Crude protein content in hybrids of Paspalum evaluated in the Pampa Biome of Southern Brazil


Received for publication: 28 January, 2019. Accepted for publication: 30 April, 2019 Doi: 10.15446/agron.colomb.v37n2.77535

1 Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul (Brazil).
² Noble Research Institute, Ardmore (USA).
³ Universidade Federal do Pampa, Rio Grande do Sul (Brazil).
* Corresponding author: marianaravila@gmail.com

Agronomía Colombiana 37(2), 189-192, 2019

Crude protein content in hybrids of Paspalum evaluated 
in the Pampa Biome of Southern Brazil

Contenido de proteína bruta en híbridos de Paspalum evaluados 
en el Bioma de Pampa en el sur de Brasil

Karla Saraiva de Ávila¹, Raquel Schneider-Canny², Mariana Rockenbach de Ávila³*,  
Miguel Dall’Agnol¹, and Eder Alexandre da Motta¹

ABSTRACT RESUMEN

The use of forage species adapted to the local environment 
allows an easier management, and greater production and 
stability. It also allows the conservation of the natural genetic 
resources, and the reduction of the costs and risks of production 
that further result in higher sustainability of the system. Forage 
quality may not be considered as important as biomass pro-
duction in many forage systems. However, when forage plants 
constitute most or all of the ruminant diet it assumes sub-
stantially greater importance. Therefore, the goal of this study 
was to evaluate the crude protein (CP) content of hybrids of P. 
plicatulum x P. guenoarum, in a region of Southern Brazil in 
the Pampa biome. The hybrids evaluated were: 10202, 1020104, 
102084, 102080, 1020133, 102058, 102069 (P. plicatulum “4PT” 
x P. guenoarum “Azulão”), 103063, 10308, 103042, 103040, 
103061, 103077, 103087, 103093, 103031, 103020, 103084, and 
103037 (P. plicatulum “4PT” x P. guenoarum “Baio”). The CP 
analyzes were performed on the leaves of the genotypes in 
each harvest. The hybrid 102069 “Azulão” presented the best 
CP content (16.4%) compared to the other genotypes in both 
years. These results are encouraging for forage breeding studies 
with species of the genus Paspalum.

El uso de especies forrajeras adaptadas al entorno local permite 
un manejo más sencillo y una mayor producción y estabilidad. 
También permite la conservación de los recursos genéticos 
naturales, la reducción de los costos y riesgos de producción, 
lo que resulta en una mayor sostenibilidad del sistema. La 
calidad del forraje no puede considerarse tan importante como 
la producción de biomasa en muchos sistemas forrajeros. Sin 
embargo, cuando las plantas forrajeras constituyen la mayor 
parte o la totalidad de la dieta para rumiantes, asume una 
importancia sustancialmente mayor. Por lo tanto, el objetivo 
de este estudio fue evaluar el contenido de proteína cruda (PC) 
de los híbridos de P. plicatulum x P. guenoarum, en una región 
del sur de Brasil en el bioma de Pampa. Los híbridos evaluados 
fueron: 10202, 1020104, 102084, 102080, 1020133, 102058, 
102069 (P. plicatulum “4PT” x P. guenoarum “Azulão”), 103063, 
10308, 103042, 103040, 103061, 103087, 103093, 103031, 103020, 
103084 y 103037 (P. plicatulum “4PT” x P. guenoarum “Baio”). 
Los análisis de PC se realizaron en las hojas de los genotipos en 
cada cosecha. El híbrido 102069 presentó el mejor contenido 
de PC en comparación con los otros genotipos en ambos años. 
Estos resultados son alentadores para los estudios de cría de 
forrajes con especies del género Paspalum.

Key words: forage plants, forage quality, forage breeding. Palabras clave: plantas forrajeras, calidad del forraje, mejora-
miento de forrajeras.

intraspecific and interspecific variability is high (Sartor et 
al., 2009). Paspalum species occur in most of the herbaceous 
communities in the distinct Brazilian ecosystems. It has 
suitable characteristics to be used for grazing as well as 
beneficial chemical composition for ruminant production 
(Valls, 2000).

The use of forage species adapted to the local environment 
allows an easier management, and greater production and 
stability. It also allows the conservation of the natural 

Introduction

Worldwide, forage plants are the cheapest way to produce 
and provide food to animals, enabling meat and milk 
production at low costs (Follett et al., 2001). Species of the 
genus Paspalum are the most important forage constitu-
ents of the natural grasslands in South America (Novo 
et al., 2016). The greatest diversity of species is found in 
the Central and Southern regions of Brazil and Paraguay, 
Eastern Bolivia and Northeastern Argentina; therefore, 

SCIENTIfIC NoTE

http://dx.doi.org/10.15446/agron.colomb.v37n2.77535


190 Agron. Colomb. 37(2) 2019

genetic resources and the reduction of the costs and risks of 
production, resulting in higher sustainability of the system 
(Townsend, 2008). 

The quality of forage plants is a factor that greatly affects the 
productivity of grazing ruminants. Therefore, evaluation 
of the crude protein (CP) content plays a very important 
role in the qualitative analysis of forages. In diets that do 
not provide a minimum of 7% of CP in the dry matter, the 
recycled urea is not enough to meet the nitrogen demand 
of rumen microorganisms, resulting in a decreased feed 
intake and digestibility (Van Soest, 1994). These factors 
determine the amount of ingested nutrients, which are 
necessary to meet the maintenance and production re-
quirements of the animals (Gomide, 1993). The selection 
of genotypes with greater forage production, forage quality 
and wide adaptability to diverse environments is one of the 
main goals in forage breeding programs. 

Steiner et al. (2017) obtained higher forage production with 
two native ecotypes of P. guenoarum and two ecotypes 
of P. notatum compared to the cultivar “Pensacola” (P. 
notatum) which demonstrates the possibility to use native 
ecotypes as cultivated pastures. Forage quality may not be 
considered as important as biomass production in many 
forage systems. However, when forage plants constitute 
most or all of the ruminants’ diet it assumes substantially 
greater importance (Brink et al., 2015). Therefore, the goal 
of this study was to evaluate the CP content of hybrids of P. 
plicatulum x P. guenoarum in a region of Southern Brazil 
in the Pampa biome.

Materials and methods

The experiment was carried out in the state of Rio Grande 
do Sul, in the municipality of El dorado do Sul, Depressão 
Central region, Brazil (30º05’ S, 51º39’ W, 40 m a.s.l.) dur-
ing two growing seasons, from February to April 2013 and 
from February to April 2014. The average annual tempera-
ture varied from 8.5-8.7ºC (June and July, coldest months) 
to 29.4-30.2ºC (January and February, hottest months). 
The average annual rainfall was approximately 1445 mm 
(Bergamaschi et al., 2013). Nitrogen fertilizer (as urea) was 
applied in the amounts of 180 and 130 kg ha-1 of N in 2013 
and 2014, respectively.

Artificial hybridizations were performed in greenhouse 
by the Forage Plants Breeding Group at the Department 
of Forage Plants and Agrometeorology (DPFA) of the Fed-
eral University of Rio Grande do Sul (UFRGS). Hybrids 

obtained from these crosses were previously evaluated in 
the field (individual plants) during the summer of 2010 and 
throughout the year 2011. The genotypes with the highest 
forage production were selected to compose the present 
study (Forage Plants Breeding Group, 2013). The hybrids 
evaluated were: 10202, 1020104, 102084, 102080, 1020133, 
102058, and 102069, which resulted from crosses between 
Paspalum plicatulum “4PT” x P. guenoarum “Azulão”, and 
the hybrids 103063, 10308, 103042, 103040, 103061, 103077, 
103087, 103093, 103031, 103020, 103084, and 103037, which 
resulted from crosses between P. plicatulum “4PT” x P. gue-
noarum “Baio”. The parents (“4PT”, “Azulão” and “Baio”) 
and the cultivar “Aruana” (Megathyrsus maximus) were 
used as controls. “Azulão” and “Baio” are native to the state 
of Rio Grande do Sul, Southern Brazil, while ecotype “4PT” 
is native to Corrientes, Argentina. “Aruana” is a warm-
season grass used in animal production systems in Brazil.

Five clonal plants of each genotype were planted, spaced 
by 20 cm, in a 1 m row. Each row was planted 50 cm apart. 
The experimental design was a randomized complete block 
(RCBD) with four replicates. The plants were harvested 
when 80% of the genotypes reached 35 cm height, leaving 
a 15 cm stubble height. The harvests were carried out on 
February and March 2013 and February and April 2014. 
The plant samples were separated into leaves, stems and 
inf lorescences. Subsequently, the samples of the plant com-
ponents were placed to dry in a forced air circulation oven 
at 55ºC for 72 h to obtain the dry matter weights, which 
were used to determine the CP content. 

The CP analyzes were performed on the leaves of the 
genotypes in each harvest. The CP content was determined 
according to the methods proposed by AOAC (1984) in the 
Animal Nutrition Laboratory of Embrapa Pecuária Sul. 
The data were submitted to analysis of variance (ANOVA) 
and an F test at 5% probability using SAS software (SAS 
Institute, 2002). When differences between genotypes were 
observed, a means comparison was performed using Scott-
Knott test at 5% probability.

Results and discussion

There was significant genotype x harvest interaction 
(P<0.05) for CP content in both years. At the harvest per-
formed in February 2013, the CP content ranged from 11.4% 
(102084 and 103031) to 16.3% for hybrid 102069 (Tab. 1). 
Higher CP content values were observed with the hybrids 
102069, 102080 and 10308 compared to the ecotypes “4PT”, 
“Azulão” and “Baio” and cultivar “Aruana”. In April 2013, 



191Saraiva de Ávila, Schneider-Canny, Rockenbach de Ávila, Dall’Agnol, and da Motta: Crude protein content in hybrids of Paspalum  
evaluated in the Pampa Biome of Southern Brazil

the CP content ranged from 11.1% for hybrid 102080, to 
18.5% (103042). In this harvest, hybrids 103042 and 102069 
had higher CP content than the ecotypes “4PT”, “Azulão” 
and “Baio” and cultivar “Aruana” (control). At the harvest 
performed in February 2014, the CP content ranged from 
10.9% (103084) to 17.8% for hybrid 102069. Higher values 
for CP content were observed at the second harvest in 2014 
(April) ranging from 12.8% (103087) to 20.4% (102069). In 
both harvests of 2014, the hybrid 102069 showed higher 
CP content than ecotypes “4PT”, “Azulão” and “Baio” and 
cultivar “Aruana”.

The CP content observed in some Paspalum interspecific 
hybrids was higher compared to other studies reported in 
the literature. Echevarria et al. (2016) evaluated Urochloa 
interspecific hybrid BRS RB331 Ipyporã and observed a CP 
content of 13.8%. Evaluating species of Megathyrsus maxi-
mus, Urochloa brizantha and Urochloa decumbens, Lima 
et al. (2018) reported CP contents of 10.2, 4.1 and 10.8% 
respectively. In a study with acessions of Paspalum atratum 

Swallen and Paspalum lenticulare Kunth, Marcon et al. 
(2018) observed CP content of 10.1 and 10.8% respectively.

The CP content is an important trait for the selection and 
improvement of nutritional characteristics in forage plants. 
Steiner et al. (2017) described mean values of 14.7% and 
14.2% for CP content from “Azulão” and “Baio”, respec-
tively. The findings in this research revealed that there were 
hybrids with higher CP content than the ecotypes used 
as parents and the commercial cultivar, especially hybrid 
102069 that had superior CP content in all harvests and 
years. The National Academies of Sciences, Engineering, 
and Medicine (2016) recommends 12% of CP for finish-
ing cattle. Therefore, it can be considered that CP values 
found for some hybrids and its progenitors are satisfactory 
for cattle weight gain even in the most demanding classes. 

Average across genotypes and higher CP content values 
were observed on April 2014 when compared to the other 
harvests (Tab. 1). 

TABLE 1. Crude protein content (%) of leaf blade samples of interspecific hybrids and ecotypes of the genus Paspalum, and the cultivar “Aruana” 
evaluated in Eldorado do Sul, RS, Brazil.

Genotypes
Harvest

february 13 April 13 february 14 April 14 Mean

102069 16.3 C-a 15.7 C-b 17.8 B-a 20.4 A-a 17.6

102080 15.4 A-b 11.1 C-f 13.5 B-c 15.4 A-c 13.9

10308 15.1 A-b 13.3 B-d 13.3 B-c 15.0 A-c 14.2

102058 14,5 B-c 12.9 C-d 14.0 B-b 16.2 A-b 14.4

103042 14.4 C-c 18.5 A-a 13.7 D-c 16.3 B-b 15.7

10104 14.1 B-c 12.6 C-e 14.8 A-b 14.8 A-c 14.1

103087 12.7 A-e 12.3 A-e 11.6 B-e 12.8 A-e 12.4

103077 13.9 B-c 12.8 C-d 13.9 B-c 16.2 A-b 14.2

“4PT” 13.8 B-d 12.9 C-d 13.6 B-c 15.0 A-c 13.8

“Azulão” 13.7 C-d 12.8 D-d 14.4 B-b 16.4 A-b 14.3

103061 13.6 A-d 12.3 B-e 12.3 B-d 13.6 A-d 13.0

10202 13.5 C-d 12.6 D-e 14.1 B-b 14.8 A-c 13.8

103093 13.3 C-d 14.2 B-c 14.4 B-b 15.2 A-c 14.3

103037 13.3 B-d 12.4 C-e 13.4 B-c 15.8 A-b 13.7

103063 13.1 B-e 13.3 B-d 12.7 B-d 14.9 A-c 13.5

“Baio” 14.0 B-c 14.0 B-c 14.2 B-b 15.3 A-c 14.4

1020133 12.5 C-e 12.3 C-e 13.6 B-c 14.3 A-d 13.2

103040 12.3 C-e 13.1 B-d 13.0 B-c 14.8 A-c 13.3

103084 12.3 B-e 11.5 C-f 10.9 C-f 13.3 A-e 12.0

103020 11.9 B-f 12.1 B-e 12.6 B-d 13.7 A-d 12.6

“Aruana” 11.9 B-f 12.5 B-e 12.4 B-d 13.2 A-e 12.5

102084 11.4 C-f 12.6 B-e 13.7 A-c 13.4 A-e 12.8

103031 11.4 D-f 12.2 C-e 13.6 B-c 14.5 A-c 12.9

Mean 13.4 13.0 13.5 15.0 13.8

Means followed by the same lowercase letters in rows and uppercase letters in columns do not differ by the Scott-Knott test at 5% probability.



192 Agron. Colomb. 37(2) 2019

This result can be attributed to cumulative effect of the 
nitrogen application in the second year, which may have 
provided benefits to increase CP content of the genotypes. 
Pereira et al. (2011), evaluating ecotypes of P. guenoarum 
and P. lepton (ex-nicorae), also observed the variation in 
the CP content between harvests and related it to the effect 
of nitrogen fertilization to increase CP.

The improvement of Paspalum species through artificial 
hybridization can be an important tool to obtain novel 
genetic resources with higher CP for pasture-based live-
stock production.

Conclusions

The hybrid 102069 (Paspalum plicatulum “4PT” x P. gue-
noarum “Azulão”) presented the best CP content compared 
to the other genotypes in both years. These results are 
encouraging for forage breeding studies with species of 
the genus Paspalum. Promising hybrids can be used in 
new crossings in order to continue to increase forage nutri-
tional characteristics or to be released as new cultivars. The 
hybrid 102069 will be used in coming evaluations within 
the Forage Plants Breeding Program of UFRGS. Since the 
hybrid progeny may include individuals for the sexual or 
apomictic type of reproduction, it is important to evaluate 
the reproductive biology of these hybrids. This analysis is 
already in progress. 

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