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Herbicide promotes physiological and biochemical changes even in tolerant species. The objective of this study was to evaluate the interference of the herbicides clodinafop-propargyl and 2,4-D in the antioxidant system of wheat, and iodosulfuron-methyl in wheat and ryegrass. Two studies, divided into three experiments, were conducted in an entirely randomized design in a greenhouse and phytotron. The first study tested herbicides iodosulfuron-methyl, clodinafop-propargyl, 2,4-D, and a control without application in wheat. The second, divided into two experiments with wheat and ryegrass, tested iodosulfuron-methyl doses (0, 1.75, 3.5, and 7.0 g a.i. ha-1). The variables analyzed were the concentrations of chlorophylls a, b, carotenoids, hydrogen peroxide (H2O2), lipid peroxidation (TBARS), electrolyte leakage, and antioxidant system activity. The herbicide treatments iodosulfuron-methyl, clodinafop-propargyl, and 2,4-D decreased the concentrations of chlorophylls and carotenoids in wheat plants. The herbicides promoted oxidative stress with increased H2O2 and TBARS concentrations. Increasing the dose of iodosulfuron-methyl provided a reduction in the activity of the enzymatic antioxidant system in wheat and ryegrass. [ABSTRACT FROM AUTHOR]

This study determined the effect of different defoliation frequencies in a long-cycle ryegrass cultivar on yield components and the physiological and sanitary quality of seeds. Four defoliation frequencies were applied (without, one, two, and three defoliations). The time between defoliations was 350 degree-days. At the first, second, and third defoliation time, the plants were 15 cm, 20 cm, and 35 cm, respectively, and were lowered to half their height. The yield components and plant structure were evaluated through the tillers, along with the physiological quality of the seeds, which was verified by germination tests, first germination count, accelerated aging, tetrazolium test, field emergence, and weight of a thousand seeds. For the sanitary quality analysis, the percentage (%) of fungi incidence in the seeds was verified. The second defoliation determined the seeds’ high physiological and sanitary quality due to the higher amount of primary and secondary tillers produced concerning the other treatments. However, there was no significant difference for the third defoliation since the aerial tillers issued the same quality of seeds originated from primary and secondary tillers. The average incidence of fungi such as Colletotrichum sp., Fusarium sp., Phoma sp., and Dreshslera spp. was lower in ryegrass plants subjected to three defoliations. [ABSTRACT FROM AUTHOR]

The canopy structure and morphogenesis of ryegrass (Lolium multiflorum Lam.) was investigated after it was over seeded with Tifton 85 (Cynodon spp.) and intercropped with red clover (Trifolium pratense L.). Time intervals between cuts were determined by different thermal sums (125, 250, 375, and 500 degree-days [DD]). Cuts were conducted at a height equivalent to 50% of the average canopy height. Morphogenic and structural data were collected from July to October of 2016 and 2017, from a completely randomized block experimental design. Canopy height, extended tiller height, pseudostem length, and forage mass were fitted to linear equations according to the thermal sums. Interaction of ryegrass with red clover was the highest (12.1%) for longer cut intervals (375 and 500 DD). The leaf appearance rate (0.0080 leaf/DD), phyllochron value (128.8 DD), and senescence rate (0.10 cm/DD) of ryegrass were comparable between the different intervals. The slowest elongation rate (0.06 cm/DD) with the shortest interval duration between cuts (171.6 DD) was observed in the 125 DD interval. According to the findings from this 2-year experiment, the use of a 250 DD cut interval was recommended between grazing events, taking into account the efficiency of forage use, ryegrass leaf, stem ratio, and interactions with red clover in the canopy under rotational stocking. [ABSTRACT FROM AUTHOR]

The objective of this research was to carry out a survey, through the levels of physical purity, percentage of pure seeds, number of other seeds, and the physiological quality through germination, in the samples of ryegrass seeds analyzed in laboratories accredited by the Ministry of Agriculture, Livestock and Supply in Rio Grande do Sul. Data from 3959 ryegrass samples analyzed from the period 2014 to 2017 were compiled. Quality of the seeds was presented through the percentage of samples within the standards recommended for commercialization, for the variables germination, pure seeds, seeds of cultivated species, wild, noxious, tolerated and noxiously forbidden, in all factors, cultivar, region of origin, category and crop of seed production. Quality of the lots of ryegrass seeds, analyzed by the laboratories of Rio Grande do Sul, obtained in the harvest of 2013 the lowest percentage of lots approved for commercialization, 57.96%, and the harvest of 2014, 2015 and 2016 with 89.60% 91.39% and 91.34%, respectively. In regions where livestock predominates, the percentage of ryegrass seed lots approved for commercialization was lower. [ABSTRACT FROM AUTHOR]

The excretion of urinary nitrogen (N), one of the most important environmental contaminants from livestock systems, is highly correlated with milk urea N content. The objective of this research was to evaluate the use of different types of corn supplementation on milk urea N in grazing dairy cows. Twelve Holstein × Jersey lactating dairy cows were divided into six uniform groups according to milk production, lactation stage and live weight. Treatments were compared according to a 3 × 3 replicated Latin square experimental design, with three periods of seventeen days (twelve days to adaptation and five to measurements). The experimental treatments were exclusively grazing (G); grazing + supplementation with 4.2 kg DM of corn silage (CS) and grazing + supplementation with 3.2 kg DM of ground corn (GC). The pasture used was annual ryegrass (Lolium multiflorum L.) and white oats (Avena sativa L.). The milk protein production increased 65 g/day in the GC treatment group compared to the G and CS groups. The supplemented dairy cows showed lower milk urea N (-2.8 mg/dL) than unsupplemented cows, but the N utilization efficiency (g N output in milk/g N intake) did not change between treatments (average = 0.26). Additionally, there was a relationship between milk and plasma urea nitrogen concentrations (R² = 0.64). In conclusion, for dairy cows grazing annual temperate pastures, corn ground supplementation increased milk protein production and reduced the excretion of milk urea N, whereas corn silage reduced the excretion of milk urea N without affecting milk protein production. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the leaf tissue flows in Italian ryegrass (Lolium multiflorum Lam.), in different phenological stages, grazed by lambs, and managed under three herbage allowances (6, 9 and 12 kg DM/100 kg body weight under rotational stocking method. The experimental design was completely randomized, with repeated measures arrangement. Forage allowances determined similar growth and intake flows, actual and potential utilization efficiencies of grass and they were different in the phenological stages of Italian ryegrass. The intake of leaf blade, as a percentage of body weight, was higher in the 12% herbage allowance. Considering leaf tissue flows, Italian ryegrass can be managed in forage allowances that vary between 6 and 12 kg DM/100 kg body weight. [ABSTRACT FROM AUTHOR]

The objective was to evaluate the effects of times of emergence of the weed ryegrass species and wild radish on barley. The experiment was conducted in a randomized block design, arranged in a 2x5 factorial design, with three replicates. In factor A were allocated the competing species (ryegrass and wild radish) and in factor B the emergence periods (14 and 7 days before, on the same day, 7 and 14 days after crop emergence). At the beginning of barley flowering, the following variables were quantified: plant height, number of stalks or stems, leaf area, and shoot dry mass of crop and weeds. All barley variables had increased in value with the delay in weed emergence. The species, cultivated or weeds, that emerged earlier showed greater competitive ability, dominating the environment when emerging 14 days before each other. The later the emergence of weeds with respect to the crop, the less the interference they cause, and, thereby, the crop presents a greater ability to compete with the weeds for available resources in the environment. [ABSTRACT FROM AUTHOR]

The objective in this study was to characterize the productive potential, monthly yield distribution, and forage plantpart and botanical composition of black oats and annual ryegrass under harvest strategies in São Paulo. The experimental design was completely randomized with treatments corresponding to the combination among stand composition (exclusive oats, exclusive annual ryegrass, or oats + ryegrass, O+R) and harvest strategies (at 95% LI or every 30 days of regrowth, FIXED), in a factorial arrangement with three replications. Stands managed by LI accumulated 1580kg DM ha-1 harvest-1, and those managed by FIXED 2020kg DM ha-1 harvest-1. Leaf proportion was higher in ryegrass (70%), followed by O+R (64%) and oat (52%). Swards managed by LI had higher proportion of leaves and less stem than those harvested at FIXED intervals. The proportion of ryegrass was higher under the LI management (64%), than under the FIXED (70%). Over time there was the replacement of oats by ryegrass in the mixed canopy composition. Exclusive ryegrass stands are recommended. Both harvest strategies can be adopted for these winter forages in integrated systems of agriculture and livestock. [ABSTRACT FROM AUTHOR]

Morphogenetic and structural characteristics of Italian ryegrass (Lolium multiflorum Lam.), utilized by female lambs and managed with different forage masses (FM) were studied. The experimental design was completely randomized, with two area replications and three treatments, consisting of forage masses: "High", "Mean" and "Low", corresponding to 1,800-2,000; 1,400-1,600 and 1,000-1,200kg ha'1 of dry matter (DM), respectively. The grazing method was continuous with variable stocking rate. Data were subjected to correlation analysis and polynomial regression. Pseudo stem's height and length of the intact and defoliated leaf blades and number of senescent leaves of Italian ryegrass increased linearly with the increase of forage mass. Number of green leaves was adjusted to the quadratic regression model, number of leaves in elongation and tiller population density did not adjust to any regression model. Management of Italian ryegrass with forage masses between 1,100 and 1,800kg ha'of DM did not cause changes in its morphogenetic characteristics, but causes differences in the structural characteristics of the canopy. When managed with 1,460kg ha 'of DM, tillers of Italian ryegrass maintain greater number of green leaves. Meanwhile, when managed with 1,800kg ha 'of DM it has a higher number of leaf blades in senescence, and leaves with greater length. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the practical application of herbicide, overseeded annual ryegrass for the establishment of forage peanut (Arachis pintoi) in natural vegetation. The experiments was conducted from October 2007 to November 2008, Estação Experimental Terras Baixas (ETB) - Embrapa Clima Temperado, Capão do Leão - RS. The treatments were arranged in a randomized block design in split plots with four replications. The plots were represented by the treatments with and without herbicide (3L ha-1 of commercial herbicide glyfosate). The subplots were defined by the absence of forage peanut, the presence of forage peanut, the presence of forage peanut overseeded with annual ryegrass. The frequencies of species of natural vegetation were not influenced by grazing and overseeded ryegrass. The establishment of forage peanut Arachis pintoi is benefited by the herbicide. However, it is a practice that causes a significant reduction of species of forage interest. The presence of annual ryegrass provides a favorable environment for forage peanut during the cool season. [ABSTRACT FROM AUTHOR]

This trial aimed to evaluate the nutritive value of white oat (IPR 126), black oat (IAPAR 61), common black oat, common annual ryegrass and dual purpose wheat (BRS Tarumã), sowed on different dates (4th and 24th April, May 14th, and June 3rd 2008). Randomized completely block design was used with four replicates. Cutting regime was done according to sward surface height target, varying to each forage species, as well as stubble height. Harvested material was analyzed in terms of crude protein content (CP), neutral detergent fiber (NDF) and total digestible nutrients (TDN). There was significant interaction between sowing dates and forage species over all nutritive variables analyzed. CP and TDN of oats and ryegrass were higher in early sowing dates, and NDF content increased in the latest sowing dates. On the contrary, BRS 'Tarumã' had lesser nutritive value in earliest sowing date. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effect of levels of crude glycerin in the supplement intake and performance of suckling lambs on rye grass pasture, beyond the qualitative and quantitative characteristics of ryegrass pastures. It was used 32 suckling lambs distributed between the treatments: 0, 10, 20 and 30% of crude glycerin, replacing corn, in the isoproteic supplement (18% CP) offered daily in an amount equivalent to 2% of body weight. There was no effect (P>0.05) of the levels of crude glycerin on the qualitative and quantitative characteristics of pastures, composition of crude protein and neutral detergent fiber, stocking rate supported by rye grass pasture, neither on supplement intake, average weight gain and number of days to slaughter the lambs. Levels up to 30% of crude glycerin, replacing corn, provided in the supplement to suckling lambs grazing ryegrass didn't compromise the supplement intake, performance and termination period of the animals. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the relative contribution of stem in the vertical structure of Aruana guineagrass and annual ryegrass pastures submitted to strategies of rotational grazing by sheep. Treatments for Aruana guineagrass corresponded to grazing when the swards intercepted 95 and 98% of the incident light (LI) until the postgrazing heights of 10 and 15cm. For annual ryegrass, treatments corresponded to grazing when the swards reached 15 and 25cm (pre-grazing heights) until the post-grazing of 4 and 8cm. The experimental design for two species was a completely randomized in a 2x2 factorial scheme, with three replications. To quantify the stem mass present at each 5cm in the vertical structure of the pastures two samples were taken per experimental unit (paddocks of 196m2) using a square of 25cmx25cm. Cut samples was separated in leaves, stem and dead material. Regardless of plant species or pre-grazing height, approximately 90% of the stem is present up to 50% of sward height, suggesting that reported intake reduction beyond this point can be attributed to difficulties in forage manipulation and apprehension. [ABSTRACT FROM AUTHOR]

The objective of the present study was to evaluate the methodology of the accelerated aging test to evaluate the physiological potential of s ryegrass seeds, as well as verify the possibility of the use of unsaturated and saturated solution of NaCl as an option for control of water uptake by seeds during the test without reducing its sensitivity. Four lots of ryegrass seeds were tested for germination, seedling emergence, speed emergence and accelerated aging (periods of 24, 48, 72 and 96h, with or without the use of saturated and saline solution of NaCl). The use of unsaturated and saturated solution of NaCl reduces water absorption by ryegrass seeds during the accelerated aging test, resulting in a rate of deterioration is less pronounced ,less drastic and more uniform results. Option 24h with unsaturated solution (SNS) was only able to stratify plots into two groups and should not be designated as promising. Thus, it should be used the 48h saturated NaCl solution (SSS), which stratified into three lots. [ABSTRACT FROM AUTHOR]

In order to evaluate the satellite image patterns between such cool season cereals cultivated areas intended for grazing or grain production, Normalized Difference Vegetation Index (NDVI) temporal profiles were analyzed. This data was acquired from twenty nine wheat and annual ryegrass cultivated areas in the states of Rio Grande do Sul and Paraná. For each area, the cultivated species (wheat or ryegrass), as well as the respective central point coordinates, acquired via Global Positioning System (GPS) was informed. NDVI values were extracted over each monitored area from MODIS (Moderate Resolution Imaging Spectroradiometer) sensor images, with spatial resolution of 250 meters. The NDVI temporal profiles showed that grain production areas have a typical agricultural field spectral pattern. The same pattern was not observed for the grazing pasture areas. The differences observed in these temporal patterns are defined by the changes that grazing has imposed on the phenology and morphology of these plants. [ABSTRACT FROM AUTHOR]

It was evaluated the effect of nitrogen fertilization in ryegrass pasture (Lolium multiflorum Lam.) on the production of meat lamb under continuous grazing. Ryegrass pasture was established under no-tillage cropping in area of animal-crop integration system. The fertilization was held with 60kg of P2O5 ha-1 and 60kg of K2O ha-1. The treatments corresponded to the doses 0; 75; 150 e 225kg of N ha-1, in the urea form (45% de N) in single application, 35 days after seeding. The evaluation period was of 84 days. The forage was influenced quadratic ally by N rates, with minimum point at 182.75kg of N ha-1. However, the supply of leaf blades (LFM) was not influenced by doses of N (3.8kg LFM 100kg-1 live weight) or by the average daily weight gain, averaging 0.133 kg of LW an day. For stocking rate and live weight gain per area the doses of N increased 3.0 kg of LW-1 ha-1 and 1.1kg of LW ha-1, respectively for each kg of N applied. Nitrogen fertilization provides increases in animal productivity which results in increase kg of meat produced in this system. [ABSTRACT FROM AUTHOR]

The impact of energy supplementation on the performance and carcass caracteristics of 24 Aberdeen Angus x Charolais steers grazing an annual ryegrass (Lollium multiflorum L.) and Oats (Avena strigosa Schreb) pasture managed in order to avoid constrains to animal performance was evaluated. Treatments were levels of supplementation of 0; 0.4; 0.8 and 1.2% BW with a corn and mineral based supplement. Animals were slaughtered as they achieve 4,5mm of fat cover in the rump (P8) evaluated ultrasonography. No differences were observed in fat deposition, measured in live animals with ultrasound at the end of performance period, and in live weight gain, which showed average values of 3,9mm and 1,54kg d-1 respectively. Blood serum levels of urea were linearly decreased and cholesterol linearly increased by energy supplementation, with no differences in the serum levels of glucose and triglicerides. Energy supplementation linearly increased the killing-out proportion and carcass weight gain, but no differences were observed on the rib eye area, slaughter weight and hot carcass weight, wich averaged 67,85cm2, 438,95kg e 227,75kg. Increasing the levels of supplementation resulted in higher killing-out proportion and higher carcass daily gains, without changes in performance and carcass parameters evaluated. [ABSTRACT FROM AUTHOR]

Meat composition is an important aspect on evaluation of sensory and nutritional quality of the product. This work had the objective of evaluating tissue composition and fatty acids profile of loin lambs weaned at 42 days of mean age and finished on ryegrass pasture with levels (0%; 1% and 2% of BW; ad libitum) of daily concentrate supplementation. The experiment was allocated in randomized blocks design with three replications. Lambs were slaughtered when individual live weight reached 32kg. Tissue composition was determined in right loin and left loin was used for fatty acids profile analyses. Analysis of variance and regression were performed by using SAS (2001). The concentrate supplementation of lambs finished on pasture did not affect (P>0.05) muscle and bone development, however, promoted linear increase on intermuscular and total fat. Levels of supplementation did not affect (P>0.05) the amount and percentage of each fatty acids in lambs meat. The concentrate supplementation of weaned lambs finished on ryegrass pastures increased fat covering on carcass without changing meat quality to human feeding considering fatty acids profile. [ABSTRACT FROM AUTHOR]

The incorporation of ryegrass residues on the soil in rice irrigated fields can improve the physical, chemical and biological soil properties. It can also accelerate the redox reaction during the soil flooding, allowing a higher availability of nutrients to the plants, which responds with a higher growing and nutrient absorptions. The objectives of this research are to quantify the nutrient absorptions, the rice crop growing, and to determine the concentration of nutrients in the soil solution on a flooding Albaqualf soil. For this, increasing doses of ryegrass residues were applied in the soil surface. A greenhouse experiment was carried out using a randomized complete block design with six doses of ryegrass residues (0.0; 1.25; 2.5; 5.0; 7.5 and 10.0Mg ha-1) applied to the soil surface. Cultivar 'BRS 7 Taim' pre-germinated seeds were sown in plastic pots. The soil in the pots was flooded 15 days after this procedure and plants were hept in this condition for an additional 45 days. In the rice plants were evaluated the dry matter weight of the shoots and the following nutrients: N, K, P, Ca, Mg, Fe, Mn, Cu and Zn. In the soil solution were evaluated the redox potential (Eh), pH, and the concentration of Mn, Fe, K, Ca, Mg. Results show that the addition of increasing doses of ryegrass residues in the flooded soil surface until 10Mg ha -1 strengthened the soil redox reaction process increasing the concentration of Mn, Fe, Ca, Mg and K in the soil solution. It also increased the K and Fe contents in the aerial part of rice plants as well increased their dry matter weight. [ABSTRACT FROM AUTHOR]

The objective of this study was to estimate lower base temperature Tb of three diploid (Comum, Fepagro São Gabriel, and LE 284 and two tetraploid (Avance and INIA Titán) ryegrass genotypes. With the estimated Tb, it was also possible to investigate if these genotypes may have seasonal production, which helps in programming herds feeding schedules. Five sowing dates (11/05, 07/06, 05/07, 09/08 e 01/09/2007) were performed in Santa Maria, RS, Brazil. Two methods were used to estimate Tb: least deviation method and relative development method. Tb values varied from 7.0 to 8.5°C for diploid genotypes and from 9.0 to 10.6°C for tetraploid genotypes, depending upon the method. Diploid ryegrass germoplasm have no risk of seasonal decrease in forage production, whereas tetraploids, mainly Avance, may have their growth and development decreased from June to August in Santa Maria because of minimum air temperature. [ABSTRACT FROM AUTHOR]

Leaf tissue flow in Italian ryegrass (Lolium multiflorum Lam.) was quantified in three grazing intensities. The intensities corresponded to the disappearance of 21.1 ('Low'), 43.3 ('Mean') and 61.0% ('High') of the initial forage mass on each grazing cycle. The experimental animals were ewe lambs and the thermal sum of 313 degree-days determined the interval among grazing. The experimental design was completely randomized with three treatments and four replicates. In intensity 'Low' the highest growth and senescence flows were registered, respectively, 85.6 and 54.6kg ha day-1 of DM. In 'Mean' and 'High' intensities the growth and intake flows were higher in the beginning of pasture utilization and the senescence flow increased with the development of the Italian ryegrass cycle. It is recommended the use of the 43.3% grazing intensity which allowed greater values of intake flow, with mean growth and senescence flows. [ABSTRACT FROM AUTHOR]

The aim of this research was to evaluate the effect of undegradable protein supplementation to dairy cows grazing Italian ryegrass. Twelve Holstein cows in the mid lactation were used and treatments were 0 (zero) and a mixture (60:40) of ground corn + corn gluten meal (4.0kg cow day-1) evaluated along three periods of fifteen days. Cows were distributed in four groups (two per treatment) and assigned to Italian ryegrass plots submitted to intermittent grazing with a herbage allowance of 24kg of DM cow day-1. Pre-grazing herbage mass (2325kg of DM ha-1) and sward surface height (15.8cm) were similar on plots and crude protein and NDF of ingested forage were 18.9 and 53,0%, respectively. Supplementation did not affect herbage DM intake (mean=8.5kg cow day-1) but, both, total DM intake and metabolisable energy increased 3.0kg and 42MJ cow day-1, respectively. Supplementation increased milk production (4.0 kg.cow.day-1) but did not change protein and fat milk content (32.8 and 29.2g kg-1). At low herbage allowance, supplementation with corn ground meal (22% of crude protein) increase milk production on proportion of 1:1 and studies should be done at conditions of non- limitant herbage allowance. [ABSTRACT FROM AUTHOR]

This research aimed at evaluating the nutritive value by determining the organic matter (OM), in vitro OM digestibility (IVOMD), total digestibility nutrient (TDN), in vitro dry matter digestibility (IVDMD), crude protein (CP) and neutral detergent fiber (NDF) of four pasture-based system grazed by Holstein cows. The treatments were sod seeding of ryegrass (Lolium multiflorium Lam. cv. 'Common') over coastcross (Cynodon dactylon L. Pers.,); sod seeding of ryegrass plus white clover (Trifolium repens L., cv. 'Yi') over coastcross ryegrass plus white clover or ryegrass. From May 15th to October 24th, 2006, in five grazing periods, the pregraze herbage mass (PM), botanical and structural compositions and stocking rate (SR) were evaluated. Hand-plucked samples were collected to analyze the nutritive value. The experimental design was completely randomized, with four treatments (pastures) and two replications (paddocks). Differences in PM and SR averages were not detected among treatments. Better results of nutritive value were associated of ryegrass leaf lamina biomass in all pastures. Small differences on nutritive value were observed on sod seeding 'coastcross' systems compared to ryegrass plus white clover or ryegrass pastures. The mean values of OM, IVOMD, TDN, IVDMD, CP and NDF of the pastures were 89.52; 69.50; 60.95; 70.96; 23.03 and 51.87%, respectively. [ABSTRACT FROM AUTHOR]

Body development of beef heifers grazing Italian ryegrass pasture (Lolium multiflorum Lam.) was evaluated. The animals received different alternatives of mineral supplement: associated or not to ionophore addition and the treatments were: 'Common salt': mineralization with sodium chloride; '40P salt': mineralization with mineral salt plus 40g of phosphorus per kilo of product; 40P salt + ionophore: mineralization with 40g of phosphorus plus 2000mg of lasalocid per kg of product. The values of crude protein, neutral detergent fiber and Ca and P of the apparently consumed forage, salt intake, body condition and body weight:height relation were similar (P>0.05) between animals receiving 'common salt', '40P salt' and '40P salt+ionophor'. For beef heifers grazing ryegrass pasture without intake restriction, the lasalocid associated to mineral salt provides a greater body weight at twelve months age and a positive financial. [ABSTRACT FROM AUTHOR]

This study had the objective to evaluate Pampa Corte Model's reliability in predicting beef cattle performance in grazing systems. For this purpose, model's predicted values were compared to available data base of published papers. Correlation coefficients above 90 % were obtained between simulated and real data in all tested alternatives. Model's data base should be enlarged by forage productivity data in different climatic conditions. Mixtures of Italian ryegrass and oat need more studies to obtain qualitative parameters (crude protein degradability and neutral detergent fiber), as well, animal performance in the single pastures of oat or Italian ryegrass. [ABSTRACT FROM AUTHOR]