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Articles
by
Zurong Wang |
Total Records (
2 ) for
Zurong Wang |
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Zurong Wang
,
Sandro Cerrate
,
Cesar Coto
,
Fenglan Yan
and
P.W. Waldroup
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This study was conducted to evaluate the bioavailability
of an organic copper source, MINTREX® Cu, compared with reagent
grade Cu sulfate as a source of Cu in broiler diets. Nutritionally
complete basal diets were supplemented with either copper sulfate or
MINTREX Cu to provide diets with 0, 10, 25, 50, 125, 250 and 500 mg
kg-1 of supplemental Cu. Fifty commercial broiler strain (Cobb
500) male chicks were placed in each of 48 pens. Each diet (except for 500
mg kg-1) was fed to four replicate pens. The 500 mg
kg-1 level was fed to two replicate pens for each source. There
were two feeding phases including starter (0-21 d) and grower (21-35 d).
At the end of each phase, birds were weighed by pens and two birds per pen
(four birds per pen for the 500 mg kg-1 levels) were killed to
take liver and tibia samples for analysis of Cu concentration. Overall,
there was no effect of Cu source or dietary Cu concentration on feed
conversion or mortality. At 14 d the birds in the MINTREX treatment
weighed significantly more than the birds in the Cu sulfate treatment.
High Cu concentrations markedly decreased (p<0.0001) body weight
regardless of Cu sources in both phases. Elevated dietary Cu concentration
significantly increased (p<0.01) tibia ash Cu concentration for both Cu
sources in both phases; however there was no good linear relationship
between tibia Cu accumulation and non-zero Cu consumption. There were
marked effects (p<0.05) of Cu source, concentration and their
interaction on 14 d dry liver Cu concentration. Based on dry liver Cu
concentration regressed on non-zero copper consumption, the relative
bioavailability of MINTREX Cu was 111.63% for 14 d and 110.71% for 35 d
when bioavailability of reagent grade Cu sulfate was set as 100%. This
indicated that MINTREX Cu source has greater biological availability than
reagent grade Cu sulfate for broilers. |
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Zurong Wang
,
Sandro Cerrate
,
Cesar Coto
,
Frances Yan
and
Park W. Waldroup
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A study was conducted to evaluate the use of constant or
increasing levels of Distillers Dried Grains with Solubles (DDGS) in diets
for broilers. Diets were formulated for starter (0-14 d), grower (14 to 35
d) and finisher (35 to 42 d) periods to contain 0, 15, or 30% DDGS. Diets
were formulated on digestible amino acid basis to meet current U.S.
poultry industry nutrient levels and were maintained isocaloric and
isonitrogenous. Varying levels of DDGS were fed during the study; with
some birds receiving a constant level while others received increasing
amounts as the bird aged. The DDGS levels used in the study were as
follows (starter-grower-finisher, %): 1) 0-0-0; 2) 0-15-15; 3) 0-15-30; 4)
0-30-30; 5) 15-15-15; 6) 15-15-30; 7) 15-30-30; 8) 30-30-30. Starter diets
were crumbled, while grower and finisher diets were pelleted. Each of the
dietary treatments was fed to four replicate pens of 25 birds each. Body
weights and feed consumption were determined at 14, 35 and 42 d of age. At
the conclusion of the study five representative birds were processed for
dressing percentage and parts yield. The results indicated that increasing
DDGS levels had a trend to reduce the weight:volume ratio and visually
decreased pellet quality. Diets containing 15% DDGS could be fed
throughout the entire feeding period of 1 to 42 d of age with no adverse
effects on live performance or carcass composition when diets were
formulated on a digestible amino acid basis. Inclusion of 30% DDGS in the
diet reduced the weight:volume ratio and markedly reduced pellet quality.
Birds fed diets with 30% DDGS during the starter or grower periods had
reduced body weight, elevated feed conversion and typically had reduced
breast meat yield, compared to birds fed diets with 15% DDGS or birds fed
the control diet with no DDGS. Feeding DDGS for the last seven days prior
to slaughter after being fed diets with 15% during starter or grower
period might possibly be acceptable in terms of body weight gain and feed
conversion but still resulted in a significant reduction in breast meat
yield. It is possible that some of the essential amino acids that were not
considered in the formulation of the diets may become marginal or
deficient in diets with 30% DDGS. Further studies are suggested to
evaluate needs for these amino acids in diets with high levels of DDGS. |
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