Open Journal of Forestry
2013. Vol.3, No.4B, 7-9
Published Online October 2013 in SciRes (
Copyright © 2013 SciRes.
Reproductive Trends in Cebu Cattle Grazing Rice Crop Residues
in Colombian Tropical Dry Forest
Elisa Sierra-Montoya1, Rolando Barahona-Rosales1, Z. Tatiana Ruíz-Cortés2
1National University of Colombia, Medellín, Colombia
2Faculty of Agrarian Sciences, Group of Research BIOGÉNESIS, University of Antioquia, Medellin, Colombia
Received August 2013
The objective of this study was to describe the trend of reproductive performance of primiparous and
multiparous cows that grazed rice crop residues located in a Dry Tropical Forest of Colombia, taking into
account the rainfall pattern of the place. In this study, 89 primiparous and 309 multiparous Cebu cattle
records were analyzed. Mean, mean standard deviation for age at first calving and open days of primipar-
ous Cebu cattle were 41.05 ± 1.85 months and 269.7 ± 36.25 days respectively. Confidence intervals
(95%) for both reproductive parameters were 36.8 - 45.3 months and 202.7 - 336.6 days respectively. For
multiparous Cebu cattle, the mean and mean standard deviation for open days and calving interval were
245.6 ± 36.8 days and 17.5 ± 0.9 months respectively. Confidence intervals 207.1 - 366.9 days and 13.9 -
20.7 months respectively. The mean rainfall since 1999 until 2012 was 1202 mm per year. The reproduc-
tive trend of the primiparous cattle showed an increasing behavior of age at first calving since 1999 until
2012, that can possibly be explained due to the decreasing behavior of the rainfall throughout the years,
that can affect the nutritional value and offer of the grass that can grow in the borders of the crop, such as
Guinea and Star grass, and eventually affect the body condition and weight necessary to be ready for the
first estrous. An inverse behavior of open days occurred, showing a decreased trend along the last years of
research. This fact could have happened due to the intensive use of the enriched rice straw with urea and
molasses lately. Regarding to the reproductive trend of the multiparous cattle, there is no an evident pat-
tern of it. Factors such as rainfall, temperature, nutrition and management should have affected it. Further
research on this topic is needed.
Keywords: Rice Crop Residue; Reproduction; Cebú Herd
In 2012, Colombia (South American) has a bovine livestock
of 20.432.140. The beef production orientation is represented
by 49.6%, almost half of the herd, and it represents a very im-
portant economic income for the country.
Recent concern about the reproductive performance of these
beef and double purpose cattle has increased scientific research.
Free Trade Agreements between Colombia and other countries
such as the US and EU and policies as the Strategic Arrange-
ment of the Colombian Cattle Herd 2019, demand products as
meat of great quality. Lately, accelerated demographic growth
and urbanization (FAO, 2009) (Delgado, Ehui, & Cour, 1999)
results in the raising of the per capita income, triggering the
demand of meat and milk products. In order to achieve the goal
of beef productivity, Colombian cattle reproductive perfor-
mance must be enhanced taking into account nutrition and re-
productive management as the main issues to improve.
A considerable amount of beef cattle of the Colombian herd
grazes low quality forages and crop residues, as rice and maize.
These crops residues have severe deficiencies in protein, energy
and minerals contents, which can affect the reproductive per-
formance of beef cattle. This herd has specific reproductive per-
formance due to nutrition, management and climatic variables,
but published analyzed data are missing.
Data from a rice producer farm that has Cebu (Bos indicus)
cows located in Alvarado, Tolima, Colombia was collected
between 1999 and 2012, with the main objective of describing
the trend of reproductive development of primiparous and mul-
tiparous cows including rainfall patterns.
Materials and Methods
Data were obtained from a beef herd of the Hacienda Cali-
canto, a 170 hectares farm located in the municipality of Alva-
rado, Tolima, Colombia, at 439 meters above the sea level, in a
life zone of Dry Tropical Forest (Holdrige, 1967), The average
temperature was 26˚C, with a bimodal rainfall pattern during
the year; almost 8 months had low pluviosity. Most of the land
is dedicated to plant rice crops. When rice crops were harvested,
Cebu cattle were introduced to graze the residues of the crop:
the straw, with the main purpose of reducing the residue and
also incorporing it to the soil through trampling, for almost 4 or
5 months. The animals were supplemented with amonificated
rice straw, which means that the bales of rice straw were
enriched with a mixture of water, molasses and urea. The water
was ad libittum consumed. The Cebu cattle estrous was visually
detected by observations of the sire with penis deviation, and
registrated; 12 hrs later, artificial insemination was performed
as the main reproductive event registered in the farm. Confir-
mation of pregnancy was done by rectal palpation every 6
months. The cows give birth to calf in the rice field; calves
were suckling until 7 or 8 months, when males were sold and
females were retained to replace the old cows.
Copyright © 2013 SciRes.
Reproductive events from 1999 through 2012 of this Cebu
cows were used, including primiparous (n = 89) and multipar-
ous (n = 309) ones. Variables analysed such as the age at the
first calving, open days and calving period were included to
describe changes in reproductive performance of these cows
grazing rice crop residues. Data were put into 2-year groups (1:
1999-2000, 2: 2001-2002, 3: 2003-2004, 4: 2005-2006, 5:
2007-2008, 6: 2009-2010, 7: 2011-2012). Rainfall data from
1999 through 2012, except 2005, were described as a bimodal.
Bromatologic analysis was performed to amonificated rice straw
and rice straw to indicate the quality of the food consumed by
Statistical Analysis
Data were analyzed using the software SPSS version 14.0.
Descriptive statistic was performed. Mean and mean standard
deviation were calculated to describe the reproductive perfor-
mance of primiparous Cebu cattle (age at first calving and open
days) and multiparous Cebu cattle with 2 and more calvings
(open days and calving interval) within the period between
1999 and 2012; same analyses were performed for rainfall pe-
riod variables. Confidence level was 95% (p 0.05).
The average reproductive performance of the primiparous
Cebu cattle related to age at first calving is 41.05 ± 1.8 months
and open days mean is 269.7 ± 36.2. Regarding to the multi-
parous Cebu cattle, (2 or more parturitions), the open days av-
erage is 245.6 ± 36.84, and the calving interval average is 17.5
± 0.9 months.
Figure 1 depicts the age at first calving trend of the primi-
parous Cebu cattle. There is a similar behavior from 1999-2000
until 2009-2010, with an average age of 40.5 months at first
calving, but this age increases from 39.9 months to 45 months
from 2009-2010 to 2011-2012. Open days have a completely
different behavior starting with an average of 163 days (5.4
months) that increases until 2001-2002. Afterward this repro-
ductive parameter keeps a steady behavior until 2007-2008
when it increases to 390.58 days in 2009-2010. Subsequently it
decreases to 170.75 days in 2011-2012.
The confidence interval is 36.8 - 45.3 months of age at first
calving, and 202.7 - 336.6 of open days.
Figure 1.
Age at first calving and open days in primiparous Cebu cows (n = 89)
from 1999 to 2012 at Hacienda Calicanto, Colombia-South America.
Figure 2 represe nts the im portant variation of both open days
and calving interval of multiparous Cebu cows from 1999 to
The confidence interval is 207.2 - 366.9 open days a nd 13.9 -
20.7 months of calving interval.
Figure 3 shows the average rainfall between each two-year
period since 1999 until 2012.
Table 1 shows the bromatologic quality of the straw con-
sumed by the animals on Hacienda Calicanto. The crude protein
of the rice straw supplies the minimum value of protein for the
ruminal bacteria maintenance, which means that the probability
for these bacteria to grow in ruminal population is low, so the
Microbial Protein passing to the posterior digestive tract of the
ruminant is eventually minimal.
Reproductive trend of the primiparous Cebu herd of Hacien-
da Calicanto were similar to those published in 1996; authors
reported a mean age at first calving of 38.2 months, (García,
Maldonado-Estrada, & López, 2003; Haile-Mariam & Makon-
nen, 1996). Cattle Federation breeders in Colombia (FEDE-
GAN, 2006), stated that for beef production system in Colom-
bia, the age at first calving was 42 months. Similar results were
obtained recently (Khan & Chowdhury, 2011), with a mean of
Figure 2.
Open days (months) and calving interval (months) of multiparous Cebu
cows (n = 309) from 1999 to 2012 at Hacienda Calicanto, Colombia-
South America.
Figure 3.
Average rainfall for 2-year-period from 1999 until 2012 at Hacienda
Calicanto, Colombia-South America.
Copyright © 2013 SciRes.
Table 1.
Bromatologic analysis of rice straw and amonificated rice straw consumed by Cebu cows (398) at Hacienda Calicanto, Colombia-South America.
% % % % Cal/g % % % mg/kg % mg/kg % mg/kg mg/kg
Rice Straw 7.5 69.1 44.3 1.06 3891 15.86 0.15 0.08 103 0.13 257 1.81 712 21
Rice Straw 12 64 38.6 1.85 3841 17.25 0.42 0.04 48 0.16 177 1.27 42 11
4 months of calving interval for Sahiwal x Cebu cattle grazing
rice crop residues.
Regarding to the multiparous Cebu cattle, similar results with
14, 6 months period of calving interval were reported in Sahiw-
al cattle (Rehman & Khan, 2012); in multiparous Colombian
cattle (FEDEGAN, 2006) 18.3 months and 14.8 months in Ce-
bu cattle grazing Bothriochloa pertusa and Dichantium arista-
tum in North Colombian Tropical Dry Forest (García et al.,
In Sahiwal x Cebu multiparous cows grazing rice straw 209
open days average was reported (Khan & Chowdhury, 2011), a
similar behavior of the performance of the Cebu cows in this
Factors such as suckling stimulus and low nutritional status
of the animal (limited dietary energy and protein intake) can
explain the long period of open days (Rutter & Randel, 1984;
Wiltbank, 1979).
A similar inter-calving period of Cebu cattle was reported
many years ago, where Cebu cows had 19 months of the calv-
ing interval (Luktuke & Subramanian, 1961).
The primiparous Cebu cattle showed a steady reproductive
performance until 2009-2010, where this parameter decreased
severely. Possibly, this effect could be due to lowest rainfall
during this 2-year -period that could have affected the comfort
and welfare of the animals. It could have also affected the pas-
ture availability and quality as well as the consumption beha-
vior of the animals, because at low rainfall, high temperatures
and radiation are frequently experimented in this life zone. Both
high a low rainfall can affect the reproductive performance of
the Cebu cattle.
A similar issue cou l d ha ve happened to the multiparous cattle,
who in 2004-2005 and 2007-2008 presented the highest calving
period of all, possibly because of the lowest rainfall during
these years.
The reproductive trend of the primiparous cattle showed an
increasing behavior of age at first calving since 1999 until 2012,
that can possibly be explained due to the decreasing behavior of
the rainfall throughout the years, that can affect the nutritional
value and offer of the grass that can grow in the borders of the
crop, such as Guinea and Star grass, and eventually affect the
body condition and weight necessary to be ready for the first
conception. An inverse behavior of open days occurred, show-
ing a decreased trend along the last years of research. This fact
could have happened due to the intensive use of the enriched
rice straw with urea and molasses lately.
Concerning the reproductive trend of the multiparous cattle,
there is no an evident pattern, which means that factors such as
rainfall, temperature, nutrition and management should affect it.
Alternative ways of nutrition of these cows that graze rice
crop residues, such as planting fodder trees in the borders of the
crop, as Leucaena, Gliricidum sp. are proposed. Further re-
search on this topic has to be done.
The authors acknowledge the owner of the farm, Dr. Alberto
Mejía Fortich, who facilitated the research in Hacienda Cali-
canto, Mr. Jorge Eliecer Robayo, the administrator and the
cowboys Jorge, Dionicio and Angel María, who helped during
the investigation.
*Proyect: “Investigaciones para el incremento de la produc-
tividad silvopastoril y los servicios ambientales en el proyecto
Ganadería Colombiana Sostenible” financiado por COLCIEN-
CIAS. Centro para la Investigación en Sistemas Sostenibles de
Producción Agropecuaria-CIPAV. Universidad Nacional de
Colombia—Sede Medellín, Colombia. Grupo de Investigación
BIOGÉNESIS, Facultad de Ciencias Agrarias, Universidad de
Antioquia, Medellín, Colombia.
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