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Liu G.,Chinese Academy of Agricultural Sciences | Liu G.,Shanghai Bright Holstan Co. | Zhang C.,Chinese Academy of Agricultural Sciences | Zhang C.,Yangzhou University | And 8 more authors.
Livestock Science | Year: 2010

In this study, canonical correlation analysis was applied to estimate the relationships of DHI data with milk Ig (IgG1, IgA, and IgM) and Lf concentrations. Specifically, we evaluated the relationships between two groups of variables: milk IgG1, IgA, IgM and Lf concentration as variables (y) and lactation number, stage of lactation, daily milk production, milk fat, protein, lactose, milk total solids and somatic cell score (SCS) as variables (x). The results indicated that four canonical variables were identified. The canonical correlations of the first and second pairs of canonical variables were 0.662 and 0.469 respectively, which were highly significant and accounted for 91.6% of the variability observed in the data. Stage of lactation, daily milk production, milk protein and SCS were the significant factors affecting milk Lf concentration in both canonical correlations and multiple correlation analysis, and lactation number was the significant factors affecting milk IgG1 concentration. The first standardized canonical variation combination could be regarded as a predictable measure of Lf concentration and the second as a predictor of IgG1 level. These results indicated that dairy producers could select cows for increased Ig and Lf production using DHI data directly. Crown Copyright © 2009.

Sun P.,Chinese Academy of Agricultural Sciences | Sun P.,Supervision Center Beijing | Wang J.,Chinese Academy of Agricultural Sciences | Jiang Y.,Chinese Academy of Agricultural Sciences
Food Chemistry | Year: 2010

Probiotics exert health benefits on human and animals when administered in adequate amounts. The objective of this study was to assess the effects of Enterococcus faecium (SF68) on intestinal colonisation and immune function of BALB/c mice. Six-week-old female BALB/c mice were orally administered with E. faecium (SF68). Results showed that the total anaerobe and lactobacilli in the faeces increased (P < 0.05), while the number of faecal enterobacteria decreased (P < 0.05) in E. faecium-fed mice. Furthermore, supplementation of E. faecium (SF68) increased the percentage of double positive (DP) cells in peripheral blood, the concentration of plasma IgG, and the levels of interleukin-4 (IL-4), interleukin-6 (IL-6) and interferon-γ (IFN-γ) in splenocytes of the mice (P < 0.05). This study demonstrated that E. faecium SF68 affects the intestinal microbial flora and modulates the immune responses, which indicates a viable probiotic characteristic of E. faecium SF68 in modification of immune function. © 2010 Elsevier Ltd. All rights reserved.

Sun P.,Chinese Academy of Agricultural Sciences | Sun P.,Supervision Center Beijing | Wang J.Q.,Chinese Academy of Agricultural Sciences | Shen J.S.,Chinese Academy of Agricultural Sciences | And 2 more authors.
Journal of Dairy Science | Year: 2011

Melamine (1,3,5-triazine-2,4,6-triamine) may be degraded into cyanuric acid and some other compounds by rumen microorganisms. This study was conducted to assess the transfer of melamine and cyanuric acid in to milk and tissues by dairy cows fed different doses of melamine. Forty mid-lactation dairy cows (157±43 d in milk, 20.8±1.4kg of milk/d) were divided into 4 groups (n=10/group) using a completely randomized design. The groups were fed the following amounts of melamine (purity≥99.5%) at 0 (control), 300 [treatment (Trt) 1], 500 (Trt 2), and 1,000 (Trt 3) mg/d per cow, respectively. The trial lasted for 18 d (12-d feeding period, followed by a 6-d clearance period). Milk samples were collected from the 4 groups on d 1, 2, 3, 4, 8, 12, 13, 14, 15, and 18, and analyzed for melamine and cyanuric acid. On d 13, 3 cows from Trt 2 and Trt 3 were randomly selected and slaughtered; tissue samples including kidney, liver, mammary, bladder, gluteus medius, and longissimus dorsi were collected for melamine and cyanuric acid analyses. Milk and tissue samples were analyzed for melamine and cyanuric acid using a simultaneous liquid chromatography tandem mass spectrometry procedure. Neither melamine nor cyanuric acid was detected in concentrated feed that was being fed to the cows. In melamine-treated groups, milk melamine concentration increased quickly and reached a stable level by d 4 and was at similar levels on d 8 and 12 after the first administration of melamine. Milk melamine levels in treated groups were 0.18, 0.27, and 0.50mg/L for Trt 1, Trt 2, and Trt 3, respectively, and were highly correlated (R2=0.91) with melamine dosing levels. No cyanuric acid was detected in any of the milk collected from the various groups. Melamine residue levels in tissues of Trt 3 were about 2-fold higher than that in Trt 2, with the highest concentration being found in kidney. No differences in cyanuric acid levels in tissues were found between Trt 3 and Trt 2. Liver, kidney, and bladder tissues were found to contain the highest cyanuric acid levels. This study shows a relationship between dietary melamine levels and cyanuric acid levels found in tissues, which might be the result of melamine being converted to cyanuric acid by microorganisms in the rumen. © 2011 American Dairy Science Association.

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