Introduction
⌅Currently there is environmental worsening due to the adverse socioeconomic impact that is in the agricultural sector, which is the result of the inadequate use of natural recourses. As well as the incorrect application of technologies so it is necessary to take strategies to mitigate and reverse the agricultural reality into a sustainable activity (Barragán-Hernández and Cajas-Girón 2019Barragán-Hernández, W.A. & Cajas-Girón, Y.S. 2019. Cambios bromatológicos y estructurales en Megathyrsus maximus bajo cuatro arreglos silvopastoriles. Ciencia y Tecnología Agropecuaria, 20(2): 231-258, ISSN: 2500-5308. https://doi.org/10.21930/rcta.vol20num2art:1458).
One of the main limiting factors for animal production in the tropics of Latin American and Cuba is the low availability and poor forages quality. Aspect that influence on the low livestock productivity, especially in areas of soils of natural low fertility, low drainage and with seasonal droughts (Patiño-Pardo et al. 2018Patiño-Prado, R.M., Gómez, R. & Navarro, O.A. 2018. Calidad nutricional de Mombasa y Tanzania (Megathyrsus maximus, Jacq.) manejados a diferentes frecuencias y alturas de corte en Sucre, Colombia. Revista CES Medicina Veterinaria y Zootecnia, 13 (1): 17-30, ISSN: 1900-9607. http://dx.doi.org/10.21615/cesmvz.13.1.2.).
Among these strategies it is the introduction of meadow species with high productive potential, adaptability to the changeable conditions of the environment and soil conditions, the Megathyrsus maximus specie is a grass with adequate response to the tropical conditions, although their real potential cannot be expressed by the edaphoclimatic conditions, mainly by the annual distribution of rains, and jointly with other factors of the environment and management, bring with it that these ones did not totally show their productive performance. These elements interact and have marked effect on the growth of species and varieties in the different months of the year, causing a lack of food mainly in the dry season (Herrera et al. 2020Herrera, R.S., Verdecia, D.M. & Ramírez, J.L. 2020. Chemical composition, secondary and primary metabolites of Tithonia diversifolia related to climate. Cuban Journal of Agricultural Science, 54(3): 425-433, ISSN: 2079-3480. https://www.cjascience.com/index.php/CJAS/article/view/976. and Cedeño-Aristega et al. 2021Cedeño-Aristega, M. J. C., Murillo, R. A. L., Coronel, A. L. E., & Garaicoa, D. A. R. 2021. Producción y composición química de Megathyrsus maximus cultivares Tanzania y Mombasa bajo condiciones del subtrópico ecuatoriano. Ciencia Latina Revista Científica Multidisciplinar, 5(4): 6427-6443, ISSN: 2707-2215. https://doi.org/10.37811/cl_rcm.v5i4.777.).
In the last years the advances reached in the field of production and animal nutrition needs the precise knowledge of yields and nutritional contribution of grasses and forages, which constitutes the higher source for animal feeding and more economic. For this, it is important to know the nutritive quality of the different grasses and forages, green or preserve, which take part of the ration and allow exteriorizing the high production potential of animals (Mojica-Rodríguez y Burbano-Erazo 2020Mojica-Rodríguez, J. E., & Burbano-Erazo, E. 2020. Efecto de dos cultivares de Megathyrsus maximus (Jacq.) en la producción y composición de la leche bovina. Pastos y Forrajes, 43(3): 177-183, ISSN: 2078-8452. http://scielo.sld.cu/pdf/pyf/v43n3/en_2078-8452-pyf-43-03-177.pdf.).
Due to the above, researchers about yield performance, chemical composition, digestibility and energy contribution of Megathyrsus maximus vc. Tanzania under several edaphoclimatic conditions in different areas of Granma province is of great importance, especially by the expectations that has being creating by their productive potential and wide level of adaptation to the different climatic conditions and wide range of soils. Hence, the objective of this research was to evaluate the productive performance, chemical characterization, digestibility and energy contribution of Megathyrsus maximus vc. Tanzania to different regrowth ages in both seasons of the year, under the climatic conditions of Granma province.
Materials and Methods
⌅Location of the experimental area, climate and soil
⌅The research was developed in areas of the UEB "Pedro A. Borras Astorga" located in Yara municipality, in the Empresa Agroindustrial de Granos "Fernando Echenique", during the two season of the year: rainy season (July-September, 2020) and dry season (November, 2020- January, 2021).
The soil in the area was fluvisol (Hernández et al. 2015Hernández, A., Pérez, J. M., Bosch, D., Rivero, L. & Camacho, I. 2015. Nueva versión de la clasificación genética de los suelos de Cuba. La Habana, Cuba: Instituto de suelos. La Habana, Cuba: AGROINFOR, 64 p., ISBN: 959-246-022-1.), with pH of 6.4. The content of P2O5, K2O and total N was 2.6, 37.5 and 34 (mg/100g of soil, respectively) with 3.3 % of organic matter.
During the rainy season, the rainfalls were of 731.4 mm; the average, minimum and maximum temperature recorded values of 26.73, 22.31 and 34.92 ºC, respectively and the relative humidity was 80.78, 51.02 and 96.22 %, for the average, minimum and maximum, respectively. In the dry season, the rainfalls reached values of 270 mm; the temperature was 24.05, 18.29 and 31.58 ºC for the average, minimum and maximum, respectively and the minimum, average and maximum relative humidity with averages of 76.21, 44.16 and 97.03 %, values that correspond with the historical average for the region.
Treatment and experimental design
⌅A random block design was used, the treatments consisted on the regrowth age (30, 45, 60 and 75 days) and four replications.
The experimental plots 25 m2 (5x5 m) were sowing in February, 2020 with 50 cm between rows and 20 cm between plants. The plants had an establishment period until July, 2020, where the uniformity cut was made. From there, samplings at 30, 45, 60 and 75 regrowth days were made, eliminating 50 cm of border effect and all the material from the harvestable area at 10 cm above soil level. The yield of total dry matter, leaves and stems, length and width of leaves and leaf/ stem ratio were evaluated (Herrera 2006Herrera, R.S. 2006. Fisiología, calidad y muestreos. In: Fisiología producción de biomasa y sistemas silvopastoriles en pastos tropicales. Abono orgánico y biogás. Ed. EDICA, San José de las Lajas, Mayabeque, Cuba. 1-108 p. ISBN: 978-959-7171-05-8). Then two kilograms were taken for each of the treatments and replications for further analysis in the laboratory. No fertilization, irrigation and chemical treatment was used to eliminate weeds. At the beginning of the experiment the population of the varieties in the plots was 97 %.
Determination of chemical composition
⌅The samples after collecting were dried in an air forced-draft oven at 65 °C, later were milled to 1mm particle size and stored in amber bottles until their analysis in the laboratory. The DM, CP, ash, OM, P and Ca were determined according to AOAC (2016)AOAC, G.W. 2016. Official Methods of Analysis of AOAC International. 20th ed., Rockville, MD: AOAC International, ISBN: 978-0-935584-87-5, Available at: http://www.directtextbook.com/isbn/9780935584875. [Consulted: September 22, 2016].; NDF, ADF, ADL, cellulose (Cel), hemicellulose (Hcel) and cellular content (CC) according to Goering and Van Soest (1970)Goering, H.K. & Van Soest, P.J. 1970. Forage fiber analyses: Apparatus, reagent, procedures and some applications. In: Agriculture Handbook No. 379. Ed. U.S.D.A. Agricultural Research Service, Department of Agriculture, United States of America, p. 20. https://handle.nal.usda.gov/10113/CAT87209099.; the dry matter digestibility was quantified by Aumont et al. (1995)Aumont, G., Caudron, I., Saminadin, G. & Xandé, A. 1995. Sources of variation in nutritive values of tropical forages from the Caribbean. Animal Feed Science and Technology, 51(1-2): 1-13, ISSN: 0377-8401. http://doi.org/10.1016/0377-8401(94)00688-6. and the metabolizable energy and net lactation energy were established according to Cáceres and González (2000)Cáceres, O. & González, E. 2000. Metodología para la determinación del valor nutritivo de los forrajes tropicales. Pastos y Forrajes, 23(1): 87-92, ISSN: 0864-0394. https://hal.science/hal-01190063/document.. All analyzes were performed in duplicate and by replication.
Statistical analysis and calculations. Analysis of variance was performed according to the experimental design and mean values were compared using Duncan (1955)Duncan, D.B. 1955. Multiple range and multiple F test. Biometrics, 11(1): 1-42, ISSN: 1541-0420. https://doi.org/10.2307/3001478. multiple range test. For the normal distribution of the data the Kolmogorov-Smirnov (Massey 1951Massey, F.J. 1951. The Kolmogorov-Smirnov test for goodness of fit. Journal of the American Statistical Association, 4(543): 68-78, ISSN: 1537-274X. http://dx.doi.org/10.2307/2280095.) test was used and for the variances the Bartlett (1937)Bartlett, M. 1937. Properties of sufficiency and statistical tests. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 160(2): 268–282, ISSN: 1471-2946. http://doi.org/10.1098/rspa.1937.0109. test.
Results and Discussion
⌅The yield during both season of the year (figure 1) had increases in accordance the plant maturity advance, with significant differences for p<0.05, among all the ages under study, with the highest results at 75 days of 4.02 and 2.56 tDM/ha/cut and increases of 2.35 and 1.54 tDM/ha/cut (58.46 and 40.62 %) for the rainy and dry season, respectively.
The increases of the dry matter yield with the regrowth age in both seasons of the year are due, mainly, that the plant increases the photosynthetic activity and with it the synthesis of structural carbohydrates, so there is increase in the accumulation of dry matter in the supporting organs as stems, with their higher amount during the rainy season. These results coincide with those reported by Verdecia et al. (2015)Verdecia, D. M., Herrera, R. S., Ramírez, J. L., Acosta, I. L., Uvidia, H., Santana, A. & Almanza, D. 2015. Potencialidades agroproductivas de dos cultivares de Megathyrsus maximus en la Región Oriental de Cuba. REDVET. Revista Electrónica de Veterinaria, 16(11): 1-9, ISSN: 1695-7504. https://www.redalyc.org/pdf/636/63643094002.pdf., for Valle del Cauto and Méndez-Martínez et al. (2019Méndez-Martínez, Y., Reyes-Pérez, J.J., Luna-Murillo, R.A., Verdecia, D.M., Rivero-Herrada, M., Montenegro-Vivas, L.B. & Herrera, R.S. 2019. Yield components and bromatological composition of three Megathyrsus maximus cultivars in Guayas area, Ecuador. Cuban Journal of Agricultural Science, 53(4): 437-446, ISSN: 2079-3480. https://www.cjascience.com/index.php/CJAS/article/view/928/994., 2020Méndez Martínez, Y., Reyes Pérez, J.J., Luna Murillo, R.A., Verdecia, D.M., Espinoza Coronel, A.L., Pincay-Ronquillo., W.J., Espinosa-Cunuhay, K.A., Macías-Pettao, R.K., & Herrera, R.S. 2020. Effect of climate area on yield and quality of three varieties of Megathyrsus maximus. Cuban Journal of Agricultural Science, 54(2):1-12, ISSN: 2079-3480. http://cjascience.com/index.php/CJAS/article/view/956.), for the cultivars Común, Tanzania, Mombasa and Tobiatá under the conditions of three regions of Ecuador, and find interaction variety- climatic zone. In addition, they stated that for the livestock in the tropic are difficult times, where the activity depends on the forage supply, while these ones in turn are in function of the soils and water, among other factors.
The farmers suffer this situation due to the forests degradation, later the forages and soils. This circle of economic, environmental and social degradation is a complex phenomenon at global scale recognized by the United Nations, named desertification. Process that is based on the reduction or loss of the biological or economical productivity of the earth bioproductive system that includes soil, vegetation, other biota components and ecological and hydrological processes, especially in the ecosystems from the dry areas, due to the way of using the earth and combination of resulting processes of the human activities and climatic factors (Maricelis et al. 2022Maricelis, L., Herrera, M. & Padilla, C. 2022. Modelos matemáticos para describir la producción de semilla Megathyrsus maximus vc. Mombasa. Revista Ciencia Universitaria, 20 (3): 1-29, ISSN: 978-959-16-4723-8, https://www.uaeh.edu.mx/ciencia_universitaria/revistas/2/revista.pdf.).
On the other hand, Cedeño-Aristega et al. (2021)Cedeño-Aristega, M. J. C., Murillo, R. A. L., Coronel, A. L. E., & Garaicoa, D. A. R. 2021. Producción y composición química de Megathyrsus maximus cultivares Tanzania y Mombasa bajo condiciones del subtrópico ecuatoriano. Ciencia Latina Revista Científica Multidisciplinar, 5(4): 6427-6443, ISSN: 2707-2215. https://doi.org/10.37811/cl_rcm.v5i4.777. under the Ecuadorean subtropics when evaluating Megathyrsus maximus cultivar Tanzania and Mombasa with rainfalls of 2061 mm and the average temperature for the rainy an dry season is 24.5 and 25.0 °C, respectively and sandy soil, find yields of 4-6 tDM/ha, productions higher to those reported in this research. These differences are marked by environmental factors that most contrast in the grasses performance like: time, locality, year, fertilization and irrigation, as well as also the specific and general adaptability of the cultivars in favorable and unfavorable environments (Milera et al. 2017Milera, M.D., Alonso Amaro, O., Machado Martínez, H.C., & Machado Castro, R.L. 2017. Megathyrsus maximus. Resultados científicos y potencialidades ante el cambio climático en el trópico. Avances en Investigación Agropecuaria, 21(3): 41-62, ISSN: 0188-7890. https://revistasacademicas.ucol.mx/index.php/agropecuaria/issue/view/30/52.). Although about the cultivar under study it can be state that this grass is easily adapted to different climatic conditions, although when there is excess of rains it can be affected influencing on their productive yields. However, it has been a widespread and introduced grass in the tropical zone by their advantages. Also, it was reported that in early age is most use by the animal due to the high capacity of leaves production (Maricelis et al. 2022Maricelis, L., Herrera, M. & Padilla, C. 2022. Modelos matemáticos para describir la producción de semilla Megathyrsus maximus vc. Mombasa. Revista Ciencia Universitaria, 20 (3): 1-29, ISSN: 978-959-16-4723-8, https://www.uaeh.edu.mx/ciencia_universitaria/revistas/2/revista.pdf.).
For the dry matter yield of leaves and stems (figure 2), there was a similar performance to the total yield, with significant differences for p<0.05 as the plant maturity advanced with increases up to 60 days for the leaves in the rainy season with 2.40 tDM/ha/cut, for later decrease up to 75 days in 0.15 tDM/ha/cut; while for the leaves in the dry season and stems in both seasons, increased up to 75 days with the highest values (1.70 and 0.86 tDM/ha/cut, respectively).
During the study periods the increase of the stems with the age and decrease of leaves for the rainy season from the 60 days is link to that during this stage there is stem growing and increase in the senescence of leaves, influenced by the climate conditions that interact and has marked effect on the growing and developing of species and varieties of grasses in the different months of the year, causing a seasonal unbalance in the yields, that cause high amounts during the rainy season (May- October) and low during the dry season (November- April). To this situation is added that, the soils destined to grasses cultivation, most of them are of low fertility and bad, that jointly to the climate, negative effects on the productivity and persistence of forages (Herrera 2022Herrera, R.S. 2022. Evaluation of Cenchrus purpureus varieties tolerant to drought in the western region of Cuba. Cuban Journal of Agricultural Science, 56(2): 135-143, ISSN: 2079-3480. http://scielo.sld.cu/scielo.php?script=sci_arttext&pid=S2079-34802022000200005.).
These aspects has been taking into account for the introduction of improvement species with adaptability to the different livestock systems, with higher potentialities from the productive point of view and nutritional quality, as the case of the variety under study (Tanzania). Hence that, Herrera et al. (2018)Herrera, R.S., García, M. & Cruz, A.M. 2018. Study of some climate indicators at the Institute of Animal Science from 1967 to 2013 and their relation with grasses. Cuban Journal of Agricultural Science, 52(4): 411-421, ISSN: 2079-3480. https://cjascience.com/index.php/CJAS/article/view/831. showed that the plant species exits, they reproduce and live in certain edaphoclimatic contexts, which can be consider as tolerance to those conditions. In the case of this study it can be verify, where the distribution of rains make important influence on the yield of this Megathyrsus maximus variety.
This performance is due, according to Avellaneda-Cáceres et al. (2019)Avellaneda-Cáceres, A., Navarro, J.A. & Micheloud, J.F. 2019. Impactación ruminal y abomasal en vacas de cría asociada al consumo de pasturas diferidas de Megathyrsus maximus cv. Gatton. Revista FAVE-Sección Ciencias Veterinaria, 18(1): 12-16, ISSN: 2362-5589. https://doi.org/10.14409/favecv.v18i1.8234, that the growing and productivity of grasses is influence by the climatic conditions mainly by the annual distribution of rains, that join to other environment factors and of management (fertilization, irrigation and cut frequency), had an effect on the grasses and forage did not totally reached their productive potential, which is showed in different zones in the tropics, in Ecuador in the Interandean regions, Amazonia and the coast as showed Uvidia et al. (2015)Uvidia, H., Ramírez, J., Vargas, J., Leonard, I. & Sucoshañay, J. 2015. Rendimiento y calidad del Pennisetum purpureum vc Maralfalfa en la Amazonía ecuatoriana. REDVET. Revista Electrónica de Veterinaria, 16(6): 1-5, ISSN: 1695-7504. http://www.veterinaria.org/revistas/redvet/n060615.html., Méndez-Martinez et al. (2020)Méndez Martínez, Y., Reyes Pérez, J.J., Luna Murillo, R.A., Verdecia, D.M., Espinoza Coronel, A.L., Pincay-Ronquillo., W.J., Espinosa-Cunuhay, K.A., Macías-Pettao, R.K., & Herrera, R.S. 2020. Effect of climate area on yield and quality of three varieties of Megathyrsus maximus. Cuban Journal of Agricultural Science, 54(2):1-12, ISSN: 2079-3480. http://cjascience.com/index.php/CJAS/article/view/956. and Derichs et al. (2021)Derichs, K., Mosquera, J., Ron-Garrido, L.J., Puga-Torres, B. & De la Cueva, F. 2021. Intervalos de corte de pasto Saboya (Panicum máximum Jacq.), sobre rendimiento de materia seca y composición química de su ensilaje. Siembra, 8 (2): e2506, ISSN: 2477-8850. https://doi.org/10.29166/siembra.v8i2.2506.; De Lucena-Costa et al. (2018)De Lucena-Costa, N., Jank, L., Avelar-Magalhães, J., Azevedo-Rodrigues, A.N., Dos Santos-Fogaça, F.H., Burlamaqui-Bendahan, A. & De Seixas-Santos, F.J. 2018. Características morfogênicas e estruturais de Megathyrsus maximus cv. Tanzânia-1 sob intensidades de desfolhação. PUBVET, 12(4): 1-7, ISSN: 1982-1263. https://doi.org/10.22256/pubvet.v12n4a67.1-7. in Boa Vista, Brasil and Verdecia et al. (2015)Verdecia, D. M., Herrera, R. S., Ramírez, J. L., Acosta, I. L., Uvidia, H., Santana, A. & Almanza, D. 2015. Potencialidades agroproductivas de dos cultivares de Megathyrsus maximus en la Región Oriental de Cuba. REDVET. Revista Electrónica de Veterinaria, 16(11): 1-9, ISSN: 1695-7504. https://www.redalyc.org/pdf/636/63643094002.pdf. in Valle del Cauto, Cuba.
On the other hand, Fortes et al. (2016)Fortes, D., Valenciaga, D., García, C.R., García, M., Cruz, A.M. & Romero, A. 2016. Evaluation of three varieties of Megathyrsus maximus in the dry period. Cuban Journal of Agricultural Science, 50(1): 131-137, ISSN: 2079-3480. http://scielo.sld.cu/pdf/cjas/v50n1/cjas15116.pdf. under the west of Cuba conditions and low rainfalls (53 mm) and average temperatures of 27 °C, reported 5.45 and 1.87 tDM/ha in leaves and stems, respectively in Mombasa variety and Oyedeji et al. (2016)Oyedeji, S., Onuche, F.J., Animasaun, D.A., Ogunkunle, C.O., Agboola, O.O. & Isichei, A.O. 2016. Short-term effects of early-season fire on herbaceous composition, dry matter production and soil fertility in guinea savanna, Nigeria. Archives of Biological Sciences, 68(1): 7-16, ISSN: 1821-4339. http://dx.doi.org/10.2298/ABS150526002O. in Nigeria showed yields under monoculture conditions of Común variety of 0.53, 0.40 and 0.65, 0.52 tDM/ha, for the dry matter yield of leaves and stems, in the rainy and dry season, respectively with rainfalls of 200-300 mm, as well as, averages temperatures of 33-34 ºC. Therefore, Sánchez-Hernández et al. (2019)Sánchez-Hernández, M.A., Valenzuela-Haro, Y.E., Morales-Terán, G., Rivas-Jacobo, M.A., Fraire-Cordero, S., & Hernández-Sánchez, S. 2019. Guinea grass (Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs) growth in response to chemical fertilization in warm humid climate. Agroproductividad, 12(8): 47-52, ISSN: 2594-0252. https://core.ac.uk/download/pdf/249321565.pdf. and Tapia-Coronado et al. (2023)Tapia-Coronado, J.J., Suárez-Paternina, E.A., Barragán-Hernández, W.A., Atencio-Solano, L.M., & Mejía-Kerguelen, S.L. 2023. Desempeño agronómico y nutricional de cuatro cultivares de Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L en la región Caribe colombiana. Pastos y Forrajes, 46: e05, ISSN: 2078-8452. https://payfo.ihatuey.cu/index.php?journal=pasto&page=article&op=view&path[]=2320., when applying chemical fertilization and humid climate of Oaxaca Mexico and the humid and dry Caribbean of Colombia duplicate the reported productions under Cuba conditions, showing the manage effect and the excellent response to the fertilization of these species.
The length and width of leaves was increased as the regrowth age advance in the two season of the year, with significant differences for p<0.05, showing the highest values at 75days (81.75 and 2.88 cm for the rainy season and 57.00 and 2.33 cm for the dry season), with increase in its value in 47.18 and 37.5 % and 53.07 and 44.21 %, respectively. The number of leaves decreased and the stems increased with the plant age, for both seasons and the best results were at 30 days (80.92 and 19.08 % and 84.87 and 15.13 %, respectively), when decreasing the leaves in 37.72 and 31.31 %; the stems increased with 44.86 and 56.52 % in the rainy and dry season, respectively (table 1).
| Age, days | Leaves, cm | Leaf and Stem, % | ||||||
|---|---|---|---|---|---|---|---|---|
| Rainy season | Dry season | Rainy | Dry | |||||
| Length | Width | Length | Width | Leaves | Stems | Leaves | Stems | |
| 30 | 43.18a | 1.80a | 26.75a | 1.30a | 80.92a | 19.08a | 84.87a | 15.13a |
| 45 | 57.48ab | 2.15b | 37.25b | 1.55b | 67.84b | 32.15b | 81.63b | 18.37b |
| 60 | 71.78b | 2.56c | 47.00c | 1.90c | 59.00c | 32.50c | 68.40c | 26.60c |
| 75 | 81.75c | 2.88d | 57.00d | 2.33d | 50.40d | 34.60d | 58.30d | 34.80d |
| SE± | 4.17 | 0.11 | 2.92 | 0.10 | 2.91 | 1.58 | 2.79 | 1.97 |
| P | 0.001 | 0.0001 | 0.0001 | 0.0001 | 0.0001 | 0.0001 | 0.0001 | 0.0001 |
abcd Uncommon letters in row differ to p<0.05 according to Duncan (1955)Duncan, D.B. 1955. Multiple range and multiple F test. Biometrics, 11(1): 1-42, ISSN: 1541-0420. https://doi.org/10.2307/3001478.
The increase of the length and width of leaves with the plant age in both seasons of the year, are due to the physiological response of the plants, increase of the intensity of the photosynthetic activity, which can be affected during the dry season due to the decrease of rains causing a humidity deficit in the soil and influencing on the assimilation of CO2 and consequently affecting the productive response of the grass (Patiño-Prado et al. 2018Patiño-Prado, R.M., Gómez, R. & Navarro, O.A. 2018. Calidad nutricional de Mombasa y Tanzania (Megathyrsus maximus, Jacq.) manejados a diferentes frecuencias y alturas de corte en Sucre, Colombia. Revista CES Medicina Veterinaria y Zootecnia, 13 (1): 17-30, ISSN: 1900-9607. http://dx.doi.org/10.21615/cesmvz.13.1.2.).
On the other hand, the decrease of leaves ratio and increase of stems during the study period, is due that during the first regrowth weeks appears lower number of tillers and need of the plant of create the necessary substances for their development make possible the higher amount of leaves and low stems ratio (Herrera 2022Herrera, R.S. 2022. Evaluation of Cenchrus purpureus varieties tolerant to drought in the western region of Cuba. Cuban Journal of Agricultural Science, 56(2): 135-143, ISSN: 2079-3480. http://scielo.sld.cu/scielo.php?script=sci_arttext&pid=S2079-34802022000200005.). However, their decrease is associated according to Reyes-Pérez et al. (2019)Reyes-Pérez, J.J., Méndez-Martínez, Y., Luna-Murillo, R.A., Verdecia, D.M., Macias-Pettao, R., & Herrera, R.S. 2019. Quality of three Brachiaria varieties in Guayas area, Ecuador. Cuban Journal of Agricultural Science, 53(2): 177-187, ISSN: 2079-3480. https://cjascience.com/index.php/CJAS/article/view/888. and Méndez-Martínez et al. (2019Méndez-Martínez, Y., Reyes-Pérez, J.J., Luna-Murillo, R.A., Verdecia, D.M., Rivero-Herrada, M., Montenegro-Vivas, L.B. & Herrera, R.S. 2019. Yield components and bromatological composition of three Megathyrsus maximus cultivars in Guayas area, Ecuador. Cuban Journal of Agricultural Science, 53(4): 437-446, ISSN: 2079-3480. https://www.cjascience.com/index.php/CJAS/article/view/928/994., 2020Méndez Martínez, Y., Reyes Pérez, J.J., Luna Murillo, R.A., Verdecia, D.M., Espinoza Coronel, A.L., Pincay-Ronquillo., W.J., Espinosa-Cunuhay, K.A., Macías-Pettao, R.K., & Herrera, R.S. 2020. Effect of climate area on yield and quality of three varieties of Megathyrsus maximus. Cuban Journal of Agricultural Science, 54(2):1-12, ISSN: 2079-3480. http://cjascience.com/index.php/CJAS/article/view/956.), to the increase of the stems length and their thickness, as well as the aging. The seasonal growing of the morphological components of the plant has direct relation with the edaphoclimatic and management conditions to which the forage is passes through. The amount of leaves and stems, as well as their growing responds to the genotype-environment interaction, result in the increase or decrease of grasses yields. The knowing of this effect, allows to know the availability and, in consequence, to adopt management strategies of the grass (Velasco et al. 2018Velasco, M., Hernández, A., Vaquera, H., Martínez, J., Hernández, P. & Aguirre, J. 2018. Análisis de crecimiento de pasto guinea (Panicum maximum Jacq) cv. Mombasa. Revista MVZ Córdoba, 23(Supl): 6951-6963, ISSN: 1909-0544. http://dx.doi.org/10.21897/rmvz.1415. and Schnellmann et al. 2019Schnellmann, L.P., Verdoljak, J.J.O, Bernardis, A., Martínez-González, J.C. & Castillo-Rodríguez, S.P. 2019. Frecuencia y altura de corte en Panicum maximum cv Gatton Panic. Agronomía Mesoamericana, 30(2): 553-562, ISSN: 2215-3608. https://doi.org/10.15517/am.v30i2.34216.).
With the science development it has been showed that not only the climatic factors influence on the morphological development of the, in this sense in Méndez-Martínez et al. (2020)Méndez Martínez, Y., Reyes Pérez, J.J., Luna Murillo, R.A., Verdecia, D.M., Espinoza Coronel, A.L., Pincay-Ronquillo., W.J., Espinosa-Cunuhay, K.A., Macías-Pettao, R.K., & Herrera, R.S. 2020. Effect of climate area on yield and quality of three varieties of Megathyrsus maximus. Cuban Journal of Agricultural Science, 54(2):1-12, ISSN: 2079-3480. http://cjascience.com/index.php/CJAS/article/view/956. studies when evaluating the effect of the climatic zone on the growth, number of leaves and stems find higher values in the area of considerable rainfalls, 245.6 mm, and 25.8 °C of temperatures while, Fortes et al. (2016)Fortes, D., Valenciaga, D., García, C.R., García, M., Cruz, A.M. & Romero, A. 2016. Evaluation of three varieties of Megathyrsus maximus in the dry period. Cuban Journal of Agricultural Science, 50(1): 131-137, ISSN: 2079-3480. http://scielo.sld.cu/pdf/cjas/v50n1/cjas15116.pdf., Cedeño-Aristega et al. (2021)Cedeño-Aristega, M. J. C., Murillo, R. A. L., Coronel, A. L. E., & Garaicoa, D. A. R. 2021. Producción y composición química de Megathyrsus maximus cultivares Tanzania y Mombasa bajo condiciones del subtrópico ecuatoriano. Ciencia Latina Revista Científica Multidisciplinar, 5(4): 6427-6443, ISSN: 2707-2215. https://doi.org/10.37811/cl_rcm.v5i4.777. and Lucero-Pita et al. (2023)Lucero-Pita, L., Gómez-Mendoza, C., Guamán-Guamán, R., Villavicencio-Abril, A., Ulloa-Cortázar, S., & Romero-Salguero, E.J. 2023. Tiempos de descanso de Panicum maximum y Brachiaria brizantha mediante tres tipos de corte. Revista de Investigaciones Veterinarias del Perú, 34(5): e24237, ISSN: 1609-9117. https://doi.org/10.15381/v34i5.24237. under west of Cuba and Ecuadorean subtropics conditions reported leaves and stems ratio of 75.5 and 24.5 %. Therefore, other factors as soils characteristics, fertilization, water availability sowing time and management plays important role in the plant systems production. The grasses are a clearly example of the above mentioned (Herrera 2022Herrera, R.S. 2022. Evaluation of Cenchrus purpureus varieties tolerant to drought in the western region of Cuba. Cuban Journal of Agricultural Science, 56(2): 135-143, ISSN: 2079-3480. http://scielo.sld.cu/scielo.php?script=sci_arttext&pid=S2079-34802022000200005.).
The importance of knowing the amount of leaves the specie can has compared with the stem is of vital importance, since the nutritive value of the plant is concentrate in a higher leaves production. In turn, this one is of high palatability for the ruminant. The reality is that the leaves percentage is a relative indicator and any variation of the luminosity intensity that favors or reduce their total weight, did not has to affect the relation if it equally influence on the leaves and stems as it is observed on the obtained results in this study (Pérez-Luna et al. 2023Pérez-Luna, E.J., Ruíz-Sesma, B., & Sánchez-Roque, Y. 2023. Rendimiento y composición química de Panicum maximum cv. Tanzania en un sistema silvopastoril en Chiapas. Biotecnia, 25 (2): 97-104, ISSN: 1665-1456. https://doi.org/10.18633/biotecnia.v25i2.1844.).
The chemical composition during the rainy season (table 2) showed significant differences for p<0.05, with increases of the cell wall components and minerals at 75 days compared with 30 days in 6.67, 4.12, 3.95, 2.70, 0.08 and 3.12 % for NDF, ADF, ADL, Si, Ca and ash, respectively while for CP, CC and OM there was decreases in their concentration in 4.80, 6.22 and 3.12 % in the same order; the phosphorous did not show a defined performance increasing their percentages up to 45 days for later decreased. For the dry season (table 3) and the same ages previous compared a similar pattern for CP, CC, P and OM was maintained and they decreased in 4.38, 3.22, 0.06 and 3.60 %, as well as increases of 2.80, 7.39, 2.55, 3.70, 0.12 and 3.60 %, respectively for NDF, ADF, ADL, Si, Ca and ashes.
| Age, days | Chemical composition, % | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| CP | NDF | ADF | ADL | CC | Si | Ca | P | Ashes | OM | |
| 30 | 9.44a | 68.04d | 31.65b | 1.22d | 31.89a | 4.63d | 0.46b | 0.16a | 9.98d | 90.02a |
| 45 | 7.94b | 69.95c | 31.96b | 3.45c | 30.15b | 5.88c | 0.50ab | 0.17a | 10.80c | 89.20b |
| 60 | 6.55c | 72.12b | 35.47a | 4.12b | 27.96c | 6.95b | 0.52ab | 0.15ab | 12.20b | 87.80c |
| 75 | 4.64d | 74.71a | 35.77a | 5.17a | 25.67d | 7.33a | 0.54a | 0.14b | 13.10a | 86.90d |
| SE± | 0.29 | 0.58 | 1.78 | 0.66 | 0.78 | 0.45 | 0.007 | 0.003 | 0.31 | 0.87 |
| P | 0.0001 | 0.0001 | 0.01 | 0.0001 | 0.0001 | 0.0001 | 0.01 | 0.001 | 0.0001 | 0.0001 |
abcd Uncommon different letters differ to p<0.05 according to Duncan (1955)Duncan, D.B. 1955. Multiple range and multiple F test. Biometrics, 11(1): 1-42, ISSN: 1541-0420. https://doi.org/10.2307/3001478.
| Age, days | Chemical composition, % | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| CP | NDF | ADF | ADL | CC | Si | Ca | P | Ashes | OM | |
| 30 | 10.11a | 67.45c | 28.27c | 1.11d | 32.53a | 4.96d | 0.66c | 0.26a | 10.90d | 89.10a |
| 45 | 8.67b | 68.24b | 29.45b | 1.89c | 31.18a | 5.89c | 0.69bc | 0.25ab | 11.60c | 88.40b |
| 60 | 7.24c | 69.33a | 34.02a | 2.04b | 30.62c | 7.37b | 0.71b | 0.23b | 12.30b | 87.70c |
| 75 | 5.73d | 70.25a | 35.66a | 3.66a | 29.31d | 8.66a | 0.78a | 0.20c | 14.50a | 85.50d |
| SE± | 0.56 | 1.34 | 0.78 | 0.006 | 0.23 | 0.34 | 0.002 | 0.004 | 0.27 | 1.02 |
| P | 0.0001 | 0.001 | 0.001 | 0.0001 | 0.0001 | 0.0001 | 0.02 | 0.002 | 0.0001 | 0.0001 |
abcd Uncommon different letters differ to p<0.05 according to Duncan (1955)Duncan, D.B. 1955. Multiple range and multiple F test. Biometrics, 11(1): 1-42, ISSN: 1541-0420. https://doi.org/10.2307/3001478.
The chemical composition (tables 2 and 3) decreased with the plant maturity. Méndez-Martínez et al. (2019)Méndez-Martínez, Y., Reyes-Pérez, J.J., Luna-Murillo, R.A., Verdecia, D.M., Rivero-Herrada, M., Montenegro-Vivas, L.B. & Herrera, R.S. 2019. Yield components and bromatological composition of three Megathyrsus maximus cultivars in Guayas area, Ecuador. Cuban Journal of Agricultural Science, 53(4): 437-446, ISSN: 2079-3480. https://www.cjascience.com/index.php/CJAS/article/view/928/994. when evaluating the cultivars Tanzania, Tobiatá and Común under Guayas, Ecuador conditions find for the Comun variety significant increases of the cell wall (50 %). Fernandes et al. (2016)Fernandes, M.H.M.R., Fernandes, J.S., De Resende, K.T., Bonfa, H.C., Reis, R.A., Ruggieri, A.C., Fernandes, J.J.R. & Santos, P.M. 2016. Grazing behavior and intake of goats rotationally grazing Tanzania-grass pasture with different post-grazing residues. Tropical Grasslands, 4(2): 91-100, ISSN: 2346-3775. https://doi.org/10.17138/TGFT(4)91-100. and Cedeño-Aristega et al. (2021)Cedeño-Aristega, M. J. C., Murillo, R. A. L., Coronel, A. L. E., & Garaicoa, D. A. R. 2021. Producción y composición química de Megathyrsus maximus cultivares Tanzania y Mombasa bajo condiciones del subtrópico ecuatoriano. Ciencia Latina Revista Científica Multidisciplinar, 5(4): 6427-6443, ISSN: 2707-2215. https://doi.org/10.37811/cl_rcm.v5i4.777. reported for Megathyrsus maximus cv. Tanzania and Mombasa values of the fibrous components (NDF, ADF, ADL) of 75, 36 and 6.12 %, respectively with the increase of the regrowth age, and they associated to the increase of the supporting tissue (stems) ratio. On the other hand, Antonio et al. (2018)Antonio, G., Gaio, M., Del Valle, T.A., Campana, M. & Gomes, J.P. 2018. Efeitos de enzimas fibrolíticas sobre a degradação in situ da matéria seca e da fibra de forrageiras. Revista Agrarian, 11(42): 363-370, ISSN: 1984-2538. http://doi.org/10.30612/agrarian.v11i42.7488 and Derichs et al. (2021)Derichs, K., Mosquera, J., Ron-Garrido, L.J., Puga-Torres, B. & De la Cueva, F. 2021. Intervalos de corte de pasto Saboya (Panicum máximum Jacq.), sobre rendimiento de materia seca y composición química de su ensilaje. Siembra, 8 (2): e2506, ISSN: 2477-8850. https://doi.org/10.29166/siembra.v8i2.2506. in Tanzania and Mombasa find concentrations of CP (7.12-17.1 %), NDF (64.35-73.6 %), ADF (34.2-52.33 %), Lignin (5.2-13.18 %), Ash (8.1-12.93 %) and OM (85.6- 88.4 %), which were influenced by the increase of the physiological age of the plant and the values of the structural components of the cell wall. The previous show that, when increasing the grasses age, there is significant increase of ADF, NDF and ADL due to the higher synthesis of structural carbohydrates, which reduce the grass quality.
Méndez-Martínez et al. (2020)Méndez Martínez, Y., Reyes Pérez, J.J., Luna Murillo, R.A., Verdecia, D.M., Espinoza Coronel, A.L., Pincay-Ronquillo., W.J., Espinosa-Cunuhay, K.A., Macías-Pettao, R.K., & Herrera, R.S. 2020. Effect of climate area on yield and quality of three varieties of Megathyrsus maximus. Cuban Journal of Agricultural Science, 54(2):1-12, ISSN: 2079-3480. http://cjascience.com/index.php/CJAS/article/view/956. find that for the variation of the chemical composition there was only interaction variety- zone for CP and the cell wall components (NDF, ADF, ADL, CEL and HCEL) there were not differences, which agree with those stated by Schnellmann et al. (2019)Schnellmann, L.P., Verdoljak, J.J.O, Bernardis, A., Martínez-González, J.C. & Castillo-Rodríguez, S.P. 2019. Frecuencia y altura de corte en Panicum maximum cv Gatton Panic. Agronomía Mesoamericana, 30(2): 553-562, ISSN: 2215-3608. https://doi.org/10.15517/am.v30i2.34216., Lucero-Pita et al. (2023)Lucero-Pita, L., Gómez-Mendoza, C., Guamán-Guamán, R., Villavicencio-Abril, A., Ulloa-Cortázar, S., & Romero-Salguero, E.J. 2023. Tiempos de descanso de Panicum maximum y Brachiaria brizantha mediante tres tipos de corte. Revista de Investigaciones Veterinarias del Perú, 34(5): e24237, ISSN: 1609-9117. https://doi.org/10.15381/v34i5.24237. and Tapia-Coronado et al. (2023)Tapia-Coronado, J.J., Suárez-Paternina, E.A., Barragán-Hernández, W.A., Atencio-Solano, L.M., & Mejía-Kerguelen, S.L. 2023. Desempeño agronómico y nutricional de cuatro cultivares de Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L en la región Caribe colombiana. Pastos y Forrajes, 46: e05, ISSN: 2078-8452. https://payfo.ihatuey.cu/index.php?journal=pasto&page=article&op=view&path[]=2320., who showed that when the nutritive value of forages is analyzed, the variability is minimum between cultivars and varieties from a same genus, but it quality is affected by the fluctuations of rains and temperatures , performance showed in this study where despite of maintain a same tendency in both seasonal periods, there were obtained different numerical values. Hence, the use of improvement grasses with high adaptability to the different conditions in the livestock systems and similar chemical composition, are elements that should be considered when selecting the varieties for their use in the livestock production systems.
The rainfalls can cause stress in the different crops if it is in deficit as in excess. The water abundance causes anoxia in the roots, affecting their aerobic respiration, absorption of minerals and water, if this situation is extended in non tolerant species, causes decrease of the assimilation and translocation of the carbon, causing metabolic changes which activate the anaerobic respiration, which involve low energy efficiency and bioproductivity in the plant, While, the water stress by lack of water decrease the concentration of the cell wall in the leaves and stems of the grasses, although in a changeable way in their structural components (cellulose, hemicelluloses) and polyphenols (lignin), due to the need of the plant of having high carbohydrates values in soluble ways during the osmotic fits (Álvarez 2019Álvarez, A. 2019. Variación de los periodos de crecimiento para tres pastos tropicales, bajo los efectos del cambio climático. Pastos y Forrajes. 42(2): 95-104, ISSN: 0864-0394, http://scielo.sld.cu/pdf/pyf/v42n2/en_2078-8452-pyf-42-02-104.pdf.).
The above is showed in Montenegro et al. (2018)Montenegro, L., Espinoza, I., Sánchez, A., Barba, C., García, A., Requena, A. & Martínez-Marín, A. 2018. Composición Química y cinética de degradación ruminal in vitro del ensilado de pasto saboya (Megathyrsus maximus) con inclusión de residuos de frutas tropicales. Revista Científica, FVC-LUZ, 28(4): 306-312, ISSN: 0798-2259. http://www.saber.ula.ve/bitstream/handle/123456789/45363/art8.pdf?sequence=1&isAllowed=y. results in Común variety, when reporting 8.61, 73.70 and 33.91 % for CP, NDF and ADF, respectively with rainfalls of 500 mm and temperatures of 32 ºC. Mojica-Rodríguez et al. (2017)Mojica-Rodríguez, J.E., Castro-Rincón, E., Carulla-Fornaguera, J. & Lascano-Aguilar, C.E. 2017. Efecto de la edad de rebrote sobre el perfil de ácidos grasos en gramíneas tropicales. Revista Corpoica - Ciencia y Tecnología Agropecuaria, 18(2): 217-232, ISSN: 2500-5308. http://dx.doi.org/10.21930/rcta.vol18_num2_art:623. and Montalvão et al. (2018)Montalvão, D., Abdalla, A.L., Tavares, P., Zanuto, G., Dias, T.P., McManus, C., Abdalla, A.L. & Louvandini, H. 2018. Morphological characteristics, nutritive quality, and methane production of tropical grasses in Brazil. Pesquisa Agropecuária Brasileira, 53(3): 323-331, ISSN: 1678-3921. https://doi.org/10.1590/S0100-204X2018000300007., reported contents of CP, NDF, ADF, ADL, HCEL and CEL of 10.2, 70.8, 46.6, 5.8, 24.2 and 40.7 %, respectively when evaluating the effect of the regrowth age on the quality of Mombasa and Tanzania cultivars, and the differences in relation with this research can be attributed to the prevailing climatic conditions, to the fertilization effect, of the nutrients dilution by the rains, higher stem growing, experimental and management conditions among other factors.
The low values of minerals and organic matter find in this study (tables 2 and 3) can be attributable to the effect of the low rainfalls during the study period (731.4 mm in the rainy season and 270 mm in the dry season) which allow the minerals fluctuated and during the period of higher lack of rainfalls caused their dilution effect on the water concentration in the forage and their values did not higher during the dry season (De Barros et al. 2017De Barros, E., Pereira, F.V., Henrique, P., Ferracciú, L.R., Olinda, B. & Alves, E. 2017. Growth of tropical grasses in Oxisol contaminated by nickel. Chilean Journal of Agricultural Research, 77(3):273-280, ISSN: 0718-5839. https://doi.org/10.4067/S0718-58392017000300273.). While, Méndez-Martínez et al. (2018)Méndez-Martínez, Y., Verdecia, D.M., Reyes-Pérez, J.J., Luna-Murillo, R.A., Rivero-Herrada, Marisol., Montenegro-Vivas, L.B. &. Herrera, R.S. 2018. Quality of three Megathyrsus maximus cultivars in the Empalme area, Ecuador. Cuban Journal of Agricultural Science, 52(4): 423-433. ISSN: 2079-3480. https://www.cjascience.com/index.php/CJAS/article/view/834. and Montalvão et al. (2018)Montalvão, D., Abdalla, A.L., Tavares, P., Zanuto, G., Dias, T.P., McManus, C., Abdalla, A.L. & Louvandini, H. 2018. Morphological characteristics, nutritive quality, and methane production of tropical grasses in Brazil. Pesquisa Agropecuária Brasileira, 53(3): 323-331, ISSN: 1678-3921. https://doi.org/10.1590/S0100-204X2018000300007. reported similar results with ash percentages (9-14) and OM (85-90) for this species and concluded that the variability of these indicators depends of the own characteristics of each species and effect of the edaphoclimatic conditions.
The differences between climatic seasons are attributable according to Pereira et al. (2017)Pereira, I., Mercêdes, J., de Pinto, K.A., Ferreira, W. & Araujo, W. 2017. Brachiaria pasture occupation during the dry season in Brazilian savannah conditions. Global Science and Technology, 9(3): 151-162, ISSN: 1984-3801. https://openurl.ebsco.com/EPDB%3Agcd%3A15%3A16830399/detailv2?sid=ebsco%3Aplink%3Ascholar&id=ebsco%3Agcd%3A121300848&crl=c., Méndez-Martínez et al. (2020)Méndez Martínez, Y., Reyes Pérez, J.J., Luna Murillo, R.A., Verdecia, D.M., Espinoza Coronel, A.L., Pincay-Ronquillo., W.J., Espinosa-Cunuhay, K.A., Macías-Pettao, R.K., & Herrera, R.S. 2020. Effect of climate area on yield and quality of three varieties of Megathyrsus maximus. Cuban Journal of Agricultural Science, 54(2):1-12, ISSN: 2079-3480. http://cjascience.com/index.php/CJAS/article/view/956. and Lucero-Pita et al. (2023)Lucero-Pita, L., Gómez-Mendoza, C., Guamán-Guamán, R., Villavicencio-Abril, A., Ulloa-Cortázar, S., & Romero-Salguero, E.J. 2023. Tiempos de descanso de Panicum maximum y Brachiaria brizantha mediante tres tipos de corte. Revista de Investigaciones Veterinarias del Perú, 34(5): e24237, ISSN: 1609-9117. https://doi.org/10.15381/v34i5.24237. to the effect of the climate factors, specifically of rains and temperatures that favors higher growing and development of the plant (maturity). It is know that the minerals are the most in the young parts and in growing, especially in the shoots, young leaves and top roots and their decrease during the rains is related with the dilution caused by the plant development.
Regarding the quality indicators (tables 4 and 5) in both seasonal periods a decrease of these ones occurs, in the rainy season the DMD, OMD, ME, NLE and ENE were reduced in 7.65, 8.10 percentage units, 1.46, 0.88 and 1.17 MJ/kg DM, respectively while in the dry season were of 19.88, 19.17 percentage units, 3.09, 2.28 and 2.54 MJ/kg DM, respectively. These results coincide with those reported by Méndez-Martínez et al. (2019Méndez-Martínez, Y., Reyes-Pérez, J.J., Luna-Murillo, R.A., Verdecia, D.M., Rivero-Herrada, M., Montenegro-Vivas, L.B. & Herrera, R.S. 2019. Yield components and bromatological composition of three Megathyrsus maximus cultivars in Guayas area, Ecuador. Cuban Journal of Agricultural Science, 53(4): 437-446, ISSN: 2079-3480. https://www.cjascience.com/index.php/CJAS/article/view/928/994., 2020Méndez Martínez, Y., Reyes Pérez, J.J., Luna Murillo, R.A., Verdecia, D.M., Espinoza Coronel, A.L., Pincay-Ronquillo., W.J., Espinosa-Cunuhay, K.A., Macías-Pettao, R.K., & Herrera, R.S. 2020. Effect of climate area on yield and quality of three varieties of Megathyrsus maximus. Cuban Journal of Agricultural Science, 54(2):1-12, ISSN: 2079-3480. http://cjascience.com/index.php/CJAS/article/view/956.) in Común, Tanzania and Tobiatá varieties and argued that this performance is due to the anatomic characteristics of each variety and climatic variations, since these cultivars has higher proportion of available leaves for animal intake, there is not many differences as to their growing in the different season s of the year which make them promising for livestock feeding.
| Age, days | % | MJ/kgDM | |||
|---|---|---|---|---|---|
| DMD | OMD | ME | NLE | ENE | |
| 30 | 47.12ª | 48.66ª | 6.98ª | 3.82ª | 3.32ª |
| 45 | 45.33b | 47.59ª | 6.56ab | 3.64ab | 3.08ª |
| 60 | 43.22c | 44.37b | 6.32b | 3.37b | 2.71b |
| 75 | 39.47d | 40.56c | 5.62c | 2.94c | 2.15c |
| SE± | 1.03 | 0.96 | 0.03 | 0.04 | 0.04 |
| P | 0.0001 | 0.001 | 0.001 | 0.001 | 0.001 |
abcd Uncommon different letters differ to p<0.05 according to Duncan (1955)Duncan, D.B. 1955. Multiple range and multiple F test. Biometrics, 11(1): 1-42, ISSN: 1541-0420. https://doi.org/10.2307/3001478.
| Age, days | % | MJ/kgDM | |||
|---|---|---|---|---|---|
| DMD | OMD | ME | NLE | ENE | |
| 30 | 56.46ª | 57.05ª | 8.45ª | 4.93ª | 4.42ª |
| 45 | 53.56b | 54.72b | 7.86b | 4.48ab | 4.13ª |
| 60 | 45.77c | 47.66b | 6.74c | 3.66b | 3.09b |
| 75 | 36.58d | 37.88d | 5.36d | 2.65c | 1.88c |
| SE± | 1.73 | 1.96 | 0.04 | 0.04 | 0.04 |
| P | 0.0001 | 0.001 | 0.001 | 0.001 | 0.001 |
a,b c d Uncommon different letters differ to p<0.05 according to Duncan (1955)Duncan, D.B. 1955. Multiple range and multiple F test. Biometrics, 11(1): 1-42, ISSN: 1541-0420. https://doi.org/10.2307/3001478.
The decrease of the quality by the increase in the forages maturity, with decrease of DMD, OMD, ME and NLE was reported by Montalvão et al. (2018)Montalvão, D., Abdalla, A.L., Tavares, P., Zanuto, G., Dias, T.P., McManus, C., Abdalla, A.L. & Louvandini, H. 2018. Morphological characteristics, nutritive quality, and methane production of tropical grasses in Brazil. Pesquisa Agropecuária Brasileira, 53(3): 323-331, ISSN: 1678-3921. https://doi.org/10.1590/S0100-204X2018000300007. and Tapia-Coronado et al. (2023)Tapia-Coronado, J.J., Suárez-Paternina, E.A., Barragán-Hernández, W.A., Atencio-Solano, L.M., & Mejía-Kerguelen, S.L. 2023. Desempeño agronómico y nutricional de cuatro cultivares de Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L en la región Caribe colombiana. Pastos y Forrajes, 46: e05, ISSN: 2078-8452. https://payfo.ihatuey.cu/index.php?journal=pasto&page=article&op=view&path[]=2320. and they obtained similar results in the relation between the fraction fibrous and nitrogen, explaining that as the regrowth age increase there is a decrease of leaves percentage and stems increase, and so low levels of CP and g high of the cell wall components that affects the organic matter degradation and energy contribution due to the lower efficiency of rumen microorganisms. In Fernandes et al. (2014Fernandes, A.M., Deresz, F., Sampaio, D., Ferraz, F.C. & Siqueira, L. 2014. Nutritive value of Tanzania grass for dairy cows under rotational grazing. Revista Brasileira de Zootecnia, 43(8): 410-418, ISSN: 1806-9290. http://dx.doi.org/10.1590/S1516-35982014000800003., 2016Fernandes, M.H.M.R., Fernandes, J.S., De Resende, K.T., Bonfa, H.C., Reis, R.A., Ruggieri, A.C., Fernandes, J.J.R. & Santos, P.M. 2016. Grazing behavior and intake of goats rotationally grazing Tanzania-grass pasture with different post-grazing residues. Tropical Grasslands, 4(2): 91-100, ISSN: 2346-3775. https://doi.org/10.17138/TGFT(4)91-100.) studies notified for Tanzania variety digestibility of the dry matter and crude protein of 63.66 to 58.04 % and 54.1 a 56.31 %, respectively, with decrease influenced by the fibrous fraction increase and foliage decrease and consequent the biomass quality.
The variability of the digestibility and energy contribution due to the climate effect, was showed by Valles-de la Mora et al. (2016)Valles-de la Mora, B., Castillo-Gallegos, E. & Bernal-Barragán, H. 2016. Rendimiento y degradabilidad ruminal de materia seca y energía de diez pastos tropicales cosechados a cuatro edades. Revista Mexicana de Ciencias Pecuarias, 7(2): 141-158, ISSN: 2448-6698. https://www.scielo.org.mx/pdf/rmcp/v7n2/2448-6698-rmcp-7-02-00141-en.pdf. and Méndez-Martínez et al. (2020)Méndez Martínez, Y., Reyes Pérez, J.J., Luna Murillo, R.A., Verdecia, D.M., Espinoza Coronel, A.L., Pincay-Ronquillo., W.J., Espinosa-Cunuhay, K.A., Macías-Pettao, R.K., & Herrera, R.S. 2020. Effect of climate area on yield and quality of three varieties of Megathyrsus maximus. Cuban Journal of Agricultural Science, 54(2):1-12, ISSN: 2079-3480. http://cjascience.com/index.php/CJAS/article/view/956., who when evaluating the effect of the seasonal nature in the quality of Megathyrsus maximus cv. Tanzania, Común and Tobiatá in three moments of the year (March-June, 200 mm and 30 ºC; August-November, 400 mm 32 ºC and January -April, 80 mm and 28 ºC) and two regions (Guayas 117.2 mm and 23.87 °C; Empalme 245.6 mm and 25.80 °C) find the best results in the interval January- April of low rainfalls and higher average temperature with digestibility of 73.8 % and a difference of 14.1 percentage units with respect to the period of higher rains and the best energy contribution was for the one of higher rainfalls, while for the climatic zones there were not differences for the regions with differences of 0.89 % and 0.69 MJ/kg DM.
When using fibrolite enzymes in Megathyrsus maximus cv. Mombasa, Antonio et al. (2018)Antonio, G., Gaio, M., Del Valle, T.A., Campana, M. & Gomes, J.P. 2018. Efeitos de enzimas fibrolíticas sobre a degradação in situ da matéria seca e da fibra de forrageiras. Revista Agrarian, 11(42): 363-370, ISSN: 1984-2538. http://doi.org/10.30612/agrarian.v11i42.7488 notified increases in the digestibility of DM, NDF, ADF, ADL, hemicelluloses and cellulose of 1.7, 3.1, 4.7, 2.1, 2.3 and 4.6 %, respectively explaining that the cellulose and hemicelluloses are fermented by the rumen microorganisms with relative easily. Therefore, as the lignin content increases, this one is joined to the carbohydrates which were not available for the rumen microorganisms and digestive enzymes, so the fermentation degree decreased, which can be zero, depending on the lignifications intensity. Each type of lignocelluloses complex has a maximum fermentation degree by the microorganisms, and this one can be alter when treatments of the material are performed. The increase in the degradation of the fibrous fraction when the enzymes are used in the foods confirms that the lignin is a degradation limiting factor.
Ortega-Aguirre et al. (2015)Ortega-Aguirre, C.A., Lemus-Flores, C., Bugarín-Prado, J.O., Alejo-Santiago, G., Ramos-Quirarte, A., Grageola-Núñez, O. & Bonilla-Cárdenas, J.A. 2015. Características agronómicas, composición bromatológica, digestibilidad y consumo animal en cuatro especies de pastos de los géneros Brachiaria y Panicum. Tropical and Subtropical Agroecosystems, 18(3): 291-301, ISSN: 1870-0462. https://www.redalyc.org/articulo.oa?id=93944043005. and Avellaneda-Cáceres et al. (2019)Avellaneda-Cáceres, A., Navarro, J.A. & Micheloud, J.F. 2019. Impactación ruminal y abomasal en vacas de cría asociada al consumo de pasturas diferidas de Megathyrsus maximus cv. Gatton. Revista FAVE-Sección Ciencias Veterinaria, 18(1): 12-16, ISSN: 2362-5589. https://doi.org/10.14409/favecv.v18i1.8234 when studing five Megathyrsus maximus varieties (Común, Tanzania, Enano, Mombaza and Tobiatá), did not find significant differences in the digestibility and reported DMD above 47% and considered that the causes of this performance is the constitutive similarity of the different cellular components of the plant in function of the variety. It is of highlight that the digestibility and energy contribution values of this study are in the range of those reported in the international literature. On this matter, several researchers has been reported that the link of grasses from Megathyrsus genus is ideal to intensify the livestock systems, due to their high yields and nutritional quality for the development of sustainable systems, been in monoculture or in associations in silvopastoral systems (Barragán-Hernández y Cajas-Girón 2019Barragán-Hernández, W.A. & Cajas-Girón, Y.S. 2019. Cambios bromatológicos y estructurales en Megathyrsus maximus bajo cuatro arreglos silvopastoriles. Ciencia y Tecnología Agropecuaria, 20(2): 231-258, ISSN: 2500-5308. https://doi.org/10.21930/rcta.vol20num2art:1458 and Contreras-Santos et al. 2021Contreras-Santos, J.L., Martínez-Atencia, J. & Falla-Guzman, C.K. 2021. Carbono acumulado en raíces de especies vegetales en sistemas silvopastoriles en el Norte de Colombia. Revista de Ciencias Ambientales, 55(1): 52-69, ISSN: 2215-3896. http://dx.doi.org/10.15359/rca.55-1.3.).
Conclusions
⌅It is concluded that the evaluated cultivar during the dry season has good performance for the morphological components and yield, so it constitutes a viable option for the livestock production systems during the low food availability. Despite there were similar performance in both climatic seasons and lower management during the dry season for the growing of leaves and cell wall components has high digestibility and energy contribution so their adaptability and potentialities in low rainfall ecosystems is confirmed.