Effect of cutting time on agronomic and nutritional characteristics of nine commercial cultivars of Brachiaria grass compared with Napier grass during establishment under semi-arid conditions in Rwanda

Abstract

A study was conducted to identify the most productive cultivars and their cutting management to optimize nutrient productivity in semi-arid areas of Rwanda. Four cultivars of Brachiaria brizantha (Piatá, MG4, Marandú and Xaraes), two cultivars of Brachiaria humidicola (Llanero and Humidicola), two cultivars of Brachiaria hybrid (Mulato and Mulato II) and one cultivar of Brachiaria decumbens (Basilisk) were evaluated against Napier grass (Pennisetum purpureum) in an on-farm trial in a complete randomised block design with four replicates. Forage samples were collected at 60, 90 and 120 days after planting (DAP) and analysed for dry matter (DM), crude protein (CP), organic matter (OM) and neutral detergent fibre (NDF). The nutritional values were also estimated using in vitro gas production (IVGP) and its kinetic parameters, in vitro apparent degradable dry matter (ivADDM), digestible organic matter (DOM), metabolisable energy (ME), partitioning factor (PF) and degradable efficiency factor (DEF). For all cultivars and species, the DM, CP, OM, ivADDM and DOM increased from 60 to 90 DAP and declined thereafter. The NDF contents increased with increase in plant age. Grasses cut at 90 DAP had the highest gas production. The ME differed among grasses and DAP where Piatá had the highest. Furthermore, degradability parameters (A, B, C) and half time (T 1/2 ) differed among grasses and between cutting times. The PF and DEF were correlated with ME. The most promising cultivars were Basilisk, Marandú, Piatá and Mulato II because of their high in these nutritional characteristics.Key words: Chemical composition, metabolisable energy, degradability parameters, degradation efficiency factor. INTRODUCTIONIntensification of ruminant livestock production is gaining momentum in a number of sub-Saharan African countries due to increasing population pressure and decline in grazing areas (Thornton and Herrero, 2014). Even farmers with access to open grazing land experience frequent feed shortage due to climate change and variability (Chirat et al., 2014).Feeds and feeding, especially for dairy cows are a critical issue for smallholder farmers in Rwanda, mostly during the dry season (Klapwijk et al., 2014). In the tropics, grasses are the most ecologically reliable and economically justifiable feed resources (Pedreira et al., 2011) because of their morphological characteristics which enable efficient water use, and rapid recovery after periods of drought (Batistoti et al., 2012). Therefore, improving tropical forages is essential for environmental protection and sustainable livestock feed and food futures for livestock and people (Baudron et al., 2015). Brachiaria grasses are among the most important tropical grasses that originated from Africa and improved in Americas through agronomic selection and breeding (Miles et al., 2004). They have demonstrated to be highly productive, nutritive and socially acceptable in Asia and Africa for different livestock production systems (Vendramini et al., 2014). In tropical areas, the most sensitiv...

Comparative Evaluation of Selected Grass Species for Agronomic Performance, Forage Yield, and Chemical Composition in the Highlands of Ethiopia

“…e increasing trend of DMY with advancement in the stage of maturity was due to increase in the structural carbohydrate and reduction in the moisture content of the grass. e present study is in line with the findings of different authors [31,32] who reported that tiller density differed among the local range grasses in Kenya. Variations in DMY production across the ecotypes can be attributed to differences in growth rate and growth habit, which are mediated through the genotypic and phenotypic differences.…”

Morphoagronomical and Nutritive Performance of Brachiaria Grasses Affected by Soil Type and Fertilizer Application Grown under Rainfed Condition in Ethiopia

“…Te highest IVDMD was recorded from hybrid Mulato-I (68%) with fertilizer in both soil types and the lowest IVDMD was recorded from mutica (47.275) at red soil without fertilizer. In line with the current study [56] reported that IVDMD diferences are afected by brachiaria grass cultivars. In general, the mean IVDMD value (60.68) of the current study explaining that these grass cultivars are promising feed resources to be a better feed stuf as compared to the major feed resources (crop residues and hay) in Ethiopia.…”

“…Contrary to this study, increased fertilizer application did not bring the OM diference between B. decumbens v. Basilisk and B. ruziziensis cv. Kennedy where conducted in Indonesia [56]. Te concentrations of mineral nutrients in a forage plant could be infuenced either by environment or agronomic practice management.…”

“…Te efect of fertilizer application could not bring satisfactory fber levels for the ruminant animals although lower fbers as compared to the nonfertilized one reported in the current study. In general, there is a positive trend that fertilizer application could reduce the forage fbers and in turn improve forage quality [56,57]. Te positive infuence of fertilizer could be explained in terms of faster plant growth, raise new leaves, tillers, and shoots and indeed reduces the fber content.…”

The effect of cutting regime and genotype on growth, seed yield, seed quality and herbage yield of seven Urochloa (syn. Brachiaria) grass genotypes in the Adamawa region of Cameroon

“…This result is T A B L E 8 Pearson's correlation coefficients for different agronomic parameters in Urochloa grass genotypes for the year 2020 at Wakwa, Cameroon. et al, 2012); (Mupenzi et al, 2017) (Maass et al, 2015). However, variances in growth habit, which are mediated by genotypic and phenotypic variances, may be the cause of variations in dry matter yield production across genotypes in our present study.…”