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Revista mexicana de ciencias agrícolas
Print version ISSN 2007-0934
Rev. Mex. Cienc. Agríc vol.13 n.7 Texcoco Sep./Nov. 2022 Epub Nov 22, 2022
https://doi.org/10.29312/remexca.v13i7.3333
Research notes
Chemical composition of four forage grasses from the state of Jalisco
1Departamento de Zootecnia-Universidad Autónoma Chapingo. Carretera México-Texcoco km 38.5, Chapingo, Estado de México. CP. 56230. Tel. 595 9521500.
2Colegio de Postgraduados-Campus Montecillo. Carretera México-Texcoco km 36.5, Montecillo, Texcoco, Estado de México. CP. 56230. Tel. 595 9520200.
In the Mexican tropics, livestock farming is based on extensive production systems, and it is important to know the nutritional content of forages, therefore the objective of this study was to evaluate the chemical composition of: Cenchrus ciliaris L., Megathyrsus maximus cv Guinea, Ixophorus unisetus and Megathyrsus maximus cv Tanzania, grasses established and frequently used in the Tropics for animal feed. The samples from the locality ‘San Luis Tenango’, Tonaya, Jalisco were analyzed at the Laboratory of Animal Nutrition, Department of Zootechnics, Chapingo Autonomous University. The following was determined: ashes (Ash), crude protein (CP), ethereal extract (EE), neutral detergent fiber (NDF), cellular content (CC), acid detergent fiber (ADF) and cellulose (Cel). Data analysis was performed with three repetitions and each repetition was considered an experimental unit. Pearson’s correlation and the separation of means by Tukey (p< 0.05) were performed. CP was positively correlated with Ash and CC and negatively correlated with NDF and ADF (p< 0.05). Megathyrsus maximus cv Guinea was the forage species with the highest amount of CP (12.9 g (100 g)-1), followed by (p< 0.05) Megathyrsus maximus cv Tanzania (8.7 g (100 g)-1). Megathyrsus maximus cv Guinea showed the highest percentage of Ash, 11.7 g (100 g)-1 and the lowest values of ADF and Cel and its NDF value (74.8 g (100 g)-1) was low (p< 0.05), slightly higher than that of Ixophorus unisetus (73.5 g (100 g)-1). Therefore, Megathyrsus maximus cv Guinea was the grass with the highest nutritional value.
Keywords: crude protein; neutral detergent fiber; nutritional value; proximate analysis; Van Soest method.
En el trópico mexicano la ganadería está basada en sistemas de producción extensivos y es importante conocer el contenido nutricional de los forrajes, por ello el objetivo del presente estudio fue evaluar la composición química de: Cenchrus ciliaris L., Megathyrsus maximus cv Guinea, Ixophorus unisetus y Megathyrsus maximus cv Tanzania, gramíneas establecidas y utilizadas con frecuencia en el trópico para la alimentación animal. Las muestras provenientes del Rancho ‘San Luis Tenango’, Tonaya, Jalisco se analizaron en el Laboratorio de Nutrición Animal, Departamento de Zootecnia, Universidad Autónoma Chapingo. Se determinó: cenizas (Cen), proteína cruda (PC), extracto etéreo (EE), fibra detergente neutro (FDN), contenido celular (CC), fibra detergente ácido (FDA) y celulosa (Cel). El análisis de los datos se hizo con tres repeticiones y cada repetición se consideró una unidad experimental. Se realizaron la correlación de Pearson y la separación de medias por Tukey (p< 0.05). La PC resultó correlacionada positivamente con Cen y CC y negativamente con FDN y FDA (p< 0.05). Megathyrsus maximus cv Guinea fue la especie forrajera con mayor cantidad de PC (12.9 g (100 g)-1), seguida por (p< 0.05) Megathyrsus maximus cv Tanzania (8.7 g (100 g)-1). Megathyrsus maximus cv Guinea mostró el mayor porcentaje de Cen, 11.7 g (100 g)-1 y los valores más bajos valores de FDA y Cel y su valor de FDN (74.8 g (100 g)-1) fue bajo (p< 0.05), levemente superior al de Ixophorus unisetus (73.5 g (100 g)-1). Por tanto, Megathyrsus maximus cv Guinea fue la gramínea con mayor valor nutricional.
Palabras clave: análisis proximal; fibra detergente neutro; método de Van Soest; proteína cruda; valor nutritivo
Mexico ranks eighth in the world in cattle population, with an inventory of more than 31 million heads, a figure that corresponds to 2.31% of the world herd (SADER-SIAP, 2021). Villegas et al. (2001) mention that the livestock activity of our country is of great importance, both for the economic participation and for the considerable sector that works in it. Also, (Enríquez et al., 2011) indicate that: in the tropical regions of Mexico, 64% of the cattle herd is kept, in 33% of the national territory, where 35% of the meat and 25% of the milk that the country produces are generated.
The livestock areas of Mexico are derived mainly from the ecology of the places, since the country has a great diversity of soils, topographies and climates, extending from the arid and semiarid zones of the north to the tropical regions of the Gulf and the Yucatan Peninsula. Due to the climatic characteristics and the soil-plant-animal relationship, the Mexican geography has been divided into the regions: arid and semiarid, temperate, dry tropical and humid tropical (SEMARNAT, 2021), some authors mention the mountain region (Herrera et al., 2008; López-Carmona et al., 2021).
Grasses are the basis of animal feed in the Mexican tropics. According to a study by Cruz et al. (2011) in the humid tropics, the seasonal distribution of the total yield, on average of 24 genotypes of Brachiaria grass, was: 83% in the rainy season, 9% in the north wind season and 8% in drought. The component with the greatest contribution to yield was that of leaves, with the following seasonal trend: north winds>dry>rainy, with averages of 77.6, 71.7 and 57.6%, respectively. The highest growth rate occurred in June (rainy season) with an average of 189 kg DM ha-1 d-1, which gradually decreased to 4 kg DM ha-1 d-1 in May of the following year (dry season), a result that coincided with that obtained by Ramírez et al. (2010) in the dry tropics of the state of Guerrero.
The soil factors that limit the production and persistence of forages are: acidic pH, high levels of exchangeable aluminum, manganese, poor meadow management and low availability of nutrients and organic matter, factors that together cause low persistence in most introduced forage species (Cruz et al., 2011).
Grasses are used as the main food source for ruminants and represent the largest volume of the diet, as they are cheaper, have a large production capacity and grow easily (Martínez et al., 2017). On the other hand, nutrient consumption is one of the main factors that restricts animal production in the tropics and can only be controlled if the nutritional value of forages does not constitute a limiting factor (Olafadehan and Okunade, 2018).
The relationship between the chemical composition and the availability of dry matter of the grass largely defines the productive potential of a cattle production system under grazing conditions (Torres et al., 2020). If the management criteria related to defoliation frequencies and cut heights are applied correctly, benefits in terms of productivity can be obtained from this system (Patiño et al., 2018).
Likewise, cut frequency and height influence the structure of the canopy of a meadow and affect the leaf:stem ratio, growth rate, stem population, leaf expansion rate and the removal of apical meristems, variables related to production (Rojas et al., 2020) and forage quality, in addition to influencing the longevity of plants by affecting their reserve carbohydrates (Cruz et al., 2011). This paper aims to study the chemical composition of four tropical grasses used for animal nutrition in the state of Jalisco: Cenchrus ciliaris L., Megathyrsus maximus cv Guinea, Ixophorus unisetus and Megathyrsus maximus cv Tanzania.
Location
The samples were collected at the locality ‘San Luis Tenango’ located in the Municipality of Tonaya, Jalisco, coordinates 19° 47’ north latitude and 103° 58’ west longitude, 820 m altitude. The characteristic soil of the municipality is chromic cambisol and the associated soils are eutric regosol and pelic and chromic vertisols. Two types of climates were distinguished at the site: warm-subhumid and semi-warm-semi-humid, which correspond to 57.6 and 42.4% of the area, respectively. The average annual temperature is 22.4 °C, with an average maximum of 33.4 °C and an average minimum of 10.9 °C. The average annual rainfall is 800 mm (IIEG-Jalisco, 2018).
Obtaining of samples
On November 15, 2019, approximately at five weeks of regrowth, the plants were manually cut, bagged and labeled and dried at 55 °C in a forced air oven to constant weight. Subsequently, they were ground (1 mm mesh) and identified, placed in plastic bags for their analysis in the Laboratory of Animal Nutrition of the Department of Zootechnics of the Chapingo Autonomous University, State of Mexico.
Determined variables
The following variables were determined: crude protein (CP), ethereal extract (EE), ashes (Ash), neutral detergent fiber (NDF), cellular content (CC), acid detergent fiber (ADF), cellulose (Cel) and hemicellulose (Hcel) (AOAC, 1990; Van Soest et al., 1991), all in g (100 g)-1 of dry sample.
Experimental design and statistical analysis
A completely randomized experimental design was used, with the four grasses as treatments, three repetitions for each variable. After performing the analysis of variance and the Tukey test for mean separation (p< 0.05), a Pearson correlation analysis was performed among all pairs of variables. The statistical package used was Statistical Package for the Social Sciences (SPSS, 2011) version 8.0.
Ashes (Ash)
For Ash of Megathyrsus maximus cv Guinea, a value of 12.2 g (100 g)-1 has been reported (Castrejón et al., 2017). In this study, values of 11.6 g (100 g)-1 were found (Table 1). For Ash in Cenchrus ciliaris L., values of 8.9 g (100 g)-1 (Ramírez et al., 2003) and 9.1 g (100 g)-1 (Castrejón et al., 2017) were found, the latter similar to that of the present study, 9.6 g (100 g)-1 (Table 1). It was observed that the ash content is high (close to 10%) in these grasses.
Table 1 Proximate analysis of four grasses from the state of Jalisco, g (100 g)-1 on a dry basis.
| Species | Ash | OM | CP | EE |
| Megathyrsus maximus cv Tanzania | 10.5 c | 89.5 b | 8.73 b | 1.2 b |
| Cenchrus ciliaris L. | 9.6 d | 90.4 a | 7.9 c | 1.1 b |
| Ixophorus unisetus | 11.1 b | 88.9 c | 7.6 c | 2.1 a |
| Megathyrsus maximus cv Guinea | 11.6 a | 88.4 d | 12.9 a | 1.2 b |
Means in the same column with a different letter are statistically different (p< 0.05). Ash= ashes; OM= organic matter (100- Ash); CP= crude protein; EE= ethereal extract.
Crude protein (CP)
For CP in Megathyrsus maximus cv. Guinea, the following values have been reported: 6.95 g (100 g)-1 (Ardila and Laredo, 1984), 8.09 g (100 g)-1 (Reyes et al., 2009), 10.49 g (100 g)-1 (Núñez et al., 2019), 10.1 g (100 g)-1 (Schnellmann et al., 2020) and 6.5 g (100 g)-1 ( Bautista-Tolentino et al., 2011). Values lower than that found in the present study, 12.9 g (100 g)-1 (Table 1). For CP in Cenchrus ciliaris L., values of 10.2 g (100 g)-1 (Ramírez et al., 2003) and 14.85 g (100 g)-1 (Sánchez et al., 2017) have been obtained. Values higher than those obtained in the present study, 7.9 g (100 g)-1 (Table 1). For CP in Ixophorus unisetus, values of 9.6% g (100 g)-1 (Molina et al., 1985), 12.88 g (100 g)-1 (Guevara et al., 1962) were found, which were higher than those found in the present study, 7.6 g (100 g)-1 (Table 1). Therefore, in this study, Megathyrsus maximus cv Guinea surpassed the others in CP.
Ethereal extract (EE)
A study by Guevara et al. (1962) indicates that the EE content of Ixophorus unisetus was 2.13 g (100 g)-1, a value higher than that obtained in the present study, 2.1 g (100 g)-1 (Table 1), in the experiment carried out no coincidences were recorded.
For EE in Megathyrsus maximus cv. Guinea, a value of 4.71 g (100 g)-1 has been reported (Castrejón et al., 2017), higher than that found in the present study, 1.2 g (100 g)-1 (Table 1). For EE in Megathyrsus maximus cv Tanzania, a value of 5.19 g (100 g)-1 (Castrejón et al., 2017) has been reported, a value higher than that found in the present study, 1.24 g (100 g)-1 (Table 1). Therefore, in this study, the grasses studied showed low EE value.
Table 2 Van Soest analysis of four grasses from the state of Jalisco, g (100 g)-1 on a dry basis.
| Species | NDF | CC | ADF | Cel | Hcel |
| Megathyrsus maximus cv Tanzania | 78.9 a | 21.1 d | 44.3 b | 36.1 c | 34.6 a |
| Cenchrus ciliaris L. | 77.2 b | 22.8 c | 47.3 a | 39.4 b | 29.9 b |
| Ixophorus unisetus | 73.5 d | 26.5 a | 48.3 a | 42.8 a | 25.2 c |
| Megathyrsus maximus cv Guinea | 74.8 c | 25.2 b | 39.1 c | 32 d | 35.7 a |
Means in the same column with a different letter are statistically different (p< 0.05). NDF: neutral detergent fiber or cell walls; ADF= acid detergent fiber; CC= cellular content (100-NDF); Cel= Cellulose; Hcel= hemicellulose (NDF-ADF).
Neutral detergent fiber (NDF)
For NDF or cell walls in Megathyrsus maximus cv. Tanzania, values of 72.2 g (100 g)-1 (Patiño et al., 2018), 74.6 g (100 g)-1 (Reyes et al., 2009) have been reported. The latter was similar to that found in the present study: 78.9 g (100 g)-1 (Table 1). For NDF in Cenchrus ciliaris L., 72.2 g (100 g)-1 (Ramírez et al., 2003), 62 g (100 g)-1 (Valle et al., 2004) and 68.85 g (100 g)-1 (Sánchez et al., 2017) have been reported. In the present study, values similar to those of the first two authors were found, 77.21 g (100 g)-1 (Table 2).
For NDF in Megathyrsus maximus cv Guinea, values of 68.36 g (100 g)-1 (Ardila and Laredo, 1984), 72.7 g (100 g)-1 (Reyes et al., 2009), 62.3 g (100 g)-1 (Schnellmann et al., 2020) and 80.2 g (100 g)-1 (Bautista-Tolentino et al., 2011) have been reported. In the present study, a value of 74.79 g (100 g)-1 was obtained, similar to that obtained by Reyes et al. (2009). The value of NDF or cell wall obtained in the present study was high, so these grasses are not recommended for young ruminants, but for animals with well-developed rumen.
Acid detergent fiber (ADF)
For ADF in Ixophorus unisetus, values of 32.8 g (100 g)-1 (Molina et al., 1985) have been reported, a much higher value of 48.3 g (100 g)-1 was found in this work (Table 2). For ADF in Megathyrsus maximus cv Guinea, a value of 47.44 g (100 g)-1 was found (Ardila and Laredo, 1984). A value higher than that found in the present work, 39.1 g (100 g)-1 (Table 2). Low ADF values compared to high NDF values are an indication that these grasses contain high hemicellulose values.
Cellulose (Cel)
For Cel in Megathyrsus maximus cv. Guinea, a value of 12.2 g (100 g)-1 has been reported (Castrejón et al., 2017). A very low value compared to that of the present study, 31.9 g (100 g)-1 (Table 2) probably due to the older age of this plant with respect to that studied by Castrejón et al. (2017).
Correlations
Positive correlations were found between Ash and CP and negative correlations between CP with ADF and CP with Cel (Table 3). This probably means that the most mineral-accumulating grass is also the most protein accumulating. In this study, the grass with the highest Ash content was Megathyrsus maximus cv Guinea and it was also the one with the highest CP content (Table 1). The negative correlations between CP and ADF and between CP and Cel are also reflected in Megathyrsus maximus cv. Guinea, which, although it produced high CP values, also showed the lowest ADF and Cel values. In contrast, Cenchrus ciliaris and Ixophorus unisetus, which produced the highest ADF and Cel values, also produced the lowest CP values. Negative correlations between CP and NDF and between CP and ADF have recently been observed by other researchers in grasses (Sánchez et al., 2017) and it is suggested that the harvest age should be carefully monitored, so that the plant does not become so fibrous, and its crude protein does not decrease so much.
Table 3 Pearson correlation coefficients between the variables determined in four grasses from the state of Jalisco.
| Ash | CP | EE | NDF | ADF | Cel | CC | Hcel | |
| Ash | 1 | 0.702* | 0.335 | -0.637* | -0.631* | -0.428 | 0.637* | 0.227 |
| CP | 1 | -0.393 | -0.215 | -0.956** | -0.882** | 0.215 | 0.722** | |
| EE | 1 | -0.715** | 0.496 | 0.678* | 0.715** | -0.791** | ||
| NDF | 1 | 0.009 | -0.228 | -1** | 0.496 | |||
| ADF | 1 | 0.968** | -0.009 | -0.864** | ||||
| Cel | 1 | 0.228 | -0.955** | |||||
| CC | 1 | -0.496 | ||||||
| Hcel | 1 |
*= p< 0.05, **= p< 0.01. Ash= ashes; CP= crude protein; EE= ethereal extract; NDF= neutral detergent fiber or cell walls; ADF= acid detergent fiber; Cel= cellulose; CC= cellular content (100-NDF); Hcel= hemicellulose (NDF-ADF).
Literatura citada
AOAC. 1990. Methods of analysis of the Association of Official Analytical Chemists. 15th Ed. Association of Official Analytical Chemists. Arlington. VA.. 771 p. [ Links ]
Ardila, G. A. y Laredo, C. M. A. 1984. Variación nutricional en pastos Guinea y Angelón de la zona ganadera del César, Colombia. Instituto Colombiano Agropecuario. 131-140 p. http://hdl.handle.net/20.500.12324/23345. [ Links ]
Bautista, T. M.; López, O. S.; Pérez, H. P.; De La Cruz, V. M. M. and Gallardo, L. F. 2011. Forage productivity in agroecosystems using traditional and rotational cattle grazing in Paso de Ovejas, Veracruz, Mexico. Trop. Subtrop. Agroecosys. 13(3):279-290. [ Links ]
Castrejón, P. F. A.; Corona, G. L.; Rosiles, M. R.; Martínez, P. P.; Lorenzana, M. A. V.; Arzate, V. L. G. y Olivos, A. P. 2017. Características nutrimentales de gramíneas, leguminosas y algunas arbóreas forrajeras del trópico mexicano: fracciones de proteína (A, B1, B2, B3 y C), carbohidratos y digestibilidad in vitro. 1ra . Ed. Facultad de Medicina Veterinaria y Zootecnia-Universidad Nacional Autónoma de México (UNAM). 172 p. [ Links ]
Cruz, L. P. I.; Hernández, G. A.; Enríquez, Q. J. F.; Mendoza, P. S. I.; Quero, C. A. R. y Joaquín, T. B. M. 2011. Desempeño agronómico de genotipos de Brachiaria humidicola (Rendle) Schweickt en el trópico húmedo de México. Rev. Fitotec. Mex. 34(2):123-131. [ Links ]
Enríquez, Q. J. F.; Meléndez, N. F.; Bolaños, A. E. D. y Esqueda, E. V. A. 2011. Producción y manejo de forrajes tropicales. Centro de Investigación Regional Golfo Centro-Campo Experimental La Posta, Medellín de Bravo, Veracruz, México. Libro técnico núm. 28. 443 p. https://redgatro.fmvz.unam.mx/assets/produccion-forrajes.pdf. [ Links ]
Guevara, M.; Guash, M. y Orlich, R. A. 1962. Composición de los varios forrajes y alimentos usados en la ganadería de Costa Rica. Ministerio de Agricultura y Ganadería. Servicio Técnico Interamericano de Cooperación. Boletín técnico núm. 40. 19 p. http://www.mag.go.cr/bibliotecavirtual/Q54-9709.pdf. [ Links ]
Herrera, A. G.; Agoa, P. V.; López, D. S.; Ochoa, N. A. y Ruiz, G. I. 2008. Producción de biomasa y capacidad sustentadora de los pastizales del noroeste del estado de Michoacán. Clave SIP20080021. Centro Interdisciplinario de Investigación para el Desarrollo Integral- Instituto Politécnico Nacional (IPN) Michoacán. 55 p. [ Links ]
IIEG-Jalisco. 2018. Tonaya diagnóstico del municipio. Instituto de Información, Estadística y Geográfica del Estado de Jalisco. https://iieg.gob.mx/contenido/Municipios/Tonaya.pdf. [ Links ]
López, C. M.; Jiménez, F. G.; Ben de J.; Ochoa, G. S. y Nahed, T. J. 2021. El sistema ganadero de montaña en la región norte-Tzotzil de Chiapas, México. Veterinaria México. 32(2)93-102. http://www.redalyc.org/articulo.oa?id=42332202. [ Links ]
Martínez, P. G.; Peri, P. L.; Huertas, H. A.; Schindler, S.; Díaz, D. R.; Lencinas, M. V. and Soler, R. 2017. Linking potential biodiversity and three ecosystem services in silvopastoral managed forest landscapes of Tierra del Fuego, Argentina. Inter. J. Bio. Sci. Ecosys. Serv. Manag. 13(2):1-11. Doi: 10.1080/21513732.2016.1260056. [ Links ]
Molina, D. E. J.; Osorio, C. H. y Guzmán, P. S. 1985. Evaluación nutritiva de Hatico (Ixophorus unisetus) y Pangola (Digitaria decumbens) en el valle del Cauca. Acta Agronómica. 35(2):80-101. [ Links ]
Núñez, D. J.; Ñaupari, V. J. y Flores, M. E. 2019. Comportamiento nutricional y perfil alimentario de la producción lechera en pastos cultivados (Panicum maximum Jacq). Rev. de Investigaciones Veterinarias del Perú. 30(1):178-192. [ Links ]
Olafadehan, O. A. and Okunade, S. A. 2018. Fodder value of three browse forage species for growing goats. J. Saudi Soc. Agric. Sci. 17(1):43-50. [ Links ]
Patiño, P. R. M.; Gómez, S. R. y Navarro, M. O. A. 2018. Calidad nutricional de Mombasa y Tanzania (Megathyrsus maximus, Jacq.) manejados a diferentes frecuencias y alturas de corte en Sucre, Colombia. CES Medicina Veterinaria y Zootecnia. 13(1):17-30. [ Links ]
Ramírez, R. G.; García, G. y González, H. 2003. Valor nutritivo y digestión ruminal del zacate buffel común (Cenchrus ciliaris L.). Pastos y Forrajes. 26(2):149-158. [ Links ]
Ramírez, R. O.; Hernández, G. A.; Carneiro, S. S.; Pérez, P. J.; Jacaúna, S. J. S.; Castro, R. R. y Enríquez, Q. J. F. 2010. Características morfogénicas y su influencia en el rendimiento del pasto Mombaza, cosechado a diferentes intervalos de corte. Trop. Subtrop. Agroecosy. 12(2):303-311. [ Links ]
Reyes, A. S. J.; Soto, M. A. C.; Ornelas, E. G.; Treviño, E. M. R.; Negrete, J. C. y Barragán, H. B. 2009. Estimación del valor nutricional de pastos tropicales a partir de análisis convencionales y de la producción de gas in vitro. Téc. Pec. Méx. 47(1):55-67. [ Links ]
Rojas, G. A. R.; Maldonado, P. M. Á.; Sánchez, S. P.; Magadan, O. F.; Álvarez, V. P. and Rivas, J. M. A. 2020. Growth analysis of grass Mulato II (hybrid Urochloa) by variety of cutting intensity. Inter. J. Agric. Environ. Bio. 5(4)2020. https://doi.org/10.35410/IJAEB.2020.5523. [ Links ]
SADER-SIAP. 2021. Secretaría de Agricultura y Desarrollo Rural-Servicio de Información Agroalimentaria y Pesquera. Población ganadera. Información sobre el número de animales que se crían en el país con fines de producción. https://www.gob.mx/siap/documentos/poblacion-ganadera-136762?idiom=es. [ Links ]
Sánchez, G. R. A.; Morales, N. C. R.; Hanson, J.; Santellano, E. E.; Jurado, G. P.; Villanueva, A. J. F.; y Melgoza, C. A. 2017. Caracterización forrajera de ecotipos de zacate buffel [Pennisetum ciliare (L.) Link] en condiciones de temporal en Debre Zeit, Etiopia. Rev. Mex. Cienc. Agríc. 8(1):13-26. [ Links ]
Schnellmann, L. P.; Verdoljak, J. J. O.; Bernadis, A. X.; Martínez, G. J. C.; Castillo, R. S. P. y Limas, M. A. G. 2020. Frecuencia y altura de corte sobre la calidad del Megathyrsus maximus (cv Gatton panic). Ciencia & Tecnología Agropecuaria. 21(3):1-11. [ Links ]
SEMARNAT 2021. Regiones ecológicas-ganaderas. http://dgeiawf.semarnat.gob.mx:8080/ibi-apps/wfservlet?ibif-ex=d2-agrigan04-01&ibic-user=dgeia-mce&ibic-pass=dgeia-mce&nombreentidad=*. [ Links ]
SPSS. 2011. Statistical Package for the Social SciencesInstitute. SPSS-X. User’s Guide. Version 8, Chicago IL. USA. [ Links ]
Torres, S. N.; Moctezuma, V. M.; Rojas, G. A. R.; Maldonado, P. M. Á.; Gómez, V. A. y Sánchez, S. P. 2020. Comportamiento productivo y calidad de pastos híbridos de Urochloa y Estrella pastoreados con bovinos. Rev. Mex. Cienc. Agríc. 24(esp):35-46. [ Links ]
Valle, J. L.; Palma, J. M. y Sangines, G. L. 2004. Biomasa y composición nutricional de la asociación Cenchrus ciliaris-Gliricidia sepium al establecimiento. Avances en Investigación Agropecuaria. 8(2):1-8. [ Links ]
Van Soest, P. J.; Robertson, J. B. and Lewis, B. A. 1991. Methods for dietary fiber, neutral detergent fiber, and non-starch polysaccharides in relation to animal nutrition. J. Dairy Sci. 74(10):3583-3589. https://doi.org/10.3168/jds.S0022-0302(91)78551-2. [ Links ]
Villegas, D. G.; Bolaños, M. A. y Olguín, P. L. 2001. La ganadería en México. Instituto de Geografía Universidad Nacional Autónoma de México (UNAM). México. 145 p. [ Links ]
Received: July 01, 2022; Accepted: August 01, 2022
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