Panicum Maximum Research Articles

Mapping Soil and Pasture Attributes for Buffalo Management through Remote Sensing and Geostatistics in Amazon Biome.

Simple SummaryBuffalo breeding in the Amazon biome can contribute significantly to local community development and, thus, is considered an essential income source. However, in Amazon regions, the inadequate breeding of these animals can lead to considerable negative consequences for the environment. Therefore, it is crucial to develop methodologies to improve animal management and grass yield. One of these methodologies is related to Precision Agriculture (PA), adapted for pasture and animal monitoring. Along these lines, we seek to utilize geostatistical techniques and remote sensing applications to better understand Buffalo grazing under a rotating system. In particular, we analyze forage Dry and Green Matter, as well as pH in pasture soils, demonstrating the obstacles against and advantages of the implementation of precise techniques for decision making and increasing grass productivity. We describe ways in which geostatistical soil pH mapping can be conducted, as well as the premises necessary to include remote sensing data in the analysis of pasture variables. Implementing these results in buffalo management systems can contribute to greater productivity and increasingly sustainable livestock.The mapping of pastures can serve to increase productivity and reduce deforestation, especially in Amazon Biome regions. Therefore, in this study, we aimed to explore precision agriculture technologies for assessing the spatial variations of soil pH and biomass indicators (i.e., Dry Matter, DM; and Green Matter, GM). An experiment was conducted in an area cultivated with Panicum maximum (Jacq.) cv. Mombaça in a rotational grazing system for dairy buffaloes in the eastern Amazon. Biomass and soil samples were collected in a 10 m × 10 m grid, with a total of 196 georeferenced points. The data were analyzed by semivariogram and then mapped by Kriging interpolation. In addition, a variability analysis was performed, applying both the Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) derived from satellite remote sensing data. The Kriging mapping between DM and pH at 0.30 m depth demonstrated the best correlation. The vegetative index mapping showed that the NDVI presented a better performance in pastures with DM production above 5.42 ton/ha−1. In contrast, DM and GM showed low correlations with the NDWI. The possibility of applying a variable rate within the paddocks was evidenced through geostatistical mapping of soil pH. With this study, we contribute to understanding the necessary premises for utilizing remote sensing data for pasture variable analysis.

Epiphytic yeasts as potential antagonists against Fusarium head blight of wheat (Triticum aestivum L.) caused by Fusarium graminearum sensu stricto

Fusarium head blight (FHB), caused by Fusarium graminearum , is a significant disease of wheat in all wheat-growing areas. In this study, we screened a total of 344 yeast epiphytes isolated from cereal and weed plants against F. graminearum in vitro . Twelve potential antagonists were selected and subjected to in planta screening trials. In the in vitro bioassay trials, the highest average percentage inhibition of 64.31% (Isolate MGO2) was observed. The in vivo evaluation of the best 12 isolates showed a reduction in FHB severity and deoxynivalenol (DON) concentration of up to 15.62% (Isolate WL3) and 28.96% (Isolate SCH7), respectively. We observed a positive correlation between Area Under the Disease Progress Curve (AUDPC) and percentage seed infection. The 100-seed weight, however, was negatively correlated to both the AUDPC and the percentage seed infection. The best three yeast antagonists were selected based on AUDPC units, percentage seed infection, and 100-seed weight parameters and were identified as Papiliotrema flavescens (Isolates WL3 and WL6) and Pseudozyma sp. (Isolate MGO1) using 16S rRNA sequence analysis. These three yeast antagonists showed biocontrol efficacy against F . graminearum, and their incorporation in an integrated management programme could provide enhanced FHB control. To the best of our knowledge, this is the first report of yeast epiphytes isolated from Panicum maximum, and Ophiopogon japonicus tested as potential biological control agents against F. graminearum.

Production Potential and Quality of Panicum maximum Cultivars Established in a Semi-Arid Environment

This study was conducted to examine the forage production potential and quality of Panicum maximum cultivars in a semi-arid environment, in four different periods. Six cultivars were evaluated: Aruana, Massai, Mombasa, BRS Tamani, Tanzania, and BRS Zuri. The experiment was laid out in a randomized-block design with four replicates, and assessments took place in four different periods (establishment, dry season, transition, and rainy season). Forage accumulation rate (FAR), chemical composition, digestibility, and in vitro rumen degradation kinetics were evaluated. There was an interaction effect between cultivars and evaluation periods for all variables, except dry matter (DM) content. The highest FAR occurred in cvs. BRS Tamani (47.0 kg DM/ha/day) and BRS Zuri (86.9 kg DM/ha/day) in the establishment and rainy periods, respectively, while cv. Aruana showed the lowest FAR (14.5 kg DM/ha/day). The highest crude protein contents were found in cv. BRS Tamani in the transition period; cv. BRS Zuri in the dry season; and cv. Tanzania in the rainy season (128.2, 116.7, and 95.0 g/kg DM, respectively). Cultivar Aruana showed the highest average in vitro dry matter digestibility (810.0 g/kg DM). Cultivars Aruana and Zuri exhibited the highest means of the total in vitro gas production (23.59 and 20.24 mL/100 mg DM, respectively). Cultivars BRS Tamani and BRS Zuri had the best response in terms of forage accumulation and nutritional value. The quality of cv. Massai remained constant throughout the year. All Panicum maximum cultivars evaluated here have the potential for use in animal production systems in a semi-arid environment.

Suitability Evaluation of Three Tropical Pasture Species (Mulato II, Gatton Panic, and Rhodes Grass) for Cultivation under a Subtropical Climate of Australia

Exploring improved tropical forages is considered to be an important approach in delivering quality and consistent feed options for dairy cattle in tropical and subtropical regions. The present study aimed to study the suitability of three improved tropical grasses, Chloris gayana ‘Rhodes grass cv. Reclaimer’ (RR), Megathyrsus maximus ‘Gatton Panic’ (GP), and Brachiaria ruziziensis x B. decumbens x B. brizantha ‘Brachiaria Mulato II’ (BM) evaluating their carbon assimilation, canopy structure, herbage plant–part accumulation and quality parameters under irrigated conditions. An experiment was conducted at Gatton Research Dairy (27°54′ S, 152°33′ E, 89 m asl) Queensland, Australia, which has a predominantly subtropical climate. Photosynthesis biochemistry, canopy structure, herbage accumulation, plant part composition, and nutritive value were evaluated. Photosynthesis biochemistry differed between pasture species. Efficiency of CO2 assimilation was highest for GP and quantum efficiency was highest for BM. Pasture canopy structure was significantly affected by an interaction between pasture species and harvest. Forage biomass accumulation was highest in GP, while BM produced more leaf and less stem compared to both GP and RR. A greater leafy stratum and lower stemmy stratum depth were observed in the vertical sward structure of BM. Brachiaria Mulato II showed greater carbon partitioning to leaves, leaf: stem ratio, canopy, and leaf bulk density. It also demonstrated greater nutritive value (Total digestible nutrients (TDN), acid detergent fibre (ADF), neutral detergent fibre (NDF), neutral detergent insoluble protein (NDICP), Starch, nonfibre carbohydrates (NFC), metabolisable energy (ME), mineral profile (Mg, P, K, Fe, Zn) and dietary cation–anion difference (DCAD) for leaf, stem, and the whole plant. Greater quantum efficiency, leaf accumulation, and nutritive value of BM observed in the present study suggest BM as an attractive forage option for dairying that warrants further research in pasture-based systems in tropical and subtropical climates.

Efficacy of the herbicides indaziflam and clomazone on problematic weeds of family poaceae to sugarcane crop

It is believed that indaziflam gives a longer period of weed control compared to clomazone, irrespective of the type or texture of the soil. Thus, the aim of this study was to evaluate pre-emergent control in five problematic weed species of family Poaceae to sugarcane, using the herbicides indaziflam and clomazone in two soils of different textures. Two experiments were carried out, one in a soil of a sandy-loam texture and the other in a clayey soil. For both experiments, a randomised block design of split plots was chosen, with four replications. The treatments consisted of the herbicides indaziflam (75 and 100 g ai ha-1), clomazone (1080 g ai ha-1) and a control with no herbicide. In the subplots, the treatments were Digitaria horizontalis, Panicum maximum, Rottboellia cochinchinensis, Urochloa decumbens and Urochloa plantaginea. Both herbicides were more effective in the clayey soil, but with indaziflam (100 g ai ha-1), more than 90% control of the weeds remained after 240 days after application (DAA), whereas for clomazone, control remained only up to 90 DAA. The herbicide clomazone did not satisfactorily control the weeds in the sandy-loam soil. The herbicide indaziflam did not control U. decumbens in the sandy-loam soil. D. horizontalis and R. cochinchinensis were the most sensitive species to the herbicide indaziflam, irrespective of soil texture.

Range grasses to improve soil properties, carbon sustainability, and fodder security in degraded lands of semi-arid regions

Tropical grasses are the primary source of forage for livestock and a valuable resource for improving soil health and environmental sustainability in semi-arid regions. A study was carried out in a semi-arid region of central India to determine the short-term (6-year) impact of nine range grasses on soil physio-chemical and biological properties, carbon stock, and forage security. The experiment was carried out in a randomized block design with three replications. Results show that the majority of the grass roots were distributed in the upper soil layer (0–10 cm, 63.5–76.5 %), and then in the middle (10–20 cm, 21.3–25 %) and lower (20–30 cm, 2.2–11.5 %) layers. Perennial tussock grass (Heteropogon contortus (L.) P. Beauv. ex Roem. & Schult) had a higher root volume (2219 mm3), followed by Guinea grass [Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs] (1860 mm3). A lower soil bulk density (BD, 1.11–1.23 g cm−3), higher gravimetric water content (GMW, 14.0–17.8 %), and soil organic carbon (0.38–0.73 %) were recorded for grass-cultivated plots compared to the barren land (1.38 g cm−3, 13.0 %, and 0.28 %, respectively). The perennial tussock grass and Guinea grass resulted in the highest soil microbial biomass carbon (SMBC, 70.1 mg kg−1 soil) and enzyme activities (dehydrogenase, 17.09 μg TPF g−1 day−1 and fluorescein diacetate activity 4.94 μg fluorescein g−1 h−1). The considerable improvement in soil properties with minimal inputs resulted in a higher sustainable yield index and carbon sustainability index in plots planted with Guinea grass (0.9 and 89.29) and perennial tussock grass (0.89 and 71.61). Therefore, the cultivation of either Guinea grass or perennial tussock grass as an intercrop or sole crop in the semi-arid environment can be an ecologically sound strategy to improve soil health, C sequestration, and fodder supply.

RUMEN PARAMETERS OF WEST AFRICAN DWARF SHEEP FED Panicum maximum SUPPLEMENTED WITH VARYING LEVELS OF Gmelina arborea LEAVES

Purpose: This experiment was carried out to assess the rumen characteristics of West African dwarf sheep fed varying level of Panicum maximum supplemented with Gmelina arborea leaves.
 Methodology: Twenty (20) healthy West African Dwarf sheep with average weight of 10+0.55kg and were randomly allotted to five (5) diet with four (4) animals per treatment in a completely randomized design. The diets compared were A (100% Panicum maximum); B (75% Panicum maximum + 25% Gmelina arborea leaf); C (50% Panicum maximum + 50% Gmelina arborea leaf); D (25% Panicum maximum + 75% Gmelina arborea leaf); and E (100% Dried Gmelina arborea leaf). The diet samples were analyzed for chemical composition and anti-nutritive components. At the end of feeding trial, rumen liquor from the experimental animals were collected for rumen fermentation characteristics Data were collected on volatile fatty acids (VFAs) production rumen pH and ammonia nitrogen. 
 .Findings: The results obtained showed that the chemical composition and the anti-nutrient content in the diets were significantly (P<0.05) different. Dry matter was highest in diet E (82.50%) and lowest in diet A (36.50%). The crude protein ranged between (9.75%) in diet A and (18.33%) in diet E. the Neutral detergent fibre, Acid detergent fibre and Acid detergent lignin was highest in diet B (63.30%), A (31.50%) and C (16.60%) respectively. the anti-nutrient content of the diet showed no any negative effect on the animals. The acetic acid (5.93%), propionic acid (5.65%), butyric acid (5.40%), valeric acid (5.37%), total volatile fatty acids (34.37mmol/liter), lactic acid (7.37%) and pH (8.25) of the rumen were significantly (p<0.05) higher in animals on diet B than those on diets A, C, D and E. Animals on diet D had the highest values in terms of rumen ammonia concentration (0.53mg/100ml) followed closely was diet C and E with the value (0.48mg/100ml).
 Uique contribution to theory, practice and policy: It can be concluded that feeding West African Dwarf (WAD) sheep with Panicum maximum supplemented with Gmelina arborea leaves offers potential results in supplying fermentable nutrients needed to enhance favourable rumen environment for effective microbial activities without any adverse effect on on the rumen parameters status of the animals.

IDENTIFICACIÓN TAXONÓMICA DE Mocis latipes Guenée (LEPIDOPTERA: EREBIDAE) EN PASTOS FORRAJEROS DE VERACRUZ, MÉXICO

<p><strong>Background.</strong> Cultivation of forage grasses is an important component in the dual-purpose cattle production system; however, insect pests can decrease fresh material yields. <strong>Objective. </strong>To taxonomically identify the causal agent that damages the cultivars <em>Panicum maximum </em>(Jacq.) cv. Mombasa and<em> Panicum maximum </em>cv. Zuri. <strong>Methodology.</strong> In two locations in the central region of Veracruz, specimens of an insect in the larval and pupal stages were collected using the quadrant method in an area of 50 ha. Subsequently, in the laboratory, larvae were boiled for two minutes and preserved in 70% alcohol. Meanwhile, pupae were placed in a brood chamber with foliage to obtain adults and to extract their genitalia, which represents the most important morphological structure for the identification of a species. <strong>Results.</strong> The total number of collected larvae was 650, and 65 pupae, all reaching the adult stage. Based on the taxonomic morphology, the species <em>Mocis latipes</em> or striped grassworm was determined. Damage was estimated at approximately 40% per hectare.<strong> Implications.</strong> Correct identification of the pest insect allows the implementation of a strategy for proper management. <strong>Conclusion.</strong> The species<em> M. latipes</em> was identified in forage grasses <em>P. maximum</em> cv. Mombasa and <em>P. maximum </em>cv. Zuri in Veracruz.</p>

Phosphorus availability in an Oxisol in pastures grown in Southern Brazilian Amazonia

The objective of this study was to verify and compare the P availability in an Oxisol cultivated with Megathyrsus maximus cv BRS-Zuri and Urochloa decumbens cv Basilisk and to predict the best soil P extractor in pastures in Southern Amazonia. Two experiments were carried out, one with BRS-Zuri grass and the other with Signal grass. The experimental design was randomized blocks with five doses of P2O5 based on the maximum capacity of adsorption of P (MCAP), corresponding to 0, 3, 6, 12 and 24% MCAP, with doses 0, 54, 108, 216 and 432 kg ha-1 of P2O5, with four replicates. In each cut of the grasses were determined the dry mass, the accumulation of leaf P and by the Mehlich-1 and resin extractors verified the available P. There were effects of P2O5 doses on the variables analyzed in both grasses. The appropriate class of P by Mehlich-1 was 14.6 mg dm-3 (BRS-Zuri) and 7.2 (U. decumbens) mg dm-3, by the resin extractor was 20.5 mg dm-3 (BRS-Zuri) and 14.40 mg dm-3 (U. decumbens). The resin extractor yielded the highest correlation indexes between PR and soil P content.

Intake, performance, and feeding behavior of Holstein and Holstein × Gyr heifers grazing intensively managed tropical grasses during the rainy season

Holstein × Gyr and Holstein are the primary dairy breeds used in tropical systems, but when rearing under pasture, feed intake, behavior, and performance might differ between them. This study aimed to evaluate the voluntary intake, nutrient digestibility, performance, and ingestive behavior of Holstein and Holstein × Gyr (½ Holstein × ½ Gyr) heifers managed in a rotational system of Guinea grass (Panicum maximum Jacq. cv. Mombaça). The experiment was conducted during the summer season throughout four periods of 21 d. Two 8-heifers (four Holstein and four Holstein × Gyr) groups, averaging 258.6 ± 24.79 kg and 157.1 ± 24.99 kg BW, were used. Each group grazed a separate set of 16 paddocks, and all heifers received a concentrate supplement daily. Heifers were weighed at the beginning and end of the experiment. Fecal, forage and concentrate samples were evaluated for their DM, CP, crude fat, ash, NDF, and indigestible NDF. Feeding behavior was evaluated through 24 h of live observation for 48 h of each experimental period. Grazing, ruminating, resting, and intake of concentrate times were recorded, and rumination criteria, bout criteria, mealtime, meal frequency, and meal duration were calculated. There was no difference in total dry matter intake (DMI), but forage DMI of Holstein × Gyr was 11.70 % greater than the Holstein heifers. The Holstein × Gyr heifers had greater NDF intake and feed efficiency tended to show greater CP and NDF digestibilities, consequently, they had greater average daily gain (ADG). Holstein grazed less than Holstein × Gyr heifers in the afternoon. Ruminating time was 18.43 % lower for Holstein than Holstein × Gyr heifers, and rumination criteria (i.e. longest non-feeding interval within a rumination event) were greater for Holstein heifers. Holstein heifers presented more prolonged rumination bouts and resting time than Holstein × Gyr heifers. Holstein × Gyr can ingest and ruminate greater amounts of fibrous material, and Holstein heifers needed to spend more time ruminating the cud. Overall, even though the behavior was not markedly different between breeds, rearing young Holstein heifers in tropical pasture conditions is less suitable than Holstein-Gyr because of their lower ADG. Therefore, this management condition seems appropriate for Holstein × Gyr but inappropriate for Holstein dairy heifers.

Rainfed-based production of Megathyrsus maximus in sub-Saharan Africa: the case of the semi-arid environment of Sudan

The performance of rainfed-based Megathyrsus maximus (syn. Urochloa maxima and Panicum maximum) was investigated in the semi-arid pastures of Sudan. Split-plot complete design experiments with three replications were applied for two consecutive seasons (2020–2021). The treatments were two in situ rainwater harvesting systems [i.e. ridges plus terraces (RD) and terraces (TR)], three seeding rates (i.e. 1.5, 2.5 and 3.5 kg ha−1) and two urea fertilisation rates [0 kg ha−1 (Z) and 95 kg ha−1 (F)]. These treatments were compared to a control (a flat, unfertilised and zero-tillage plot). Hydrological, biological and chemical indicators were used in the assessment. The results showed that the adopted RWH improved semi-arid pastures, with the RD treatment providing the best results for sustaining biomass production, water use efficiency, nutritional quality and soil quality. The highest plant density (112 000 plants ha−1) was associated with the RD3.5 treatment. The FSR1.5-RD treatment resulted in the greatest plant length (63.5 cm) and number of leaves per plant (34.59), whilst the FSR3.5-RD resulted in both the highest fresh biomass (25.9 t ha−1) and dry biomass (6.3 t ha−1). The chemical compositions of M. maximus (i.e. crude protein, organic matter and nitrogen contents) were also substantially improved by fertilisation. The water use efficiency of M. maximus was plant-, management- and climate-dependent.

Petroleum hydrocarbons reduction by selected tropical grass species in oil-based drill cuttings contaminated soil

The potential of phytoremediation of oil-based drill cuttings (OBDCs) contaminated soil was assessed by measuring the level of petroleum hydrocarbons reduction. The contamination experiment was simulated in a randomized complete block design by factorial of 6 × 3 × 2 × 2 for grass species (Pennisitum purpureum, Panicum maximum, Andropogon gayanus, Heteropogon contortus, Axonopus compressus, and Chloris virgata), drill cuttings treatments (0%, 25%, and 50% OBDCs contamination), time (0 day of planting and 105 days of harvesting), and growth stage (young and mature). The parameters assessed were total petroleum hydrocarbons (TPHs) in soils, roots, and shoots; bioconcentration factor in roots and shoots; and translocation factor. The TPH reductions achieved in 25% treatment level were young A. compressus (58.01%), mature P. purpureum, young A. gayanus and C. virgata (44.24%), young P. purpureum (27.67%), mature A. compressus (25.29%), mature H. contortus (2.56%), mature P. maximum (4.01%), and unplanted soils (2.10%). Thus young A. compressus, A. gayanus, C. virgata, and mature P. purpureum are recommended for TPH reduction in 25% OBDCs contaminated soils. Young P. purpureum and mature A. compressus can be used to achieve 25% − 27% TPH reduction.

Forage yield of Guinea grass (Megathyrsus maximus Jacq.) using mineral fertilization during two seasons of the year

Objective: To determine the dry matter yield of Guinea grass (M. maximus Jacq.) in response to mineral fertilization with N-P-K in a tropical humid climate. Design/Methodology/Approach: We conducted an experiment with Guinea grass in Loma Bonita, Oaxaca, Mexico, during the cold front season (November 2018 to February 2019) and the dry season (March to May 2019). The following N-P-K fertilization formulations were used: 00-00-00, 100-00-00, 140-20-00, 180-40-20, 200-00-00, 240-40-20, 260-60-40, and 300-00-00. The response variables were: plant height (cm), chlorophyll content, and dry matter yield (kg ha-1). Results: The fertilization with the highest nitrogen, phosphorus, and potassium levels (p£0.05) increased the dry matter yield, the chlorophyll content, and the height of the Guinea grass above the control. Study Limitations/Implications: Mineral fertilization improved the productive performance of Guinea grass. However, studying more seasons is necessary to validate the results obtained. Findings/Conclusions: The fertilizer formulas with 260-60-40 and 240-40-20 N-P-K units improved the productive performance of Guinea grass. Consequently, the season of the year had a considerable influence on grass yield in a humid tropical climate

In vitro fermentative characteristics and chemical quality of tanzania grass with organic and chemical fertilization

Objective: To evaluate the chemical quality and in vitro fermentative characteristics to find the optimum cutting point of Panicum maximum cv. tanzania grass under four fertilization schemes. 
 Methodology: The grass was tanzania, which received chemical (F1), vermicompost (F2), compost (F3) and compost+lixiviate (F4) fertilizations. The grass was cut at 20, 35, 50, 50, 65, 80 and 105 days. Neutral detergent fiber (NDF), acid detergent fiber (ADF), crude protein (CP), dry matter (DMD), NDF (NDFD) and ADF (ADFD) degradations and in vitro gas production were determined. The experimental design was a 4x6 factorial arrangement in a completely randomized system with fertilization and days of cutting as factors.
 Results: F3-65, F1-65, F4-80 and F1-8 d higher NDF content; F1-65 d higher ADF; F1-20 d higher CP (p≤0.05). F4-50 and F2-50 d higher gas production; F4-20, F4-35, F4-50, F2-20, F2-35, F1-20 d higher DMD, F2-20 and F4-20 d higher NDFD; F4-20, F4-35, F4-65 and F2-20 d higher ADFN (p≤0.05).
 Limitations/implications: Lack of previous research studies on organic fertilization of tanzania.
 Conclusions: Fertilization with vermicompost or compost+lixiviate improve chemical content, in vitro gas production and degradations of tanzania grass

Forage accumulation, morphological composition and height of Panicum maximum cv. tanzania with organic and chemical fertilization

Objective: To evaluate the dry matter accumulation, morphological composition and height in the Panicum maximum cv. Tanzania grass in order to determine the optimal cutting point under four fertilization schemes. Methodology: Tanzania grass was evaluated with fertilizations: T1) chemical (120-60-00 NPK), T2) vermicompost (10 t ha-1), T3) compost (10 t ha-1), and T4) compost + leachate. Cuts were made every 14 days where dry matter (DM), morphological composition and height were measured. A randomized complete block design was used, with an arrangement of measures repeated over time. Results: The maximum accumulation of DM in the T1, T2 and T3 treatments was at 80 days after cutting, the maximum height was with T1 at 80 days after cutting with 206.2 cm. Fertilization with biological products such as vermicompost, compost+leachate and compost presented a higher proportion and conservation of leaves over time. Study Limitations/Implications: Grasslands are not seen as a crop so in most cases they are not fertilized; when they are, it is done with chemical fertilization so there is little information about organic fertilization in tropical fodders. Conclusions: The optimal cutting point is from 50 DAC for chemical treatment, compost+leachate and vermicompost. Fertilization with vermicompost or compost+leachate can be an inexpensive and affordable option for producers to fertilize their meadows.

Nitrogen metabolism of two tropical forage grass species: nitrogen availability × cultivars

The understanding about N metabolism in roots and/or shoots of forage grasses should help determine how some cultivars use N more efficiently. This study was designed to determine whether two Brachiaria brizantha cultivars and two Panicum maximum cultivars differ in their N metabolism. Two cultivars of Panicum maximum and two cultivars of Brachiaria brizantha were investigated under the supply of low and high nitrogen rates in a greenhouse experiment. Some characteristics such as dry mass production, total nitrogen, nitrate and ammonium concentrations and contents; nitrate reductase (NR) and glutamine synthetase (GS) activities; and total free amino acid concentrations in shoots and roots were measured. The results showed that Panicum cultivars showed higher NR activity and GS activity in diagnostic leaves (DL) than Brachiaria cultivars. Brachiaria cultivars showed the highest ammonium concentrations in roots at low N supply and Panicum cultivars at high N supply. The total amino acid concentrations in DL were highest in Panicum and root total amino acid concentrations were highest in Brachiaria. Panicum and Brachiaria cultivars differed in their nitrogen metabolism with varying N supply. The results indicate that at low nitrogen supply to the pasture, Brachiaria brizantha cultivar Piatã may be an option to use in less intensive production environments, instead of high dry mass production. For those pastures with high nitrogen availability, the cultivars Mombaça and Aruana of Panicum maximum were clearly superior to Piatã, which suggests priority in the selection of these cultivars to be used in more intensive production systems that apply more nitrogen

Growth Performance, Semen Quality and Health Status as Affected by using Panicum Maximum in Rabbits Feed

The purpose of this study was to investigate replacement of clover hay in rabbit diets with Panicum maximum hay (Pmh) and how affected digestibility, growth performance, carcass characteristics, semen quality, economic efficiency, and health status. A total of 60 New Zealand White weaned male rabbits, aged 6 weeks and weighing an average of 720±42g, were randomly classified into four dietary groups (15 rabbits each). The control group was fed a baseline diet with 36% clover hay (D1). The other three groups were provided diets with 12, 24, and 36% Pmh to replace the clover hay in the basal diet (D2, D3, and D4 respectively). Feed intake, digestibility, CF and NFE, nutritive value (TDN and DE), daily body weight gain, FCR, and carcass percentage all decreased slightly (P<0.05) with increasing Pmh replacement up to 24 percent (D2 and D3) and significantly (P<0.05) with the highest replacement level (D4) when compared to the control. A replacement had no significant effect on semen quality. Replacement, on the other hand, increased net income by increasing Pmh levels as a result of lower overall feed costs, and the highest replacement level provided the best relative economic efficiency compared to control (114%). The hematological parameters were within normal limits and the histological alterations had no negative effect on the animals' physiological activities. Finally, using Pmh instead of clover hay in rabbit diets can be used as an alternative, save and more economical feed in rabbit diets.

FEED INTAKE AND GROWTH RATE OF WEST AFRICAN DWARF GOATS FED DIFFERENT PROPORTIONS OF RUMEN WASTE, POULTRY WASTE AND CASSAVA PEEL WASTE

Purpose: Rumen waste, poultry waste and cassava peel waste are sources of environmental pollution but could serve as feed resources for ruminant animals. This study was undertaken to ascertain the nutritive value of composite diets with varied proportions of these waste in West African dwarf goats.
 Methodology: Four experimental diets were formulated in which diet 1 was a standard (control) diet. Diets 2, 3 and 4 contained the wastes in varied proportions of 5, 15, and 25%. The goats where offered a basal diet of concentrate containing Brewer’s dried grain (BDG), vitamin/mineral salts mixtures and Panicum maximum. A feeding trial was conducted using sixteen (16) West African dwarf (WAD) goats in a completely randomized design (CRD). Feed intake and weight changes were determined. Chemical composition of the experimental diets was analyzed. 
 Findings: Results of chemical composition of the diets showed absence of significant (P > 0.05) variation in nutritional composition except diet 3, which had greater (P < 0.05) value of Crude Protein (21.00 %) and NDF (61.00 %). Also, diets 2 and 3 had the least (P < 0.05) metabolizable energy of 3.91 and 5.65 MJ/Kg DM respectively. Results of feeding trial showed significantly (P < 0.05) low nutrient intakesfor composite diets 2, 3 and 4 compared to the control (diet 1). Growth performance result showed that goats on diet 1 and 4 significantly (P < 0.05) gained weight (1.07kg and 0.97kg respectively), while goats on diet 2 and 3 significantly (P < 0.05) lost weight (-1.63kg and -0.56kg respectively). Feed conversion efficiency followed a similar trend. Results shows that the goats on diet 1(control) and diet 4 (25% RW, 5% PW and 15% CP) were better utilized by the WAD goats during the feeding trial. This difference can be attributed to poor palatability and acceptability of diets 2 and 3 as well as nutrient imbalance as required for proper rumen function. Therefore, an appropriate combination of these non-conventional feed materials or wastes, as indicated by diet 4, can be fed successfully to small ruminant animals.

Performance of blackhead Ogaden sheep fed different grasses (Chloris gayana, Pennisetum purpureum, Panicum maximum and Cynodon dactylon) basal diets and the same concentrate mixture

A study was conducted to determine the effect of feeding Rhodes grass (RG; Chloris gayana) as treatment 1 (T1), elephant grass (EG; Pennisetum purpureum as T2), guinea grass (GG; Panicum maximum as T3) and bermuda grass (BG; Cynodon dactylon as T4) supplemented with a similar amount of concentrate mixture (CM; wheat bran (WB) and Noug seed cake (NSC) at 67:33 ratio) on performance and economy of fattening of Blackhead Ogaden sheep. The study consisted of a feeding and digestibility trials of 90 and 7 days long, respectively. Twenty-four intact yearling Blackhead Ogaden sheep with an initial body weight (BW) of 15.83±0.04 kg (mean±SD) were used in a randomized complete block design based on their initial BW with four treatments and six replications. All animals received 300 g dry matter (DM) of CM. Nutrient concentration of RG, EG, GG, BG, NSC and WB were 5.5, 8.8, 7.6, 7.9, 24.3 and 14.0% crude protein (CP), and 83.3, 74.5, 75.4, 81.5, 39.0 and 45% neutral detergent fiber, respectively on DM basis. Intake of DM was 696, 700, 719 and 716 g/day (SEM = 0.004) for T1, T2, T3 and T4, respectively and was lowest for T1 and highest for T3. The CP intake was also lowest for T1 (89 g/day), and similar among the other 3 treatments (99-103 g/day). Digestibility of CP and organic matter were highest for T2, intermediate for T3 and T4 and lowest for T1. Average daily gain was in the order of T2 > T3 = T4 > T1 (27, 63, 50 and 45 g/day (SEM = 13.1) for T1, T2, T3 and T4, respectively); whereas hot carcass weight did not significantly differ among treatments (5.7, 6.4, 6.1 and 6.3 kg (SEM = 0.36) for T1, T2, T3 and T4, respectively). Total return, net income and marginal rate of return were all in the order of T2 > T4 > T3 > T1. Therefore, based on biological performance as well as economic return, sheep fed elephant grass perform better. However, variations in performance and economic return among the four grass species needs to be taken cautiously as part of the difference might have attributed to differences in the stage of maturity of the grasses up on harvest for feeding the lambs. Keywords: Blackhead Ogaden sheep, Digestibility, Feed intake, Performance, Weight gain.

Major weeds of Ecuador IV. Coffee plantations in Jipijapa

Coffee is a crop of economic importance in Ecuador, grown in area of 199 215 ha, 38,6% of it in Canton of Jipijapa, located in the south of the province of Manabí. Coffee here is grown by small farmers, who spend who spend little annually for the maintenance of plantations. One of the main constraints for getting optimal crop yields is the presence of weeds, which affect water stress during dry spells, and bring about deficient plant uptake of essential nutrients. Weeds are not usually properly controlled in all areas of this crop. Some farmers eliminate weeds twice or three times a year, others do that only once. The most common control method is hand hoeing, but some growers use foliar-applied herbicides, any of these practices are commonly carried out without knowledge of prevailing weed species. Suitable weed management strategy should include data about main weeds and their biology during dry and rainy seasons in Jipijapa. To this end, in 15 ha of coffee plantations during 2014 dry period and in another 15 ha during 2015 rainy one, weed cover and species present were visually evaluated using a scale 0-5, where 1- up to 5% weed cover and 4-more than 50%. These values were processed to determine Absolute and Relative Frequencies, average weed cover and finally Severity Infestation (SI). A total 39 weed species belonging to 19 families were found in both seasons, mostly broadleaves plants, while grasses were found in less shady spots of the plantations. The prevailing weed during rainy period appears to be Senna occidentalis followed by Commelina erecta, Laportea aestuans, Alternathera flavescens and Xanthosoma spp., while during dry season, the fern Pteridium aquilinum was the leading species followed by perennials Alternathera flavescens and the C4 grass Megathyrsus maximus. The species found only responded to the humidity conditions in each season and not to the effect of a certain control measure. Most of the evaluated plantations show poor crop management, scarce crop plant density, and even coffee planted in favor of the slope. Improved plantation management is the key measure to reduce the weed presence of weeds. In the rainy season, with more weed abundance, two early weeding operations, with an additional one later are advisable, while in the dry season, in the case of plantations with adequate shade, one weeding may satisfactorily reduce the weed presence. Perennial Geophila macropoda, found during rainy season, is a potential living cover in coffee plantations since it may help to reduce soil erosion and smothers weeds.