Introduction
Dairy production depends on the dairy cattle
reproduction, while effective calf management depends
on the structure and quality of feeds early in life. Ideally,
good-quality colostrum, milk, or its replacers should
provide 9–12 g of daily liveweight gain per 1 kg. Poor
weight gain is associated with poor immunity. However,
if daily liveweight gain exceeds 15 g, it often causes
obesity and affects the development of the mammary
gland, which reduces milk production in adulthood.
Good-quality calf starters prolong dairy cow’s
productive lifetime and increase its fertility. Second,
third, and fourth calves are known to grow into more
valuable cows capable of higher milk yields and fertility.
The determining factors for effective calf rearing are their
health, weight, and first calving age, which depend on the
quality of colostrum and feeds in the first three months of
life [1].
During this time, one calf consumes 300–350 L
of milk. However, feeding whole milk to dairy calves
reduces the marketability of dairy production and
increases the cost of herd management.
Calf milk replacers (CMR) can increase the
marketability and reduce these costs [2]. In Russia, CMR
market volume is 120,000 tons per year. The market
demands are satisfied by 30%, of which import accounts
for 20%.
Russia possesses sufficient resources of milk whey
to produce CMRs. The rapidly increasing pork and
soybeans production can provide animal fat and highquality
vegetable protein for CMR formulations.
A good CMR fulfills the following functions:
– providing controlled weight gain;
– replacing as much milk in calves’ diet as possible;
– offering opportunities for using any whey, except for
salted one;
– introducing fat in sufficient quantity;
– ensuring high microbiological indicators;
– increasing productivity while demanding little
investment.
CMRs for young farm animals can be classified
according to the main components:
– skim milk and vegetable/animal fats;
– whey protein concentrates and vegetable/animal fats;
and
– whey, vegetable protein concentrates, and vegetable/
animal fats.
These three CMRs have the same feeding efficiency,
but the plant-based CMRs are more economical. They
include protein concentrates that need special quality
standards. For instance, they should contain a particular
set of available amino acids but no such antialimentation
factors as oligosaccharides, allergenic proteins, various
inhibitors that might affect feed digestion, etc. These
factors can be eliminated by using special technologies,
e.g. protein purification or molecular weight change.
To ensure proper development of skeletal system,
качественными кормами, направлено на обеспечение воспроизводства и поддержание молочного стада. Цель работы –
комплексная оценка качественных характеристик молозива и заменителей молока, а также технологических подходов в этой
области.
Объекты и методы исследования. Молозиво и заменители цельного молока (ЗЦМ), методы их обработки; анализ процессов
получения новых видов ЗЦМ, направленных на ресурсо- и энергосбережение.
Результаты и их обсуждение. Приведены потребности телят в молозиве, обсуждены качественные характеристики
первичного молока и подходы к их регулированию. Особое внимание уделено микробиологическим показателям первичного
молока, значению молозива в формировании иммунитета молодняка. Охарактеризованы возможности ферментативного
регулирования функциональных свойств молозива в результате гидролиза белков с применением высокоактивной
эндопептидазы (алкалаза). Рассмотрены варианты использования различных ферментных препаратов и бактериальных
заквасок для получения гидролизованного и ферментированного молозива. Проведен анализ основных процессовых
показателей ЗЦМ с промежуточной влажностью. Обоснована целесообразность применения ряда методик для определения
жирнокислотного и белкового состава концентрированных ЗЦМ. Отмечено, что способы получения ЗЦМ оказывают
существенное влияние на значения анализируемых показателей.
Выводы. Воспроизводство и реализация генетического потенциала молочного стада, а также экономика
сельскохозяйственного производства определяются факторами, связанными с питанием молодняка сельскохозяйственных
животных. Ферментативная обработка сырья является перспективным подходом для получения продуктов с улучшенными
функциональными свойствами. Практическое применение глубоких гидролизатов молозива представляется целесообразным,
в том числе в составе специализированных продуктов детского, спортивного и диетического питания.
Ключевые слова. Молозиво, заменители цельного молока, гидролиз, антигенность, иммуноглобулины, ферменты,
жирнокислотный состав
Финансирование. Работа выполнена в рамках государственного задания Министерства науки и высшего образования
Российской Федерации (Минобрнауки России) (тема № АААА-А20-120011500098-1).
Для цитирования: Quality Control of Colostrum and Protein Calf Milk Replacers / V. D. Kharitonov, V. A. Asafov,
E. L. Iskakova [et al.] // Food Processing: Techniques and Technology. – 2021. – Т. 51, № 1. – С. 188–195. https://doi.
org/10.21603/2074-9414-2021-1-188-195.
190
KharitonovV.D. et al. Food Processing: Techniques and Technology, 2021, vol. 51, no. 1, pp. 188–195
a good CMR should contain available macro- and
microelements, which need to be introduced in such a
way as to ensure effective utilization.
Acid whey poses a certain challenge: it needs acidity
regulators that provide the required osmotic pressure in
the intestinal tract of animals.
If all the above factors are taken into account, new
technologies and formulations of plant-based CMRs can
ensure necessary weight gain and productivity.
As for soy-based CMRs, which are based on soy flour,
milk, and cereal flour, they have a lot of disadvantages as
they cannot be applied to very young animals and may
reduce their productivity in the future [1, 2]. The research
objective was to provide comprehensive assessment
of the qualitative indicators of colostrum and milk
substitutes, as well as to define possible technological
options in this area.
Study objects and methods
The studies were carried out on the premises of two
organizations: Laboratory of Resource-Saving Processes
and Functional Products at the All-Russian Scientific
Research Institute of the Dairy Industry (Moscow,
Russia) and the Research Laboratory of Applied
Biological Issues at Belarusian State University (Minsk,
Belarus).
The research featured colostrum, and calf milk
replacers (CMR) produced by the All-Russian Research
Institute of Dairy Industry. The assessment methodology
was based on physicochemical, biochemical, and
sanitary-hygienic indicators, as well as on the criteria for
the optimal weight gain of baby calves. The study made
it possible to define the efficiency factors, to develop
control methods for quality indicators and composition,
and to analyze the processes of obtaining new resourcesaving
and energy-efficient CMRs [3].
The study involved contemporary approaches
to defining the biologically active properties of
native, fermented, and hydrolyzed colostrum, i.e.
the fluorometric method for antioxidant activity, the
impedimetric method for antimicrobial effect, and the
Ames test for antimutagenic effect [4, 5].
Results and discussion
Colostrum quality assessment. Colostrum is a
valuable source of highly-concentrated biologically
active substances of protein nature:
– lysozyme, lactoperoxidase, and lactoferrin that perform
the functions of nonspecific immunity;
– immunoglobulins responsible for specific protection in
the first hours after birth; and
– transfer factors that serve as a signaling environment
for triggering the mechanism of specific body defense.
The quality of colostrum defines health status, weight
gain, and calf raising economy. The list of important
factors includes the IgG content, bacterial contamination,
and storage conditions.
High-quality colostrum for calf feeds should meet
the following requirements: IgG content ≥ 50 g/L of
immunoglobulins; amount of colostrum = 10% of the
body weight (≈ 4 L); feeding time after calving ≤ 6 h;
microbiological purity ≤ 100,000 CFU/mL [6, 7].
Bacterial contamination of colostrum can cause
various diseases. Moreover, bacteria prevent immunoglobulin
absorption. In this regard, microbiological
control methods for colostrum microflora are priority
scientific issues because colostrum quality on dairy
farms needs to be improved. Heinrichs et al. studied
heat treatment of colostrum in order to reduce
bacterial and pathogenic growth while increasing IgG
absorption. The scientists also established the upper
limit of immunoglobulin absorption from colostrum
and its substitutes, as well as assessed the possibility
of introducing lactoferrin and sodium bicarbonate into
maternal colostrum [8].
The IgG concentration in the blood was found to
affect calves’ resistance to diseases. The amount of
absorbed immunoglobulins depends on their consumption
with colostrum, as well as on the efficiency of absorption
from the intestinal tract [9–11].
The calf should receive the first portion of colostrum
within the first hour after birth, and it should be at
least 70 mL/kg of body weight. The rate of feeding
colostrum during the first day depends on the IgG content
(Table 1) [12].
Colostrum immunoglobulins that a calf receives in
the first hours after birth lengthen the period of passive
immunity. Endogenous antibody synthesis sufficient to
protect calves from infectious diseases usually develops
at 1–3 months [9, 10].
A sufficient amount of high-quality colostrum allows
lacto- and bifidobacteria to colonize the intestines. The
normal intestinal microflora of calves consists of equal
numbers of lactobacilli, bifidobacteria, and Escherichia,
while the staphylococcus population is half as low [13].
Colostrum contamination occurs in the udder
or teat canal. It can also be caused by poor sanitary
conditions. Bacterial contamination of colostrum starts at
100,000 CFU/mL, but experts notice negative effects
already at 50,000 CFU/mL [14].
Table 1. Amount of colostrum in calves’ diet,
depending on the age and IgG concentration
Time after
birth, h
Colostrum feeding rate at a particular IgG
concentration, L
25 g/L 50 g/L 75 g/L 100 g/L
1 4.0 2.0 1.3 1.0
3 — 2.5 1.6 1.3
6 — 2.9 1.9 1.5
9 — — 2.2 1.7
12 — — 2.5 1.9
15 — — 2.8 2.2
18 — — — 2.4
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Low-temperature treatment at 63–66°С decreases
the level of microbiological contamination of colostrum
without affecting its immunomodulatory properties [15].
These methods reduce colostrum deficiency by
reserving it from healthy cows starting with the third
lactation. Mature cows produce better colostrum
compared to heifers. The density of their milk is higher
by 0.02 g/cm3, IgG content – by 73.4–122.2 mg/mL, IgA
and IgM – by 8 mg/mL and 6 mg/mL, respectively, and
the mass fraction of dry matter – by 2.4% [12].
One of our previous research showed that raw
colostrum obtained from farms in the Moscow Region
did not meet the above requirements for microbiological
parameters [3]. One of our previous studies featured
the possibility of reducing the bacterial contamination
of colostrum by its fermentation with Lactobacillus
acidophilus (strain No. 630, not viscous). The method
improved microbiological indicators, increased the
amount of lactic acid cultures, and raised the antioxidant
activity of fermented colostrum because the bacterial
proteolytic system was broken down by proteins [4].
Colostrum surpasses whole milk in nutritional
value and composition of biologically active components
[16–19], which makes it a promising raw material
for functional and diet foods for children, athletes,
etc. One of our previous studies also featured the
physicochemical and biologically active properties of
colostrum fermented with L. acidophilus and treated with
proteolytic enzyme (alkalase) [4].
The research defined the peptide composition,
antioxidant activity, antimutagenic properties, and
antimicrobial action of skim colostrum samples subjected
to hydrolysis and fermentation. Enzymatic hydrolysis
appeared to provide better proteolysis (17.4%) than
fermentation with L. acidophilus (7.5%). The antioxidant
activity of the peptide fractions of hydrolyzed and
fermented colostrum increased by 4.1 and 2.0 times as
compared to the original colostrum (dry solids content).
As the proportion of the peptide fraction and the degree
of colostrum proteolysis increased, the antiradical activity
increased and the level of induced mutation (in the Ames
test) decreased. Low molecular weight fractions of
hydrolyzed colostrum developed specific peptides with
antimicrobial activity.
As a result, they were found to be more effective
against Escherichia coli, test strain ATCC 8739, than
against Staphylococcus aureus, ATCC 6538 grampositive
strain [4]. Complexation of hydrolysates with
cyclic oligosaccharide (β-cyclodextrin) made it possible
to preserve the antimutagenic effect, increase the
antibacterial effect of colostrum peptides, and improve
their organoleptic properties [5]. The research results
proved relevant when introducing inclusion complexes
into functional products.
The abovementioned studies allowed us to obtain
samples of hydrolyzed and fermented colostrum with
confirmed biologically active properties [4, 5]. Therefore,
fermentation and hydrolysis proved able to regulate the
functional properties of products, which can be used in
developing new feeds for young farm animals.
Analysis of approaches to assessing the quality
indicators of new types of milk replacers. Various CMRs
can increase marketability and reduce costs in dairy
farming [3, 20].
The types of CMRs that are popular in contemporary
dairy farming are based on:
– skim milk and non-dairy fats;
– whey protein concentrate and non-dairy fats;
– whey and specialized concentrates and isolates of soy
protein and non-dairy fats; and
– whey, soy flour, and non-dairy fats.
The first three types are complete balanced feeds
adapted to the needs of calves. They provide an average
daily weight gain of 650–900 g. The fourth is intended
for older calves. For an adapted feed, it contains too
much lectins, oligosaccharides, and allergens.
According to the production method, CMRs are
divided into whole milk replacer, which is a liquid
product dried on a spray dryer, and regenerated milk
prepared by dry mixing of ingredients, including fat.
Each method has its own advantages and
disadvantages. Regenerated milk is more technologically
advanced in terms of production. However, fats have to
be introduced since calf feeds should not contain free
fats. If free facts are present in the feed, calves absorb
it poorly and develop slowly. As a result, regenerated
milk has a low fat percentage (12%). The fat:protein
ratio is 0.5:1, while in milk it is 1.2:1. Thus, calves may
not receive the energy necessary for growth and have to
consume more feed to replenish it.
The main condition for the CMR production is that
replacers should be cheaper than whole milk and provide
a required growth rate.
The correct economic assessment of CMR cost is the
cost of feed per 1 kg of weight gain. It justifies the use
of whey-based replacers, specialized concentrates, and
isolates of soy proteins and non-dairy fats. These CMRs
are as effective as CMRs based on skim milk, but their
raw material composition is significantly cheaper. Low
energy consumption and specific capital investments are
important factors in CMR production.
CMRs with intermediate moisture are quite
advantageous as they make it possible to:
– reduce spray drying costs;
– use any kind of whey, except for salted one;
– add fat in any required amount;
– start a low investment production;
– use methods of fermentation of protein fractions;
– obtain products with specified probiotic properties; and
– achieve good recombination before use;
– obtain a product with a high degree of fat emulsification
and a minimum content of free fat.
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KharitonovV.D. et al. Food Processing: Techniques and Technology, 2021, vol. 51, no. 1, pp. 188–195
CMR production for young farm animals has acquired
industrial scales in most developed countries. In Russia,
it started in the 1970s [20, 21].
Specialists dealing with CMR technologies focus on
regulating their composition and functional properties
and calculating the rational content of the mass fraction
of solids. One of the topical areas of research is the
development of new methodological approaches to the
CMR technology, e.g., how to avoid drying stage and
produce concentrated CMR. The production methodology
and quality assessment of concentrated CMRs include the
following stages:
1. Technological and processing options and
parameters for obtaining various products based on dry
and concentrated CMRs. Parameters that provide the
required levels of optimization, composition, quality, and
physicochemical properties involve technological modes
at all production stages, including biotechnological
transformation of raw materials components during
processing.
2. Parameters that ensure increased ecological safety,
as well as low energy and resource consumption.
3. Interconnection between quality indicators and
properties of dry and concentrated products, production
modes, and energy consumption.
4. Parameters that assess the end use based on
objective testing, including zootechnical research.
5. Indicators of economic efficiency.
This methodology requires the basic technological
regimes that determine the optimal ranges of the mass
fraction of dry substances at various stages of dehydration
and in the final product. These technological modes
depend on the physicochemical and thermophysical
properties of the product during production [22].
These specific features mean that the methodology
for concentrated CMR production must observe some
specific approaches. For instance, the efficiency of
dehydration decreases during the first stage following
the increase in the concentration of the mass fraction of
dry substances. During vacuum evaporation, the heat
transfer coefficient decreases as the mass fraction of
dry substances increases during thickening. Another
limiting factor is that viscosity increases together
with the concentration of the mix, which increases
energy consumption and can terminate the dehydration
process [20].
Dehydration usually presupposes a two-stage
scheme of sequentially mounted reverse osmosis units.
As a result, it is possible to estimate the approximate
permissible concentrations of the condensed product.
For example, the limiting concentration of milk whey is
25% when using reverse osmosis plants and 57% when
using vacuum evaporators. These values depend on the
properties of the mix before concentration and require
experimental testing.
The mass fraction of the dry matter of concentrated
CMRs can be controlled by adding additional components
to the mix – dry or texturized. These processes in
combination with direct methods of concentration make
it possible to control the mass fraction of dry substances
in a rather wide range. The upper values are affected by
viscosity, gelling properties, and stratification, which
depend on temperature and some other factors.
Another important task of concentrated CMR
production is to achieve maximal storage stability.
This indicator can be improved using several
effective techniques, e.g. pasteurization or cold storage,
which inhibits bad microflora. Other methods of
inhibiting pathogenic microflora include fermentation,
preservatives, heat sterilization, and ultraviolet
treatment [20].
From the point of view of production economy, long
shelf life is not important since it increases additional
costs for intermediate storage and related equipment.
The optimal storage temperature for milk replacer is
determined by its delivery radius and the technical
capabilities of each customer.
The approximate storage time for concentrated CMRs
is based on some assumptions.
The first assumption is that the production time and
use in practical conditions do not fluctuate. For example,
the production time does not exceed two days, even
taking into account its storage at the plant and a 20%
time cushion. The time the CMR spends on the farm is
approximately the same. Thus, the rational value of the
storage stability of concentrated CMRs depends only
on the delivery radius and time. The delivery time takes
no more than one day within a radius of up to 400 km.
Therefore, delivery time hardly affects the need to
increase the storage stability of concentrated CMRs.
What is more important is customer’s interest in
creating a stable, long-term supply of a concentrated
CMR on the farm. As a result, producers may want to
stock the CMR for the subsequent targeted delivery to the
customer in particular amounts.
Like many other multicomponent products with
intermediate moisture content, CMRs require a
complex multifactorial production process that can be
implemented in various ways using various technological
and technical methods of raw material processing
(Fig. 1).
Figure 1 shows that the basic principles of processing
multicomponent products remain the same, while
specific technological methods are constantly being
improved. Recent studies in the field of animal and plant
biotransformation revealed some new plant raw materials
and more effective means that facilitate and control
emulsification of vegetable fats and protein hydrolysis [4,
5, 23–31].
Such innovations help to achieve these goals (Fig. 1)
if based on the analysis of a set of interrelated process
parameters at all production stages.
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Харитонов В. Д. [и др.] Техника и технология пищевых производств. 2021. Т. 51. № 1 С. 188–195
New types of raw materials and processing methods
require new methods for assessing properties, quality,
and physicochemical parameters of the product, e.g.
the degree of emulsification of fats and changes in the
antigenicity of plant proteins at particular production
stages. For instance, the main indicators of high-fat
CMRs include the dispersed composition of vegetable
fats, assessed by the average diameter of the fat globules
and their level of monodispersity in the CMR.
Another indicator is the protein coating of the
fat globules. However, no official indicator has been
developed so far for assessing protein globule membranes
in concentrated CMRs. Qualitative assessment of this
indicator and change patterns in fat stability in various
processing modes are associated with dairy fat without
protein membranes. In liquid dairy products, such fat
is usually called destabilized, whereas in dry dairy
products, it is called free fat with surface free fat [26].
However, these indicators are not decisive for assessing
the properties of concentrated CMRs, for the reasons
mentioned below.
Free fat without globule membranes produce
almost no oxidative taste in dry whole milk during six
months of storage, even at 30°C. In dairy fats, the rate
of oxidative spoilage is highly inertial and depends on
the state of fatty acids, antioxidants, oxygen contact
surface, processing conditions, and storage conditions.
In concentrated CMRs based on milk fats, their oxidation
degree is always relatively low because they are based on
fresh milk [27].
Taking into account these factors and the relatively
short shelf life of concentrated CMRs, which does not
exceed several weeks, the oxidation degree of the fat
phase can be considered a limiting factor only for the
initial value immediately after production. However,
increased oxidation is an important factor when
producing concentrated CMRs with non-dairy animal and
vegetable fats.
As a result, the oxidation degree of non-dairy fats is
a limiting factor: the values of this indicator should be
equal to the dairy fat of pasteurized milk. Thus, when
producing a concentrated CMR, the oxidation degree of
fat phase should be determined before adding it to the
mix, not before feeding it to baby calves. Based on the
data mentioned above, the analysis of the total content
of unprotected fat, destabilized or free, should take
place after the methodology is improved and sample
preparation is thoroughly studied.
Additional tests required for fat phase assessment
include the assessment of its fatty and amino acids, as
well as the dispersion of fat globules, which should
correspond to the average size of fat globules in raw milk.
The assessment methodology for protein properties of
a concentrated CMR also has its peculiarities because of
its plant origin and different initial composition. In this
regard, reducing the level of anti-nutritional substances
in the protein composition is of great importance. As a
result, assessing the antigenic properties of the protein
and its polypeptide profile is also extremely important.
These indicators affect the zootechnical indicators
when feeding milk replacers to young farm animals.
Therefore, they should be controlled at various
production stages, using traditional or novel techniques
of biotransformation of the original protein raw material.
Conclusion
The main factor that determines the efficiency
and economy of feed for young farm animals is the
bioavailability of its protein and fat components.
The present research analyzed the qualitative
indicators of colostrum and milk replacers. The analysis
revealed that some of their physicochemical properties
need additional control, i.e. the concentration of
immunoglobulins, the polypeptide and amino acid profile
of the protein component. The sanitary and hygienic
indicators of primary milk can be controlled using various
approaches, e.g. thermal inactivation or fermentation of
colostrum with acidophilus bacillus, which reduces the
number of pathogens.
The animal and vegetable fats that are part of milk
replacers have some specific properties. Therefore,
Figure 1. Basic processing procedures and required indicators of concentrated milk replacers
Decreasing
resource
and energy costs
Increasing
storage
stability
Increasing
useful
properties
Increasing
economic efficiency
and competitiveness
Mixing
and dosing
Biotransformation
of protein
Emulsification
(homogenization)
of fat
Concentrating raw materials
to the required mass fraction
of dry substances in the mix
Ajusting production modes to the required indicators of the finished product
their assessment should be based on the methods for
determining the average diameter of fat globules, fatty
acid composition, and the initial oxidation state of fats.
A complex study of the fat phase requires methods that
make it possible to establish the peptide and amino acid
profile, as well as to assess the level of anti-nutritional
and antigenic properties. In concentrated milk replacers,
the qualitative and quantitative indicators of the
protein and fat components depend on the methods and
parameters their production.
Only by controlling the quality of colostrum and using
high-quality whole milk replacers, farmers can provide
rapid weight gain, earlier calving, high productivity, and
prolonged lactation.
Contributon
V.D. Kharitonov supervised the project and wrote
the paragraph about concentrated milk replacers.
V.A. Asafov collected the material on colostrum and
wrote the respective paragraph. E.L. Iskakova performed
the experimental research on the hydrolysis of plant
proteins, processed the obtained data, and described
the results. N.L. Tankova performed the experimental
studies of colostrum fermentation, processed the
data, and described them. T.M. Halavach conducted
the experimental research on enzymatic colostrum
hydrolysis, described the properties of the obtained
peptides, processed the data, and described the results.
V.P. Kurchenko supervised the project, collected research
material, and performed its synthesis.
Conflict of interest
The authors declare that there is no conflict of
interests regarding the publication of this article.

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