Roberto
Luiz Teodoro1,2 , Rui da Silva Verneque1,2 Maria Gabriela
C.D. Peixoto1
1 Researcher of Embrapa Dairy Cattle - Rua Eugênio
do Nascimento, 610 – Bairro Dom Bosco 36.038-330
Juiz de Fora – MG, Brazil, rteodoro@cnpgl.embrapa.br
2 CNPq scholarships,
1.Introduction
During the first four centuries
of Brazil’s history, cattle breeding was developed
with the use of European cattle (Bos taurus taurus),
originated from temperate weather countries. However,
at the tropics, weather characteristics and management
are very special, leading to a condition of stress to
these animals, which could lead them to a decrease in
production and even death. Only from the middle of the
last century, producers learned not to fight against
nature, getting from India the Zebu cattle (Bos taurus
indicus), which nowadays occupies the largest part of
our continental country. Then, in a few years the Zebu
did what the European cattle were not able to do in
many centuries: to adapt naturally to the adverse conditions
of the Brazilian tropics.
The extraordinary development of Brazil’s bovines,
particularly in Central, Northern and Northeastern Brazil,
was mainly due to the introduction of the Indian breeds.
Zebu animals revigorated the existing degenerated cattle,
introducing the lacking rusticity to the specialized
bovine of European origin, through crossings, allowing
them to survive, reproduce and, mainly, to produce at
the predominant management conditions. It is estimated
that Brazil imported around 800,000 bovines of Europeans
breeds, against only 6,000 of the Zebu breeds. Nevertheless,
it is also estimated that nowadays around 80% or more
of the Brazilian bovine has genes of the Zebu breeds
in their genetic composition, demonstrating its importance
in the development and improvement of the national herd
of cattle.
Under a scientific vision we thought that the better
way to preserve and save the Zebu cattle in Brazil was
to improve it for milk production and its contents,
looking also for its welfare and confort.
Brazil is now an important center of cattle raising
and selection some Zebu breeds, occupying a good place
in the ranking not only quantitatively but, mainly due
to high quality level of the cattle, which is a response
to the criterious work of selection and improvement,
specially inside the farms. Nowadays it continues through
consolidated national programs, which intend to do the
improvement of these breeds.
In the beginning of the Zebu importation some animals
were brought from Africa, but it was at India that the
pioneers of our cattle raising found animals from different
Zebu lineages, classified according to their features,
functions and utilities, which after crossing with native
cattle in Brazil showed to cattle breeders the solution
of the majority of their problems. Among the introduced
breeds the ones who predominated were Nelore (originated
at Ongole), Gyr and Guzerá (originated at Kankrej),
followed by Sindi and Kangayan. The Nelore, Gyr and
Guzerá breeds were initially explored mainly
for the meat, the former being the most predominant
and hence occupying a large share of the national raising
cattle herd. The Gyr breed, and recently the Guzerá
breed, have been undergoing, in the last decades, an
intensified process of selection and improvement for
milk production through programs of progeny test and
multiple ovulation and embryo transfer nuclei (MOET).
The Sindi breed, which has low numeric expression but
a high potential for milk production, has been raised
in small nuclei mainly at the Northeast region of Brazil,
a very dry region of our country. Very few farms has
also started to work recently with Nelore cattle for
milk production.
2. Productive and reproductive traits
of Indian cattle in Brazil
2.1. Gyr breed
The Gyr breed is explored
mainly for milk production in India. According to Ledic
(1995), when introduced in Brazil this breed was selected
for meat production, showing later a lower efficiency
in comparison to other Zebu breeds under our environmental
conditions. However, it showed potential for milk production
and at the 1930’s several herds of this breed
were formed. The selection for milk production in Gyr
has coming since this time. In 1985 it was established
the progeny test for this breed involving a few number
of breeders under supervision and technical coordination
of Embrapa, from the Brazilian government. The first
results from sire evaluations were reported in 1993.
Information about productivity and reproductivity of
the Gyr breed are shown in Table 1.
Table
1. Average for productive and reproductive traits of
Gyr cows from herds involved in the progeny test for
milk production in Brazil.
Trait |
Number
of observations |
Mean |
Maximum |
Milk
yield at 305 days *(kg) |
27,431 |
2,599 |
14,580 |
Milk
yield per lactation * (kg) |
27,431 |
2,778 |
16,882 |
Lactation
length (days) |
27,431 |
291 |
619 |
Milk
fat content (%) |
16,771 |
4.6 |
7.0 |
Age
at first calving (months) |
6,911 |
45.2 |
65.5 |
Calving
interval (days) |
15,365 |
492 |
730 |
* adjusted to the adult
age (between 7 and 8 years old)
This program started with
only ten young sires at the first year, increasing this
number each year and now we are testing 30 sires a year.
These young sires, sons of the best cows and proved
bulls are tested in collaborating farms, where are produced
their progenies. They are tested for milk production
and its content, as fat and protein milk, lactose and
total solids since the market at nowadays is just paying
for them. Until now, 161 bulls were proved for these
traits and around 140 more bulls are in test (Verneque
et al., 2007). Almost 50,000 lactation records form
the data bank of this breed. At the begin the mean of
milk production was around 2,300 kg per lactation and
now it is around 2,800 kg, with 290 days of lactation
length, in the Gyr population. It was due mainly the
selection but also due to the improvement of the management,
what it is also important. The market of Gyr semen increased
almost 563% in this period, coming from 70,000 dosis
sold in 1992, with the first results of the progeny
test, to almost 600,000 dosis sold in the last year.
It represents the success and acceptability of the program
for the breeders in Brazil and Latin America.
2.2. Guzerá breed
In India the Kankrej breed,
equivalent to Guzerá in Brazil, is used for milk
production and traction work due to its bulk. In Brazil,
since its introduction, it has been used for milk and
meat production, although the selection for milk production
has intensified only at the beginning of the 1990’s.
In 1994 the progeny test for milk was initiated and
also a program at the open MOET selection nucleus for
milk production. The productive performance of these
animals is presented in Table 2.
Table 2.
Average for productive and reproductive traits of Guzerá
cows from herds involved in the progeny test for milk
production in Brazil.
Trait |
Number
of observations |
Mean |
Maximum |
Milk
yield at 305 days *(kg) |
2,298 |
2,339 |
7,234 |
Milk
yield per lactation * (kg) |
2,298 |
2,400 |
7,255 |
Lactation
length (days) |
2,298 |
285 |
554 |
Milk
fat content (%) |
851 |
4.9 |
6.9 |
Age
at first calving (months) |
575 |
44.2 |
64.7 |
Calving
interval (days) |
1,040 |
456 |
721 |
* Adjusted
to the adult age
The progeny test here, similar to the
Gyr program, has proved until now 45 young bulls with
other 35 in testing (Teodoro et al., 2007). The MOET
(multiple ovulation and embryo transfer) nuclei breeding
system consists of a nuclei herd with the best animals
available across all herds, in which the MOET technique
is used intensively to promote selection. Contemporary
families are formed with at least three females and
a male. A very important factor to be considered in
this system is the high genetic initial lift that can
be obtained. Once the initial generation is formed by
a small number of elite animals, there will be a high
genetic superiority of these animals in relation to
the basic population. In developing countries, where
there are difficulties in introducing conventional systems
for progeny tests, since neither artificial insemination
nor milk control are applied at the ideal frequency,
the concentration of financial, human and animal resources
at MOET nuclei can allow the use of current technologies
(Smith, 1988). Considering this information, a MOET
nuclei for selection of the Guzerá breed was
introduced in 1994 at “Taboquinha” Farm,
located in the district of Itambacuri, in Minas Gerais
state. This was a farm with good facilities for field
evaluation of progenies produced by CENATTE (Center
of Technical Assistance and Embryos Transference) from
the elite cows selected for milk yield. This work is
also carried out in association with Guzerá breeders
and with technical assistance by the Brazilian Center
of Guzerá Improvement (CBMG), the Association
of Guzerá Breeders from Brazil (ACGB), the Veterinary
School of UFMG and Embrapa Dairy Cattle Research Center.
Fifty two families with a total of 105 young males were
proved in the MOET nucleus with the results being more
faster than the progeny test that spend about six to
seven years for proving a bull.
A recent study of the genetic trend for this population
since at the begin of the program shows a genetic gain
about six kg of milk per year and the double of gain
only in the MOET population, showing the advantage for
using these technology, associated with the Progeny
test.
2.3. Nelore breed
Although in Brazil the Nelore breed,
or Ongole, has been selected for meat production, a
number of animals have been selected for milk since
the 1970’s. Dairy Nelore’s selection has
begun in 1972 at the Calciolândia Farm, also in
Minas Gerais state. The breeder, who selects Nelore
for extensive raising, Gyr and Guzerá for milk
production, observed that the milkers regularly milked
some Nelore cows for milk consumption of their families.
Thus he decided to form a herd of these animals selected
among the progenies with potential for milk production.
For starting this study, they selected cows which presented
well developed udders, more prominent mamarial veins
and better raised calves. Once identified, these cows
passed through a process of domestication and milking,
and were monthly submitted to the official dairy control.
Those cows with milk production greater than 1,200 kg
at the end of the lactation were then selected and their
progeny used, either as bulls or as cows.
The breeding stock always increased from the search
for cows with dairy traits. It is important to mention
that the selection of cows with potential for milk production
varied from 2 to 4%, meaning that a minimum of two in
100 young cows were incorporated to the dairy breeding
stock due to a good lactation (greater than 1,200 kg).
Besides selecting cows with potential for milk production
within the herd, since 1983 some cows were bought from
other breeders. This practice, which still takes place
nowadays, allowed the incorporation of new lineages
into the breeding stock. Table 3 shows the evolution
of the selection for more than 25 years.
Table 3.
Number of calvings, average for productive and reproductive
traits for Nelore breed, selected for milk production.
Year
of Calving |
Number
of Calvings |
Milk
yield at305 days* (kg) |
Lactation
length (days) |
Calving
intervals (days) |
Age
at first calving (months) |
74 |
10 |
1,200 |
264 |
- |
40.2 |
79 |
31 |
1,329 |
257 |
464 |
36.5 |
80 |
30 |
1,330 |
255 |
498 |
34.7 |
90 |
162 |
1,535 |
250 |
430 |
40.1 |
91 |
142 |
1,559 |
247 |
449 |
38.9 |
98 |
110 |
2,011 |
260 |
440 |
35.8 |
Table 4 shows averages for
some productive and reproductive traits for cows alive
presently. It is interesting to observe that, in general,
lactation length is about eight months and the average
daily yield is 7.8 kg. The calving interval is lower
than 15 months and the age at first calving is three
years and three months. Milk yields about 5,000 kg are
also observed, showing a genetic potential for milk
production.
Table 4. Productive and reproductive performance of
Nelore breed selected for milk production.
Trait |
Number
of observations |
Mean |
Maximum |
Milk
yield at 305 days *(kg) |
228 |
1,882 |
4,397 |
Milk
yield per lactation * (kg) |
228 |
1,927 |
4,917 |
Lactation
length (days) |
228 |
246 |
396 |
Milk
fat content (%) |
89 |
4.3 |
6.4 |
Age
at first calving (months) |
85 |
39.0 |
64.3 |
Calving
interval (days) |
104 |
445 |
730 |
* Adjusted
to the adult age
2.4. Sindi breed
The Sindi breed,
descended from Paquistan but also easily found in India,
was introduced in low numbers at the beginning of this
century in Brazil, together with the other zebu breeds.
Animals of this breed are in general small, have a good
milk production and are well adapted for regions with
adverse environment and difficulty for handling large
animals. This breed presents some racial characteristics
very similar to the Gyr breed, which possibly occasioned
its absorption into the large Gyr population. Nowadays,
few nuclei of the breed are still kept, apparently pure,
in several Brazilian regions mainly at the Northeast
and the North ones. Some cattle breeders, independently,
technically accessorized by Embrapa Dairy Cattle, keep
some sort of data control of their animals, including
milk production, reproduction and measures of racial
conformation, in order to better recognize its potential
and to genetically evaluate it as pure or crossbred,
multiplying and spreading it into regions which better
raising conditions, mainly at Brazil’s Northeast.
Table 5 shows averages for some traits of the production
and reproduction for the Sindi breed, obtained in two
different herds, both at Paraíba State, Northeast
region. Genetic evaluations of these animals have been
carried out by the Embrapa Dairy Cattle with the purpose
of identifying those animals which are superior, and
hence could be intensively breed.
Table 5.
Productive and reproductive performance of Sindi cows
at Northeastern region of Brazil.
Trait |
Number
of observations |
Mean |
Maximum |
Milk
yield at 305 days *(kg) |
446 |
2,299 |
6,589 |
Milk
yield per lactation * (kg) |
446 |
2,235 |
7,253 |
Lactation
length (days) |
446 |
275 |
457 |
Age
at first calving (months) |
143 |
37.6 |
59.8 |
Calving
interval (days) |
253 |
459 |
725 |
* Adjusted to the adult age
3. Impact of the Zebu in the Brazilian
dairy cattle
The Zebu has been intensively used in
crossings with European breeds resulting in animals
with a good productivity in the majority of the productive
systems prevailing in Brazil. However, when selected
for milk production it was verified that pure zebu has
responded to the improvement of management and to the
selection process. Due to the small population under
selection, the biggest impact that these breeds can
have on the national dairy cattle is as a genetic material
supplier, mainly as source of semen from tested bulls.
It is also possible to increase the female reproductive
efficiency through embryos transfer (TE) and “in
vitro” fertilization (FIV), generating a higher
number of progenies from superior cows. It is important
however, that animals sampled in these works should
be selected based on traits of economic importance and
not only based on their morphological characteristics.
4. References
LEDIC, I.L.1995. O Gyr Leiteiro. DBO
Rural, v,14, n.181, p.113-132.
SMITH, C. 1988. Genetic improvement
of livestock, using nucleus breeding units. World. Anim.
Review., v.65, p.2-10.
VERNEQUE, R.S., TEODORO, R.L.;; PEIXOTO,
M.G.C.D. 2007. Programa Nacional de Melhoramento do
Guzerá para Leite: Resultados do Teste de Progênie,
do Arquivo Zootécnico Nacional e do Núcleo
MOET. Juiz de Fora, MG. EMBRAPA-CNPGL, 28p. EMBRAPA-CNPGL.
Documentos, 119.
VERNEQUE, R.S., TEODORO, R.L., PEIXOTO,
M.G.C.D., LEDIC, I.L., MACHADO, M.A. 2007. Programa
Nacional de Melhoramento do Gir Leiteiro. Sumário
Brasileiro de Touros. Resultados do Teste de Progênie
Maio 2007. Juiz de Fora, MG. EMBRAPA-CNPGL, 56 p. EMBRAPA-CNPGL.
Documentos, 118.
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