Effects of selenium yeast on rumen fermentation, lactation performance and feed digestibilities in lactating dairy cows - PowerPoint PPT Presentation

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Effects of selenium yeast on rumen fermentation, lactation performance and feed digestibilities in lactating dairy cows

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Title: Effects of selenium yeast on rumen fermentation, lactation performance and feed digestibilities in lactating dairy cows Author: boko Last modified by – PowerPoint PPT presentation

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Title: Effects of selenium yeast on rumen fermentation, lactation performance and feed digestibilities in lactating dairy cows


1
Effects of selenium yeast on rumen fermentation,
lactation performance andfeed digestibilities
in lactating dairy cows
  • C. Wang A, Q. Liu A,?, W.Z. Yang A,B, Q. Dong A,
    X.M. Yang C, D.C. He C, P. Zhang D, (July 2009)
  • Presented by AbouBaker Elhajee

2
Introduction
  • Selenium is recognized as an essential trace
    element.
  • It is a powerful catalytic element constituting
  • the active centre of about 20 selenoproteins
  • Selenium displays metabolic function related to
    maintenance of integrity and defenses of the
    organism.

3
Supplementation
  • Se content within plants can be extremely
    variable. Consequently, selenium in diets can be
    deficient.
  • Se supplementation may be required to improve the
    performance and health of dairy , enhance the
    nutritional quality of the milk product

4
Forms
  • Inorganic Se (i.e., sodium selenite or selenate)
    and organic Se (i.e., selenium-yeast SY).
  • Most studies reported that organic Se is less
    toxic than inorganic Se, Bioavailability of SY
    higher than inorganic Se sources , leads to
    higher Se content in milk.

5
  • Results of SY on milk yields and milk components
    from literature are inconclusive.
  • These contrasting results could be due to
    differences in the composition of the diet and/or
    to the dose of SY and lactation period of dairy
    cow (Juniper et al., 2006)..

6
Objectives
  • The aim of this work was to evaluate the effects
    of SY supplemented dose on rumen fermentation,
    lactation performance, milk selenium content and
    feed digestion in mid-lactation dairy cows.

7
Materials and methods
  • Animals and experimental design.
  • - Twenty-eight Holstein dairy cows were
    assigned to a replicated 44 Latin square.
  • - Treatments were control, LSY, MSY and HSY
    with 0,150, 300, and 450 mg SY per kg of (DM)
    respectively.
  • - Experimental periods were 45 days with 30
    days of adaptation and 15 days of sampling.

8
  • Dry matter intake, milk yield, milk components
    and milk selenium.
  • - Feed offered and refused were measured daily
    for each cow (DM intake).
  • - Milk yields were recorded daily.
  • - Milk Samples for analysis of
    milkcomposition and measure milk Se
    concentration.

9
  • Rumen pH and fermentation characteristics.
  • - were measured on two consecutive days at the
    beginning (days 1 and 2) and end (days 44 and 45)
    of each period. At 0, 3, 6, and 9 h after the
    morning feeding, samples (about 100 mL) of rumen
    fluid were obtained anaerobically via the
    esophagus using a stomach tube
  • - Ruminal pH was immediately measured using an
    electric pH meter

10
  • Rumen pH and fermentation characteristics.
  • -Samples were then strained through four layers
    of cheesecloth. Five milliliters of filtrate was
    preserved by adding 1 mL of 250 g/L (w/v)
    meta-phosphoric acid to determine acetate,
    propionate and butyrate, and 5 mL of filtrate was
    preserved by adding 1 mL of 20 g/L (w/v) H2SO4 to
    determine NH3.

11
  • Apparent digestibility in the total tract
  • -Cows were dosed via the esophagus with 5 g of
    chromic oxide per day per cow in two equal
    proportions at 0700 and 1900 h from days 23 to
    43 of each period as a digestion marker..
  • -fecal samples were collected from the rectum of
    each cow during days 31 to 43 of each period .

12
Results
  • Ruminal pH and fermentation.
  • -There was no significant difference in ruminal
    pH .
  • -Ratio of acetate to propionate was lower for
    LSY, MSY and HSY than for control

13
  • Dry matter intake, milk yield, milk components
    and milk selenium
  • -Dry matter intake was not affected.
  • -Milk yields were higher for LSY and MSY than
    for HSY and control
  • -Milk selenium content was linearly and
    quadratically increased as increasing SY
    supplementation.

14
  • Digestibility in the total tract.
  • Were higher for LSY and MSY than for control
    and HSY.

15
Conclusion
  • Increasing supplementation of cow diet with
    selenium yeast from 150 to 300 mg/kg dietary DM
    compared with control increased milk yield and 4
    FCM.
  • Improved milk production was likely due to the
    increased total digestibilities of feeds since
    DMI was not affected.
  • The further increase of SY dose from 300 to 450
    mg/kg dietary DM was not beneficial

16
Recommendation
  • Selenium yeast modulates the digestive
    microorganisms or enzymes in a dose-dependent
    manner and the optimum SY supplemented dose was
    about 300 mg/kg in the present experimental
    conditions.
  • SY supplementation in the diets of lactating
    dairy cows could be an efficient way to increase
    milk Se content.

17
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