Tropical Grasslands-Forrajes Tropicales最新文献

{"title":"Principal component analysis applied to the study of yield and nutritional characteristics of forage cultivars","authors":"Rodrigo Gonçalves De Carvalho, Ronilton Araújo De Souza, J. Silva, A. B. Pimentel, M. Ferreira, Michelle Christina Bernardo de Siqueira, Djane Leite de Amorim Santos","doi":"10.17138/tgft(10)109-115","DOIUrl":"https://doi.org/10.17138/tgft(10)109-115","url":null,"abstract":"The objective of this study was to evaluate the importance of various yield and nutritional characteristics for the differentiation of forage cultivars using principal component analysis (PCA). Data were obtained from an experiment conducted with a complete randomized block design (RCBD) with 6 replications. Eleven cultivars of forage grasses of the species Urochloa brizantha, U. ruziziensis, Megathyrsus maximus, Cenchrus ciliaris, Andropogon gayanus and Setaria sphacelata were evaluated. For yield characteristics, PCA revealed that the first 3 components explained 82.0% of total variation between forage cultivars. Similar results were observed for nutritional characteristics with the first 3 components explaining 91.4% of total variation in leaf chemical composition and 83.8% of variation in stem chemical composition. Variables that contributed most to discrimination between forage cultivars were: number of tillers per plant; number of leaves per plant; median leaf width; stem dry matter yield; leaf:stem ratio; % dry matter, % crude protein (CP) and % neutral detergent fiber of leaves; and % CP, % ether extract and % acid detergent fiber of stems. PCA was effective in identifying the key parameters that need to be measured in evaluating grass species and allowed a reduction in the number of yield and nutritional characteristics to be assessed in experiments designed to evaluate forage cultivars. This reduced both the workload and the costs involved while still allowing valid conclusions.","PeriodicalId":56049,"journal":{"name":"Tropical Grasslands-Forrajes Tropicales","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49594159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Resultados económicos del empleo de harina de forraje de Tithonia diversifolia en la dieta de diferentes categorías de aves","authors":"Nadia Báez Quiñones, Bárbara Rodríguez, Tomás E. Ruíz, Ysnagmy Vázquez, Humberto Díaz Rodríguez","doi":"10.17138/tgft(10)149-155","DOIUrl":"https://doi.org/10.17138/tgft(10)149-155","url":null,"abstract":"The present study evaluated economically the use of tithonia (Tithonia diversifolia) forage meal in the diets of broilers; layers replacements and laying hens, as a partial replacement of corn and soybean meals. The data used come from feeding experiments carried out between 2018–2021 at the Cuban Institute of Animal Science. The direct costs involved in establishing this crop and making the meal were considered. The total feeding costs, and costs per animal, per kg of gain, per ton of live weight produced, per kg of eggs and per 1,000 eggs were estimated for the different treatments (Control 0%; T1-5%; T2-10%; T3-15% and T4-20% of tithonia meal in the ration). In all cases, feeding costs decreased with the greater use of tithonia meal. The best results in feeding costs reductions per kilogram of live weight gain for broilers (7 to 42 days) were obtained with T3 (14.78%); for layer replacements (weeks 9 to 18) with T4 (20.94% per animal); and with T3 in laying hens (weeks 23 to 44), with a 19.34% decrease in costs per thousand eggs produced. It has been demonstrated that the inclusion of tithonia forage meal in the diet of these species, as partial replacement of corn and soybean meals, constitutes a viable productive and economic alternative, which could contribute to reduce the importation of traditional and highly expensive feed ingredients.","PeriodicalId":56049,"journal":{"name":"Tropical Grasslands-Forrajes Tropicales","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45786051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inoculación con rizobios y hongos micorrízicos arbusculares en plantas de Leucaena leucocephala en etapa de vivero y en sustrato con pH neutro","authors":"Gustavo Crespo-Flores, Hugo M. Ramírez-Tobias, M. R. Vallejo-Pérez, H. Méndez-Cortés, Pedro J. González-Cañizares","doi":"10.17138/tgft(10)98-108","DOIUrl":"https://doi.org/10.17138/tgft(10)98-108","url":null,"abstract":"The objective of this work was to evaluate the effect of the simple and combined inoculation with three local rhizobia isolates (R1, R2 and R3) and two species of arbuscular mycorrhizal fungi (Glomus cubense -AMF1- and Claroideoglomus claroideum -AMF2-) on mycorrhizal colonization, nodulation, growth and biomass production of Leucaena leucocephala in a substrate with a close to neutrality pH under greenhouse conditions. Thirteen treatments were evaluated in a completely randomized design with five replications. The inoculation and co-inoculation promoted greater plant growth with respect to the control without inoculation and to the fertilization treatment. Within the inoculation and co-inoculation treatments, one rhizobium isolate (R2) stood out for producing the highest plant height and leaflet production, while the R3 + AMF1 and R3 + AMF2 combinations promoted the highest plant height, and also promoted higher biomass together with R1 + AMF1. In addition, the R3 + AMF2 combination stood out for presenting a high number of AMF spores, frequency and intensity by AMF colonization, and nodule activity. It is concluded that inoculation with local rhizobia isolates and their combination with AMF favors the development of mycorrhizal structures, nodulation, growth and biomass production of L. leucocephala grown in a substrate with neutral pH. Isolate R2 and the combination R3 + AMF2 were identified as effective inoculants to increase plant growth.","PeriodicalId":56049,"journal":{"name":"Tropical Grasslands-Forrajes Tropicales","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47362955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of growth stage on nutritional value of barley and triticale forages for goats","authors":"Hande Isıl Akbag","doi":"10.17138/tgft(10)116-123","DOIUrl":"https://doi.org/10.17138/tgft(10)116-123","url":null,"abstract":"The nutritional composition and in vitro gas production of barley and triticale forages at tillering, stem elongation, and ear emergence stages were studied. The mean crude protein (CP), neutral detergent fiber (NDF) and water-soluble carbohydrate (WSC) content was higher in barley than triticale. The supplementation of wheat grain in in vitro incubation had no effect on the gas production of barley and triticale forage. The nutritive value of barley and triticale forages is highly influenced by growth stage and is high during the early stage of growth during tillering and stem elongation. Barley and triticale forages have potential as feed for dairy goats and although barley had a higher CP content, both have adequate ME and CP levels to meet the nutritional requirements of adult goats with 50 kg body weight in early lactation.","PeriodicalId":56049,"journal":{"name":"Tropical Grasslands-Forrajes Tropicales","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42715198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A maceration treatment of leucaena foliage improves its nutritional value by reducing mimosine concentration","authors":"M. D. Honda, A. Youkhana, T. Idol, D. Borthakur","doi":"10.17138/tgft(10)1-14","DOIUrl":"https://doi.org/10.17138/tgft(10)1-14","url":null,"abstract":"Giant leucaena produces high dry matter yields but the foliage contains mimosine, a non-protein amino acid that is toxic to animals, especially non-ruminants. Reducing mimosine concentration in foliage following harvesting may allow for greater use of Giant leucaena and mitigate the negative aspects of higher mimosine concentration in some varieties. We  evaluated two methods for post-harvest treatment of foliage of a highly productive interspecific hybrid variety ‘KX2’ for reducing mimosine concentration: (i) maceration treatment; and (ii) extraction with 0.1 N HCl. Mimosine as a percentage of leaf dry matter ranged from less than 1% DM to around 3% DM. Although both methods reduced mimosine concentration, extraction by 0.1 N HCl also reduced gross energy, protein and carbohydrate concentrations of leucaena foliage. The maceration treatment, on the other hand, caused little reduction in crude protein and crude fat concentrations but markedly increased the carbohydrate concentration. ADF and NDF concentrations were also reduced as a result of maceration treatment. The estimated gross energy concentration in macerated foliage was not significantly lower than in unprocessed foliage. A suitable mechanical method for post-harvest maceration of leucaena foliage, e.g. a wood-chipping machine, could be used to reduce mimosine concentration in the foliage, making it safer for feeding to livestock and enhancing the feed value, especially for non-ruminants. These methods should be tested by conducting feeding studies to determine the possible benefits in animal performance from feeding macerated foliage.","PeriodicalId":56049,"journal":{"name":"Tropical Grasslands-Forrajes Tropicales","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49477444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of different supplements on performance of steers grazing Mombaça guineagrass (Megathyrsus maximus) during the dry period","authors":"Camile Sanches Silva, V. Euclides, D. B. Montagner, I. Araújo, G. S. Difante, M. A. O. Orrico Junior","doi":"10.17138/tgft(10)44-51","DOIUrl":"https://doi.org/10.17138/tgft(10)44-51","url":null,"abstract":"To mitigate the low animal performance on Mombaça guineagrass pasture during the dry period, feeding 2 types ofsupplement to 2 genetic groups was evaluated. The experimental design was a randomized block design following a 2 ×2 factorial arrangement with 4 replications. The treatments consisted of feeding 2 levels of supplement (0.25 and 1.0% of body weight; BW), named low-cost supplement (LCS; US$ 11.75/steer) and high-cost supplement (HCS; US$ 62.80/steer), respectively, for 130 days (July–October; dry season) to 2 genetic groups: Caracu and F1 Senepol × Caracu. The steers were supplemented daily and weighed every 28 days. Pastures were evaluated monthly to estimate the herbage accumulation rate, herbage mass (HM), leaf, stem and dead material percentages and nutritive value. HM, morphological components and nutritive value were independent of supplement type fed (P>0.05). There were decreases in HM (3,720 to 3,205 kg DM/ha), daily herbage allowance (14.0 to 9.4 kg DM/100 kg BW) and leaf percentage (33.4 to 21.2%) and increase in dead material percentage (53.3 to 67.7%) throughout the experimental period. In vitro organic matter digestibility (59.9%), crude protein concentration (10.0%), neutral detergent fiber (72.1%) and acid detergent lignin (2.9%) remained constant from July to September but increased markedly in October. Steers supplemented with HCS performed better (P<0.05) than those which received LCS (1.005 vs. 0.565 kg liveweight gain/head/day, respectively). Regardless of supplement type, F1 Senepol × Caracu steers had greater average daily gains than pure Caracu steers (0.88 vs. 0.71 kg/hd/d, respectively). Feeding HCS to steers in the dry season would produce better performance than LCS and could reduce time to reach slaughter weight but weight changes during the subsequent wet season should be monitored to assess the extent of any compensatory gain by the low-cost group during this period to reduce the weight advantage of the high-cost group.","PeriodicalId":56049,"journal":{"name":"Tropical Grasslands-Forrajes Tropicales","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42049338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phenotypic and genetic variability induced in Lehmann’s love grass (Eragrostis lehmanniana) through gamma irradiation","authors":"Alan Álvarez-Holguín, C. Morales-Nieto, C. Avendaño-Arrazate, Raúl Corrales-Lerma, F. Villarreal-Guerrero","doi":"10.17138/tgft(10)63-68","DOIUrl":"https://doi.org/10.17138/tgft(10)63-68","url":null,"abstract":"This study assessed the morphological and nutritional diversity induced through gamma irradiation in Lehmann’slove grass. Seed were irradiated at doses of 0, 100, 200, 300, 450, 600, 900, and 1400 Gy. Ten agronomic traits relatedwith forage quality were evaluated and used to select the mutants, which were confirmed by cluster analysis andmultivariate analysis of variance and then characterized by nutritional and molecular characterization. Mutants with16–20% less (p<0.05) lignin and 36–68% more protein content than the control genotype were found. Genetic distances of 0.38 and 0.49 also revealed differences (p<0.05) between the mutants and control genotype. The phenotypic and genetic variability, induced through gamma irradiation, resulted in the identification of two first generation mutants with outstanding agronomic traits and nutritional quality.","PeriodicalId":56049,"journal":{"name":"Tropical Grasslands-Forrajes Tropicales","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48540701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of land use change on an andosol through physicochemical and biological indicators","authors":"María-Cristina Ordoñez, L. Galicia, Juan Fernando Casanova Olaya","doi":"10.17138/tgft(10)52-62","DOIUrl":"https://doi.org/10.17138/tgft(10)52-62","url":null,"abstract":"The conversion of forests to agricultural land can dramatically alter soil properties, but soil resistance, which is theability of soil properties or processes to remain unchanged in the face of a specific disturbance or stress, remainsunclear. We evaluated the impact of land use change and agricultural management on changes on an andosol in theCauca department, Colombia, through the analysis of physicochemical variables and biological indicators (dimensionlessresistance index, where +1 is the highest resistance and -1 is the lowest resistance) that allowed the assessment of soilresistance. The land uses analyzed included (1st) forest, which was approximately 100 years of age, plus areas of the same forest (70% of the area), which had been replaced by (2nd) natural pastures and (3rd) forage crops in the year 1985, i.e. 30 years before the observations. All physicochemical variables except soil clay content were significantly affected by the change from forest to natural pasture. Similarly, the change from forest to forage cropping affected all physicochemical variables as well as resulting in a decrease in soil microbial biomass but an increase in microbial activity. We found that the metabolic quotient (-0.32) had the lowest resistance, followed by the microbial coefficient (0.19), microbial biomass (0.32) and microbial activity (0.39), suggesting that soil stress caused by disturbance has a marked impact on the number and activity of the soil microflora. By contrast the change from forest to natural pastures was not associated with any effect on microbial biomass and its activity, suggesting that the continuous input of organic matter to the soil through the supply of organic residues from diversified root systems and nutrients from livestock urine and manure favored the preservation and resistance of microbial processes in the soil. These findings suggest that deforestation to establish natural pasture has less impact on soil stability and health than cultivating the soil following clearing.","PeriodicalId":56049,"journal":{"name":"Tropical Grasslands-Forrajes Tropicales","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48572944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Canopy responses of signal grass cv. Basilisk pastures subjected to three fertilization regimes at two stubble heights","authors":"Bruna Scalia De Araújo Passos, V. R. Herling, Manoel Eduardo Rozalino Santos, L. R. Carvalho, L. E. T. Pereira","doi":"10.17138/tgft(10)32-43","DOIUrl":"https://doi.org/10.17138/tgft(10)32-43","url":null,"abstract":"The impacts of fertilization regimes and stubble heights in signal grass cv. Basilisk pastures were evaluated during latespring and summer in Brazil. Liming and N, P and K fertilization were applied to generate gradients in soil fertility tomaintain soil base saturations around 35%, 50% and 65%, increase soil P concentration and the proportion of K in soilcation exchange capacity, combined with two stubble heights of 10 and 15 cm. Herbage accumulation was not affectedby fertilization regimes and stubble height reaching 10 t/ha of dry matter during the growing season. Cutting at 10cm maximizes the leaf mass and leaf area index and decreases dead material mass without the need of high soil basesaturation and NPK fertilization rates to sustain plant growth. However, this stubble height required longer regrowthperiods to attain 95% of light interception (LI95%). A stubble height of 15 cm is preferred when short regrowth periods are required. The canopy height at the point of LI95% does not change with fertilization regimes, but the LI95% is reached at different canopy heights in late spring and summer in signal grass pastures. The adoption of a moderate fertilization regime is recommended as a strategy to obtain an equitable forage distribution between late spring and summer.","PeriodicalId":56049,"journal":{"name":"Tropical Grasslands-Forrajes Tropicales","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46082985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hints for writing papers for submission to Tropical Grasslands-Forrajes Tropicales","authors":"B. G. Cook","doi":"10.17138/tgft(10)vii-x","DOIUrl":"https://doi.org/10.17138/tgft(10)vii-x","url":null,"abstract":"Preamble of the Volume 10, Issue 1","PeriodicalId":56049,"journal":{"name":"Tropical Grasslands-Forrajes Tropicales","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44415660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}