الفهرس 
Milk FeverOnly 14 pages are availabe for public view
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Abstract
High producing dairy cows may suffer hypocalcaemia after
parturition because of losing Ca in milk. Hypocalcaemia is known as milk
fever and it may be clinical or subclinical. Milk fever causes decreasing
milk production and may lead to the death. Milk fever is known also to be
associated with some metabolic disorder, such as: ketosis, fatty liver and /
or some reproductive problem, such as: retained placenta, mastitis and
metrities,
So, to avoid all previous, we should care about transition period
which is a critical period. It starts three weeks before parturition (Close up
period) up to three weeks after parturition (early lactation period). Interest
in this period avoids the occurrence of diseases and reduces the lack of
production by about 14% and the lack of seasons by 3 to 4 seasons
compared to animals with careless in this period.
The main objective of this study was to investigate the effect of
pre-parturient DCAD levels on milk fever, rumen fermentation,
digestibility, milk production and productive and reproductive
performance of lactating Holstein cows.
Dietary cation anion balance (DCAB) can be used to determine
the relationship between cations which have a positive charge like sodium
(Na), potassium (K), magnesium (Mg) and calcium (Ca), and anions
which have a negative charge such as chloride (cl) and sulfur (S). Cations
in the diet promote more blood alkaline (higher pH), which is associated
with milk fever. Anions promote blood acidity (lower pH) which is
associated with reduced incidence of milk fever.
DCAD is expressed as mille Equivalents (mEq)/100g DM or
mEq/kg DM. Several equations has been suggested to calculate DCAD:
(Na+ + K+ ) – (Cl- + S-) = mEq/100 gm of DM. (Tucker et al., 1992b)
Twenty Late pregnant Holstein cows (3 to 4 weeks before calving)
were used through the experiment. Animals were divided according to
the parity to four groups, five cows each. Animals were housed in four separate open areas provided with water sinks and shades. Animals were
tied at feeding time to be fed individually according to NRC (2001). All
groups were fed a basal diet consisting of berseem 30Kg, concentrate
feed mixture (CFM) 6Kg, rice straw 6 Kg &soya bean meal (SBM) 75g
as a carrier for anionic salts/head/day.
Cows were divided randomly into four groups, five cows each. All
animals were fed on the basal diet and the following additives
Treatment (1) : Control group received soybean meal without anion
salts (soybean meal was used as a carrier for anionic
salts which added to other groups).
Treatment (2) : Received (150 gm) anionic salt to achieve DCAD
equal zero mEq /Kg DM.
Treatment (3) : Received (350 gm) Soybean meal + anionic Salt to
achieve DCAD equal (-150) mEq /Kg DM.
Treatment (4) : Received (350 gm) Anio-Norel compound to achieve
DCAD equal (-150) mEq /Kg DM.
Results as the following
1. Results indicated that serum calcium concentration increased
significantly (p < 0.05) with decreasing DCAD. With positive DCAD
(+90mEq/Kg DM) serum calcium concentration was (6.944 mg/dl),
increased significantly to (7.589 mg/dl) with (zero DCAD). When
DCAD decreased to (-150 /mEq/Kg DM), serum Calcium
concentration increased to (8.133 & 8.367 mg/dl) with anionic salts &
Anio-Norel, respectively with no significant differences between
(group 3 & group 4).
2. Data showed that urinary calcium concentration had the same trend of
blood calcium concentration. Urinary calcium concentration increased
with decreasing DCAD level from (1.001 mg/dl) for (+90
mEq/Kg/DM) up to (2.156 mg/dl) for (-150 mEq/kg/DM). However,
there was a significant difference (p < 0.05) between (group 3& group
4).3. Data showed that blood magnesium concentrations had no significant
differences (p< 0.05) among groups where it ranged between (2.189
mg/dl) for (+90 mEq/kg DM) DCAD level and (1.677 mg/dl) for
(–150 mEq/Kg DM ) DCAD level.
4. Results indicated that urinary magnesium increased with decreasing
DCAD level. Values were (2.714 mg/dl) for animals fed diets with
DCAD (+ 90 mEq/kg DM) and (4.192 mg/dl) for DCAD level (-150
mEq/kg DM). However, there was no significant difference between
(group 3 & group 4).
5. Results indicated that serum phosphorus concentration decreased with
decreasing DCAD level.
6. Urinary phosphorus concentrations were not affected by time before or
after parturition.
7. Results indicated that urinary pH decreased from (8.111) for group 1
to (6.578) in group 4. However, there were no significant differences
between group 1 and 2 (8.111 and 7.978) respectively. While group (3)
7.022 decreased significantly than group 1 and 2. group 4 (6.578)
decreased significantly when compared to group 3. Urinary pH did not
differ significantly before and after parturition (7.400) and (7.441)
respectively.
8. The present values of serum total protein, Albumin, Globulin and A/G
ratio are within the normal range and not affected with treatments.
9. The present values of serum ALT (GPT) and AST (GOT) are also
within the normal range.
10. The present values of serum createnine and Urea are within the
normal range.
11. Data indicated that there was a significant interaction between
treatment and time before and after parturition effects on BHBA
concentration. This interaction was reflected in the following
observation:
1. At 7 days before parturition there were no significant
differences among groups 2. On the day of parturition group 1 had the highest BHBA
concentration (8.943 mg/dl) followed by group 2 & 3 (7.743,
7.730 mg/dl), respectively and the lowest was for group 4,
with no significant difference between group 2 & 3.
3. At 7 days after parturition group 3 & 4 showed the lowest
BHBA concentration with no significant difference between
them. group 2 had significantly higher BHBA concentration
than group 3 & 4.
4. group 1 had the highest BHBA concentration (10.000 mg/dl).
12. Results indicated that milk yield was lowered by treatment (3)
compared with the other groups which had statistical similar values.
These values of milk production may reflect the dry matter intake
through the transitional period.
13. The relationship in monthly milk production tended to be linear in
treatments (1&2) while it was more quadratic in treatment (4)
revealing more persistence for Anio-Norel group.
14. Data showed a trend of lowered dry matter intake with more anionic
diets. (Decreased in DCAD).
15. Rumen pH tended to be lower with treatments (2) and (3) where
anionic salts were added to the diet, compared with control group.
However when Anio- Norel was used the pH values increased, to be
similar to treatment (2) (p< 0.05) but still significantly less than
control and more than treatment (3) (p> 0.05).This can be explained
by buffer effect of yeast and magnesium oxide included in Anio-
Norel mixture. Total volatile fatty acid concentrations were increased
with treatments (2) and (3) when compared with control and Anio-
Norel groups. Ammonia concentrations were lower with treatments
(2) and (3) (14.8mg/100ml) while they were higher for control and
Anio- Norel groups (16.4, 16.3 mg/100ml), respectively.
16. When Acid Insoluble Ash (AIA) and Acid Detergent Lignin (ADL)
were used to calculate the digestibility of nutrients, values obtained
were in general higher significantly (p>0.05) for ADL when compared with AIA. This is true for all nutrients except for crude
protein where differences were not significant.
17. Results indicated that progesterone decreased dramatically at
parturition where it was 1.64 ng/dl (7 days pre-partum) to 0.285 ng/dl
at parturition and 0.468 ng/dl (7 days post-partum).