Different requirements of dairy animals are as follows
Water is the
cheapest nutrient. Animal get water from three sources:
Metabolic water is an insignificant
source compared with the water ingested freely or in feed. The sum
of Free water Intake and the water ingested in feed is the total
water intake (TWI). Large amount of fresh and clean drinking water
should be available to the dairy animals all the times. Three to
four units of water is normally required by dairy animal for each
unit of dry feed consumed.
Requirement of water is governed by different factors like what is
the physiological state of the animal, what type of feed consumed,
and what are climatic conditions. Water requirement of a dairy
animal when not in milk is 26 to 37 liters per day, and this
requirement increases at a rate of four litres for each litre of
milk produced. Requirement of water can also be determined by this
Water intake (gal/day) = 4.22 + (0.19 x DM intake) + (0.108 x pounds
of milk) + (0.374 x ounces of sodium)
+ (0.06 x minimum daily temperature in F)
Dairy animals are very sensitive to the quality of
water as availability of inadequate or poor quality water can limit
milk production and growth and may cause even health problems.
Dry Matter Intake
matter intake is quantity of dry matter which is consumed by an
animal over a period for 24 hours. It is usually measured in %age.
DMI is normally calculated as 3-4 % of body weight. An average size
cattle DMI is 2.5 - 3% of body weight. A dairy animal may reach maximum
daily DMI (4% of Body weight) not later than 10 weeks after calving.
The capacity to
do work is called energy. It is the basic requirement of animal and
essential to maintain normal body functioning. Energy is
quantitatively the major nutrient required by dairy cattle after
fats and protein are the main sources of energy. Mostly the energy
is supplied to the dairy cattle from carbohydrates being the most
economical. Protein is also a good source of energy but it is
usually 5 to 10 times higher in price as compared to carbohydrates
and therefore its use is less as energy source. Fat is very good source of energy and
supply 2.25 more energy as compared to carbohydrates and protein. It
is mainly included in the rations of young calves but may also be
added to the rations of lactating dairy animals.
On the basis of
energy losses in body energy can be divided as follows:
refers to the total energy in feed, which is determined by complete
oxidation (burning) of the feedstuff and measurement of the heat
produced. The energy value is expressed in calories. Common
feedstuffs are similar in gross energy content, but differ in
feeding value because of differences in digestibility.
is gross energy minus fecal (manure) loss. These losses will be
greater for high fiber rations than for low fiber rations.
include those in urine and gas. In the rumen, considerable methane
is produced, representing an energy loss because the animal cannot
use methane and must eructate (belch) the gas. These losses, added
to fecal losses, are considered in calculating the metabolizable
Heat is produced
during digestion and metabolism. Other than during cold weather,
this heat has no value and represents a loss of energy. The
remaining energy is net energy (NE). NE system divides energy into
NE for maintenance (NEm), NE for growth (NEg) and NE for lactation (NEl).
NEl is energy required for maintenance plus milk
production during lactation.
nutrients (TDN) is another method of expressing the energy content
of feeds or the energy requirements of cattle. TDN is comparable to
digestible energy. It has been in use longer than the net energy
system and more values are available for feedstuffs.
+ Digestible crude fiber
+ Digestible protein
+ (Digestible ether extract x 2.25)
Carbohydrates are the major source of energy in diets for dairy
cattle and usually comprise 60-70% of total diet. The main function
of carbohydrates is to provide energy for rumen microbes and the
host animal. A secondary, but essential, function of certain types
of carbohydrates is to maintain the health of the gastrointestinal
tract. There are two major categories of carbohydrate as structural
carbohydrates and non structural carbohydrates. Non structural
carbohydrates are found inside the cell of plants while structural
carbohydrates are found inside the cell wall. Non structural
carbohydrates are more soluble than structural carbohydrates.
structural carbohydrates include sugars, starches, organic acids,
and other reserve carbohydrates such as fructans and are major
sources of energy for high producing dairy cattle. Non structural
carbohydrates are highly digestible.
Structural carbohydrates include cellulose hemicellulose, and lignin are classified as fiber, giving
structure and strength to plant tissues. Simple-stomach animals,
cat, dogs and poultry, cannot digest much fiber. Adult ruminants
digest fiber because the microbial population in the rumen breaks it
down into usable products. Lignin, which is also a component of
plants, is not a true carbohydrate. This compound is virtually
indigestible. Feed digestibility is lowered when lignin is present
in large amounts, such as in mature forages.
Crude fiber, acid detergent fiber, and neutral detergent fiber are
the most common measures of fiber used for routine feed analysis,
but none of these fractions are chemically uniform. Neutral
detergent fiber measures most of
the structural components in plant cells (i.e. cellulose,
hemicellulose, and lignin). Acid detergent fiber does not
include hemicellulose, and crude fiber does not quantitatively
recover hemicellulose and lignin. Neutral detergent
fiber is the method that best separates structural from
nonstructural carbohydrates in plants, and NDF measures
most of the chemical compounds generally considered to comprise
fiber. Within a specific feed stuff, concentrations
of NDF, ADF, and crude fiber are highly correlated, but for mixed
diets that contain different fiber sources, the correlations among
the different measures of fiber are lower. Neutral detergent fiber
is the best expression of fiber available currently, but
recommendations are also given for ADF because of its wide spread
Neutral detergent fiber (NDF) consists of ADF plus hemicellulose,
and is often called cell walls. Because NDF represents the total
fiber in a feed, it is highly correlated to intake, rumination, and
total chewing time. Corrected for physical form, NDF provides the
best measurement of effective fiber for formulating dairy rations.
The fineness at which forages are chopped during harvesting can
alter the effectiveness of fiber for maintaining chewing activity.
Hay crop silages should be chopped at a minimum of 3/8 inch
theoretical length of cut (TLC) to provide 15 to 20 percent (weight
basis) of the particles greater than two inches long. Chopping at
1/4 inch TLC provides only about 10 percent of the forage particles
greater than two inches long. Corn silage should be chopped at 1/4
to 3/8 inch TLC. Rations based on 1/4 inch TLC silage should include
5 pounds of long stem hay to provide adequate "effective" fiber.
Hay crop silage chopped at 3/16 inch TLC with less than 7 percent
coarse particles should be fed with 8 to 10 pounds of long hay.
Holstein cows need to chew about 11 to 12 hours per day or 12 to 14
minutes per pound of DM eaten to keep milk fat above 3.5 percent.
High fiber by-product feeds supply some "effective" NDF and can be
used to partially replace NDF coming from forages in the ration.
Whole cottonseed possesses the best forage NDF replacement value of
commonly available by-product feeds fed in milking cow rations.
Starch, sugar, and pectin make up the highly digestible carbohydrate
fraction in feeds termed non-fiber carbohydrates (NFC). Subtracting
percent (DM basis) NDF, CP, ether extract or fat and ash from 100
provides an estimate of NFC percent in feeds.
(NFC% = 100 - [%NDF + %CP +
%fat + %ash])
The term nonstructural carbohydrate is often used interchangeably
with NFC but is analytically determined and may be slightly
different from NFC.
Carbohydrate status of dairy rations has traditionally been
evaluated with regard to measures of structural carbohydrates—ADF or
NDF. However, optimum microbial growth in the rumen requires
adequate amounts of NFC along with degradable intake protein (DIP)
in the ration. Insufficient amounts of NFC in rations depress
microbial growth and digestion of feed in the rumen, while excess
NFC in rations causes acidosis and/or low milk fat tests.
is required in animal rations to
provide the supply of amino acids needed for tissue repair and
synthesis, hormone synthesis, milk synthesis and many other
physiological functions. Amino
acids are supplied by the digestion of microbial protein, and by
feed protein that escapes microbial breakdown in the rumen.
Protein requirements are expressed as crude protein (CP), either in
amounts or as a percentage of the dietary DM. Crude protein is
determined by multiplying the nitrogen content in a feed by the
factor 6.25 (feed protein averages 16 percent nitrogen). Feedstuffs that contain nitrogen in a
form other than proteins or peptides are called nonprotein nitrogen
(NPN) sources. Urea and ammonium slats are examples of NPN sources.
They have crude protein value, but they do not supply any amino
acids directly. Nitrogen of NPN sources is utilized by ruminal
microorganisms. They convert it into amino acid and use them for
their growth. These microbes then pass into small intestine where
they are digested and amino acids are released for absorption and
utilization, the same way as amino acids released from the digestion
of true proteins in feeds.
All feed protein sources are not degraded in the rumen to the same
extent. Three protein terms describe the fate of dietary protein in
Degradable intake protein (DIP) is
the portion of feed protein broken down to ammonia or amino
acids by the rumen microbes.
Soluble intake protein (SIP) is the
portion of DIP that is rapidly degraded in the rumen. Generally,
SIP is about half of the DIP.
Undegradable intake protein (UIP)
is the portion of feed protein that is not degraded by the rumen
microbes and remains intact as it passes through the rumen.
Other terms for UIP include by-pass protein and escape protein.
Values for UIP, SIP and DIP can be expressed as either a percent of
the dietary DM (for example, a feed may contain 17 percent CP and
6.8 percent UIP in the DM) or as a percent of the CP (for example,
40 percent UIP calculated by 6.8/17). The sum of DIP and UIP,
expressed as percent of CP, must equal 100. Diets for high producing
dairy cows should contain 19 percent CP with 38 percent of the CP as
UIP, 62 percent as DIP and 30 percent as SIP; or 19 percent CP with
7.2 percent UIP, 11.8 percent DIP and 5.7 percent SIP in the dietary
The optimal diet fed to dairy cattle will meet the nitrogen
requirement of rumen micro-organisms for maximum synthesis of
micro-organism protein and allow for maximum escape or bypass of
high quality feed protein for digestion in the small intestine.
Protein synthesis by rumen microbes will depend on feed intake,
organic matter digestibility, feed type, protein level, and feeding
system. Since 4.5 pounds of microbial protein synthesis per day is
near the maximum, the remainder of the protein must be derived from
UIP sources. Young, fast-growing heifers and high-producing cows may
require additional UIP sources beyond their normal diet to meet
their amino acid requirements. Excess protein, above requirements,
is used as a source of energy.
Urea is a good example of NPN. Its use in
dairy cattle feeding is limited by its lack of palatability and the
animal’s ability to utilize it for protein synthesis. Its
utilization is affected by the way it is fed, the availability of a
source of the carbon compounds needed for protein synthesis and the
level of protein of the total ration. Starches are a very effective
source of carbon compounds for ruminants amino acid synthesis.
Cellulose is less effective as it is degraded too slowly and simple
sugars degraded too rapidly to be mass effective. NPN is not very
effective utilized by high producing cows being fed relatively high
levels of total ration protein (14-15% of the DM). It can however be
more effectively utilized by lower producing cows being fed lower
levels of total ration protein (up to 12 to 13% of the DM).
Minerals are essential dietary
constituents and required in relatively small quantities. On the
basis of requirement minerals are classified as micromineral and
macromineral. Macrominerals are those which are required in
relatively large amounts while micro minerals are those which are
required in small amount. Microminerals are also called trace
Sodium is an extracellular and
potassium an intracellular cation, while chloride is associated with
sodium as an extracellular anion. These minerals help in acid base
balance along with bicarbonate ions, electrolyte balance, fluid
balance and regulation of osmotic tension. Sodium and sodium
chloride are usually provided in the form of common salt. However
potassium chloride may also be used as a source of chloride,
excessive levels of chloride without sodium or potassium can
contribute to acidosis in dairy animals. The deficiency of sodium
causes poor growth, poor feed utilization, dehydration and decreased
cardiac output. The first sign of sodium deficiency is craving for salt
manifested by licking of wood, skin, soil etc.
Milk contains about 0.15% potassium.
Heat stress increases the need for potassium because of its greater loss in
sweat. Potassium deficiency does not normally occur since roughages
supply sufficient potassium to meet the dairy animals requirements. The
signs of severe potassium deficiency in lactating animal include a marked
decrease in feed intake, loss in weight, decreased milk yield, pica,
loss of hair glossiness, decreased pliability of the hide, lower
plasma and milk potassium and higher haematocrit (PCV), potassium (3% or above) in
every lush forages growing on high potassium soils in cool weather
may cause both grass tetany and milk fever of lactating animals.
It is required for growth of hair,
hooves and horn. Milk contains 0.03% sulphur, much of which is in
the form of amino acids, methionine and cystine.
The adult animal body contains
about 0.044% of magnesium and is closely related to calcium and
phosphorus. About 70% of magnesium is
present in bones, while the rest is in soft tissues and body fluids.
Milk contains about 0.15% magnesium. Magnesium requirement increase with the level
of milk production. Magnesium toxicity is not known to be a problem
in dairy animals. Oil cakes and leguminous fodders are rich sources
of magnesium. Tolerance level of magnesium in diary animals is 0.50 %.
It is the major element present
in animal body from 1 to 1.6%. More than 90% of body calcium is present in
bones and teeth while the rest is found in soft tissues and body
fluids. Whole milk contains about 0.12% calcium. Calcium serves a
number of physiological functions in the body such as coagulation of
blood, acid base balance, excitability of nerves, muscle tone, and
activates enzymes like lipases, peptidases. Deficiency of Ca causes
rickets in young animals and osteomalacia in adults. In addition
slow growth, poor bone development, reduced milk yield and increase
incidence of milk fever are also caused by calcium deficiency.
It is the major intracellular anion
found in animal body. Whole milk contains 0.09%. About 80% of the
total body phosphorus is present in bones, 10% in combination with proteins,
fats and carbohydrates. Deoxyribonucleic acid and ribonucleic acid
which are required for gene expression and protein synthesis,
contain phosphorus. As a component of phospholipid phosphorus forms
the cell membrane structure and helps in absorption and
transportation of lipid. Its deficiency leads to rickets, poor growth, arched back,
muscular weakness and poor reproductive performance. Excessive
phosphorus intakes may cause bone resorption, elevated plasma
levels and urinary calculi. High calcium, iron and aluminium in feeds
predispose the animals to phosphorus deficiency.
Probably cobalt as such has no
physiological function in animal body but as a component of vitamin
B12 it plays an important role. It is utilized by the rumen microbes
for the synthesis of vitamin B12. Deficiency of cobalt causes
anorexia, anemia, progressive emaciation, rough hair coat,
restlessness and decreased milk production.
Copper helps in utilization of iron,
hemoglobin synthesis, maturation of RBCs, pigmentation of hair,
myoglobin synthesis and bone formation. It is also a component of
superoxide dismutase involved in antioxidation process. Thus
protecting cells form any damage. A deficiency of copper results in
anemia and depigmentation of hair. Black hair turns grey and red
becoming yellow. Swelling of long bones, stiff joints, delayed
oestrus and reproductive failure take place due to Copper deficiency.
Iodine is deficient in many hilly
subhilly areas of Pakistan. The iodine uptake is also reduced by
plants in summer months under tropical conditions and supplemental
iodine above the requirement is beneficial to improve milk
production in buffaloes. Goiter (an enlargement of thyroid glands)
occurs in newborn calves if their mothers are fed iodine deficient
ration. The necks of calves are also swollen. They are weak at
birth or they are born dead. Calves may be born blind and hairless.
Fertility is reduced in both sexes.
Iron is essential because it is a
constituent of hemoglobin, the oxygen carrier in the blood. It plays
a key role in oxygen transportation and oxidative process. Deficiency
symptoms are anemia, loss of appetite, depressed body weight gain
painful respiration even on slight exercise. The higher
concentration of iron in feeds and fodders in tropical countries may
hamper availability of phosphorus, Zinc , and copper.
It is involved in several enzymatic
systems required for metabolism of amino acids and nucleic acids,
oxidative phosphorylation, synthesis of fatty acids, cholesterol and
mucopolysaccharides. Manganese deficiency in calves leads to weak
and twisted legs and enlarged joints.
Molybdenum is an indispensable
component of enzyme xanthine oxidase which is found in milk
distributed widely in animal tissue. Yet a deficiency of molybdenum has not
been observed in cattle. Molybdenum is known largely for its toxic
effects. It toxicosis is a practical problem in grazing cattle in
many areas of the world. There is a antagonistic relationship
between molybdenum and copper. Elevated dietary molybdenum increases
both the animals requirements of copper and the amount of copper that causes toxicosis.
Increased dietary copper can reduce the toxic effects of molybdenum.
If the level of copper in the body is low, a lesser amount of
molybdenum is toxic. High levels of both molybdenum and sulphur interfere with Cu absorption.
As a component of enzyme glutathione
peroxidase selenium serves as an antioxidant. Like molybdenum,
selenium was known for its
toxic effects, before it was discovered to be an essential nutrient
for ruminants. It is needed in trace amounts to prevent retarded
growth, reproductive problem, retained placenta, while muscle
disease and some mastitis problems. Selenium is closely associated
with vitamin E. both selenium and vitamin E protect cells form the
detrimental effects of peroxidation but each takes a different
approach. Deficient or toxic selenium areas are widely scattered
throughout the world.
Zink is associated with many enzymes as
an essential component or activator and is responsible for
metabolism of carbohydrates, lipids, proteins and nucleic acids. As
a component of alcohol dehydrogenase, it helps in conversion of
retinol to retinal and vice versa. Zink is adversely affected when
excess quantities of calcium are present. Moderate excesses of zink
are not toxic to dairy animals. Galvanized pipes and galvnanized
buckets which are commonly used to provide water to dairy animals
contribute zink along the way. Anorexia depressed growth feed intake
and feed utilization, reduced testicular growth and development,
loss of hair, scaly skin, unhealthy appearance and stiffness of
joints are the signs of zinc deficiency.
Factor Affecting Mineral Requirement
The requirements of minerals are
governed by many factors including:
Dietary concentration of the
Its chemical form and solubility
Its status in animal body
Breed, age, physiological state of
Relative concentration of other
Loss of body fluid due to trauma
Infection and disease
Vitamins are complex organic compounds
that are required in traces by various farm animals for maintenance,
normal growth, production, reproduction and health. Vitamins are
classified as fat soluble vitamins and water soluble vitamins. Fat
soluble vitamins include A, D, E and K while water soluble vitamins
are vitamins B, (B1, B2, B6, B12), choline, pantothenic acid, folic
acid and vitamin C.
Vitamin A is the most important of all
vitamins. It is not found in plants and strictly a product of animal
metabolism. Its precursor is carotene which is present in plants.
Animal body has the ability to transform carotene into vitamin A.
Vitamin A is required for the normal functioning of the osteoclasts
and osteoblasts in the epithelial cartilages. It is important for
the vision of animal.
Vitamin D is significant for regulating
calcium and phosphorus metabolism. It promotes intestinal absorption. Sources
of vitamin D are fish oils, eggs, milk and liver. Vitamin D can be
formed in body by exposure to sun.
Vitamin E is an antioxidant associated
with selenium. It stimulates the immune system and reduces the
incidence of oxidized flavor when consumed at high levels. It may
aid in protection against white muscle disease caused by a
deficiency of selenium. It is also involved in formation of
Vitamin K functions as a stimulant to
blood coagulation. Either vitamin K1 (phylloquinone) or vitamin K2
(menaquinone) meets the needs of dairy animals. Green, leafy
materials of any kind, both fresh and dry, are good sources of
vitamin K1. Normally, vitamin K2 is synthesized in large amounts in
the rumen; therefore, dietary supplementation is not recommended.
When animal consumes mouldy sweet clover hay which is high in
dicumarol, blood coagulation may be impaired followed by general
haemorrhage. This syndrome commonly called sweet-clover disease or
sweet-clover poisoning responds to treatment with vitamin K.
The B-complex group of vitamins includes thiamin (B1),
riboflavin (B2), vitamin B6 (pyridoxine), biotin, choline,
folic acid, niacin (nicotinic acid, nicotinamide), pantothenic acid
(vitamin B5), vitamin B12 (cobalamin, cyanocobalamin).
Recent evidence suggests a need for supplemental niacin under
certain conditions, and possibly supplemental choline and thiamin in
the case of mature dairy animals, for which microbial synthesis and
quantities in feeds may be inadequate, especially during diseased
conditions or periods of stress. Dairy animals of all ages have a
physiological need for most of the B vitamins, especially
biotin, choline, niacin, pantothenic acid, riboflavin, thiamin,
vitamin B6, and vitamin B12. In young
calves, deficiency signs have
been noticed when there is inadequate intake of these vitamins, but
even without a functioning rumen, their needs for these B vitamins appear to be met when they are
fed whole milk. However, when young calves are fed milk
replacers, it is advisable to ascertain the adequacy of vitamin
intakes until their rumens are functional.
Thiamin (Vitamin B1):
deficiency of thiamin in the calf may cause polioencephalomalacia,
characterized by lack of muscular coordination, convulsions,
progressive blindness, listlessness and sudden death, usually
preceded by diarrhoea and
dehydration. This condition is mainly found in dairy animals fed
high concentrate rations, and it has been linked to increased
microbial thiaminase activity and the production of thiamin analogue
in the rumen.
Riboflavin (Vitamin B2):
Since the rumen bacteria synthesize riboflavin in adequate amounts,
it is, therefore, not a dietary essential in ruminants. Also, it is
present in many feedstuffs. In the calf, its deficiency is
characterized by hyperemia (presence of blood in the mucosa of the
mouth), lesions in the corners of the mouth and along the edges of
the lips, loss of hair, especially on the belly, and excess
salivation. Riboflavin plays role in the intermediary metabolism and
assimilation of nutrients. It helps form flavoprotein enzymes and
coenzymes, which act in metabolic release of feed energy in the
Vitamin B6 (Pyridoxine, Pyridoxamine,
Vitamin B6 is considered important in several enzyme systems
concerned with metabolism of proteins. Tryptophan will not be
completely metabolized in the absence of this vitamin. Its
deficiency has been produced in calves fed a synthetic diet. The
deficiency has been characterized by loss of appetite, cessation of
growth, and epileptic seizures in some, but not all. Calves respond
to vitamin B6 therapy if it is initiated in the early stage of the
Biotin is also a part of many enzyme systems in intermediary
metabolism. In ruminants, microbial synthesis in
rumen takes care of dietary needs. However, in calves, its deficiency has
been characterized by paralysis of the hind quarters. Signs
of deficiency did not develop when synthetic milk was supplemented
with 9 micrograms/kg of feed.
Niacin (Nicotinic Acid, Nicotinamide):
Niacin forms a part of two important co-enzymes (NAD and NADH).
These enzymes are involved in a
series of reactions in the metabolism of all nutrients, in which
biological oxidation-reductions take place. Niacin is
required by the young preruminant calf. In addition, rumen microbes
may not synthesize adequate amounts of niacin to meet needs of high
producing animals in early lactation. The major reason for
improvement in milk production that occurs with added niacin may be related to the role of niacin in
carbohydrate and lipid metabolism and resultant decrease in
ketosis. Niacin may also influence rumen fermentation, as evidenced
by greater microbial protein synthesis and increased
levels of rumen propionate with
niacin supplementation. When dairy animals are fed heated soybean
meal, rumen response to niacin is greater than when they are
fed unheated soybean meal.
Folic Acid (Folacin):
Folic acid plays an important role in intermediary metabolism. Due
to its synthesis in the rumen, it is not a dietary essential.
Pantothenic Acid (Vitamin B5):
Pantothenic acid forms part of co-enzyme A, which is essential for
the nutrients to enter the
tricarboxylic acid cycle in metabolism. Its deficiency in calves is
characterized by a scaly dermatitis around the eyes and muzzle, loss
of appetite, diarrhea, weakness, inability to stand, and
convulsions. Its deficiency is unlikely to occur in animals with
normally functioning rumens (microbial synthesis).
Vitamin B12 (Cobalamin):
Vitamin B12 deficiency has been produced in preruminant calves by
feeding them a diet having no animal protein. Signs of deficiency
included poor appetite and growth, muscular weakness, and poor
Vitamin C (Ascorbic):
A deficiency of vitamin C can reduce
the ability of neutrophils to migrate to the site of inflammation
allowing for increased oxidative damage to the neutrophils and
reduced production of major anti microbial agent hypochlorous acid.
Ascorbic acid may also modulate the immune system via its role in
regulation of hormones associated with stress. There is a close
synergism between ascorbic acid and vitamin E is enhancing
neutrophil function and minimizing free radical damage. Vitamin C
can quench free radicals and there by protect the structural
integrity of the cell of immune system.
Vitamin c is synthesized in the rumen
of buffalos and cattle. It is in generally assumed that endogenously
produced ascorbic acid is sufficient to meet the metabolic demands
of ruminants. Under specific environmental and physiological
conditions, the amount of ascorbic acid produced by the animal may
be insufficient to meet its requirement.
Dairy Cow Nutrition
cow nutrition varies with phases of lactation and gestation.
Lactation period of dairy cow is divided into five phases:
1. This is phase of early lactation consists of early 70
days postpartum. This is the period during which milk production
increases rapidly, peaking at 6 to 8 weeks after calving. During
this phase nutrient requirements are not fulfilled because feed
intake does not keep pace with nutrient needs for milk production,
especially for energy, and body tissue will be mobilized to meet
energy requirements for milk production. Ration adjustment is an
important management practice during early lactation. Fiber level in
the total ration should not be less than 18 percent ADF, 28 percent
NDF. Forage should provide at least 21 percentage units of NDF or
about 75 percent of the total NDF in the ration. Physical form of
the fiber is also important. Normal rumination and digestion will be
maintained if greater than 20 percent of the forage is 2 inches in
length or longer. Chopping (less than 3/8 inch theoretical length of
chop—TLC), grinding, and/or pelleting all reduce physical form of
fiber and its effectiveness to stimulate rumination. Protein
is a critical nutrient during early lactation. Rations may
need to contain 19 percent or more crude protein to meet
requirements during this period.
Nutrients requirements must be met to avoid the problems like
ketosis or low peak production. Loss of 1 litre milk in peak
production leads to loss of 100 litres milk for lactation.
2. This phase is from 70 to 140 days postpartum during which
animal reaches peak DM intake. During this phase animal is at its
peak production and this production should be maintained as long as
possible. Animal should be provided high quality forage along with
3. This period is of mid to late lactation i.e. 140 to 305 days
postpartum. During this phase milk production is declining and the
cow is pregnant. Animal require nutrients for milk production and
replace body weight lost during early lactation. Lactating cows
require less feed to replace a pound of body tissue than dry cows.
Young cows should receive additional nutrients for growth
(2-year-old, 20 percent more; 3-year-old, 10 percent more than
4. Phase 4 is dry period that covers 60 to 14 days before
parturition. This is a critical phase of the lactation cycle. A
good, sound nutritional management during this phase may lead to
high milk yield during the following lactation and minimize
metabolic problems at or immediately after parturition as animal is
preparing for next lactation during this phase.
requirements include body maintenance, fetal growth, and replacing
any additional body weight not replaced during phase 3. Nutrients
requirements during this phase are lowest. Animal should be provided
1.8-2.1% DM of body weight. A minimum of 12 percent CP in the DM is
recommended. Concentrate requirements druing this phase are less.
Give 1 Kg Concentrate per day to maintain ruminal movements and
microflora. A high
forage (85%) content is thought to be beneficial to maintain maximum
rumen volume and motility. Due to higher chewing activity more
saliva is produced, which will buffer the rumen
and help maintain a higher rumen pH which will allow rumen wall
lesions to recover from high gain rations during lactation.
and phosphorus requirements should be met, but large excesses must
be avoided. Dry cow rations above 0.6 percent calcium and 0.4
percent phosphorus (DM basis) have substantially increased milk
fever problems. Adequate amounts of vitamin A, D, and E in rations
to improve calf survival and lower retained placenta and milk fever
problems should be proved. Trace minerals, including selenium for
most producers, should be adequately supplemented in dry cow diets.
5. This period is called transition period or close up period
which includes last two weeks of parturition. Nutritional
requirements for fetal growth are higher during this phase. Good
nutritional planning is required during this phase to get high milk
production after parturition. DMI intake decreases and energy
requirement increases to meet fetal growth so high energy diets
should be provided. Mineral and vitamin supplementation is also
required. Ingredients like concentrate to be used during lactation
should be started in small amounts during this phase as it reduces
the nutritional stress after parturition. CP % should be exceeded
upto 15%. Feeding some of additional protein in the form of
undegradable protein may be beneficial in supplying amino acids for
fetal growth. Fat content in the ration should be limited as high
fat feeding will depress DM intake. In case of problem of edema salt
should be removed from the ration.