2. • Heat stress occurs when the combination of
environmental temperature, relative humidity,
solar radiation and air movement cause the
temperature of the cow to exceed its zone of
thermo neutrality
• The best way to deal with heat stress is to
prevent it from occurring.
• The objective of the management tools are to
prevent heat stress from occurring.
3. • As the environmental temperature increases, the
reliance on evaporative cooling (sweating and
panting) to dissipate body heat increases.
• However, high relative humidity reduces the
effectiveness of evaporative cooling and during
hot, humid summer weather dairy animals can’t
eliminate sufficient body heat and body
temperatures rise.
4. • Lactating buffaloes and cows create a large
quantity of metabolic heat and accumulate
additional heat from radiant energy. Buffaloes
tend to be more uncomfortable because they
have fewer sweat glands under the skin than
cows.
• Thermal environment is a major factor that can
negatively affect production and reproduction in
dairy animals, especially in animals of high
genetic merit
5. • High ambient temperature is also one of the
major factors for reproductive failures and
embryonic mortality, especially in buffaloes.
• Feed intake is reduced and milk yield is
alarmingly decreased.
• The scarcity of fodder and milk make summer
season lean for the dairy farmers and they are
unable to keep pace with the demands of milk
6. DIRECT IMPACT OF HEAT STRESS AND ITS SIGNS
• Depressed feed intake
• Decreased milk yield
• Milk fats and protein %
• Elevated somatic cell counts as well as increased
risk of mastitis
• Weight loss and reduced reproduction.
7. Once the heat load on a dairy animal becomes
severe the animal may show signs of distress like
• Seeking shade
• Refusing to lie down
• Reducing feed intake
• Crowding water holes
• Splashing water from toughs
• Labored breathing
• Excessive salivation
• Convulsions and even death.
8. Under heat stress, particularly buffaloes show
the following signs
• Increased reddening of hide on the brisket, under
the belly and between the legs
• Protruded tongue
• Panting
• Salivation
• Obvious blood shot eyes
• Reduced feed intake
• Reduced milk yield
• Very hot to touch and increased rectal
temperature
9. • The body temperature of a buffalo is lower than
that of a cow in spite of the fact that its black skin
absorbs much heat and its skin has only one-sixth
the density of sweat glands that a cow skin has.
This explains why buffalo like to wallow in water
when the temperature and humidity are high
• The rectal temperature and respiratory rates
were significantly higher during direct exposure
to solar radiation in the noon time than the
values obtained when the animals were kept
under shade in the barn
• Pregnancy rate was decreased from 90% in
winter to 62.5% in summer
10. EFFECT OF HEAT STRESS ON FEED INTAKE,
DIGESTION AND FEED UTILIZATION
• Feed intake is reduced due increased ambient
temperature.
• High environmental temperature may affect the
rumen micro organisms that synthesize Vitamin
B complex, amino acids and fatty acids on which
the nutrition of ruminants largely depends.
• In addition, reduction of blood flow to rumen
epithelium and reduction of rumination is
noticed during dehydration and heat stress
11. EFFECT OF HEAT STRESS ON PRODUCTION
• The high temperature causes stress due to increased
body heat leading to low heat dissipation from the body
surface. High heat load in lactating buffaloes reduces
their milk production and shorten duration of lactation
periods
• The incidence of silent heat or poor expression will be
more common at high temperatures during summer
particularly in buffaloes that have limited access to
water for either drinking and/ or wallowing.
• These buffaloes at high temperatures may also fail to
conceive due to silent heat or poor expression of heat,
loss of conception, causing long dry periods and inter
calving intervals ultimately affecting milk production
12. EFFECT OF HEAT STRESS ON REPRODUCTION
• Heat stress causes infertility in farm animals
and represents a major source of economic
loss
• Heat stress affects reproduction in all major
farm species. Dairy buffalo and cattle are
particularly sensitive to heat stress because of
the metabolic heat produced
14. MEASURES TO OVERCOME HEAT STRESS
COOLING BY
REDUCING AMBIENT
AIR TEMPERATURE
Misters
High
Pressure
Foggers
Evaporative
Cooling
Pads and
Fans
ENHANCING THE COW'S NATURAL MECHANISM
OF HEAT LOSS
Sprinkler
and Fan
Cooling
Systems
(Direct
Evaporative
Cooling)
Sprayers
in Parlor
Exit
Lanes
Cooling
Ponds
Shades
Artificial Shade
Permanent
Shade
Structures
Portable
shades
Natural
Shade
15. COOLING BY REDUCING AMBIENT AIR
TEMPERATURE
• Misters
• High Pressure Foggers
• Evaporative Cooling Pads and Fans
16. Misters
• The use of misters reduced water intake of
the misted cows versus the unmisted controls.
• This was probably because the misted cows
were not as hot and so transpired, sweated,
less water than the unmisted controls.
17. Fans
• The use of fans, particularly in areas of poor
ventilation, is generally considered beneficial
in preventing cows from becoming hot.
18. Sprinkling
• Sprinkling (not misting) the cow with water to
fully wet her body and using fans to evaporate
the water cools the cow and encourages
greater feed intake and milk production
19. ENHANCING THE COW'S NATURAL MECHANISM
OF HEAT LOSS
• Cooling Ponds/ Wallowing tanks
• Cooled Water
• Shades
i. Natural shade
ii. Artificial shade
20. Cooled Water:
• It should be available as fresh and clean. Drinking
water three-four times a day is a need in summer
months in general farm practice.
• Showering/splashing of water on the body thrice
a day (morning, noon and afternoon) decreases
heat stress.
21. Wallowing :
• Wallowing is the cheapest
and least laborious device
to beat the heat in
summer. Buffaloes are
made to wallow in
clusters in ponds, rivers,
tanks or other water
bodies for hours together.
• Wallowing is an important
route of heat loss in view
of the labile body
temperature which
enables the animal to
store body temperature.
22. Natural Shade
• Trees are an excellent source of shade and if
given the choice cows will generally seek the
protection of trees rather than man-made
structures.
23. Artificial Shade
• These shades should be
oriented in a
North/South direction,
provide about 40 to 45
square feet of shade per
cow, and be about 12 to
13 feet high. There
should be a raised dirt
mound under the shades
to prevent accumulation
of moisture, and it should
be groomed regularly.
24. Changes in feeding:
• Cow maintenance requirements increase with
heat stress while dry matter intake goes down.
Consider increasing feeding frequency (an extra
feeding or two), feeding at a cooler time of day,
or even changing the ration. Summer rations will
require a buffer and better forage quality.
25. DROUGHT MANAGEMENT
• During a drought situation, every measure
needs to be taken to save useful cattle from
mortality or distress sale by making
arrangements for drinking water, fodder and
medicines etc
26. Feeding Management
• Emphasis on green fodder conservation in view of
looming threat of drought becomes important.
• However, in the face of unpreparedness,
appropriate feed enrichment and
supplementation strategies become more
imperative.
• Choice of supplements is critical.
• Feed ingredients bearing high energy/ protein
are preferred with minerals.
• .
27. • Lack of green fodder causes vitamin deficiency
(particularly Vit. A & E), therefore,
supplementation becomes essential.
• A buffalo producing 15 to 18 Liters milk per day,
requires 60 to 75 thousand, 15 to 20 thousand,
400 to 500 IU of vitamin A, D3, E, respectively,
which can be met by feeding 10g Brivita
• Supplementary feeding of grains / oil cakes can
be given twice a week
28. • Use of grain as supplement for animals is hard to
justify because of scarce availability and long-
time storage problem so, feeds during drought
for animals include fodder trees and urea-treated
straw [4% urea with Molasses].
• By-products such as oil seed cake should be used
• Urea molasses enrichment of straw can be done
using 1.00 quintal straw, sprinkled with 20 Liter
water containing 10 kg molasses, 1 kg urea, 500
gm mineral mixture, 50 g Brivita (Vitamin A, D3
and E) and 1 kg salt for supplementing the
feeding of affected the animals economically
29. • Maize stovers/ soybean chaff etc. can be given upto 30%
in ration.
• Sugarcane tops (contain 2.3% DCP and 49% TDN)
supplemented with limestone powder.
• Leaves of mango, papal, banyan, babul, subabul, mahua,
Israili babool, kabuli kikar, vegetable leaves, fruit pulp
and waste; and dry sugarcane leaves are some
unconventional fodders for difficult drought period,
provided in gradient dose.
• Tree leaves 50%, mixed with 5% cake, 25% available pods
(Israili babool, Kabuli kikar) 15% molasses with 1 % urea
with 2 % mineral mixture and 2% salt can be fed.
• Banana stem and leaves {containing 6.5% DCP and 75%
TDN (based on DN)} can be used as animal feed @ 15 to
20 kg per animal per day.
30. • Grazing of poisonous plants and resulting toxicity
problems become more common in the absence of
quality fodder.
• Awareness in farmers is essential, especially with
regard to anti-nutritional / toxic factors as nitrate/
nitrite and HCN poisoning.
• To avoid HCN poisoning farmers should not try to take
a cut before Jowar (sorghum) reaches the height of at
least 24 inches (at initiation of milks stage).
• In available fallow lands, with any rainfall, farmers
should grow short duration drought tolerant arid type
crops like pearl millet (Bajra, Sorghum PC6 and MP
Chari) and legumes (Moong, Moth, Cowpea BL1 and
BL2) as fodder and fodder grasses (like stylo, cenchrus
ciliaris, athropogan etc.) should be cultivated
31. • In sugarcane growing areas, sugarcane tops and dry
sugarcane leaves can be utilized, enriched for crude
protein content and fed in scarcity areas.
• 50% sugarcane bagasse (3% CP and 40% TDN) + 17% oil
cake + 25% molasses mixed with 4% bran, 1% salt, 2%
mineral mixture and 1% urea is promising maintenance
ration for adult animals.
• Partially damaged / discarded wheat / other grains may
be diverted for feeding to productive animals.
• Urea Mineral Molasses Block (UMMB) can be
effectively utilized as a combined source of protein,
energy and mineral during drought situations.
• UMMB also help in preventing loss of fertility in case of
prolonged drought. These blocks can be easily
transported over long distances.