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Context: Average sward height has traditionally been used as a grazing management variable. However, such approach ignores the spatio-temporal heterogeneity of swards. Because the intake rate responds non-linearly to average height at plant level, we expected that sheep exposed to contrasting grazing methods with similar average heights would behave differently. Aims: We hypothesised that low-intensity, high-frequency grazing results in a higher daily intake rate than does high-intensity, low-frequency grazing, despite both methods having similar average sward heights over space and time. Also, we asked whether sheep exhibit the same foraging mechanisms for a given instantaneous sward state regardless of long-term grazing conditions imposed. Methods: We exposed sheep to two contrasting grazing methods with similar average height; low-intensity, high-frequency (LIHF), and high-intensity, low-frequency (HILF). We then evaluated their foraging behaviour using continuous bite-monitoring paired with detailed sward measurements during grazing down. Key results: Sward height decreased markedly during the grazing period in both treatments, but the sward height depletion was faster under HILF (7.5 cm and 20.3 cm for LIHF and HILF), which means that sward structure was severely disrupted. The animals exhibited markedly different herbage intake patterns between the grazing methods, with sheep under LIHF presenting greater total daily herbage intake (850 vs 630 g DM per individual). Also, sheep demonstrated a more stable and higher instantaneous intake rate in the LIHF. Despite the difference in total daily herbage intake, the grazing treatments did not affect the behavioural mechanisms beyond their indirect effects on the rate of change in the instantaneous sward conditions. Grazing treatments created different patterns of sward change and intake rate over time, but the local and instantaneous sward conditions determined intake rate regardless of the grazing method. Conclusions: Intake responses of sheep differed between grazing methods with similar average height due to sward heterogeneity over time and space. Grazing mechanisms were not directly affected by the treatments but were influenced by the sward heterogeneity imposed by the grazing management. Implications: Grazing management requires not only consideration of the average sward height, but also an understanding of how the resource is distributed in time and space. Most livestock in the world is raised on pastures, and the production and sustainability of these systems depend on their management. However, managers have disregarded the heterogeneity of pastures and their impact on grazing management. Our results demonstrated that systems with similar average sward height may have different sheep intake responses due to sward heterogeneity in time and space. [ABSTRACT FROM AUTHOR]

Este trabalho foi realizado de maio a outubro de 2003, na Estação Experimental da Universidade Federal do Rio Grande do Sul (EEA-UFRGS), tendo como objetivo avaliar e comparar a precisão do disco medidor de forragem, do bastão graduado e do medidor de capacitância em predizer a massa de forragem de pastagens de azevém anual. O trabalho constou de dois experimentos: o experimento 1 no qual foram avaliados os três métodos numa situação em que o azevém apresentava-se em fase de estabelecimento num delineamento completamente casualizado, com 32 repetições e três tratamentos; e o experimento 2, no qual foi avaliada a massa de forragem pré e pós-pastejo pelo bastão graduado e pelo disco medidor em potreiros sob lotação rotacionada. O delineamento experimental do experimento 2 foi o de blocos completamente casualizados, com quatro repetições; os tratamentos constaram de duas intensidades de pastejo (baixa e moderada) definidas por ofertas de forragem de 2,5 ou 5,0 vezes o potencial de consumo dos cordeiros que foram utilizados. No experimento 1, o bastão graduado apresentou o melhor coeficiente de determinação com a massa de forragem (r²=0,65). No experimento 2, os melhores coeficientes de determinação foram obtidos quando o pasto, sob lotação rotacionada, foi avaliado com o bastão graduado.

Variáveis morfogênicas e estruturais foram quantificadas a partir da técnica de "perfilhos marcados" no período de agosto a outubro de 1999 numa pastagem de azevém anual, mantida em quatro diferentes alturas (5, 10, 15 e 20 cm) através de lotação contínua em carga variável com ovinos. O delineamento experimental foi o de blocos completos casualizados com três repetições. Utilizaram-se 50 perfilhos marcados por unidade experimental, distribuídos ao longo de transectas. As observações foram efetuadas em dois períodos: no primeiro, da entrada dos animais até a obtenção das alturas pretendidas, não se observaram diferenças entre os tratamentos. No segundo (fase de estabilização das alturas pretendidas), a taxa de elongação foliar, o comprimento da lâmina verde total por perfilho e o tamanho das folhas apresentaram resposta positiva frente a maiores alturas de manejo, enquanto o tempo de elongação da lâmina foliar diminui com a altura. As variáveis taxa de surgimento de folhas, tempo de vida das folhas, densidade populacional de perfilhos e número de folhas vivas por perfilho não foram afetadas pelos tratamentos.

Understanding the grazing process and animal response to sward structures (e.g., sward height) is key to setting targets for efficient grazing management. We hypothesized that the short-term intake rate (STIR) of dry matter (DM) and digestible organic matter (OM) by dairy heifers is maximized with Kikuyu grass (Cenchrus clandestinus—Hochst. ex Chiov.) of intermediate sward heights. The treatments consisted of five pre-grazing sward heights (10, 15, 20, 25, and 30 cm) randomly assigned to two of ten paddocks. The experimental design included two measurements of each paddock at different periods and times of day. Three Holstein heifers (440 ± 42 kg body weight) were used to determine the STIR, which was estimated using the double-weighing technique with correction for insensible weight losses. The bite mass (BM), bite rate (BR), sward structural characteristics, and nutritional value of herbage samples were assessed. The data were analyzed using mixed models with a factorial arrangement of five sward heights, two times of day, and two evaluation periods. The sward height of Kikuyu grass that maximized both STIRs was approximately 20 cm. The STIR of the DM was 30% and 15% lower than the maximum in the shortest and tallest swards tested, respectively. In swards shorter than 20 cm, the STIR was lower because the BM decreased with sward height, whereas in those greater than 20 cm, the lower BM and STIR of DM was explained by a decrease in bulk density and bite volume. The top stratum was composed mainly of highly digestible leaf blades with similar nutrient content across sward heights; therefore the STIR of digestible OM was also maximized at 20 cm. Hence, the optimal pre-grazing sward height of Kikuyu grass should be managed at 20 cm under rotational stocking systems to maximize nutrient intake rate of dairy heifers. [ABSTRACT FROM AUTHOR]

Spatial heterogeneity is a property of natural ecosystems. Integrated crop‐livestock systems (ICLS) aim to mimic natural ecosystem functions as pillars of sustainable intensification, and grazing is a process that potentially affects spatial heterogeneity. Then, we investigated the effect of different grazing intensities, defined according to a range of sward heights (intensive grazing, 10 cm; moderate grazing, 20 cm; moderate‐light grazing, 30 cm; light grazing, 40 cm; and ungrazed), on the spatial heterogeneity and biomass productivity of mixed Italian ryegrass (Lolium multiflorum Lam.) and black oat (Avena strigosa Schreb.) pastures. The mixture was grazed by steers under continuous variable stocking, using put‐and‐take animals to maintain targeted sward heights. The pasture was in rotation with soybean in an integrated crop‐livestock system for 15 years. Data concerns pasture phase on the 15th rotation cycle. Cattle grazing at moderate to light intensities increased pasture spatial heterogeneity and total aboveground primary productivity, while intensive grazing led to homogeneous overgrazed canopies with frequent bare soil patches. Pre‐grazing sward structure suggests that the summer crop rotation buffers the contrasts created by grazing at different intensities. This study suggests that moderate to light grazing intensities increase pasture productive efficiency and create more heterogeneous canopies in ICLS, while intensive grazing should be avoided. [ABSTRACT FROM AUTHOR]

Copyright of Nucleus (16786602) is the property of Fundacao Educacional de Ituverava and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sustainable intensification of landuse practices has never been more important to ensure food security for a growing world population. When combined under thoughtful management, cover cropping and crop-livestock integration under no-till systems can benefit from unexpected synergies due to their unique features of plant-animal diversification and complex agroecosystem functions. Mimicking the nutrient coupling/decoupling processes of natural ecosystems by diversifying plant and animal components of no-till integrated crop-livestock operations is an essential feature of the design of agroecological systems that support self-regulating feedbacks and lend resilience while increasing productivity and ecosystem service provision. Focusing on grazing animals as drivers of agroecosystem change, we highlight the benefits of grazed cover crops in rotation with cash crops for primary and secondary production and for soil physical, chemical, and biological parameters. However, careful management of grazing intensity is imperative; overgrazing drives soil deterioration, while light to moderate grazing enhances overall system functioning and allows for the generation of emergent properties. [ABSTRACT FROM AUTHOR]

Annual temperate grasses go through abrupt changes in morphological composition during the growing season, which can affect ingestive behavior of grazing cattle. However, few studies have examined the effects of gradual structural changes in annual temperate pastures on the herbage intake rate during the growing season. We hypothesized that lenient grazing (removal of 40% of the initial pre-grazing height) maintains short-term intake rate ( STIR) of grazing cattle over the entire growing season, even with decreased leaf/stem ratios. The studied pastures contained Avena strigosa, Lolium multiflorum and a mixture of the two species. Short-term intake rate was measured using the double weighing technique, evaluating both bite rate and bite mass. The percentage of stem + pseudostem and leaf lamina lengths in the herbage mass were measured. Relationships between sward structure and animal ingestive behavior were also examined. As the pasture growing season progressed, the STIR of heifers grazing annual temperate grass swards was affected more by the time required to take a bite than by bite mass. Moreover, the sward structure also changed after each grazing cycle, reducing the pre-grazing leaf/stem ratio. However, reductions in the pre-grazing leaf lamina mass (up to 37% of the sward herbage mass) and/or in the leaf lamina length (up to 52% of the extended tiller height) did not affect the STIR of grazing heifers, since the animals maintained their bite mass and time per bite. In summary, with a grazing down target of 40% of the pre-grazing height, reductions in STIR of heifers grazing annual temperate grasses occurred when the pre-grazing leaf lamina percentage was <37% of the sward herbage mass and/or <52% of the extended tiller height. These results suggested that to avoid STIR reductions during the last grazing cycles, managements to stimulate tillering and delay stem + pseudostem elongation are necessary and should be investigated. [ABSTRACT FROM AUTHOR]

No-till, crop diversity and integrated crop-livestock systems are proposed managements to increase agriculture sustainability in the rice paddies of the Southern Brazilian lowlands and avoid degradation in the region. Because soil is considered a key medium in which management modifications can be measured, our study aimed to evaluate soil-quality impacts by measuring carbon and nitrogen stocks and microbial activity 18 months after the adoption of different paddy-farming systems in an Albaqualf soil of Southern Brazil. The treatments consisted of five paddy-farming systems with a range of vegetation diversity (both in time and in space) and grazing seasons. In addition, a reference area (i.e. native forest) was sampled for comparison. We verified that soil quality was affected over the short term through the adoption of no-till, crop diversity and integrated grazing practices. However, during the study period, only the system with low anthropic and/or mechanical intervention and high plant diversity differed from the traditional paddy land-use approach in Brazil in terms of soil-quality effects. This system achieved a carbon management index of 49 (approximately half that of the native forest) and had the highest enzymatic activity (similar to native forest). These outcomes were primarily due to an increase in the particulate organic matter fraction of the soil carbon stock (4·6 Mg ha−1 more than in rice monocropping). To evaluate changes in soil quality over the long term, additional studies are required. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Highlights: [•] Integrated crop–livestock systems in the Brazilian subtropics are highly diverse. [•] Livestock reduce the vulnerability of crops in rain-fed systems. [•] Crops in rotation with livestock may produce more. [•] Livestock improve many physical, chemical and biological attributes of soil. [•] Integrating crops and livestock is a unique approach to ecological intensification. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciência Agronômica is the property of Revista Ciencia Agronomica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This trial aimed to evaluate the effects of sward height management of pastures composed by black oat and Italian ryegrass upon soybean establishment and yield. The treatments were four sward management heights: 10, 20, 30 and 40cm; and no grazing control. Pasture (sward height, herbage allowance, herbage mass, stocking rate and post grazing herbage mass) and soybean (initial stand of plants and yield) attributes were evaluated. The observed sward heights were very similar to those previously intended. There was a linear increase in herbage allowance and herbage mass with increasing sward height management. Forage accumulation rate was not influenced by treatments. Stocking rate decreased linearly with increasing sward height. Post grazing herbage mass increased with increasing sward height. Treatments had effect on initial soybean stand, but soybean yield was not affected. Results suggest grazing animals do not damage succeeding crop, allowing farmers profitability enhancement by using those areas during soybean intercropping. [ABSTRACT FROM AUTHOR]

The article discusses importance and benefits of agricultural sustainability, and mentions how it could be achieved through integrated crop?livestock systems (ICLS). Topics discussed include recycling organic matter and nutrients from livestock feces to cropland and fodders consumed by livestock will create sustainability, carbon dioxide (CO2) sequestration, soil fertility, and biodiversity are important for feeding domestic herbivores, and international efforts to achieve the same.

Managing for resilience in agriculture will be required to overcome future challenges such as growing food demand, climatic uncertainty, scarce raw materials and economic instability. Identifying resilience-enhancing practices is therefore fundamental for developing sustainable agroecosystems. We aimed to assess the resilience of two agricultural systems with different levels of diversification in southern Brazil: a specialized soybean (Glycine max) system and an integrated soybean-beef cattle system. We assessed the robustness and the adaptive capacity of these systems when facing climate hazards and price volatility. The study was based on a long-term trial that has been carried out since 2001, composed of an annual rotation of no-till soybean production during the summer and grazing of mixed black oat (Avena strigosa) and Italian ryegrass (Lolium multiflorum) pasture in the winter. Treatments consisted of four grazing intensities in the integrated crop-livestock system (ICLS), defined by sward heights: 10, 20, 30 and 40 cm plus an ungrazed control representing the specialized cropping system (CS). The experiment was carried out using a randomized complete block design with three replicates. We analysed system results over five years using two methods: i) a downside risk analysis to estimate the expected losses of yield and gross value added; and ii) the Ecological Network Analysis, which was applied to each treatment and year, for the assessment of the resilience of nitrogen (N-Ɍ flow) and phosphorus (P-Ɍ flow) flows. Both methods showed that co-located crop-livestock production in an ICLS was more resilient than the specialized soybean system and had improved nutrient cycling and resource-use efficiency. The effects of grazing management on system resilience depended on the output: beef yields were more stable under lower grazing intensities, but the risk of falling below a target economic threshold was inversely proportional to grazing intensity and null when the highest grazing intensity was adopted. The ecological network analysis did not reveal differences in resilience of nutrient flows among grazing management treatments. Our study suggests that Ɍ flow (N or P) is a useful proxy for assessing the robustness and adaptability of agroecosystems. Our comprehensive resilience analysis of nutrient and economic flows provides evidence that system diversification through the integration of grazing animals into specialized cropping systems is a good strategy towards the sustainable intensification of agriculture. It would be relevant, however, to consider further studies comparing more complex system configurations and levels of diversification. • Downside risk and ascendency analyses are useful indicators of resilience. • Livestock integration into specialized soybean systems increase system resilience. • Crop-livestock integration improved nutrient recycling and land-use efficiency. • System diversification and grazing management are resilience-enhancing practices. • Both nitrogen and phosphorus flow analysis are useful to assess system resilience. [ABSTRACT FROM AUTHOR]

A correction to the article “Animal production and soil characteristics from integrated crop-livestock systems: toward sustainable intensification" by Paulo César de Faccio Carvalho and colleagues that was published in a 2018 issue is presented.

Highlights: [•] Diversity in agriculture systems drives the productivity-environment trade-off. [•] Grasslands couple C–N cycles and reduce environmental fluxes. [•] Crop–livestock integration diversifies landscape mosaics enhancing biodiversity. [•] Crop–livestock systems should provide both high productivity and ecosystem services. [Copyright &y& Elsevier]

Foraging behavior studies have supported innovations in sward management, making pastoral systems more sustainable and competitive. Based on this, we evaluated the sheep's ingestive behavior responses and the changes in sward structure during four stages of grazing down in rotational stocking, indicating the threshold level of grazing down for sheep grazing in the reproductive stage of annual ryegrass ( Lolium multiflorum Lam.) managed under two grazing intensities (low and moderate). We found evidence that the two grazing intensities each promoted a grazing down at approximately 45% of the non-limiting pre-grazing sward height. However, during grazing down at the end of the sward reproductive stage, the leaves frequency remained lower than that of inflorescences, indicating a restrictive situation for animals in each of the two grazing intensities evaluated. The sheep's ingestive behavior patterns were constrained by the modifications in sward structure. There was observed a decrease in grazing time and bite rate, and a gradual increase in the number of steps between feeding stations during the grazing down stages. Therefore, sheep's behavioral responses during the grazing down of annual ryegrass depend on: (i) grazing intensity, (ii) period of the sward reproductive stage, and (iii) forage structural and chemical composition during grazing down. [ABSTRACT FROM AUTHOR]

To test the hypothesis that the best sward structure in the grazing management strategy based on animal behaviour, called “Rotatinuous” stocking, results in higher nutrient intake and lower methane emission and intensity by sheep grazing Italian ryegrass pastures, two grazing management strategies were studied: the traditional rotational stocking (RT) with pre- and post-grazing sward target heights of 25 and 5 cm, respectively and, “Rotatinuous” stocking (RN) with pre- and post-grazing sward target heights of 18 and 11 cm, respectively. Male castrated sheep were used. The experiment was carried out in 2014 and 2015 in southern Brazil. The experimental design was a randomized complete block with four replicates. The RN treatment had better herbage chemical composition in terms of quality than that of the RT treatment, with greater (P < 0.05) crude protein and lower neutral and acidic detergent fibre. The ideal sward structure and greater chemical composition of Italian ryegrass pastures found under RN treatment resulted in greater herbage digestibility and intake of organic matter and metabolizable energy by grazing sheep than under the RT treatment. Our study highlights that management is the key strategy to reduce the environmental impact of grazing through lower CH 4 emissions in livestock grazing systems. “Rotatinuous” stocking was the more efficient grazing management strategy for mitigation of CH 4 emissions and intensity by grazing sheep, with 64% less CH 4 production per area and 170% less CH 4 emission per unit of animal product when compared to the RT treatment. [ABSTRACT FROM AUTHOR]

Highlights: [•] Model typical of crop livestock systems from subtropics. [•] Managing mixed oats and annual ryegrass pastures at 20cm lead to overall soil–plant–animal. [•] Equilibrium between animal performance and no-till crop demand for soil cover. [ABSTRACT FROM AUTHOR]

Highlights: [•] We evaluated the effect of management practices on establishment of Italian ryegrass. [•] We tested pasture's ability to re-establish following a year without seed production. [•] Grazing intensity is the first factor affecting subsequent pasture establishment. [•] Pasture establishment by self-seeding relies on the annual seed replacement. [•] Grazing must be managed to allow sufficient reproductive tiller production. [ABSTRACT FROM AUTHOR]

Abstract: In natural grasslands, plant species preferred by grazing animals are intermixed with less preferred species. We hypothesise that increasing proportion of Eragrostis plana Nees tussocks, a non-preferred diet item in natural grassland, will constrain the accessibility of the preferred diet item for grazing animals, and sheep would be less restricted than cattle. The experimental paddocks contained approximately 0, 25, 50 and 75% E. plana, in vegetative stage. Inter-tussock areas were proportionally maintained at a non-limiting forage allowance. Records were made every 1-min of the stratum (tussock, inter-tussock or intra-tussock) grazed by each of four beef heifers or four ewes. Short-term intake rate was calculated for each 45-min grazing session by weighing the animals before and after grazing, and correcting for insensible weight losses (evaporative and gaseous losses). Beef heifers reduced grazing time on the inter-tussock areas by 0.60% per each 1% increment in tussock cover, whilst ewes exhibited a smaller reduction of 0.36% (P <0.05). Virtually all of beef heifers’ reduction in inter-tussock grazing time was replaced by tussock grazing. However, the ewes were more selective and attempted to find preferred food in the intra-tussock stratum. Ewes adjusted their foraging strategies and maintained a constant short-term intake rate regardless of percentage of tussock cover. Beef heifers exhibited the highest short-term intake rate with 34% tussock cover. Beef heifers bite mass decreased when tussock cover increased over 44%, whereas no trend was detected for ewes. Tussocks may act as a vertical and/or horizontal barrier interfering with the process of bite formation and affecting bite mass of beef heifers. Conversely, ewes were able to adapt their grazing behaviour with increasing tussock cover, so that no effects on the measures taken in this study were observed. This response is consistent with the finer resolution of grazing selectivity by ewes and with the allometry of short-term intake rate. [Copyright &y& Elsevier]

Soil use and management during the winter can affect soil physical properties, reminiscent straw and performance of the crop cultivated in succession. The objective of this study was to evaluate the effect of winter soil use on these variables, cultivating black bean under no tillage system in the summer. Three experiments were carried out in the North Plateau of Santa Catarina State, Brazil, during 2007/08 crop season, with five strategies of soil use during the winter: 1) multicropping with black oat + ryegrass + commom vetch + arrow leaf clover without grazing and nitrogen fertilization (multicropping cover); 2) the same multicropping, with grazing and 100kg ha-1 of nitrogen fertilization (pasture with N); 3) the same multicropping, with grazing and without nitrogen fertilization (pasture without N); 4) oil seed radish, without grazing and nitrogen fertilization (oil seed radish); and 5) natural vegetation, without grazing and nitrogen fertilization (fallow). Highest straw dry mass is verified in multicropping cover, but the strategies of winter soil use do not affect significantly the soil bulk density and macroporosity. The soil use with winter annual pasture in crop-livestock system, cover crops and fallow does not affect the black bean performance in succession, under no tillage system. [ABSTRACT FROM AUTHOR]

We aimed to evaluate the effect of different grazing management strategies on carcass characteristics traits, meat quality and CH 4 intensity and yield of lambs grazing Italian ryegrass pastures in Southern Brazil. A grazing trial was performed (2014 and 2015) in a randomized complete block design with two grazing management targets and four replicates. Treatments were traditional rotational stocking (RT), with pre- and post-grazing sward heights of 25 and 5 cm, respectively, and 'Rotatinuous' stocking (RN), with pre- and post-grazing sward heights of 18 and 11 cm, respectively. Castrated crossbred Texel and Polwarth lambs were used. Results indicated that diet cost per kg of dry matter (p = 0.001) and per hectare (p < 0.001) were lower for RN than for RT treatment. Final live weight (p = 0.022) and hot and cold carcass weight (p = 0.006) were greater for the RN treatment. All commercial cuts were greater for RN than for RT treatment. The RN treatment presented greater (p < 0.001) production of carcass, edible food and crude protein. Feed efficiency and feed cost conversion were better for RN than for RT treatment. CH 4 intensity per kg of carcass, edible food and crude protein gain were 2.6, 2.7 and 2.1 times lower (p < 0.001) for RN. Moreover, CH 4 yield was lower (p = 0.014) for RN than for RT treatment, with an average of 7.6 and 8.3% of the gross energy intake, respectively. We conclude that the 'Rotatinuous' stocking results in a greater carcass production, carcass quality and lower diet cost, and CH 4 intensity and yield of grazing lambs. Adopting this grazing management strategy could enhance both lamb production and mitigation of CH 4 intensity and yield in grazing ecosystems, which could be considered a good example of climate-smart livestock production. Unlabelled Image • Sward management determines lamb carcass yield and associated environmental impact. • Quality and production of carcass are greater in 'Rotatinuous' stocking approach. • 'Rotatinuous' stocking mitigate CH 4 carcass intensity • 'Rotatinuous' stocking promotes feed efficiency while reducing feed costs. • This approach can be a wide-suitable example of climate-smart livestock production. [ABSTRACT FROM AUTHOR]