Fazenda Paineiras da Ingaí -
Búfalos Murrah Leiteiros |
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Fat
feeding in lactating buffaloes
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In
High yielding dairy animals experience a substantial energy deficit in early
lactation while high concentrate diets utilized to overcome this deficit tend to
depress milk fat percentage. The first trimester of lactation is particularly
critical because peak intake trails peak milk yield by as much as 8 weeks and
excessive loss of body reserves at this time can impair reproductive performance
of the animal and can depress total lactation milk yield.
Energy intake of high yield animals can be increased by feeding either more
concentrate or supplemental fat. Feeding large amounts of concentrate alters
ruminal fermentation and often depresses milk fat synthesis. Addition of fat
sources may improve the energy status of high yield dairy animals. Increasing
fat content of diets increases energy density.
Thus, if the weight of feed eaten remains constant, energy intake is increased.
High yielding animals are unable to consume enough energy from traditional feeds
to meet their requirements during early lactation. Supplemental sources of
dietary fat such as whole oil seeds and tallow, are commonly used in attempts to
provide extra energy to early lactating animals to enable them to achieve their
genetic potential for milk production.
The challenge for dairy nutritionists is to formulate diets for lactating dairy
animals that will maintain health and maximise milk yield while minimising the
cost. There has been an increasing interest in feeding fats to dairy cows and a
wide variety of fat sources are used to increase the energy density of diets fed
to cows in early lactation or to high yield dairy animals in negative energy
balance. Thus, use of fats and oils to increase energy density of diets for
dairy animals has gained wide acceptance.
Fats and oils are essential constituents of human and animal food and are
derived from animal, vegetable and marine sources. They are also carriers of
very important biological materials like essential fatty acids and phospholipids.
Annual production of vegetable oils and animal fat in
In phase I of the experiment, four isonitrogenous and isocaloric experimental
diets were fed to lactating buffaloes as total mixed ration containing no added
fat or having tallow, poultry fat or mustard oil, at 3 per cent of diet dry
matter. In phase II of the experiment tallow was added in the rations at 2, 4
and 6 per cent of the diet dry matter.
Intake of dry matter decreased in buffaloes fed supplemental tallow and poultry
fat as compared to those fed diets containing no fat or mustard oil. Higher
energetic efficiency of milk yield was observed in buffaloes fed
tallow-supplemented diet compared to those fed diets containing poultry fat and
mustard oil. Daily milk production was higher for buffaloes on diets containing
different sources of supplemental fat. Milk fat percentage was higher for
lactating buffaloes consuming supplemental tallow compared to those fed diets
containing other two sources of fat. Gain in body weight was higher for those
assigned to experimental diets versus those consuming the control diets.
Dry matter digestibility, blood pH, concentrations of glucose, total cholesterol,
triglyceride and total blood lipids did not vary due to addition of different
fat sources in the rations of lactating buffaloes. Rumen pH did not differ
significantly, whereas, acetate concentration was significantly lower in
buffaloes fed different sources of supplemental fat versus those fed control
diet. Milk production cost (Rs/kg) was significantly lower for buffaloes fed
supplemental tallow. But the production cost increased with increased level of
tallow in the diet. Income in relation to feed cost was higher for buffaloes fed
supplemental tallow and poultry fat compared to those fed the controlled diet.
The diet containing mustard oil manifested a decline in income in relation to
feed cost.
In phase II, intake of dry matter was lower but daily milk yield and milk fat
contents were higher for buffaloes consuming diets containing different levels
of supplemental tallow. The digestibility of dry matter increased significantly
at 4 per cent dietary tallow, beyond which it manifested a decline. Blood pH and
concentrations of glucose did not vary significantly due to addition of tallow
to the ration upto 6 per cent. The concentrations of total cholesterol,
tri-glyceride and total blood lipids did not vary significantly due to the
addition of 2 per cent tallow beyond which a significant rise in these
metabolites in the blood was observed. Rumen pH and concentration of butyrate
differed non-significantly but concentrations of acetate decreased and
propionate increased due to addition of tallow in the diets. The acetate to
propionate ratio decreased as the level of tallow increased in the diet. Milk
production cost (Rs/kg) was lower for buffaloes fed supplemental tallow. However,
the production cost increased with increased level of tallow in the diet. Income
over feed cost was highest for buffaloes fed 2 per cent dietary tallow beyond
which it trended to decline.
The results of the present study indicate that some of the physico-chemical
characteristics of fats/oils can affect the performance of lactating buffaloes.
The comparison of different fat sources shows that tallow is an economical
source of energy for supplementing in the diet of lactating buffaloes, whereas
mustard oil causes a decline in income-to-feed cost ratio.
Tallow upto 4 per cent of diet dry matter appears to be a suitable fat
supplement as an energy source for lactating buffaloes. The change in fatty acid
composition of buffalo's milk fat due to fat supplementation seems to be
favourable for human health.