Pasture Types Research Articles

Crude Protein as an Indicator of Pasture Availability and Quality: A Validation of Two Complementary Sensors

This study evaluated the possibility of using two complementary electronic sensors (rising plate meter (RPM) and active optical sensor (AOS)) to obtain a global indicator, pasture crude protein (CP) in kg ha−1. This parameter simultaneously integrates two essential dimensions: pasture dry matter availability (dry matter (DM) in kg ha−1) measured by RPM, and pasture quality (measured by AOS), and supports management decisions, particularly those related to the stocking rates, supplementation, or rotation of animals between grazing parks. The experimental work was carried out on a dryland biodiverse and representative pasture, and consisted of sensor measurements, followed by the collection of a total of 144 pasture samples, distributed between three dates of the pasture vegetative cycle of 2023/2024 (Autumn—December 2023; Winter—February 2024; and Spring—May 2024). These samples were subjected to laboratory reference analysis to determine DM and CP. Sensor measurements (compressed height (HRPM) in the case of RPM, and normalized difference vegetation index (NDVI) in the case of AOS) and the results of reference laboratory analysis were used to develop prediction models. The best correlations between CP (kg ha−1) and “HRPM × NDVI” were obtained in the initial and intermediate phases of the cycle (autumn: R2 = 0.86 and LCC = 0.80; and Winter; R2 = 0.74 and LCC = 0.81). In the later phase of the cycle (spring), the accuracy of the forecasting model decreased dramatically (R2 = 0.28 and LCC = 0.42), a trend that accompanies the decrease in the pasture moisture content (PMC) and CP. The results of this study show not only the importance of extending the database to other pasture types in order to enhance the process of feed supplement determination, but also the potential for the research and development of proximal and remote sensing tools to support pasture monitoring and animal production management.

Estimation of Dry Matter Yield in Mediterranean Pastures: Comparative Study between Rising Plate Meter and Grassmaster II Probe

This study evaluates two expedient electronic sensors, a rising plate meter (RPM) and a “Grassmaster II” capacitance probe (GMII), to estimate pasture dry matter (DM, in kg ha−1). The sampling process consisted of sensor measurements, followed by pasture collection and a laboratory reference analysis. In this comparative study, carried out throughout the 2023/2024 pasture growing season, a total of 288 pasture samples were collected in two phases (calibration and validation). The calibration phase (n = 144) consisted of measurements on three dates (6 December 2023, 29 February and 10 May 2024) in 48 georeferenced sampling areas of the experimental field “Eco-SPAA” (“MG” field), located at Mitra farm (Évora, Portugal). This pasture is a permanent mixture of various botanical species (grasses, legumes, and others) grazed by sheep, and is representative of biodiverse dryland pastures. The validation phase (n = 144) was carried out between December 2023 and April 2024 in 18 field tests (each with eight pasture samples), in three types of representative pastures: the same mixture for grazing (“MG” field), a commercial and annual mixture for cutting (mowing) and conservation (“MM” field), and legumes for grazing (“LG” field). The best estimation model for DM was obtained based on measurements carried out in February in the case of the GMII probe (R2 = 0.61) and December 2023 and February 2024 in the case of RPM (R2 = 0.76). The estimation decreased very significantly for both sensors based on measurements carried out in May (spring). The validation phase showed greater accuracy (less RMSE) in “MG” field tests (RMSE of 735.4 kg ha−1 with GMII and 512.3 kg ha−1 with the RPM). The results open perspectives for other works that would allow the testing, calibration, and validation of these electronic sensors in a wider range of pasture production conditions, in order to improve their accuracy as decision-making support tools in pasture management.

Physical and biochemical characteristics of tropical grass and legume pastures grazed by lambs

AbstractLarge areas of tropical grass pastures are not grazed by lambs because of the difficulties in managing high growth rate swards with high selective animals. The objective of this study was to evaluate the physical and biochemical characteristics of tropical pastures offered to lambs in continuous grazing. An upright grass and a shrub legume were set out in three pasture types and grazed by lambs: (1) aruana grass monoculture (AG—Panicum maximum Jacq. cv. IZ‐5), (2) pigeon pea monoculture (PP—Cajanus cajan [L.] Millsp. cv. Anão) and (3) contiguous swards (CS), half of the paddock with AG (CSAG) and half with PP (CSPP). The pastures were evaluated for structural characteristics, production, nutritional composition and antioxidant concentrations in four periods over 92 days of continuous grazing by lambs. Hand plucking samples, similar to animal diet, were collected for chemical analysis. Regarding height, the PP legume monoculture after 42 days of grazing had uncontrollable growth by the lambs, reaching 1.2 m in height. This same legume but as a CS beside AG (CSPP) was maintained at a lower and similar height throughout the experimental periods. In general, the leaf:stem ratio of the different pastures decreased over the experimental periods from 0.7 to 0.2. In most periods, the CS showed intermediary nutritional quality compared to AG and PP. The alpha‐tocopherol content was similar among swards, with an average of 137.2 ± 13.67 mg/kg of green matter (p > .05). Pigeon pea showed the highest levels of total tannin and condensed tannin at 63 and 92 days (p < .05). The use of tropical grass together with a legume provides a better physical structure of the pigeon pea for grazing lambs than when monoculture of this species.

PSXII-6 Canopy height as a predictor of forage biomass in native rangelands and bermudagrass pastures

Abstract Accurate and less laborious estimates of forage biomass are needed for research and management decisions in grazing lands. Our objective was to develop linear regressions to estimate forage biomass using canopy height in both native rangelands and introduced bermudagrass [Cynodon dactylon (L.) Pers.] pastures in the Cross Timbers and Southern Tallgrass Prairie Ecoregion. Twelve pastures averaging 26 acres each were equally distributed in two ranches located in the Love County, Southern Oklahoma. The native rangelands comprise native tall- and mid-grasses along with forbs and some woody shrub species. Little bluestem [Schizachyrium scoparium (Michx.) Nash] is the dominant species, with brome (Bromus L.), broomsedge bluestem (Andropogon virginicus L.), ragweed (Ambrosia psilostachya DC.), purpletop tridens [Tridens flavus (L.) Hitchc.), dropseed (Sporobolus R. Br.), and Indiangrass [Sorghastrum nutans (L.) Nash] commonly found. The introduced pastures are dominated by bermudagrass with cereal rye (Secale cereale L.) and horseweed [Conyza canadensis (L.) Cronquist] commonly found as well. Samples occurred at pre- and post-grazing conditions from summer 2022 to fall 2023. Measurements included canopy height and hand-clipping all herbaceous vegetation in a 0.25-m2 frame. Forage samples were fresh weighed then dried for 72 h at 60°C and reweighed. There were 760 and 786 samples collected at native and introduced pastures, respectively. Data were analyzed using PROC GLM of SAS (SAS Inst., Cary, NC) including canopy height (cm) and forage biomass [kg of dry matter (DM)/ha] as independent and dependent variables, respectively. Only regressions including all parameters as significant (P < 0.05) were selected, and coefficient of determination (R2) and root mean square error (RMSE) were used to evaluate the predictive ability of the regressions. There was a pasture type (native or introduced) × season interaction (P < 0.001). This interaction is likely explained by the dominant species in each pasture type across seasons as well as their phenological stage. For the native rangeland, the spring linear regression including the quadratic term had the best fit with the greatest R2 (0.56) and the least RMSE (944 kg DM/ha; Table 1). Summer and fall regressions had R2 of 0.45 and 0.24 and RMSE of 1139 and 1343, respectively. No regressions were selected for winter because parameters were not significant (P = 0.53 and P = 0.18). For the introduced bermudagrass pasture, regressions presented R2 ranging from 0.24 and 0.30 except during the winter (R2 = 0.09). These results indicate that forage biomass can be acceptably estimated using canopy height only during spring in the native rangeland.

453 Fluxes of greenhouse gases from pastures and methane emissions from beef cattle in Australia

Abstract The carbon footprint of beef cattle production may need to consider both the fluxes of greenhouse gases (GHG) of pasture ecosystems and cattle enteric emissions because these are the largest contributors to the carbon balance. The objective of the present study was to measure the fluxes of greenhouse gases from pastures and enteric methane (CH4) emissions from cattle throughout long periods of time under commercial conditions. The fluxes of CH4, carbon dioxide (CO2), and nitrous oxide (N2O) were measured throughout a period of 3 yr in multiple pasture types ranging from native to sown, and from temperate to summer pastures in New South Wales, Australia. A set of 8 dynamic chambers that automatically close for 10 min every 1.5 h were used for this purpose. The chambers measured the change in the concentration of GHG to allow for the estimation of emissions (positive flux) or sinks (negative flux). All data was then summarized to estimate daily fluxes and the global warming potential (CO2e) was calculated multiplying CH4 by 28 and N2O by 265. The final dataset contained 2,709 d of measurements across the 8 chambers. The GreenFeed system was used to measure CH4 production from cattle under varying conditions fed various diets throughout the same period. Cattle categories included weaners, heifers and steers, bulls and cows under both grazing or pen conditions. Cattle were fed a variety of diets ranging from low quality forages to high quality forages, grain supplementation, and grain-based diets. Data were averaged across many days for each animal and the final dataset contained 1,014 measurements. The CO2 flux from pastures ranged from -855 (uptake) to +339 kg CO2ּ ha-1ּ d-1 with a mean of -10.4 ± 2.19 kg CO2ּ ha-1ּ d-1. The minimum, mean and maximum CH4 fluxes were -192 (uptake), 0.015 ± 0.488, 434 g CH4 ּha-1ּ d-1, respectively, whereas NO2 values -146 (uptake), 17.1 ± 1.23, 1,293 g N2O ּ ha-1ּ d-1, respectively. These fluxes resulted in a GWP ranging from -855 (uptake), -5.83 ± 2.222, 445 kg CO2e ּha-1ּ d-1suggesting that pastures were on average a net sink of GHG throughout the present study. The CH4 production from cattle ranged from 43.6 to 404.6, with an average CH4 production of 192 ± 90.3 g CH4ּ animal-1ּ d-1, which is equivalent to 5.37 kg CO2eqּ animal-1ּ d-1. These results suggest that a hectare of livestock pastures offsets more than the CH4 produced by the average beef cattle in the present study. The fluxes of GHG from vegetation may need to be considered when estimating the contribution of livestock production to global warming.

Assessment of dry matter yield, nutritional value, and calf weight gain in Mombaza-Kudzu pasture associations.

O Objective: To evaluate the biomass production, nutritional value and animal production of an association with fabaceae species and grasses with grazing calves. Design/Methodology/Approach: The study compared Mombaza (Megathyrsus maximus) – Kudzu (Pueraria phaseoloides) association pasture against a Mombaza in monoculture control. Ten calves, five in each pasture type, were grazed in rotation for seven months. Dry matter yield, proportion of Kudzu in the association, protein, neutral detergent fiber (NDF), acid detergent fiber (ADF), ash, and daily weight gain were evaluated every 36 days. Results: Dry matter yield did not differ between pasture types, but varied by sampling dates, being higher at the onset of the rainy season (May 20th). The proportion of Kudzu in the association was low, decreasing from 8.42% to 1.71% over the study period. Lignin content increased in the association during the driest month (April). Daily weight gain was 978 g in the monoculture pasture and 678 g/day in the association, with no significant difference. Study Limitations/Implications: The low persistence of the fabaceae in the association limits the nutritional value of the pasture, consequently, the improvement of grazing animal production. Findings/Conclusions: During the drought season, both pastures exhibited the highest protein concentration and the greatest weight gain at the beginning of this period. However, the association did not result in greater weight gains due to the low persistence of the fabaceae.

Unraveling spatial heterogeneity of soil legacy phosphorus in subtropical grasslands.

Humans have profoundly altered phosphorus (P) cycling across scales. Agriculturally driven changes (e.g., excessive P-fertilization and manure addition), in particular, have resulted in pronounced P accumulations in soils, often known as "soil legacy P." These legacy P reserves serve as persistent and long-term nonpoint sources, inducing downstream eutrophication and ecosystem services degradation. While there is considerable scientific and policy interest in legacy P, its fine-scale spatial heterogeneity, underlying drivers, and scales of variance remain unclear. Here we present an extensive field sampling (150-m interval grid) and analysis of 1438 surface soils (0-15 cm) in 2020 for two typical subtropical grassland types managed for livestock production: Intensively managed (IM) and Semi-natural (SN) pastures. We ask the following questions: (1) What is the spatial variability, and are there hotspots of soil legacy P? (2) Does soil legacy P vary primarily within pastures, among pastures, or between pasture types? (3) How does soil legacy P relate to pasture management intensity, soil and geographic characteristics? and (4) What is the relationship between soil legacy P and aboveground plant tissue P concentration? Our results showed that three measurements of soil legacy P (total P, Mehlich-1, and Mehlich-3 extractable P representing labile P pools) varied substantially across the landscape. Spatial autoregressive models revealed that soil organic matter, pH, available Fe and Al, elevation, and pasture management intensity were crucial predictors for spatial patterns of soil P, although models were more reliable for predicting total P (68.9%) than labile P. Our analysis further demonstrated that total variance in soil legacy P was greater in IM than SN pastures, and intensified pasture management rescaled spatial patterns of soil legacy P. In particular, after controlling for sample size, soil P was extremely variable at small scales, with variance diminished as spatial scale increased. Our results suggest that broad pasture- or farm-level best management practices may be limited and less efficient, especially for more IM pastures. Rather, management to curtail soil legacy P and mitigate P loading and losses should be implemented at fine scales designed to target spatially distinct P hotspots across the landscape.

Soil legacy phosphorus and loss risk in subtropical grasslands

The accumulation of soil legacy phosphorus (P) due to past fertilization practices poses a persistent challenge for agroecosystem management and water quality conservation. This study investigates the spatial distribution and risk assessment of soil legacy P in subtropical grasslands managed for cow-calf operations in Florida, with two pasture types along the intensity gradient: improved vs semi-native pastures. Soil samples from 1438 locations revealed substantial spatial variation in soil legacy P, with total P concentrations ranging from 11.46 to 619.54 mg/kg and Mehlich-1 P concentrations spanning 0.2–187.27 mg/kg. Our analyses revealed that most of the sites in semi-native pastures may function as P sinks by exhibiting positive Soil P Storage Capacity (SPSC) values, despite having high levels of soil total P. These locales of higher SPSC values were associated with high levels of aluminum, iron, and organic matter that can adsorb P. In addition, our results from spatial random forest modelling demonstrated that factors including elevation, soil organic matter, available water storage, pasture type, soil pH, and soil order are important to explain and predict spatial variations in SPSC. Incorporating SPSC into the Phosphorus Index (PI) spatial assessment, we further determined that only 3% of the study area was considered as high or very high PI categories indicative of a significant risk for P loss. Our evaluation of SPSC and PI underscores the complexity inherent in P dynamics, emphasizing the need for a holistic approach to assessing P loss risk. Insights from this work not only help optimize agronomic practices but also promote sustainable land management, thus ensuring the long-term health and sustainability of grass-dominated agroecosystems.

Spatial and temporal monitoring of wildfires in Golestan province using remote sensing data

Wildfires are one of the most significant factors of ecosystem change. Knowing the wildfire regime (frequency, intensity, and distribution pattern) is essential in wildfire management. This research aims to analyze the spatiotemporal pattern of wildfires in Golestan in 2001-2021 using MODIS data, burned area product (MCD64A1). For this purpose, the annual and monthly frequency, as well as the trend of wildfires based on types of forest, pasture, and crop cover, were statistically analyzed. The local Moran pattern analysis method and kernel density function were used to analyze the spatial dynamics of wildfire. The results showed that 18,462 wildfires occurred in Golestan, the highest of which was in 2010, with 2,517 wildfires (13.8%). The lowest number of wildfires, with only 57 events (0.5%), was in 2001. Based on the local Moran model results and the kernel density function, the wildfires' extent and intensity were greater in the plains and foothills to the south and southeast of Golestan. The lowest extent and intensity of the wildfire corresponded to the eastern parts of the province. The frequency of wildfires was higher in the hot period of the year (spring and summer). However, the period of occurrence of wildfire and the peak of wildfire changes in different uses. The wildfire zones in June were wider and more intense than in other months. The frequency and spatial extent of wildfires in agricultural lands from May to July, pasture lands in July, August, and September, and forest lands in November and December were more than in other months. Weather conditions play a significant role in the occurrence of wildfire in the forest lands of Golestan. The results of this research help understand wildfire risk areas and provide a scientific basis for predicting and controlling wildfires and reducing carbon emissions related to them.

Dominant gastrointestinal strongylatosis in sheep in the context of the altitudinal zonation in Dagestan

The purpose of the research is to study the epizootology of the dominant gastrointestinal strongylatosis in sheep in different natural zones of Dagestan.Materials and methods. In 2005–2021, 180 forestomachs of the thin and thick sections of the digestive tract and 600 fecal samples from sheep at the altitude (above 2000 m above sea level) were studied based on dissection results. The study was performed by season among young animals aged up to 1 year, from 1 to 2 years and 3 years and older. The study used methods of complete helminthological dissection per K. I. Skryabin, larvae cultivation in a thermostat at 27 оC, and flotation with a saturated ammonium nitrate solution by Kotelnikov-Khrenov and Berman-Orlov.Results and discussion. Helminth infections are recorded among sheep annually on lowland, moist, steppe pastures of the plains and foothills in various combinations of multiple infections with the prevalence of 11.2–18.7% and the infection intensity of 18.5–186.4 sp./animal. In the mountain zone at altitudes above 2000 m above sea level, the quantitative and qualitative indicators of helminthosis pathogens were sharply limited. On these lands, dicrocoeliosis, monieziosis, larval echinococcosis, chabertiosis, haemonchosis, and nematodirosis were recorded in sheep with the prevalence of 3.2–10.4% and the infection intensity of 2.4–6.3 sp./animal. Gastrointestinal Strongylata dominate in sheep on all types of pastures in the lowland, foothill, and mountain zones: Chabertia ovina, Bunostomum trigоnocephalum, Trichostrongylus axei, T. capricola, T. colubriformis, T. vitrinus, Haemonchus contortus, Nematodirus filicollis, N. helvetianus, N. oiratianus, and N. spathiger.

132 Effects of supplementing corn silage to fall-calving cows grazing tall fescue on cow and calf performance and physiology

Abstract The objective was to test the effect of fescue varieties and supplemental feeding of cows grazing fescue pastures during the growing season on cow and calf performance and physiology. Multiparous and primiparous Angus crossbred cows (n= 45) averaging 151 ± 7 d of gestation at trial initiation, were stratified and assigned to pasture treatment based on estimated calving date and parity. Treatment design was a 2 x 2 factorial with two types of fescue pasture (toxin producing or non-toxin producing) and two levels of supplemental corn silage (non-supplemented or supplemented at 1% of BW DM basis). Each treatment replicate (pasture, n = 3 or 4 pastures per treatment) was stocked with 3 cows. There were seven replicates of non-toxin-producing fescue (5 ppm ± 2.50 SEM ergot alkaloids; 38.6% endophyte infection), and eight replicates of toxin producing K31 fescue pastures (507 ppm ± 0.82 SEM ergot alkaloids; 92.5% endophyte infection). Cows were fed corn silage (38% DM, 7.83% CP DM basis) daily in fenceline bunks and feeding amount was adjusted at weigh dates to maintain 1% of BW DM basis. Cows were weighed on two consecutive days at initiation and upon conclusion of the study after being fed similar diets for 4 d to minimize variation in ruminal fill. Body weight (BW), body condition score (BCS), hair score (HS), hair length (HL), and rump fat (RF) measurements were taken at initiation (the middle of the second trimester), trial mid-point (beginning of third trimester), and approximately 2 wk before estimated parturition. Cows remained on experimental pastures through parturition. Data were analyzed as a mixed model with pasture as experimental unit and cows within pasture as subsamples. Initial cow BW and BCS were 558 ± 11 kg (SEM), and 4.9 ± 0.08 (SEM), respectively. For all measures of interest there were no significant interactions observed (P > 0.16). Supplemental feeding tended (P = 0.07) to increase BW gain and rump fat (P = 0.05) regardless of fescue type. Cows grazing toxic fescue tended (P = 0.12) to have a longer hair coat. Likewise, cows grazing toxic fescue had less change in overall HS (P = 0.02). Supplemental feeding of corn silage to cows at 1% of BW DM basis while grazing fescue did not significantly affect gain differences or reduce visible symptoms typical of fescue toxicosis when grazing during the growing season.

Herbage and sheep production from simple, diverse, and legume pastures established in an agrivoltaic production system

AbstractAgrivoltaic systems combine solar energy and agriculture, promoting dual land use. Although grazing sheep in these systems is common, research on intentionally designed pastures to increase production is lacking. This study seeks to compare the herbage growth and lamb production in simple, diverse, and legume pastures in an agrivoltaic system over 2 years in Oregon. Annual herbage production in diverse pastures (4583 kg DM ha−1) was comparable to simple pastures (4457 kg DM ha−1), but higher than legume pastures (p < .05; 4023 kg DM ha−1) for the 2020/2021 growing season. In the 2021/2022 growing season, diverse pastures had a higher yield (4660 kg DM ha−1, p < .05) than simple pastures (4052 kg DM ha−1), which were similar to legume pastures (3955 kg DM ha−1). Liveweight gain (LWG; g head−1 d−1) tended (p = .06) to be higher from lambs in diverse and legume pastures compared to simple pastures in spring 2021. Liveweight production (LWP; kg ha−1 d−1) of legume pasture were greater (P < 0.05) than other pasture types, while simple pastures had the lowest LWP during this period. In summer 2021, LWG tended to be greater in lambs grazing diverse versus simple pastures. No difference was detected (all p > .05) in LWG or LWP at any grazing period in 2022. Overall, efficiency of pasture production was greatly reduced by lower light availability in all pasture types. Diversification of pastures using forbs in agrivoltaics was a good strategy for greater herbage production, while the legume pastures had poor persistence.

Effects of Using Different Concentrate Supplementation Levels in Diets of Lambs Fed Tropical Aruana (Megathyrsus maximus) or Marandu (Brachiaria brizantha) Grass: Performance, Digestibility, and Costs of Production

In Brazil, grazing is the main or only source of food for livestock. The appropriate combination of supplementation with concentrate in a lamb’s diet on pasture is an alternative that can be explored to use natural resources to produce quality meat. The aim of the current study was to evaluate the effects of different supplementation levels (0%, 1.5%, and 3% of BW) on the intake, performance, and production costs of lambs grazing on Aruana (Megathyrsus maximus) and Marandu (Brachiaria brizantha) grasses. Thirty-six non-castrated male Suffolk lambs (22.54 ± 2.72 kg) were used. The lambs were evaluated for nutrient intake and digestibility, such as dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and consumption in relation to body weight (% BW), in addition to the average daily gain (ADG), body condition score (BCS), and hot carcass weight (HCW), as well as the rising production cost of each system. The dry matter of the green leaf blades was influenced by the pasture type (p < 0.05), producing 1503.6 vs. 2977.4 kg/ha of Aruana and Marandu grasses, respectively. The concentrate supplementation level influenced the type of pasture (p < 0.05). A higher consumption of DM, CP, NDF, and organic matter was registered for the supplemented animals (p < 0.05) and on Aruana grass. The intake in relation to body weight was significantly influenced by the concentrate levels (p < 0.05). The empty body weight and HCW were significantly influenced by the supplementation levels (p < 0.05). The ADG and feed conversion (FC; kg DM/ADG) were influenced by the supplementation levels and type of pasture. The BCSs differed between the concentrate levels (p < 0.05). The supplementation improved dry matter digestibility. The ADG and FC were superior in the supplemented animals, with an advantage for those grazing on Aruana grass. The slaughter ADG was also higher in the supplemented animals. The lambs’ pasture comprising Aruana grass with 1.5% BW of concentrate supplementation showed improved production and economic results.

Influence of Grazing on Canola Grain, Canola Forage Yield, and Beef Cattle Performance

Interest is increasing in grazing winter canola (Brassica napus) as an alternative crop in winter wheat (Triticum aestivum) rotations in the Southern High Plains (SHP) of the USA and similar environments. In this stidy, winter cereal rye (Secale cereale) and winter canola pastures (forage) were compared for two winter growing seasons at New Mexico State University’s Rex E. Kirksey Agricultural Science Center at Tucumcari, NM, USA, to determine the relative effect of pasture type on late-gestation beef cows and growing yearling cattle, along with the effect of grazing on canola grain production. Canola grain yields were reduced by 25% when canola was grazed until removal approximately one month after grazing was initiated, but before the onset of rapid regrowth after winter (641 vs. 486 kg grain ha−1 for never grazed or grazed canola, respectively, p < 0.0256). No differences existed for forage mass, nutritive value, or animal performance, although forage mineral composition of canola could be a concern. Grazing winter canola as a dual-purpose crop in the SHP and similar environments is feasible when proper grazing management is applied; producers should anticipate a 20–25% reduction in grain yield, but expect animal gains to offset that loss.

Impact of fertilizing on biodiversity in pasture ecosystems

Biodiversity in grazing systems determines production efficiency, system stability and resilience, and nutrient retention. In this relation during the period 2016-2018, a scientific research experiment was conducted on a natural grass stand of the Nardus stricta L. type at an altitude of 1400 m in the area of Chuchul (Bulgaria) of the following rates of fertilization: 1. Untreated (Control); 2. Annual fertilizing with N60P60; 3. First-year fertilizing with N60, and second and third with P60; 4. First-year fertilizing with P60, and second and third with N60; 5. First and second year fertilizing with N60, and third with P60; 6. First and second year fertilizing with P60, and third with N60; 7. First year fertilizing with N60, second year with P60, third year with N60; 8. First-year fertilizing with P60, second year with N60, third year with P60. The aim of the article is to analyze the impact of fertilizing with mineral fertilizers on the biodiversity of a pasture ecosystem and to propose an appropriate way of fertilizing to improve the species diversity of useful components in the grass stand. Biodiversity was determined by the indicator botanical composition of the grass stand, and the species diversity of the components in the grass stand by botanical groups was observed under eight variants of variable mineral fertilizing. It was found that the fertilization increased share of perennial grasses and motley grasses. The species Nardus stricta L., defining the type of pasture, was replaced from the more useful types of grasses, such as: Nardus stricta L., Agrostis capillaris L., Phleum alpinum L., Festuca ovina L., Festuca rubra L., Agrostis alba L., Chrysopogon gryllus L., Dactylis glomerata L., Lolium multiflorum L. The fertilizing effect is most significant in the third year, when both the representatives of grasses and legumes were significantly increased.

Phenotypic characterization for milk traits in crossbred cattle population from the state of Norte de Santander

Crossbred cattle are used in dual-purpose systems to obtain meat and milk, becoming one of Colombia's systems with the greatest presence. However, studies characterizing productive variables in crossbred individuals are scarce, making it pertinent to conduct analyses evaluating their potential. The objective of this study was to phenotypically characterize a population of crossbred cattle from the state of Norte de Santander (Colombia) in terms of milk traits. Up to a maximum of 4 controls per female was obtained, and information on milk yield (MY), fat percentage (FP), protein percentage (PP), and somatic cell count (SCC) of first parity crossbred females was evaluated. The information was filtered and analyzed with the R program. The mean, standard deviation, and general variation coefficient were calculated for each trait and the means and deviations by non-genetic categorical factors. For the numeric factors, graphs of trends related to the response variables were made. Multiple correspondence analysis was performed, and the standardized residual values were estimated to recognize associations between levels of non-genetic factors and each trait. Mean values for controls were: 3.06±1.40 kg/day (MY), 3.21±0.40% (PP), 3.32±0.77% (FP), and 357±256x103 cells/ml (SCC). The non-genetic factors that showed the most significance were the pasture type, the control season, and the region. Thus, MY from 1.00 to 2.00 kg is associated with the levels of region 1 (R1) and summer 1 (S1), MY from 2.10 to 3.99 kg with region 2 (R2), group 1 (G1) and winter 1 (W1), MY from 4.00 to 8.30 kg with R1, group 3 (G3) and W1, PP from 2.45 to 2.99% there was association with G1, PP from 3.00 to 3.40% with group 2 (G2), PP from 3.41 to 6.04% with G3, FP of 1.94 to 3.00% is associated with R1, G3, S1, and S2, FP of 3.01 to 4.00% with R2, G1 and W1, FP from 4 to 4.82 % with region 3 (R3), G2, and S1, SCC from 8.00 to 100x103 cells/ml is associated with R1, R3, and S1, SCC of 101 to 499x103 cells/ml with R2, G1, and W1. Finally, SCC of 500 to 888x103 cells/ml is associated with R2 and W1. A variation of medium to high magnitude of the traits evaluated within the population was evidenced, revealing that no standards that allow unifying the management of animals within herds, which can affect the efficiency of dual-purpose systems.

Calculating herbage utilization and intake by dairy cows under subtropical conditions using conventional field measurement techniques or the HerbValo method.

This study aimed to evaluate the HerbValo method in comparison to conventional field measurement techniques as a tool for estimating the herbage utilization and dry matter (DM) intake by grazing dairy cows under subtropical conditions. It was carried out during 18 months in a commercial farm of Southern Brazil. The herbage utilization was estimated monthly in two to four randomly selected paddocks (total n = 40) using the rising-plate meter or the double-sampling technique. In parallel, the herbage utilization was estimated by the HerbValo method, which is based on simple descriptions of the herd, supplements, pasture and grazing management. Values of herbage utilization estimated by field techniques were linearly (P < 0.01) related to those estimated by HerbValo, with no effect of pasture type (tropical vs. temperate) on the origin or on the slope of the regression (slope = 0.97; origin = -0.1; R2 = 0.81; rsd = 0.17 t DM/ha). At cow × day level, values of herbage intake estimated by field techniques were also linearly related to those estimated by HerbValo (P < 0.01; R2 = 0.82; rsd = 1.30 kg DM/cow/day). A negative linear relationship (P < 0.01) between herbage and supplement intake was obtained for both field (slope = -1.06; R2 = 0.72; rsd = 1.64) and HerbValo (slope = -0.92; R2 = 0.82; rsd = 1.08) approaches. Herbage utilization and intake by a dairy herd in a subtropical grazing-based system can be reliably estimated by the HerbValo method with the advantage of not requiring direct field pasture measurements.

Influence of weather conditions on the productive potential of pasture ecosystems in the south of Russia (Based on artificially created models)

For the rational use of degraded pastures and the fight against desertification, it is necessary to apply phytomelioration of territories more widely. The most effective will be the use of communities consisting of shrubs, semi-shrubs and perennial grasses. To identify on this further, the study was conducted at the experimental sites of the Agroecology Research Center of the Russian Academy of Sciences in the period from 2019 to 2022. In this study, artificially created models of long-term pasture ecosystems were utilized. In the arid conditions of the south of Russia, weather conditions had the greatest impact on the productivity of the created pasture models (share of influence is 81-85%), while the yield of dry fodder mass of the herbaceous-semi-shrub layer varied from 1.2 to 3.9 t/ha, depending on the seasonality of the pasture and the composition of the soil substrate. The highest yield of phytomass is formed on pastures created on a chernozem-like sandy loam substrate (humus horizon of chernozem-like sandy loam soil) on spring-summer pastures, the yield increase is 33% higher compared to spring-summer pastures on a light chestnut sandy substrate (a product of Aeolian processing of light chestnut soil). On all types of pastures, groups of cereals were leading in terms of biomass. Analysis of the multiple regression equation between the phytomass yield of model pastures (y3), temperature (x1) and precipitation of the warm period (x2) on pastures with a chernozem–like soil substrate showed that the multiple correlation coefficient R = 0.96 - this states a close relationship between the effective indicator and two factors. The multiple determination coefficient R2 = 0.98 means that 98% of the variation in the phytomass yield level is taken into account by the regression equation and 2% is accounted for by unaccounted factors on a light chestnut sandy substrate. The moderate correlation dependence of the yield of the fodder mass of model pastures (y3) on a plot with a light chestnut sandy substrate on the temperature in the warm period (x1), the component (r=0.52) indicates a significant effect on the yield of precipitation of the warm period (x2) with r=0.94.

Compositional Characteristics, Fatty Acid Profile, Phenolic Content and Volatile Organic Compounds (VOCs) of Feta Cheese Made in Mountainous Grasslands and Plains of Greece

The study aimed to compare the physicochemical composition, fatty acid profile, phenolic content and volatile organic compounds (VOCs) of feta cheese produced in two regions in Greece (mountainous grasslands and plains). The VOC profiles of forage in the mountainous grasslands were also investigated in order to detect any relationship between the two profiles. Forbs were found to be the major functional group in the mountainous area and the most abundant VOCs were aldehydes, alcohols, and terpenes. Significant variations were observed between the main compositional features of the two types of cheeses, with the cheese produced from the milk of ewes and goats grazing in the mountainous region having a higher moisture content, lower fat content, and higher protein content. A total of 34 VOCs were identified and the most abundant groups in the cheese samples were esters, hydrocarbons, and alcohols. The fatty acid profile, phenolic content, and terpene profile of the cheese were also affected by the type of pasture. The cheese produced from the milk of ewes and goats grazing in the mountainous region also had a higher content of conjugated linoleic acid (CLA) and a lower content of saturated fatty acids (SFAs). These findings suggest that the grasslands grazed by ewes and goats in the mountainous region have a positive impact on the nutritional quality of feta cheese.

AGRONOMY OF MULATO GRASS CULTIVAR (BRACHIARIA SP.) IN GRAZING CONDITIONS IN QUINTANA ROO, MEXICO

The objective of this study was to determine the behavior of Mulato grass under grazing conditions in Quintana Roo. This work was carried out in the Chetumal Experimental Field of INIFAP in Quintana Roo, which is located 25 km from Chetumal, in the vicinity of the Juan Sarabia ejido, on km 25 of the Chetumal federal highway. For the development of the study, two hectares were used, 1 ha of Brachiaria humidícola (Chetumal) and another of Brachiaria sp. (mulato). For each type of pasture, three recently weaned steers of the Holstein for Zebu and Swiss for Zebu breeds with an approximate initial weight of 242 ± 3 kg were used the variables measured were seasonal dry matter production, plant cover and height, forage supply, and the botanical composition of the meadow. Subsequently, the steers were changed by load adjustment and the weight gain was determined. The design used was totally randomized with three repetitions per treatment and the analysis of the information was carried out through the ANOVA. No differences (P≥0.05) were found in the number of plants 12 weeks after establishment. For the coverage parameter, differences (P≤0.05) were observed with values ​​of 89% and 77 for Chetumal and mulatto grass, respectively. The values ​​of weight gain among the grasses under study (650 vs 675 for Chetumal and mulatto, respectively) did not indicate differences (P≥0.05) between them. Therefore, mulatto grass should be considered as an option for livestock in the state.