Cattle Preference Research Articles

FEEDING PREFERENCE OF WHITE FULANI CATTLE (BUNAJI) FED SACCIOLEPIS AFRICANA LEAF MEAL

Sacciolepis africana has been identified as water weed, which constitute a manace in rice and maize fields due to its aggressive growth. Utilization of Sacciolepis africana can help to mitigate the challenge and also serve as feed ruminant especially during the period of dry season. Hence, this experiment was conducted to determine the feeding preference and acceptability for Sacciolepis africana leaves by White Fulani Cattle (Bunaji). Sacciolepis africana leaves were harvested and processed into four treatments viz: Diet 1 (Freshly cut Sacciolepis africana), diet 2 (Air-dried Sacciolepis africana), diet 3 (Sun-dried Sacciolepis Africana) and diet 4 (Ensiled Sacciolepis africana). Proximate composition of the diets was carried out, and feeding preference of Bunaji cattle was observed. Results indicated that proximate composition of diets were influenced (P<0.05) by processing methods. Coefficient of Preference (CoP) of diets revealed that fresh Sacciolepis africana was most preferred with a CoP of 1.73, followed by the air-dried Sacciolepis africana with CoP values of 1.17. It is concluded that, processing Sacciolepis africana improved its nutritional composition and that the fresh Sacciolepis africana was most preferred by Bunaji cattle.

Pyric herbivory in a temperate European wood‐pasture system

AbstractThe termpyric herbivorywas first introduced in 2009, describing how fire shapes herbivory as burned areas attract herbivores and, simultaneously, herbivory shapes fuel load and fire behaviour. Pyric herbivory results in a mosaic of patches with varying levels of herbivory and grazing intensity fire intensity and frequency. The importance of pyric herbivory for ecosystem heterogeneity and biodiversity has been described for North American, Australian and African systems, but the concept remains largely untested in a European context.We introduced fire and herbivory in a full‐factorial experiment in a temperate European wood‐pasture system to test whether pyric herbivory operates in ways comparable to grassy systems elsewhere in the world. Using camera traps, we observed the behaviour of cattle in burned subplots (49 m2) compared with unburned subplots. We measured grass height and the proportion of the subplot that burned as variables affecting cattle preference and to assess how grazing affects fire behaviour. We also examined the effect on plant species and life‐form composition after six seasons of treatment.Cattle spent more time grazing in burned than in unburned subplots in the most productive paddock, where a larger proportion of the subplot burned. The proportion of a subplot that burned was positively related to pre‐fire grass height. Moreover, both grass height and the proportion of subplot burned declined in the burned subplots during the 6‐year study period and fire and cattle grazing altered the relative cover of graminoids and shrubs (Rubusspp.), with more graminoids in grazed and/or burned subplots and more shrubs in ungrazed subplots at the end of the study.Synthesis and applications. In our temperate European wood pasture, fire and (cattle) grazing interacted in ways comparable to pyric herbivory in grassy ecosystems elsewhere in the world, especially in the most productive paddock. Fire attracted grazing, with cattle grazing longer on subplots that burned more fully. Grazing also affected fire, where over the course of our experiment cattle grazing reduced grass height and the proportion of a subplot that burned. We suggest that pyric herbivory is an interesting management method to further explore in the European context to address the loss of biodiversity in open ecosystems, particularly in more productive sites.

Abundant resources compensate for the uneven distribution of ungulates in desert grassland.

Strategically managing livestock grazing in arid regions optimizes land use and reduces the damage caused by overgrazing. Controlled grazing preserves the grassland ecosystem and fosters sustainability despite resource limitations. However, uneven resource distribution can lead to diverse grazing patterns and land degradation, particularly in undulating terrains. In this study, we developed a herbivore foraging algorithm based on a resource selection function model to analyze foraging distribution patterns, predict the probability of foraging, and identify the determinants of foraging probability in cattle. The study area was a complex desert landscape encompassing dunes and interdunes. Data on cattle movements and resource distribution were collected and analyzed to model and predict foraging behavior. Our findings revealed that cattle prefer areas with abundant vegetation in proximity to water sources and avoid higher elevations. However, abundant resource availability mitigated these impacts and enhanced the role of water points, particularly during late grazing periods. The analysis showed that available resources primarily determine foraging distribution patterns and lessen the effects of landforms and water distance on patch foraging. The results suggest that thoughtful water source placement and the subdivision of pastures into areas with varied terrain are crucial for sustainable grazing management. By strategically managing these factors, land degradation can be minimized, and the ecological balance of grassland ecosystems can be maintained. Further research is needed to refine the model and explore its applicability in other arid regions.

Cattle preference in Paspalum atratum and its relationship with morphological and anatomical leaf characteristics

AbstractNew atra paspalum (Paspalum atratum Swallen) accessions were found to be differentially grazed by cattle, without differences in herbage accumulation and nutritive value. This study aimed to evaluate cattle preference, morphological and anatomical leaf traits, and their relationships at four sampling events. Five new atra paspalum accessions and the cultivar Cambá were used. The experimental unit was a 2 m × 2 m plot. Treatments were replicated four times in a completely randomized design. Cattle preference was determined in spring (December 2016 and 2017), summer (March 2017), and autumn (May 2017) using six steers Bos spp. that grazed the plots for 4 h on two consecutive days. Plant height, leaf‐blade length, leaf‐blade width, and the proportions of five leaf tissues at three leaf regions were measured at each date. The proportion of the leaf that is curved was measured in December 2017. Cattle preference was variable among accessions and sampling events. Some accessions were shorter, with shorter and more flexible leaves than Cambá (p < 0.05). The proportion of lignified tissues was greater during the spring (2016 and 2017) and summer (7%–23%) than in the autumn. One accession had the lowest proportion of lignified tissue in the warm season (8%–12%) but the highest during the fall (around 15%). The same accession had the fewest primary vascular bundles in the warm season. Cattle preference was negatively correlated with the proportion of lignified tissues, the number of primary vascular bundles, plant height, and leaf‐blade length. Cattle preference was affected by the growing season and reduced by greater presence of leaf structural tissue.

Beef Cattle Preference and Usage of Environmental Enrichments Provided Simultaneously in a Pasture-Based Environment.

Environmental enrichment can improve livestock welfare through increasing environmental complexity to promote a greater range of natural behaviours. However, there is limited understanding of the need for and impacts of enrichments for extensively managed beef cattle that can sometimes be kept in grassed paddocks devoid of additional natural and artificial features, i.e., 'barren pastures'. This trial assessed which enrichments beef cattle preferred and utilised in a barren paddock environment. Eight groups of seven Angus steers housed on pastured paddocks devoid of natural or artificial features were observed during daylight hours for two days a week over a period of three weeks, after being presented with four enrichments simultaneously: a cattle brush, a piece of hanging rope, a tree stump, and a woodchip pile. Although enrichment use generally decreased over time, the brush, stump, and woodchip maintained a higher level of use than the rope, based on the frequency of interactions and number of displacements around the enrichments (both p < 0.001). This suggests that the brush, stump, and woodchip pile were more valuable resources to the cattle, allowing for grooming and lying behaviours, although oral manipulations also occurred on the stump, woodchip, and rope. The inclusion of these enrichments can increase the complexity of barren pasture environments and allow for the increased expression of natural behaviours, potentially contributing to improved welfare.

Feeding Preferences of Domestic and Wild Ungulates for Forage Trees in the Dry Tropics

Silvopastoralism based on livestock feeding on forage trees is becoming a sustainable alternative to traditional grazing on the open pastures of dry tropical Central America. Four autochthonous trees, Acacia pennatula, Enterolobium cyclocarpum, Gliricidia sepium and Guazuma ulmifolia, and one exotic (Moringa oleifera) tree are the preferred species for these silvopastoral systems. Little is known, however, about the feeding preferences of cattle, sheep and goats for such fodder trees and whether wild ungulates (white-tailed deer, Odocoileus virginianus) feed on these plants. In this work, we conducted several multiple-choice feeding preference tests (cafeteria test) to compare the best choice to feed cattle, sheep, goats and white-tailed deer in these farming systems. Although all ruminant species included the four autochthonous trees and the exotic M. oleifera in their diets, G. ulmifolia was the preferred forage tree by far. The preference for the rest of the trees varied among our ruminant species. When M. oleifera was added to the cafeteria test, it was well accepted by white-tailed deer but little appreciated by their domestic counterparts. The use of these forage trees for livestock feeding is thus interesting not only for sustainable animal production but also to support wild herbivores in the dry tropics of Central America.

Increasing mud levels in a feedlot influences beef cattle behaviours but not preference for feedlot or pasture environments

Public scrutiny surrounds the intensive feedlot finishing of beef cattle, likely due to the assumption that cattle cannot perform their full repertoire of natural behaviours. However, it is not well-known how certain aspects of the environment influence both cattle perception of a feedlot environment and the behaviours they perform within it, particularly with increasing levels of mud. The objective of this study was to perform a Y-maze test to assess the preference of Angus steers for either a pasture environment or a feedlot at three pad scores, which were based on increasing mud depth relative to the cattle’s hoof and leg. Cattle were tested both morning and afternoon for ten consecutive days, with lying behaviours and number of steps measured using IceQube® accelerometers. Here we show that day affected cattle’s preference for pasture versus feedlot environments, with choice alternating between consecutive days (P < 0.001), and cattle also exhibited a preference for pasture at night (P = 0.04). Although the paddock environment was preferred at all pad scores, increasing mud level did not significantly influence the preference of cattle for either environment (P = 0.39), and it is likely that both environments contained rewarding stimuli. There was a significant interaction between pad score and location for lying behaviours and number of steps taken (all P < 0.001), with the highest pad score being associated with reductions in these behaviours within the feedlot. Evidence of a rebound effect for lying behaviours in the paddock for this pad score indicates that high levels of mud may negatively impact welfare when no alternative space to lie is provided.

Evaluation of Compacted Forage Feed on Kupang Cattle Feeding Behavior

Forage compact feed has the ability to cut the adaptation period of grazing cattle when transported, because they are used to consume forage. The effect of the form and type of forage formulation on the feeding behavior of cattle needs to be studied further to determine the preferences of cattle for this compact feed. This study used 36 cattle with 3 replications in each treatment. The 2 factor groups withfactorial design consisting formulation and form of feed was applied in this study. The forms of feed used in this study were wafers, pellets, dried pellets, and cubes. The formulations used in this study were formulation 1 (10% molasses, 30% indigofera leaves, 50% straw, 10% elephant grass); formulation 2 (10% molasses, 30% indigofera leaves, 60% straw); formulation 3 (10% molasses, 20% indigofera leaves, 65% straw, 5% hemp). The parameters observed in this study were eating behavior of cattle which consisted of the frequency and duration of eating, drinking, rumination, and resting. The results showed that there wasan interaction on eating frequency and cattle duration. Formulation 3 on wafer treatment had the highest feeding frequency (P&lt;0.05). Formulation 1 on wafer treatment had the highest duration of rumination (P&lt;0.05). In the conclusion, Formulation 1 and 3 with wafer shape showed the best behavior for eating.

Spatial monitoring technologies for coupling the soil plant water animal nexus

Systems-level studies aimed at determining how soil properties are linked to plant production and ultimately animal response spatially are lacking. This study aims to identify if grazing pressure is linked to soil properties, terrain attributes, and above-ground plant accumulation and nutritive value in a silvopastoral (or integrated tree-livestock) system. Overall, cattle prefer grazing native grasses (2.81 vs. 1.24 h ha−1 AU−1) and udic (dry) landscape positions compared to aquic (wet) areas (2.07 vs. 1.60 h ha−1 AU−1). Greater grazing frequency occurs in udic soils with greater phosphorus and potassium contents and with accumulated forage with less lignin (P ≤ 0.05), which correspond to reduced elevation and greater tree height and diameter (shade) during summer mob grazing. Combining spatial monitoring technologies (both soil and animal) with forage allowance can optimize grazing systems management and sustainability spatially and temporally.

What type of loafing areas do housed dairy cattle prefer?

Providing continuously-housed dairy cows with a loafing area may allow them space to express behaviours that are affected by the housing environment. The aim of this study was to investigate whether dairy cows had a preference for loafing area type and if loafing area type affected behaviour performed within it. Three groups of 12 and one group of 11 lactating cows (n = 47) were housed in a cubicle shed with two nearby loafing areas 1) a concrete-floored roofed area and 2) a grassed paddock fenced to the same size as the concrete area. After 3d baseline period without access, cows were trained to access the loafing areas over 2 days. A 5d preference test followed, where cows had free access to the cubicle shed and both loafing areas from 08:45 until 12:45 and 15:30–18:30. Behaviour was observed via live observations (scan sampling) in the mornings and afternoons and activity sensors (IceTags) continuously recorded lying bouts 24 h/d until the end of the experiment. Results of the live observations showed that the cows were in the paddock area for more of the scans than the concrete area (P < 0.01). Descriptive statistics showed cows behaving differently in the two areas, lying down more when in the paddock area and standing more when in the concrete area (lying behaviour: paddock area = 69%; concrete area = 0%). Active behaviours (loafing behaviours) such as social interactions were recorded in both loafing areas (active standing behaviour: paddock area = 8%; concrete area = 23%). The weather and ground conditions affected behaviour. In dry conditions, cows lay down in the paddock area. When the ground was saturated, the cows lay down in the cubicle shed. There was no statistical evidence of overall differences in behaviours (P = 0.35) recorded during the baseline and preference testing periods. However, based on sensor data, cows had longer lying bouts over 24 h on the days when they had access to the loafing areas compared to the days when they did not (P = 0.028). This suggests that cows prefer paddock loafing areas to concrete areas when lying opportunities are presented, but proportionately, more active standing or ‘loafing’ behaviours are performed in the concrete area.

Factors Affecting Site Use Preference of Grazing Cattle Studied from 2000 to 2020 through GPS Tracking: A Review.

Understanding the behaviour of grazing animals at pasture is crucial in order to develop management strategies that will increase the potential productivity of grazing systems and simultaneously decrease the negative impact on the environment. The objective of this review was to summarize and analyse the scientific literature that has addressed the site use preference of grazing cattle using global positioning systems (GPS) collars in the past 21 years (2000–2020) to aid the development of more sustainable grazing livestock systems. The 84 studies identified were undertaken in several regions of the world, in diverse production systems, under different climate conditions and with varied methodologies and animal types. This work presents the information in categories according to the main findings reviewed, covering management, external and animal factors driving animal movement patterns. The results showed that some variables, such as stocking rate, water and shade location, weather conditions and pasture (terrain and vegetation) characteristics, have a significant impact on the behaviour of grazing cattle. Other types of bio-loggers can be deployed in grazing ruminants to gain insights into their metabolism and its relationship with the landscape they utilise. Changing management practices based on these findings could improve the use of grasslands towards more sustainable and productive livestock systems.

Environmental variables responsible for Zebu cattle thermal comfort acquisition.

The aim of this study was to estimate, using data mining, which microclimate and behavioral variables affect the behavior of animals to seek shaded or sunny areas. The experiment was carried out between January and May 2016 in an integrated crop-livestock-forest system. In this system, we defined two different areas: shaded and sunny. Microclimatic variables (At, BGt, RH, and WS) were measured in each area on 4 consecutive days per month. With these variables, we determined the bioclimatic indicators (THI, BGHI, HLI, MRT, RTL, and ETI). In addition, we calculated the absolute difference (Δ) by subtracting the value recorded in shaded areas from the value recorded in sunny areas for all microclimatic variables and bioclimatic indicators, except for WS. The behaviors (grazing, ruminating, and other activities), posture (standing or lying), and use of areas (shaded or sunny) of 38 Zebu cattle were recorded on 2 consecutive days per month. The data mining technique was applied for analysis in a classification task. The model correctly classified 76% of the instances with a Kappa statistic of 0.51 after features selection from the database. The ΔBGt was the most important feature in the model to classify the decision of Zebu cattle to seek another area or remain in a determined area. The model was built with seven classification rules, being one simple rule, composed of the interaction between ΔBGt and rumination; and other more complex rules, composed of the interactions among the ΔBGt, WS, and rumination. The preference of Zebu cattle to seek or remain in shaded or sunny areas was influenced by eight features: rumination, drinking water, WS, ΔBGt, MRT in shade, BGHI in sun, ΔBGHI, and HLI in sun.

Forage quality and beef cow preference is affected by wrap type of conventional and reduced-lignin alfalfa round bales stored outdoors.

Storing hay outdoors can result in detrimental changes in forage quality. Additionally, alfalfa (Medicago sativa L.) cultivar may influence dry matter intake (DMI) and hay waste when feeding livestock. The objectives were to determine the effects of conventional or reduced-lignin alfalfa round bales stored outdoors and wrapped with plastic twine, net wrap, or B-Wrap on forage quality, beef cow preference, and hay waste. Round bales made from reduced-lignin (n = 12) or conventional (n = 12) alfalfa cultivars were baled and stored outdoors for 16 mo. Within each cultivar, four bale replicates were bound with plastic twine, net wrap, or B-Wrap. After storage, bales were fed in a switchback design with period confounded with alfalfa cultivar to 18 lactating Angus cows (Bos Taurus L.). The pairs had ad libitum access to three round-bale feeders where bales of each wrap type were placed for eight 48 h periods. Position of round bale wrap type was rotated according to a Latin Square arrangement. Bales were weighed and waste surrounding each feeder was collected at 24 and 48 h to calculate DMI and hay waste. Statistical significance was set at P < 0.05. Alfalfa cultivar did not impact any of the response variables (P > 0.05). At feeding, round bales wrapped in net wrap had greater (P < 0.015) moisture content (16.4%) compared with those wrapped with B-Wrap (12.8%). Neutral detergent fiber was lower (P = 0.03) in bales wrapped in B-Wrap (46%) compared with twine-tied bales (49%) while net wrapped bales were not different. Total digestible nutrients (P = 0.02), and relative feed value (P = 0.04) were lower in twine-tied bales compared with B-Wrap while net wrapped bales were not different. Twine (7.1 × 106 colony forming units [CFU]/g) and net wrap (4.7 × 106 CFU/g) bales had greater (P < 0.0001) mold counts than B-Wrap bales (4.8 × 104 CFU/g), while concentrations of other forage components and yeast counts were not different among wrap types (P > 0.05). Total DMI, and DMI during the first 24 h, were greater (P ≤ 0.032) for B-Wrap bales compared to twine-tied bales indicating preference for hay wrapped in B-Wrap; net wrapped bales were not different. Dry matter intake in the first 24 h was negatively associated with the mold count (r = −0.52; P = 0.02), and hay waste was not affected by wrap type (P > 0.05). These results confirm that wrap type affected forage quality and mold counts, which in turn influenced beef cattle preference of round bales stored outdoors.

Short-Term Eating Preference of Beef Cattle Fed High Forage or High Grain Diets Supplemented with 3-Nitrooxypropanol.

Simple Summary3-Nitrooxypropanol is an effective methane-mitigating feed additive. However, a decrease in feed intake is frequently observed in beef cattle fed a diet supplemented with 3-nitrooxypropanol. Thus, a study was conducted to determine the short-term preference of beef cattle offered diets supplemented with 3-nitrooxypropanol. When given a choice, the cattle initially showed less preference for a diet supplemented with 3-nitrooxypropanol, suggesting potential changes in organoleptic properties of the diet. However, the animals acclimatized to the supplemented diet rapidly such that there was no preference between a diet with and without 3-nitrooxypropanol within a week. Therefore, the change in the organoleptic properties of a diet supplemented with 3-nitrooxypropanol does not appear to be the main reason for reduced feed intake of beef cattle.Two experiments were conducted to examine eating preference of beef cattle for diets with or without the investigative enteric methane inhibitor 3-nitrooxypropanol (3-NOP). Nine beef steers were housed in individual stalls, each equipped with two feed bunks. The first experiment (Exp. 1) was conducted with a high forage diet and each animal received a diet without 3-NOP (CON) in one bunk and a diet with 3-NOP (dNOP) in the other bunk. The second study (Exp. 2) was conducted with the same animals about 6 months after Exp. 1 where a high grain diet without (CON) or with 3-NOP (dNOP) was offered. In Exp. 1, animals initially preferred CON compared with dNOP. Feed consumption from 0 to 3, 3 to 6, and 6 to 12 h after feeding was lower for dNOP compared with CON. However, dry matter intake (DMI) and feed consumption of dNOP gradually increased during Exp. 1 such that there was no preference between CON and dNOP on day 7. In Exp. 2, there was no preference for or against dNOP. Average DMI was greater for dNOP vs. CON, but interactions between diet and day for DMI and feed consumption rates indicated that daily preference between CON and dNOP was variable. In conclusion, beef steers initially detected a difference between CON and dNOP and selected in favor of CON rather than dNOP when they had not previously been exposed to 3-NOP. However, the animals rapidly acclimatized to a diet with 3-NOP (Exp. 1) and showed no eating preference between CON and dNOP within 7 days. This lack of preference was maintained throughout Exp. 2 when the same animals were fed a high grain diet.

Do dairy cattle use a woodchip bedded area to rest on when managed on pasture in summer?

Previous studies have demonstrated that dairy cattle prefer pasture over indoor conditions especially at nighttime, which suggests they perceive pasture as an attractive place to rest. Indeed, cows avoid and spend less time lying on hard surfaces, such as concrete or mattresses, compared to softer surfaces. This study aimed to investigate how much time cows spend lying on pasture at the end of summer when the ground can be hard, compared to a softer surface. Four groups of lactating dairy cattle (5 cows/group) had access to either pasture alone or a pasture containing two deep bedded woodchip areas for 9 consecutive days in a cross-over design. Woodchip usage and posture (upright or lying) were recorded using data loggers and video cameras. We also recorded weather conditions, surface characteristics (hardness, dry matter content, temperature) and milk production. There were no consistent significant differences in lying times of cows with or without woodchip bedded areas. Average lying times for groups with access to pasture only and the woodchip were 8.9 h/24 h (range: 7.8–10.1 h) and 8.5 h/24 h (range: 7.6–9.7 h), respectively, excluding milking times. Average number of hours per day on the woodchip was 2.1 h (range: 0–5.9 h), however, there was considerable animal variation in the use of the woodchip bedded areas. When cows were on the woodchip, they spent on average 51 % of their time lying (SEM: 7 %) and when they were on pasture they spent 36 % of the time lying (SEM: 1 %). Most of the lying, however, was on the grass. Both surfaces likely provided cows with a comfortable lying surface despite pasture being harder than the woodchip. Rainfall prior to data collection may have contributed to pasture being unusually soft for the time of year. Overall, lying times decreased with increasing heat load (air temperature, temperature-humidity index, heat load index, P < 0.001) and rainfall (P = 0.002). Cows spent less time on the grass and more time on the woodchip as the daily average air temperature increased; for each 1 °C increase in air temperature, the time spent on grass decreased by 1.0 ± 0.46 (SE) percentage points per day (P = 0.047). We speculate that this was due to woodchip being a cooler surface or attracting fewer flies than the grass. In conclusion, cows varied in their use of deep bedded woodchip areas when provided in the pasture, however, most of the time spent lying was on the grass.

Cattle select against the invasive grass tall fescue in heterogeneous pastures managed with prescribed fire

AbstractTall fescue (Festuca arundinacea) is a Eurasian forage grass extensively planted in the United States. However, an endophytic fungus in tall fescue, Epichloë coenophiala, causes health problems in cattle. We predicted that cattle prefer to graze alternative forages when available. We also predicted that cattle use tall fescue more intensively in recently burned areas, as fire can increase forage quality. We tested these predictions in four diverse‐forage pastures in Iowa, comparing use by cattle of tall fescue and four alternative forages (non‐fescue cool‐season grasses, native warm‐season grasses, non‐leguminous forbs and legumes) to their availabilities at the pasture scale. We also examined how tall fescue influences the distribution of grazing at a fine scale (0.1‐m2 quadrats). Tall fescue was the most abundant forage (46% of plants), but composed only 26% of grazed vegetation. In contrast, legumes composed 12% of available forage but 25% of grazed vegetation. Other forages were used in proportion to availability. At a fine scale, total grazing frequency (proportion of plants grazed) was lower in quadrats containing abundant tall fescue, and higher in quadrats with abundant warm‐season grasses. Grazing frequency of tall fescue and other cool‐season grasses was greatest in recently burned quadrats, but total grazing frequency did not increase after burning. Our results show that although cattle graze tall fescue, particularly following burns, they limit their use of this grass. Given that tall fescue is underused, creates health risks for cattle, and degrades wildlife habitat quality, it may be advisable to reduce tall fescue in pastures.

Cattle Preference for Annual Forages

Cattle Preference for Annual Forages

Agronomic characterization of &lt;i&gt;Paspalum atratum&lt;/i&gt; Swallen and &lt;i&gt;P. lenticulare&lt;/i&gt; Kunth

Paspalum atratum and P. lenticulare are perennial grasses, native to South America. The objective was to evaluate seasonal growth, frost tolerance, cattle preference, nutritional characteristics, seed yield and germination of 11 ecotypes of P. atratum and P. lenticulare with regard to their potential as alternatives to introduced species. Forage yield was evaluated during 3 growing seasons between 2011 and 2014. Digestibility and CP concentration were assessed in summer 2014, cattle preference in winter 2013 and summer 2015, frost tolerance after the first frosts in June 2012, flowering time during 2013 and 2014 and seed yield and germination in 2014. A marked warm-season growing period was observed for both species with annual forage yields varying from 5 to 12 t DM/ha. Flowering did not occur until autumn, with mean seed yield of 280 kg/ha and germination of 16% for P. atratum and 19% for P. lenticulare. Most ecotypes were able to tolerate winter temperatures and behaved as perennials. Although no differences were observed for DM digestibility and CP concentration among accessions, cattle preferentially grazed accession P. atratum U44. Further studies are needed to evaluate persistence under grazing and animal performance.

Effects of livestock exclusion on density, survival and biomass of the perennial sagebrush grass Hymenachne pernambucense (Poaceae) from a temperate fluvial wetland

In Argentina, the intensification of soybean production has displaced a substantial proportion of cattle ranching to fluvial wetlands such as those in the Delta of the Paraná River. Cattle grazing affects structure and dynamics of native forage plants but there is little information on this impact in populations from fluvial wetlands. This study addresses the effect of cattle ranching on density, survival, mean life-span and aerial biomass of Hymenachne pernambucense (Poaceae), an important forage species in the region. The study was carried out monthly for one year in permanents plots subject to continuous grazing and plots excluded from grazing in the Middle Delta of the Paraná River. In plots excluded from grazing, tillers showed significantly higher population density and survival, and a two-fold increase in mean life-span, while continuous grazing decreased survival of cohorts. The largest contribution to tiller density in ungrazed and grazed populations was made by spring and summer cohorts, respectively. Total and green biomass were significantly higher in the ungrazed population, with highest differences in late spring-early summer. Cattle grazing affected the relationship between tiller density and green biomass suggesting that cattle prefer sprouts because they are more palatable and nutritious than older tissue.

Forage selectivity by cattle and sheep co‐grazing swards differing in plant species diversity

AbstractInteractions between sward diversity and forage selectivity of cattle and sheep managed within mixed grazing systems are not fully understood. The objective of this study was to investigate the effect of either mono‐ or co‐grazing of sheep and cattle on swards differing in botanical composition (either diverse or grass‐dominated) on the intake choices of six target forage species. Jacobs' selection index (JSI) was employed to quantify the preference for single target species in relation to their proportion in the sward. Results revealed distinct intake preferences of sheep and cattle; as expected, sheep were more selective than cattle. To a lesser extent, the sward composition had an effect on intake preferences: cattle responded to botanical composition by changing their intake preferences, but to a lesser extent than sheep. Phleum pratense was the most preferred target forage species (JSI = 0.62). Lolium perenne, Taraxacum sect. Ruderale and Trifolium repens were also highly preferred regardless of sward composition or type of grazing (JSI = 0.47, 0.32 and 0.27 respectively). Dactylis glomerata and Festuca pratensis tended to increase in abundance after grazing events in both diverse and grass‐dominated swards. Co‐grazing of cattle and sheep facilitated a more homogeneous consumption of the target forage species evaluated.