient evidence for the ability of vitamin K2 to improve type 2 diabetes mellitus symptoms by regulating gut microbial composition. Herein, we aimed to demonstrate the key role of the gut microbiota in the improvement of impaired glycemic homeostasis and insulin sensitivity by vitamin K2 intervention. METHODS: We first performed a 6-month RCT on 60 T2DM participants with or without MK-7 (a natural form of vitamin K2) intervention. In addition, we conducted a transplantation of the MK-7-regulated microbiota in diet-induced obesity mice for 4 weeks. 16S rRNA sequencing, fecal metabolomics, and transcriptomics in both study phases were used to clarify the potential mechanism. RESULTS: After MK-7 intervention, we observed notable 13.4%, 28.3%, and 7.4% reductions in fasting serum glucose (P = 0.048), insulin (P = 0.005), and HbA1c levels (P = 0.019) in type 2 diabetes participants and significant glucose tolerance improvement in diet-induced obesity mice (P = 0.005). Moreover, increased concentrations of secondary bile acids (lithocholic and taurodeoxycholic acid) and short-chain fatty acids (acetic acid, butyric acid, and valeric acid) were found in human and mouse feces accompanied by an increased abundance of the genera that are responsible for the biosynthesis of these metabolites. Finally, we found that 4 weeks of fecal microbiota transplantation significantly improved glucose tolerance in diet-induced obesity mice by activating colon bile acid receptors, improving host immune-inflammatory responses, and increasing circulating GLP-1 concentrations. CONCLUSIONS: Our gut-derived findings provide evidence for a regulatory role of vitamin K2 on glycemic homeostasis, which may further facilitate the clinical implementation of vitamin K2 intervention for diabetes management. TRIAL REGISTRATION: The study was registered at https://www.chictr.org.cn (ChiCTR1800019663).

Meta-Analysis of Rumen-Protected Methionine in Milk Production and Composition of Dairy Cows.

This study aims to evaluate the influence of rumen-protected methionine (RPM) on the milk yield and milk compositions of dairy cows by employing a meta-analysis method. The articles in the publication databases between January 2010 and January 2022 which reported on various concentrations of RPM supplements in dairy cow diets and then monitored the milk yield and milk compositions were searched. A total of 14 studies were included, covering 27 treatments with a total of 623 dairy cows. Comprehensive Meta-Analysis V3 was used for statistical analysis, the forest map was drawn by the standard mean difference (SMD) with a 95% confidence interval (95% CI), and the SMD was calculated by a random effect model. The dose effect curve was drawn by fitting the SMD and RPM dose of each study to explore the optimal dosage of RPM. Compared with the basal diet, the RPM supplement significantly increased the percentages of milk fat (SMD (95% CI): 1.017% [0.388, 1.646]) and milk protein (SMD (95% CI): 0.884 [0.392, 1.377]). However, the milk yield (SMD (95% CI): 0.227 kg/d [-0.193, 0.647]) and lactose concentration (SMD (95% CI): 0.240% [-0.540, 1.020]) were not affected. The subgroup analysis found that the effect of the RPM supplement on the milk fat and milk protein was greater in the high-protein feed than in the low-protein feed. Multiple regression analysis showed that feeding RPM significantly improved the milk yield and milk protein percentage of dairy cows. The results of the dose-effect analysis show that the optimal range for the RPM was 7.5-12.5 g/d. RPM supplements in a dairy diet can improve the milk protein percentages and milk fat percentages of dairy cows.

Analysis of Tryptophan and Its Main Metabolite Kynurenine and the Risk of Multiple Cancers Based on the Bidirectional Mendelian Randomization Analysis.

Background: Tryptophan and its metabolites have been found related to various cancers, but the direction of this relationship is still unclear. The purpose of this study is to explore the causal associations of tryptophan and kynurenine with multiple cancers based on the bidirectional Mendelian randomization analysis. Methods: The data of a genome-wide association study meta-analysis on 7,824 individuals was used to explore the genetic variants strongly associated with tryptophan and kynurenine. Genetic instruments of four specific cancers were obtained from available summary-level data of 323,590 European participants. Bidirectional Mendelian randomization analysis was conducted to examine possible causality. Sensitivity analysis was performed to test heterogeneity and horizontal pleiotropy. COX regression analysis was conducted to explore associations between dietary tryptophan and cancer mortality in NHANES 1988-1994. Results: No evidence of any causal association of tryptophan and kynurenine with the risk of four specific cancers was shown, except for weak correlations were suggested between lung or prostate cancer and kynurenine. Multiple sensitivity analyses generated similar results. Our findings from COX regression analysis were consistent with the above results. Conclusions: Our study did not find any causal relationship between tryptophan and kynurenine and multiple cancers. The associations still need further research.

The Association and Mediating Biomarkers of Serum Retinol in Influencing the Development of Type 2 Diabetes: A Prospective Cohort Study in Middle-Aged and Elderly Population.

The aims of this research are to elucidate whether serum retinol is associated with type 2 diabetes and to explore the underlying mechanisms of the association in a prospective cohort study. A total of 3,526 diabetes-free participants aged 40 years or older were enrolled at baseline in 2010-2012. Multivariable logistic regression was adopted to evaluate the associations of serum retinol and dietary vitamin A (VA) intake with type 2 diabetes. Mediation analyses were used to reveal potential mediators in their associations. After a mean follow-up of 5.3 years, 280 incident cases of type 2 diabetes occurred. Serum retinol was positively associated with the incidence of type 2 diabetes. The multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for type 2 diabetes from the bottom to the top quintile of serum retinol were 1, 1.878 (1.202, 2.936), 2.110 (1.364, 3.263), 1.614 (1.027, 2.538), and 2.134 (1.377, 3.306) (p-trend = 0.009), respectively. Mediation analysis showed that increased homeostasis model assessment - insulin resistance HOMA-IR, triglycerides (TG), and serum xanthine oxidase (XO) activity could account for 8.5, 14.7, and 12.1% of the total effects of serum retinol on type 2 diabetes, respectively. Serum retinol concentration was not significantly associated with dietary VA intake (r = -0.010, p = 0.570). In addition, no significant relationship was observed between dietary VA intake and the risk of type 2 diabetes. Overall, elevated serum retinol might increase the risk of type 2 diabetes which is mainly mediated by increased insulin resistance, TG, or serum XO activity.

The associations of circulating common and uncommon polyunsaturated fatty acids and modification effects on dietary quality with all-cause and disease-specific mortality in NHANES 2003-2004 and 2011-2012.

BACKGROUND: Associations of dietary or supplementary intake of several unsaturated fatty acids and mortality have been widely studied but the results were still hitherto inconsistent or limited. It is still need to explore the effects of these fatty acids by using the objective biomarkers. OBJECTIVE: We aimed to investigate the relevancy of several serum n-3 and n-6 fatty acids with all-cause and disease-specific mortality to confirm their health effects and effects on the associations between dietary quality and all-cause mortality. METHODS: A total of 4132 people from NHANES 2003-2004 and 2011-2012 and the mortality information was confirmed from the NDI. CPH models adjusted for known risk factors were conducted to explore the associations between circulating n-3 and n-6 fatty acids and all-cause or CVD or cancer mortality under complex sampling. We further evaluated their effects on association between dietary quality and all-cause mortality. RESULTS: A total of 437 deaths occurred during the mean follow-up of 83.34 months, including 157 CVD death and 100 cancer death. Serum LA, ALA, EPA and DHA were associated with all-cause mortality (HR in quintile5: LA:0.584, 95%CI: 0.387-0.882, Ptrend = 0.011; ALA:0.626, 95%CI: 0.432-0.907, Ptrend = 0.008; EPA:0.535, 95%CI: 0.375-0.764, Ptrend = 0.001; DHA:0.669, 95%CI: 0.468-0.955, Ptrend = 0.031). Additionally, serum EPA and ALA were respectively related to CVD and cancer mortality (Q5 HR: EPA:0.450, 95%CI: 0.23-0.854, Ptrend = 0.009; ALA:0.387, 95%CI: 0.167-0.900, Ptrend = 0.022). Serum AA, GLA, DGLA and SDA were not associated with any risk of mortality. The effect on all-cause mortality of the lower AHEI scores can be improved by adherence to a higher serum LA, EPA and DHA (in the lowest AHEI strata, LA in tertile3 compared to tertile1 HR:0.596, 95%CI: 0.366-0.970; EPA:0.660, 95%CI: 0.454-0.959; DHA:0.666, 95%CI; 0.444-1.000). CONCLUSIONS: Our results support the recent dietary recommendations to increase the intake of plant-derived and marine-derived n-6 and n-3 to improve the ability of primary and secondary prevention.

Evaluation of liver tissue extraction protocol for untargeted metabolomics analysis by ultra-high-performance liquid chromatography/tandem mass spectrometry.

The aim of the untargeted metabolomics study is to obtain a global metabolome coverage from biological samples. Therefore, a comprehensive and systematic protocol for tissue metabolite extraction is highly desirable. In this study, we evaluated a comprehensive liver pretreatment strategy based on ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry to obtain more metabolites using four different protocols. These protocols included (A) methanol protein precipitation, (B) two-step extraction of dichloromethane-methanol followed by methanol-water, (C) two-step extraction of methyl tert-butyl ether-methanol followed by methanol-water, and (D) two-step extraction of isopropanol-methanol followed by methanol-water. Our results showed that protocol D was superior to the others due to more extracted features, annotated metabolites, and better reproducibility. And then, the stability and extraction sequence of protocol D were evaluated. The results showed that extraction with isopropanol-methanol followed by methanol-water was the optimum preparation sequence, which offered higher extraction efficiency, satisfactory repeatability, and acceptable stability. Furthermore, the optimal protocol was successfully applied by liver samples of rats after high-fat intervention. In summary, our protocol enabled a comprehensive and systematic evaluation of liver pretreatment to obtain more medium-polar and nonpolar metabolites and was suitable for high-throughput metabolomics analysis.

Effects of inorganic and organic selenium sources on the growth performance of broilers in China: A meta-analysis.

This study aims to investigate the effects of different selenium (Se) sources on the growth performance of Chinese broilers and provide a scientific rationale for adding Se additives to broiler feed. Relevant studies that meet standard inclusion criteria were identified and extracted from China National Knowledge Infrastructure and Wanfang and Chinese Scientific Journal (VIP) databases. A total of 9 studies with 539 subjects were included. A meta-analysis was performed with STATA15.0 to estimate the combined standardized mean difference (SMD) with a 95% confidence interval (95% CI). Heterogeneity test of articles was examined by Q-test, and the results showed that P values of feed conversion ratio, average daily gain (ADG), and average daily intake were all less than 0.05, suggesting a strong heterogeneity among the selected literature. Therefore, the random effect model is selected to calculate the SMD of the three indexes. The combined SMDs (95% CI) of feed:gain, ADG, and average daily feed intake (ADFI) were -0.39 (-1.03, 0.25), 0.26 (-0.29, 0.81), and -1.45 (-3.09, 0.20), respectively, and the P values were all less than 0.05. This study shows that the absolute differences in the growth performance (feed:gain, ADG, and ADFI) of broilers fed with either organic or inorganic Se supplements at the same dose were quite small. The P values of Egger's test were 0.770, 0.089, and 0.426, respectively, for the above indexes, showing no significant publication bias. Sensitivity analysis ensured the stability and reliability of the results. In summary, the effects of organic and inorganic Se in feed on the growth performance of broilers are statistically equal.

Effect of Multiple-Nutrient Supplement on Muscle Damage, Liver, and Kidney Function After Exercising Under Heat: Based on a Pilot Study and a Randomised Controlled Trial.

Objective: This study explored the effect of multiple-nutrient supplementation on muscle damage and liver and kidney function after vigorous exercise under heat. Methods: After an initial pilot trial comprising 89 male participants, 85 participants were recruited and assigned into three groups: a multiple-nutrient (M) group, a glucose (G) group, and a water (W) group. Multiple-nutrient supplements contain glucose, fructose, maltose, sodium, potassium, vitamin B1, vitamin B2, vitamin C, vitamin K, and taurine. Participants were organised to take a 3-km running test (wet-bulb globe temperature 32°C) after a short-term (7 days) supplement. Blood samples were obtained to detect biochemical parameters [glucose (GLU), aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), uric acid (UA), creatinine (Cr), creatine kinase (CK), lactate dehydrogenase (LDH), and lactic acid], inflammation factors [interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α)], and oxidative stress biomarkers [superoxide dismutase (SOD) and 8-iso-prostaglandin F (2alpha) (8-iso-PGF2α)]. Results: In the pilot trial, BUN decreased significantly in the M and G groups immediately after the running test. AST, Cr, and UA were significantly reduced 24 h after the running test with single-shot multiple-nutrient supplementation. In the short-term trial, multiple nutrients further prevented the elevation of CK (p = 0.045) and LDH (p = 0.033) levels 24 h after strenuous exercise. Moreover, we found that multiple nutrients significantly reduced IL-6 (p = 0.001) and TNF-α (p = 0.015) elevation immediately after exercise. Simultaneously, SOD elevation was significantly higher in the M group immediately after exercising than in the other two groups (p = 0.033). 8-iso-PGF2α was reduced in the M group 24 h after exercise (p = 0.036). Conclusions: This study found that multiple-nutrient supplementation promoted the recovery of muscle damage and decreased liver and kidney function caused by strenuous exercise in a hot environment, probably through the inhibition of secondary damage induced by increased inflammatory reactions and oxidative stress. In this respect, the current study has important implications for the strategy of nutritional support to accelerate recovery and potentially prevent heat-related illness. This study was prospectively registered on clinicaltrials.gov on June 21, 2019 (ID: ChiCTR1900023988).

MicroRNA-29a-3p Reduces TNFα-Induced Endothelial Dysfunction by Targeting Tumor Necrosis Factor Receptor 1.

miR-29a-3p has been shown to be associated with cardiovascular diseases; however, the effect of miR-29a-3p on endothelial dysfunction is unclear. This study aimed to reveal the effects and mechanisms of miR-29a-3p on endothelial dysfunction. The levels of vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), and E-selectin were determined by real-time PCR and immunofluorescence staining to reveal the degree of tumor necrosis factor alpha (TNFα)-induced endothelial dysfunction. A luciferase activity assay and cell transfection with a miR-29a-3p mimic or an inhibitor were used to reveal the underlying mechanisms of miR-29a-3p action. Furthermore, the effects of miR-29a-3p on endothelial dysfunction were assessed in C57BL/6 mice injected with TNFα and/or a miR-29a-3p agomir. The results showed that the expression of TNFα-induced adhesion molecules in vascular endothelial cells (EA.hy926 cells, human aortic endothelial cells [HAECs], and primary human umbilical vein endothelial cells [pHUVECs]) and smooth muscle cells (human umbilical vein smooth muscle cells [HUVSMCs]) was significantly decreased following transfection with miR-29a-3p. This effect was reversed by cotransfection with a miR-29a-3p inhibitor. As a key target of miR-29a-3p, tumor necrosis factor receptor 1 mediated the effect of miR-29a-3p. Moreover, miR-29a-3p decreased the plasma levels of TNFα-induced VCAM-1 (32.62%), ICAM-1 (38.22%), and E-selectin (39.32%) in vivo. These data indicate that miR-29a-3p plays a protective role in TNFα-induced endothelial dysfunction, suggesting that miR-29a-3p is a novel target for the prevention and treatment of atherosclerosis.

Bilateral Peripheral Facial Paralysis Combined with HIV Meningitis During Acute HIV-1 Infection: A Case Report.

Here we reported a Chinese case of bilateral peripheral facial paralysis (PFP) in human immunodeficiency virusc (HIV) infected population. A 38-year-old homosexual male patient was referred to our hospital for bilateral facial paralysis. 21 days prior to admission he had developed high fever, chills, headache, fatigue, general malaise, nausea and vomiting. Neurological examination revealed bilateral ptosis of lower lip and cheeks, as well as failure of bilateral eyes closure. Analysis of cerebrospinal fluid (CSF) revealed pleocytosis, a marked rise of micro total protein and a marked rise of intrathecal lgG synthesis. The result of HIV-1 serology was positive by ELISA and that was confirmed by western blot. His CD4 + cell count was 180 cells/mm 3. HIV-1 viral load in CSF was almost 10 times higher than that in plasma. The patient's condition improved steadily and experienced complete resolution of bilateral PFP after 2 months.

Eighteen-year alcohol consumption trajectories and their association with risk of type 2 diabetes and its related factors: the China Health and Nutrition Survey.

AIMS/HYPOTHESIS: Alcohol consumption levels frequently fluctuate over the life course, but studies examining the association between alcohol consumption trajectories and type 2 diabetes are limited. This study aims to investigate the association of alcohol consumption trajectories with the risk of type 2 diabetes and its related factors. METHODS: Weighted longitudinal data were obtained for 12,186 adults who completed a questionnaire about alcohol consumption and diabetes status as part of the China Health and Nutrition Survey (1993-2011). Participants were designated into subgroups based on alcohol consumption trajectory, and subgroup analyses included 5436 individuals who were tested for specified diabetes-related factors. Light alcohol consumption was defined as fewer than seven standard drinks per week; moderate as 7-21 drinks per week; and heavy as more than 21 drinks per week. Latent class trajectory modelling was used to identify different alcohol consumption trajectories by sex. Multivariate Cox regression models and general linear regression models were used to assess association of trajectories with type 2 diabetes and its related factors. RESULTS: Compared with stable abstainers (individuals who never drank alcohol), two trajectories in men showing reduction to moderate or light levels after heavy alcohol consumption during early adulthood were significantly associated with increased risk of type 2 diabetes (HR 1.66 [95% CI 1.18, 2.33]; HR 1.93 [95% CI 1.01, 3.70]), while no significant association between trajectories and risk of type 2 diabetes was observed in women (p for trend = 0.404). Triacylglycerol, HDL-cholesterol (HDL-C), uric acid and high sensitivity C-reactive protein were significantly higher in these two trajectories than other trajectories in men (all p < 0.05), while only HDL-C showed significant increasing trends in women. Trajectories showing light-stable, or increase to moderate, levels were not associated with reduced risk of type 2 diabetes. CONCLUSIONS: This study indicated that heavy alcohol consumption in early adulthood is significantly associated with increased risk of type 2 diabetes and higher levels of its biomarkers throughout adulthood in men. Gradually reducing alcohol consumption to moderate levels may not make a difference, which demonstrates the importance of alcohol intervention strategies in early adulthood. Although association between alcohol consumption and increased HDL-C levels has been observed, the results of this study did not support the hypothesis regarding the protective effect of moderate alcohol consumption on risk of type 2 diabetes in the Asian population. DATA AVAILABILITY: Data from China Health and Nutrition Survey was used in this study, which can be downloaded at www.cpc.unc.edu/projects/china .

Effect of straw enriched environment on behaviors of nursery piglets reared in the farrowing pens.

The aim of the present study was to study the effects of straw enriched environment on behaviors of nursery piglets reared in the farrowing pens. Fourteen litters (Large White x Landrace) weaned at 35 days of age were reared in the modified farrowing pens, flatdecks (F) or straw enriched pens (P), until 70 days of age. The behavior was observed from 7 to 10 weeks of age. Results showed that straw enriched pens significantly increased walking, total exploring and active behavior, reduced lying and exploring behavior direct to pen, but not that direct to penmates. Meanwhile, in wk8-wk10, the number of fighting piglets in P was significantly more than that in F. With increasing age, piglets exploring in total or direct to pen, and active piglets decreased gradually in F. In P, piglets exploring in total or that direct to straw decreased, and reached a trough in wk9, then rose up. Lying piglets in F increased with age while that in P increased only at 9 or 10 weeks of age. Walking piglets decreased significantly with age in both environments. The number of fighting piglets in F was a maximum in wk7 while it in P was fewer in wk7 or wk8. Furthermore, the activity of piglets in F was at peak during 08:00-10:00 hr and reached a trough during 11:00-13:00 hr. In P, refreshed straw kept piglets at a more active state during morning, shortened the activities trough at noon, and showed high activity in the afternoon. In conclusion, present straw enriched pen can prevent fighting, increase total exploring, reduce exploring direct to pen, and even affect the rhythm of behavior. It is applicable for improving welfare of nursery piglets.

Survey of mycotic mastitis in dairy cows from Heilongjiang Province, China.

A survey of the prevalence rate, pathogenic subspecies, and risk factors of mycotic mastitis in dairy cows from Heilongjiang Province, China, was conducted. Milk samples from 412 cows with chronic mastitis were collected and cultured on 8 % sheep blood agar, MacConkey agar, and Sabouraud agar with chloramphenicol. Counting of the morphologically distinct colonies was performed, as well as the isolation and identification of organisms through phenotypical and physiological criteria. Four hundred seventy-eight aerobic microorganisms were isolated. Yeasts and yeast-like fungi 35.6 % (170/478) and bacteria 64.4 % (308/478) were isolated. The fungal isolates were identified as Candida (79.4 %), Trichosporon (5.9 %), Aspergillus (7.1 %), Cryptococcus (2.4 %), and Rhodotorula (4.1 %). More than ten species of yeast were isolated including Candida krusei 50/135 (37 %), Candida rugosa 16/135 (11.9 %), and Candida lusitaniae 15/135 (11.1 %). A higher positivity (18.5 and 56.3 %) (P ≤0.05) was observed in cows from environmental temperatures of 0-15 and 15-35 °C than those at <0 °C and in cows affected by the disease for >45 and 30-45 days compared with cows suffering 10-30 days. Meanwhile, a statistically significant difference (44.9 vs. 31.4 %) (P ≤0.05) was observed under extensive raising systems vs. intensive raising systems. It appears that Candida is a major pathogen of mycotic mastitis of dairy cows. Extensive raising system, high environmental temperature (15-35 °C), and the duration of the disease (>30 days) were important risk factors of the incidence of mycotic mastitis. Here, we provide a theoretical foundation for research into preventing and treating mycotic mastitis of dairy cows in China.

Effects of Feeding Corn-lablab Bean Mixture Silages on Nutrient Apparent Digestibility and Performance of Dairy Cows.

This study estimated the fermentation characteristics and nutrient value of corn-lablab bean mixture silages relative to corn silages. The effects of feeding corn-lablab bean mixture silages on nutrient apparent digestibility and milk production of dairy cows in northern China were also investigated. Three ruminally cannulated Holstein cows were used to determine the ruminal digestion kinetics and ruminal nutrient degradability of corn silage and corn-lablab bean mixture silages. Sixty lactating Holstein cows were randomly divided into two groups of 30 cows each. Two diets were formulated with a 59:41 forage: concentrate ratio. Corn silage and corn-lablab bean mixture silages constituted 39.3% of the forage in each diet, with Chinese wildrye hay constituting the remaining 60.7%. Corn-lablab bean mixture silages had higher lactic acid, acetic acid, dry matter (DM), crude protein (CP), ash, Ca, ether extract concentrations and ruminal nutrient degradability than monoculture corn silage (p<0.05). Neutral detergent fiber (NDF) and acid detergent fiber (ADF) concentrations of corn-lablab bean mixture silages were lower than those of corn silage (p<0.05). The digestibility of DM, CP, NDF, and ADF for cows fed corn-lablab bean mixture silages was higher than for those fed corn silage (p<0.05). Feeding corn-lablab bean mixture silages increased milk yield and milk protein of dairy cows when compared with feeding corn silage (p<0.05). The economic benefit for cow fed corn-lablab bean mixture silages was 8.43 yuan/day/cow higher than that for that fed corn silage. In conclusion, corn-lablab bean mixture improved the fermentation characteristics and nutrient value of silage compared with monoculture corn. In this study, feeding corn-lablab bean mixture silages increased milk yield, milk protein and nutrient apparent digestibility of dairy cows compared with corn silage in northern China.

[Analysis of genetic variations in different goose breeds using microsatellite markers].

The genetic diversity of six goose breeds (White Goose, Zi Goose, Huoyan Goose, Wanxi Goose, Rhin, Landoise) was analyzed using microsatellite markers. Heterozygosity(H), polymorphism information content (PIC) and genetic distances were calculated for each breed based on the allele frequency. Results showed that 7 microsatellite sites were highly polymorphic, and could be used as effective markers for analysis of genetic relationship among different goose breeds. The mean heterozygosityies of were between 0.6617 (Rhin) and 0.8814 (Zi goose), among six goose breeds, the lowest was Rhin goose (0.6617) and the highest was Zi goose (0.8814). The range of mean PIC was between 0.6145 and 0.7814, which was in the similar range as the mean heterozygosities. Based on the UPGMA cluster analysis results, six goose breeds were grouped into classes, White, Zi, Huoyan and Wanxi Goose in one class, and the foreign breeds of Rhin and Landoise goose in another class. These results indicated that the dendrogram obtain from genetic distance could be used to correctly reflect the phylogenetic relationship among the six goose breeds, suggesting that microsatellite DNA marker is a useful tool to determine the genetic diversity in closely related breeds.