Tropical Grasslands-Forrajes Tropicales最新文献

{"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":" ","pages":""},"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":" ","pages":""},"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":"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":" ","pages":""},"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":"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":" ","pages":""},"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":"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":" ","pages":""},"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":" ","pages":""},"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}

{"title":"Genetic parameters of growth and biomass in Leucaena leucocephala for wood energy","authors":"R. Hendrati, N. Hidayati, E. Hardiyanto, M. Susanto, L. Baskorowati, M. Mashudi, S. Pudjiono","doi":"10.17138/tgft(10)15-21","DOIUrl":"https://doi.org/10.17138/tgft(10)15-21","url":null,"abstract":"Leucaena leucocephala is a potential species for wood-energy production in Indonesia. A study of genetic improvement was initiated with a progeny test of 80 lines from 10 seed sources. Plant height and stem diameter were measured at 6 and 18 months, growth index (GI) calculated at 18 months and wood biomass production measured at 30 months. Differences between seed sources for height and diameter were observed at 6 months but not at 18 months. Significant differences between lines within seed source were observed for height and diameter at 6 months and these differences remained at 18 months. Differences between lines for GI and biomass were significant at 18 and 30 months respectively. At 18 months, line mean heritability for height, diameter and GI were estimated to be moderate, namely 0.62, 0.61 and 0.62 respectively. At 30 months line mean heritability for biomass was moderately low (0.39). Genetic correlations between height and diameter were moderately high at 6 months (0.74) and increased at 18 months (0.82), while correlation between diameters at 6 and 18 months was high (0.93). The expected genetic gain from selecting the 25 and 10 best lines with a high line value for GI was 33.7% and 48.8% respectively, with lines from the Indonesian local seed sources found to be the best performers. Three lines from the newly introduced Tarramba cultivar also had good performance. These results are discussed in relation to the future improvement program of this species for wood energy production.","PeriodicalId":56049,"journal":{"name":"Tropical Grasslands-Forrajes Tropicales","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45903696","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":"Nutritive value of forages and diets in some small-scale dairy farms in Kiambu County, Kenya in the short rains season","authors":"G. M. Crovetto, Francesco Magnoli, Maria Chiaravalli, Timoty Njeru, Jhon Waweru Gitau, S. Colombini","doi":"10.17138/tgft(10)69-77","DOIUrl":"https://doi.org/10.17138/tgft(10)69-77","url":null,"abstract":"Sixteen selected small-scale dairy farms were investigated in Kiambu County (Kenya) during the short rains seasonto develop a snapshot of the types of rations fed, milk yields obtained and sources of fodder. On average farmers had1 ha of land and 2.2 lactating cows yielding 8.93 kg milk/cow/d with feed intake of 10.5 kg DM/d. Only 35% of feedconsumed was produced on farm. Boma Rhodes grass hay and green Napier grass were the main forage components(37.9 and 28.3% of total DM). Protein forages used were the herbaceous legumes lucerne and desmodium (19.9 and15.9% CP, respectively) and leguminous shrubs (Leucaena, Calliandra and Sesbania with 21.1% CP and 43.4%aNDFom, on average). Grasses had higher aNDFom digestibility (47.1%) than legumes (39.7%). Napier grass, BomaRhodes grass, lucerne and desmodium had fiber digestibility of 51.9, 48.6, 46.8 and 32.6%, respectively. The energyand protein balances (actual vs. requirements) of the cows were on average -19.3 and -16.4%, respectively, indicatingthat cows utilized body tissues to produce the levels of milk obtained. Mutiple correspondence analysis showed that amilk yield higher than 9.1 kg/d was associated with a level of Boma Rhodes grass <5 kg DM/d, concentration of nonfibrous carbohydrates in the diet >22.0% (DM basis), concentrate level >2.63 kg/cow/d and CP% in the ration >9.1%. To improve milk yields during this season farmers should harvest grass forage at a younger age, include leguminous forage in the diets and increase the level of concentrates fed. These strategies should be demonstrated on farms to show possible benefits.","PeriodicalId":56049,"journal":{"name":"Tropical Grasslands-Forrajes Tropicales","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43938526","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":"Agronomic characterization of Taiwan grass [Cenchrus purpureus (Schumach.) Morrone] and evaluation of its potential to produce bioethanol in the warm sub-humid climate of Mexico","authors":"Joel Ventura Ríos, J. A. Honorato Salazar, Flora Apolinar Hidalgo, Iliana Barrera Martínez, Jorge Aburto Anell, Humberto Vaquera Huerta","doi":"10.17138/tgft(10)22-31","DOIUrl":"https://doi.org/10.17138/tgft(10)22-31","url":null,"abstract":"The objective of this study was to evaluate the biomass production, chemical composition, proximate analysis, calorific value and theoretical yield of bioethanol of Taiwan grass under 6 cutting frequencies. The highest production of biomass (33 t DM/ha), cellulose content (41.3%), calorific value (17.5 MJ/kg DM) and potential bioethanol yield (7,936 L/ha) were recorded at a cutting frequency of 180 days. The highest moisture content of the dehydrated samples and ash and crude protein concentrations were observed at a harvest frequency of 30 days with 9.2, 12.1 and 10.5%, respectively. The highest concentrations of extractives were obtained at harvest frequencies of 60 and 120 days (13.9 and 13.7%, respectively), while lignin concentrations were greatest at harvest frequencies of 150 and 180 days (21.1 and 20.9%, respectively). The highest concentration of fixed carbon was observed at a harvest frequency of 90 days (18.5%), while the lowest concentration of volatile matter occurred at a harvest frequency of 30 days. The data indicate that Taiwan grass has significant potential for use to produce bioethanol but assessment of the carbon footprint, life cycle analysis, energy yield (energy produced:energy consumed) of the entire production process is needed to ensure there are positive effects on climate change and greenhouse gas emissions before this process is adopted.","PeriodicalId":56049,"journal":{"name":"Tropical Grasslands-Forrajes Tropicales","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44294276","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":"The effects of increasing concentrations of Trichanthera gigantea leaves in pellets on the nutritive value and short-term intake of diets of grass plus pellets offered to lambs reared under tropical conditions in the Caribbean","authors":"H. Jack, L. Cranston, J. Burke, M. Knights, P. Morel","doi":"10.17138/tgft(9)383-390","DOIUrl":"https://doi.org/10.17138/tgft(9)383-390","url":null,"abstract":"There is currently limited information on the benefits of increasing the concentration of Trichanthera gigantea leaves in pelleted diets offered to lambs reared under tropical conditions in the Caribbean. Twelve crossbred Barbados Blackbelly rams aged 5 months were used to determine the effects of increasing the concentrations of T. gigantea in pelleted diets, on the nutritive value and intake of grass forage plus pellets offered to lambs. Animals were randomly assigned to a basic diet (4 kg) of chopped Cenchrus purpureus plus 1 of 6 pelleted diets (500 g) comprised of either 100% intact commercial pellets or a pelleted mixture of ground commercial pellets and ground (dry fallen) T. gigantea leaf in the following ratios (T. gigantea leaves:ground commercial pellets): 20:80 (T20); 40:60 (T40); 60:40 (T60); 80:20 (T80); and 100:0 (T100). Total intakes of forage and pellets (TPI) were measured at the end of each day during a period of 7 days, and the average daily nutrient intakes of the different treatment diets were calculated. Overall, there was no significant difference in the intakes of pellets containing 0 to 80% T. gigantea leaves (P>0.05) but intakes of pellets comprising 100% T. gigantea leaves were significantly lower (P<0.0001). Both CP and soluble protein intakes declined progressively as the percentage of T. gigantea leaves in the pellets increased. While level of T. gigantea leaves in pellets fed to lambs did not generally affect total intakes of pellets, grass, or grass+pellets, animal performance on these various rations cannot be assumed to be similar until longer-term feeding studies have been performed, as reduced protein and energy concentrations in the pellets could significantly lower weight gains as level of leaf in the pellets increased.","PeriodicalId":56049,"journal":{"name":"Tropical Grasslands-Forrajes Tropicales","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49052085","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}