Effect Of Stocking Rate Research Articles

Application of Soil Multiparametric Indices to Assess Impacts of Grazing in Mediterranean Forests

In this study, the effects of different stocking rates were quantified in three study areas in a Mediterranean forest (Cuenca, Spain) by applying a multiparametric soil quality index (SQI) developed from undisturbed forest soils (>40 years). The main objective was to advance the development and application of multiparametric indices that allow for soil condition assessment. To fulfill this objective, the effectiveness of the developed multiparametric soil quality index (SQI) was analyzed as an indicator of livestock impacts on soil in the Mediterranean forest. The control areas without livestock activity were forest stands of different ages (a thicket forest stand of <30 years; a high-polewood forest stand of 30–60 years; and an old-growth forest stand of >60 years), which were compared with areas subjected to various grazing intensities (areas with permanent livestock passage: a sheepfold that had been inactive for 2–3 years and an active sheepfold; areas with intermittent livestock passage: a bare-soil area, a pine stand and a scrubland). The applied multiparametric soil quality index (SQI) was sensitive to changes in forest ecosystems depending on the stocking rates. However, to obtain greater precision in the assessment of the effects of stocking rates, the multiparametric index was recalibrated to create a new index, the Soil Status Index by Livestock (SSIL). The correlation between the quality ranges obtained with both indices in different study areas suggests that the SSIL can be considered a livestock impact reference indicator in Mediterranean forest soils.

Grazing decreased soil organic carbon by decreasing aboveground biomass in a desert steppe in Inner Mongolia

The mechanisms through which stocking rates affect soil organic carbon in desert steppe landscapes are not fully understood. To address this research gap, we investigated changes in the biomass of Stipa breviflora plant communities and soils in a desert steppe. Through our research findings, we can establish an appropriate stocking rate for Stipa breviflora desert steppe. The establishment serves as a theoretical foundation for effectively maintaining elevated productivity levels and increasing the carbon sink, thereby offering a valuable contribution towards mitigate climate change.This study examined the effects of different stocking rates on soil organic carbon input, sequestration, and output and found: (1) For soil organic carbon input, the aboveground and litter biomass of plant communities decreased with increasing stocking rate. (2) Grazing treatments did not affect soil organic carbon retention. (3) Regarding soil organic carbon output, the grazing treatments exhibited no significant alteration in soil respiration when compared to the no grazing. In summary, the primary mechanisms through which increasing stocking rates affect the soil organic carbon pool are decreased inputs from plants and increased output through wind erosion. Therefore, decreasing grazing intensity is key to improving soil organic carbon retention in the desert steppe.

Effects of Grazing Intensity on the Carbon, Nitrogen and Phosphorus Content, Stoichiometry and Storage of Plant Functional Groups in a Meadow Steppe

Studies on the impacts of grazing on carbon, nitrogen, and phosphorus stoichiometry and storage are crucial for better understanding the nutrient cycles of grasslands ecosystems. Using a controlled grazing experimental platform in a meadow steppe ecosystem, the effects of different stocking rates (0.00, 0.23, 0.34, 0.46, 0.69, and 0.92 AU ha−1) on the carbon, nitrogen, and phosphorus contents of plant functional groups were explored. The major results were: (1) The carbon content of Gramineae Barnhart was significantly reduced by grazing intensity (p < 0.05), and the organic carbon content of Cyperaceae Rotundus was significantly higher than that of the other groups; the total nitrogen content of Cyperaceae and other groups and total phosphorus contents of Gramineae, Leguminosae Sp., Cyperaceae, and other groups all increased significantly with increasing grazing intensity (p < 0.05). (2) The carbon, nitrogen, and phosphorus storage amounts of Gramineae, Leguminosae, and Ranunculaceae L. decreased significantly with increasing grazing intensity. Heavy grazing reduced the carbon, nitrogen, and phosphorus storage amounts of Cyperaceae and other groups, while the carbon, nitrogen, and phosphorus storage amounts of Compositae were the largest under moderate grazing. (3) The nitrogen content of each functional group was highly significantly negatively correlated with the C/N ratio, and the phosphorus content was highly significantly negatively correlated with the C/P ratio. Grazing and foraging affected the growth of the different functional groups, which in turn affected their carbon, nitrogen, and phosphorus content, stoichiometry, and storage. Moderate grazing improved the nutrient utilization efficiency of grassland and is beneficial for promoting sustainable grassland development.

Effects of Stocking Rate and Environmental Enrichment on the Ontogeny of Pecking Behavior of Laying Hen Pullets Confined in Aviary Compartments during the First 4 Weeks of Life.

Simple SummaryThe objective of this study was to describe the development of aggressive pecking, gentle feather pecking and severe feather pecking of non-beak-trimmed laying hen pullets during the first 4 weeks of life. The pecking behavior patterns were observed in three different experimental groups, which differed in stocking rates and the provision of enrichment material. The enrichment materials were suitable and intensely used by the pullets. The provision of pecking blocks and pecking stones is recommended as a preventive measure from the first day of life onwards for pullets housed in commercial rearing aviaries. There was no effect of reduced stocking rate, most likely due to the low variation in stocking rates.The objective of this study was to describe the ontogeny of the severe feather pecking (SFP), gentle feather pecking (GFP), aggressive pecking (AP), and enrichment pecking (EP) of non-beak-trimmed Lohmann Brown (LB)-pullets during the first 4 weeks of life (observation on 1st, 8th, 15th, 22nd, and 29th days of life) while they were kept within the compartments of a commercial rearing aviary (without access to a litter area). All chicks were placed into compartments of the middle tier of the aviary on the 1st day of life. On the 10th day of life, half of the chicks of each compartment were moved into the compartments of the lower tier. The aviary floor was covered with chick paper before the placement of the chicks and fully or partially removed from the 15th day of life onwards. The pecking behavior patterns were observed in three experimental groups (EG): NE (not enriched): group size until/after 10th day of life: 230/115; 120.8/60.4 birds/m2, no enrichment; EL (enriched, low stocking rate): group size until/after 10th day of life: 203/101, 106.6/53.6 birds/m2; and EH (enriched, high stocking rate): group size until/after 10th day of life: 230/115;120.8/60.4 birds/m2, both pecking stones and blocks as enrichment) in two rearing periods. For each pecking behavior pattern, an independent regression model with the parameters EG, chick paper, observation day, and functional area was estimated. GFP, SFP, and EP increased with age during the observation. The AP rate was highest in all EGs on the first day of life and decreased during the observation period. A pairwise comparison of NE (high stocking rate without enrichment) with EH (high stocking rate with enrichment and with EL (low stocking rate with enrichment) showed a significant effect of the EG on pecking behavior, with more SFP, AP, and GFP in NE. There were no differences between EL and EH, indicating that the provision of pecking materials had more influence than the stocking rate. However, we presumed that the difference between the stocking rates were too small to observe an effect. AP, SFP, and GFP were significantly higher on wired slats, as compared to the perches and the vicinity of the enrichment materials. The enrichment materials were suitable and intensely used by the pullets. The provision of pecking blocks and pecking stones was recommended as a preventive measure from the first day of life onwards for pullets housed in commercial rearing aviaries. There was no effect of reduced stocking rate, most likely due to the low variation in stocking rates.

Effect of Sheep Grazing, Stocking Rates and Dolomitic Limestone Application on the Floristic Composition of a Permanent Dryland Pasture, in the Montado Agroforestry System of Southern Portugal.

Simple SummaryThe Montado is a characteristic ecosystem of the Mediterranean region, where agricultural activities, animal production and forestry coexist alongside tourism, hunting and leisure activities. Animal grazing is fundamental for the conservation of the Montado, and it is imperative to clearly understand its interactions with the pasture floristic composition (PFC) of the Montado. The objective of this study was to evaluate the effect of sheep grazing, stocking rates and dolomitic limestone application on the floristic composition of permanent dryland pastures, in the Montado agroforestry system of Southern Portugal. The type of grazing influences the PFC, which may be positively or negatively impacted, depending on the adopted system. Deferred grazing seems to benefit the disappearance of undesirable plants and the appearance of desired plants. The results of this study allow for more informed management decisions and a potential increase in animal production but also improve the knowledge of conservation strategies in the Montado.The Montado is a complex agroforestry–pastoral ecosystem due to the interactions between soil–pasture–trees–animals and climate. The typical Montado soil has an acidic pH and manganese toxicity, which affect the pasture’s productivity and pasture floristic composition (PFC). The PFC, on the other hand, can also be influenced by the type and intensity of grazing, which can lead to significant decreases in the amount of biomass produced and the biodiversity of species in the pasture. The objective of this study was to evaluate the effect of grazing type, by sheep, and different stocking rates on the PFC throughout the vegetative pasture cycle in areas with and without dolomitic limestone application. Thus, four treatments (P1UC to P4TC) were constituted: P1UC—without limestone application (U) and continuous grazing (CG); P2UD—U and deferred grazing (DG); P3TD—with the application of limestone (T) and DG; P4TC—T and CG. In DG plots, the placement and removal of the animals were carried out as a function of the average height of the pasture (placement—10 cm; removal—3 to 5 cm). The PFC was characterized in winter, at the peak of spring and in late spring. The PFC data were subjected to a multilevel pattern analysis (ISA). The combination of rainfall and temperature influenced the pasture growth rates and consequently the height of the pasture at different times of the year. Therefore, with the different growth rates of the pasture throughout the year, the sheep remain for different periods of time in the deferred grazing treatments. In the four treatments, 103 plant species were identified. The most representative botanical families in the four treatments were Asteraceae, Fabaceae and Poaceae. ISA identified 14 bioindicator species: eight for the winter period, three for the late spring vegetative period and three for the TC treatment.

Using TD-NMR relaxometry to assess the effects of diet type and stocking rate on the incidence and degree of severity of myopathies in broilers

This study aimed to evaluate different feeding strategies and stocking rates (SR) on the occurrence and severity of broiler myopathies. Additionally, a second aim was to test the potential use of Time-Domain Nuclear Magnetic Resonance (TD-NMR) relaxometry for assessing white striping (WS) and wooden breast (WB) incidence and the degree of severity in broiler chicken breasts. Treatments were arranged in a 2 × 2 factorial design and consisted of two nutritional levels (regular and superior diets) and two different SR (high 47 kg/m2 or regular 59 kg/m2). Infrared thermography (IRT) images were recorded on three different days to determine the average, minimum and maximum temperatures. After 49 days of rearing, birds were slaughtered, and 75 breasts were weighed and classified according to the absence (normal breast, without the occurrence of myopathy – NB) or occurrence and severity of WB and WS. The whole breasts were analysed by TD-NMR relaxometry using the Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence and Continuous Wave-Free Precession (CWFP-T1) pulse sequence. There was no effect of diet and diet*SR interaction on the weight of breast meat; however, chickens raised at the higher density presented a lower breast weight (P < 0.0001; 490 vs. 539 g). The incidence and severity of myopathies was not influenced by the treatments (P = 0.9467); the frequencies of WB and WS were similar in the different treatments. For CPMG and CWFP-T1, three and two relaxation populations were noted, respectively. The sPLS-DA model optimisation showed a significant separation between WS and NB in terms of occurrence and severity. In conclusion, changes in diet and SR did not mitigate the occurrence or severity of WS and WB. Additionally, TD-NMR relaxometry showed to be a promising technology for evaluating and segregating breasts according to myopathy incidence and severity.

Regional Assessment of Stocking Rate Effects on Uruguayan Rangelands: A Ranch-Level Study

We analyzed the variation of plant composition, forage production, and livestock diet across a broad stocking rate gradient on Eastern Hills rangelands of Uruguay. Our approach encompassed five ranches subjected to mixed sheep-cattle grazing and combined field surveys, microhistological fecal analysis, and remote sensing techniques. We hypothesized that selectivity would decrease as stocking rate increased. Vegetation data and fecal samples were obtained in 17 paddocks in 2008. To investigate the role of stocking rate on vegetation, we focused on dominant species and forage type cover. Diet composition was analyzed at forage type level. Annual net primary productivity was estimated for each paddock using the normalized difference vegetation index derived from the MODIS (Moderate Resolution Imaging Spectroradiometer) sensor. We found a clear relationship between the variation in stocking rate and floristic and forage type composition, both suggesting a deterioration of grassland conservation status. Cool season grass cover varied from 25% to 5%, from low to high stocking rates. Dicot cover showed an opposite trend, with values around 15% in the low and moderate stocking levels and reaching 35% on high-stocked paddocks. Diet composition and diet overlap between herbivores also showed clear patterns of response to stocking rate. On the other hand, livestock selectivity interacted with herbivore type. While cattle showed the expected pattern, sheep did not decrease selectivity in winter as stocking rate increased. Contrary to expectations, annual net primary productivity was similar across the different stocking rate levels and the month of maximum productivity was generally March. Our study provides strong evidence of marked rangeland degradation; however, the lack of response in terms of ANPP and the ability of sheep to maintain selectivity under high stocking rates could help to explain the lack of responsiveness in the adoption of generalized stocking adjustments by the ranchers.

At high stocking rates, cattle do not functionally replace wild herbivores in shaping understory community composition.

Over a quarter of the world's land surface is grazed by cattle and other livestock, which are replacing wild herbivores, potentially impairing ecosystem structure, and functions. Previous research suggests that cattle at moderate stocking rates can functionally replace wild herbivores in shaping understory communities. However, it is uncertain whether this is also true under high stocking rates and the effects of wild herbivore on plant communities are moderate, enhanced, or simply additive to the effects of cattle at high stocking rates. To evaluate the influence of cattle stocking rates on the ability of cattle to functionally replace wild herbivores and test for interactive effects between cattle and wild herbivores in shaping understory vegetation, we assessed herbaceous vegetation in a long-term exclosure experiment in a semi-arid savanna in central Kenya that selectively excludes wild mesoherbivores (50-1000 kg) and megaherbivores (elephant and giraffe). We tested the effects of cattle stocking rate (zero/moderate/high) on herbaceous vegetation (diversity, composition, leafiness). We also tested how those effects depend on the presence of wild mesoherbivores and megaherbivores. We found that herbaceous community composition (primary ordination axis) was better explained by the presence/absence of herbivore types than by total herbivory, suggesting that herbivore identity is a more important determinant of community composition than total herbivory at high cattle stocking rates. The combination of wild mesoherbivores and cattle stocked at high rates led to increased bare ground and annual grass cover, reduced perennial grass cover and understory leafiness, and enhanced understory diversity. These shifts were weaker or absent when cattle were stocked at high stocking rates in the absence of wild mesoherbivores. Megaherbivores tempered the effects of cattle stocked at high rates on herbaceous community composition but amplified the effects of high cattle stocking rate on bare ground and understory diversity. Our results show that cattle at high stocking rates do not functionally replace wild herbivores in shaping savanna herbaceous communities contrary to previous findings at moderate stocking rates. In mixed-use rangelands, interactions between cattle stocking rate and wild herbivore presence can lead to non-additive vegetation responses with important implications for both wildlife conservation and livestock production.

Less Is More: Lowering Cattle Stocking Rates Enhances Wild Herbivore Habitat Use and Cattle Foraging Efficiency

Over a quarter of the world’s land surface is grazed by cattle and other livestock, which are replacing wild herbivores and widely regarded as drivers of global biodiversity declines. The effects of livestock presence versus absence on wild herbivores are well documented. However, the environmental context-specific effects of cattle stocking rate on biodiversity and livestock production are poorly understood, precluding nuanced rangeland management recommendations. To address this, we used a long term exclosure experiment in a semi-arid savanna ecosystem in central Kenya that selectively excludes cattle (at different stocking rates), wild mesoherbivores, and megaherbivores. We investigated the individual and interactive effects of cattle stocking rate (zero/moderate/high) and megaherbivore (&amp;gt;1,000 kg) accessibility on habitat use (measured as dung density) by two dominant wild mesoherbivores (50–1,000 kg; zebraEquus quaggaand elandTaurotragus oryx) across the “wet” and “dry” seasons. To explore potential tradeoffs or co-benefits between cattle production and wildlife conservation, we tested for individual and interactive effects of cattle stocking rate and accessibility by wild mesoherbivores and megaherbivores (collectively, large wild herbivores) on the foraging efficiency of cattle across both seasons. Eland habitat use was reduced by cattle at moderate and high stocking rates across both dry and wet seasons and regardless of megaherbivore accessibility. We observed a positive effect of megaherbivores on zebra habitat use at moderate, but not high, stocking rates. Cattle foraging efficiency (g dry matter step–1min–1) was lower in the high compared to moderate stocking rate treatments during the dry season, and was non-additively reduced by wild mesoherbivores and high cattle stocking rates during the wet season. These results show that high stocking rates are detrimental to wild mesoherbivore habitat use and cattle foraging efficiency, while reducing to moderate stocking rates can benefit zebra habitat use and cattle foraging efficiency. Our findings demonstrate that ecosystem management and restoration efforts across African rangelands that involve reducing cattle stocking rates may represent a win-win for wild herbivore conservation and individual performance of livestock.

Precipitation is the key determinant of topsoil δ15N values in southern Patagonia's semiarid rangelands

AbstractNitrogen (N) cycling in rangeland soils could potentially be controlled by water supply, stocking rates, or a range of other variables, such as ecosystem N stocks. To gauge the relative importance and elucidate possible interactions among these factors, we measured many abiotic variables to identify first‐order controls of δ15N for Patagonia's rangeland soils under contrasting historical grazing intensities. The results showed that δ15N values declined as water availability increased. The effects of precipitation and stocking rate on soil δ15N values were additive, and the effect of precipitation far outweighed the effects of grazing pressure. The soil N stock was a weak predictive variable for modeling variation in δ15N of the soil. Earlier assumptions about an inflection point for N cycling and δ15N values related to aridity were not confirmed. We conclude that variation in water availability drives variation in δ15N values irrespective of grazing intensity. We also conclude that meaningful interpretation of δ15N in soil will require a better mechanistic understanding of the interactions between water and N in the vadose zone than we currently possess.

Effects of fall stocking rates on naturalized cool‐season stockpiled pastures

AbstractThe potential of tall fescue (Schedonorus arundinaceus Dumort) and orchardgrass (Dactylis glomerata L.) as stockpiled forages has been documented; however, limited information describes the characteristics of other species, especially complex mixtures of cool‐season naturalized pastures. A 3‐yr study assessed the herbage mass, forage quality, and botanical composition of mixed cool‐season naturalized pastures [orchardgrass, tall fescue, clover (Trifolium spp.), narrowleaf plantain (Plantago lanceolata L.), and quackgrass (Elymus repens [L.] Gould)] in response to two stocking rates based on daily herbage allowances of 3.5% (low) or 7.0% (high) of heifer bodyweight. The stocking rate for the entire pasture area, including unoccupied paddocks during the grazing period, was 2.4 and 1.3 heifers acre−1 for the low and high treatments, respectively. Stockpiling began in August; grazing began in early November. The initial herbage mass and botanical composition were determined at the end of the stockpiling period. Herbage samples were taken throughout the fall grazing period at intervals of 11 to 19 d. The stocking rate had no effect on changes in botanical composition. Total legume percentage increased from 6% in Year 1 to 31% in Year 3 (P &lt; .05). Herbage mass declined more quickly in Year 3 than in Years 1 and 2 (P &lt; .05), probably because of the high percentage of legumes. As fall grazing progressed, crude protein content and in vitro true dry matter digestibility declined, and neutral detergent fiber content increased. Mixed cool‐season naturalized pastures could be used for stockpiling and grazed intensively without detrimental effects on subsequent stockpiling periods.

Effects of different stocking rates on interspecific relationships among dominant species and their spatial distribution characteristics in the Stipa breviflora desert steppe

Effects of different stocking rates on interspecific relationships among dominant species and their spatial distribution characteristics in the Stipa breviflora desert steppe

Effect of Stocking Rate During Gestation on Subsequent Performance of Growing Beef Cattle

Abstract Beef cows in the southeastern United States are likely maintained on pasture during mid-gestation, a critical period for fetal development of traits important to performance of the growing/finishing calf. Climate projections are for increased warming with highly variable precipitation in this region. Forage quantity and quality are affected by temperature and precipitation. Thus, in order to obtain a better understanding of downstream effects from cow nutrition during gestation on subsequent performance of growing cattle, we analyzed 579 records of crossbred steers and heifers born (fall and winter) to cows grazing typical forages in Overton, Texas. Cows were involved in a long-term stocking rate study and were assigned to either high (H; 4 cow/calf ha-1) or low (L; 2 cow/calf ha-1) treatment groups. Cow body condition scores (BCS; 1–9) were collected at breeding and weaning. Calves produced were pastured from weaning to approximately 1 to 1.5 yr of age, then shipped to a commercial feedlot and subsequently slaughtered at a commercial facility. Calf data included birth weight, weaning weight (~240 d), yearling weight, on-feed weight, final pre-harvest weight, hot carcass weight (all weights in kg), dressing percentage, marbling score, yield grade, backfat thickness (cm), ribeye area (cm2), and kidney-pelvic-heart fat (%). Differences (P &amp;lt; 0.05) between treatment groups were determined by a general linear model in SAS with stocking rate as the main effect. Mean separation was accomplished using Tukey’s test. Cow BCS (H; 4.27 ± 0.06 vs L; 5.64 ± 0.07, P &amp;lt; 0.0001), final pre-harvest weight (H; 594.80 ± 6.18 kg vs L; 619.85 ± 6.12 kg, &amp;lt; 0.005), hot carcass weight (H; 366.60 ± 3.89 kg vs L; 383.17 ± 3.74, P &amp;lt; 0.003), and ribeye area (H; 90.52 ± 0.90 cm2 vs L; 93.74 ± 1.03 cm2, P &amp;lt; 0.03) were all lower in H than L. Calf weaning weight followed a similar trend (H; 289.24 ± 2.58 kg vs L; 296.56 ± 3.08 kg, P &amp;lt; 0.07). Diminished nutritional provision to the fetus during mid-gestation was apparently manifest as epigenetic effects on offspring performance.

Wild and domestic savanna herbivores increase smaller vertebrate diversity, but less than additively

Abstract Cattle and other livestock graze more than a quarter of the world's terrestrial area and are widely regarded to be drivers of global biodiversity declines. Studies often compare the effects of livestock presence/absence but, to our knowledge, no studies have tested for interactive effects between large wild herbivores and livestock at varying stocking rates on small‐bodied wild vertebrates. We investigated the effects of cattle stocking rates (none/moderate/high) on the diversity of wildlife 0.05–1,000 kg using camera traps at a long‐term exclosure experiment within a semi‐arid savanna ecosystem in central Kenya. In addition, by selectively excluding wild ‘mesoherbivores’ (50–1,000 kg) and ‘megaherbivores’ (&gt;1,000 kg; elephant and giraffe), we tested whether the presence of these two wild herbivore guilds (collectively, ‘larger wild herbivores’) mediates the effect of cattle stocking rate on habitat use and diversity of ‘smaller wildlife’ (mammals ranging between 10 and 70 cm shoulder height and birds). Our results show that cattle enhance alpha diversity of smaller wildlife (with or without larger wild herbivore presence) and of all wildlife 0.05–1,000 kg (with or without megaherbivore presence), by altering vegetation structure. However, for smaller wildlife, this effect is less pronounced in the presence of larger wild herbivores, which also shorten grass. In the absence of cattle, mesoherbivore‐accessible sites showed higher alpha diversity of smaller wildlife than sites excluding mesoherbivores. Smaller wildlife habitat use was increased by high cattle stocking rates and wild mesoherbivores more in the presence of the other. Synthesis and applications. Our findings imply that grazing, whether by livestock or wildlife, can enhance local savanna wildlife diversity. The biodiversity benefits of localised increases in herbivory are likely to be due to shortened grass and associated visibility improvements (for predator avoidance/foraging). This suggests that land managers can increase local biodiversity by shortening grass, with wild or domestic herbivores (or both), at least in patches within a taller grass matrix.

Relationship among productive and economic variables of beef cattle in Brazil

ABSTRACT: The present study aimed to obtain, through statistical methods, the independent variables that influence the economic and productive results of Brazilian beef cattle. Economic and productive information was collected from 106 farms in Brazil. Data collection was performed by the Instituto de Métricas Agropecuárias (Inttegra). The variable selection method used was stepwise regression followed by polynomial regression analyses. The variable beef cattle economic result showed the positive effect of disbursement per head per month and average weight gain. An average daily gain of 520 g in live weight was obtained, and this variable was influenced especially by nutrition cost. The arroba production (arroba is a unit of weight corresponding to 15kg) was influenced by the linear effect of nutrition cost and stocking rate. The variable arroba production in pasture showed a linear and positive effect of average weight gain in pasture and stocking rate in pasture. For profit per arroba, the variables nutrition cost, disbursement with pasture, and average sale price had a linear effect. The independent variables that had the greatest influence on the response variables were stocking rate, average daily weight gain, and nutrition cost. Thus, increases in investment in nutrition and stocking rate should result in higher production rates and improvements in the profitability of this activity.

Effects of Nitrogen fertilisation and stocking rates on soil erosion and water infiltration in a Brazilian Cerrado farm

Ever-increasing water-food-energy demand has led to the depletion of soil resources by mainly inadequate grazing practices. Nevertheless, the effects of different grazing practices on hydrological and soil erosion processes have not yet been well-understood. Therefore, we investigated the influence of different Nitrogen application doses and stocking rates in a pasture under rotational stocking (RS) on soil erosion and water infiltration in the Brazilian Cerrado region. The experimental area was a Panicum maximum pasture and was divided into three treatments with N applications of 100, 200, and 300 kg ha-1, which respectively allowed three stocking rates from 2014 to 2018: 3 (RS-3), 4.1 (RS-4), and 5 AU ha-1 (RS-5). We respectively adopted start and stop grazing heights of 80–90 and 40–50 cm (forage height) in all treatments. To evaluate infiltration and soil erosion, we performed 28 rainfall simulations with intensities ranging from 73.5 to 93.5 mm h-1 in plots of 0.7 m2 from November 2017 to February 2018. The simulations were carried out in random sites inside the central paddocks of each treatment comprising four repetitions in each treatment under vegetation and bare soil. We found stable water infiltration (SIR) and soil loss (SLw) ranging from 65.5 to 87.2 mm h-1 and from 0.03 to 0.15 mg s-1 m-2, respectively. SIR and SLw under RS-5 were respectively 33% greater and 78% lower than under RS-3 despite the 67% higher stocking rate in RS-5. We found that higher stocking rates at optimal grazing pressure did not deteriorate water infiltration and soil erosion. Our findings reveal an opportunity for a 5-fold productivity increase while reducing soil degradation since adaptive stocking rates are supported by grazing processes along with an increase in N fertiliser dose to increase vegetation cover.

Sows-Gilts Stocking Rates and Their Environmental Impact in Rotationally Managed Bermudagrass Paddocks.

Simple SummaryMaintaining a ground cover greater than 75% and controlling nutrient loading and distribution are considered best management practices for pasture pig operations. These practices improve soil health and water quality, by minimizing runoff containing soil, water and nutrients. Those goals are not easily reached when managing pigs on pastures. This study was conducted to evaluate the effect of three sow stocking rates (10, 15 or 25 sows-gilts ha−1) on ground cover and soil nutrient concentrations of bermudagrass (Cynodon dactylon L. Pers) paddocks managed in a rotational stocking system. Increasing the Stocking rates were inversely related with the deterioration of vegetative ground cover and directly related to soil nutrient loads in the soil. The stocking rates should be kept in the range of 10 to 15 sows-gilts ha−1 to minimize the environmental impact of sows-gilts managed on bermudagrass.Ground cover maintenance and nutrients management are key elements to reduce the environmental impact of outdoor swine production. The objective of this study was to determine the effects of sows-gilts stocking rates on vegetative ground cover and soil nutrient concentrations in rotationally stocked bermudagrass (Cynodon dactylon L. Pers) pastures. Three stocking rates (10, 15 and 25 sows-gilts ha−1) were compared during three 8-week grazing periods. Increasing the stocking rate from 10 to 25 sows-gilts ha−1 decreased the ground cover of the paddocks from 65 to 48%, and increased soil nutrient concentrations (ammonium 47%; nitrate 129%; phosphorus 53%; zinc 84%; and copper 29%).

The effects of fisheries management on harvest rates of native and non‐native salmonid fish species

In central Europe, both brown trout Salmo trutta and European grayling Thymallus thymallus are threatened native salmonid species with high value in recreational angling and nature conservation. On the other hand, rainbow trout Oncorhynchus mykiss and brook trout Salvelinus fontinalis are intensively stocked non-native species of high angling value but no value for nature conservation. This study tested if harvest rates of native salmonids are negatively correlated to intensive stocking and harvest rates of non-native salmonids in inland freshwater recreational fisheries. Data were collected from 250 fishing sites (river and stream stretches) over 13 years using mandatory angling logbooks. Logbooks were collected from individual anglers by the Czech Fishing Union in the regions of Prague and Central Bohemia, Czechia (central Europe) and processed by the author of this study. In result, anglers harvested 200,000 salmonids with total weight of 80 tons over 13 years. Intensive stocking of multiple salmonid species lead to slightly lower harvests of native salmonids. Inversely, intensive harvests of multiple salmonid species lead to slightly higher harvest of native salmonids. Recapture rates of stocked salmonids were relatively low (0.6%–3.7%), proving fish stocking moderately ineffective. Since the effects of non-native salmonid stocking and harvest rates on native salmonid harvest were significant but not strong, it is suggested that rivers and streams that support fishing for non-native salmonids still support fishing for native salmonids. However, this idea does not apply for fishing sites with really high intensity of non-native salmonid stocking – harvest rates of natives were very low on these fishing sites.

Effect of drought on communal livestock farmers in KwaZulu-Natal, South Africa

Despite the size of the informal small-scale farming sector and its livestock holdings in South Africa, there has been little detailed work to assess how livestock populations are affected by drought. South Africa experienced a major drought in 2015–2016. We analysed goat and cattle census data from the Msinga area in KwaZulu-Natal, which represent the livestock of some 3 000 households. Cattle farmers in the study area lost 43% of the herd, compared with 29% for goats, in 2015–2016. Three years after the drought, cattle numbers remained depressed, whereas goat numbers had recovered. Larger herds suffered lower mortality rates, suggesting that owners of larger herds had better means to support their herds. Support to reduce drought losses and aid recovery should take into consideration the different capabilities and requirements of small and large herd owners. Effects of high stocking rates and resource condition on mortality and herd growth were apparent during the drought year of 2016, but not the other years. Most die-offs appear to have been concentrated in a short period once forage and water resources became too scarce and far to reach. Recognising when this threshold is imminent would be useful for targeting strategic interventions.

Decreasing the mob size but not stocking rate of ewes at lambing increases the survival of twin lambs born on farms across southern Australia

Context Data collected from producers in south-eastern Australia found that the survival of twin-born lambs decreased by 3.5% for each extra 100 ewes in the mob at lambing. Increasing stocking rate by 1 ewe/ha decreased lamb survival by a further 0.7%. These survey findings suggest that lamb survival could be improved by optimising the allocation of ewes to mobs and paddocks at lambing. Aim The present paper reports two experiments. Experiment 1 tested the hypotheses that (1) the survival of twin-born lambs would be greater when ewes lamb in smaller mobs and at lower stocking rates, and (2) the effects of mob size and stocking rate would be greater in Merinos than in non-Merino breeds. Experiment 2 tested the hypothesis that the survival of twin-born Merino lambs would be greater at lower mob sizes when ewes lambed at stocking rates &amp;lt;4 ewes/ha. Methods Experiment 1 investigated a 2 × 2 factorial combination of mob size (high or low) and stocking rate (high or low) on the survival of twin-born Merino and non-Merino lambs at 70 on-farm research sites across southern Australia. Experiment 2 investigated the effect of high or low mob size on the survival of twin-born Merino lambs when ewes lambed at stocking rates of &amp;lt;4 twin ewes/ha at 15 on-farm research sites. In both experiments, adult twin-bearing ewes were randomly allocated into a treatment and lambing paddock on Day 140 from the start of joining at each farm. Lamb survival in each mob was calculated based on lamb losses between pregnancy scanning and lamb marking. Key results In both experiments, the effect of mob size on lamb survival was found to be linear, with survival of twin-born lambs decreasing by between 1.9% and 2.5% per additional 100 ewes in the mob at lambing, regardless of breed (P &amp;lt; 0.001). In Experiment 1, there was no effect of stocking rate or mob size by stocking rate on lamb survival. Conclusions The present research demonstrated that reducing mob size but not stocking rate will improve the survival of twin-born lambs to marking for extensive enterprises in Australia where ewes lamb at stocking rates of up to 12 ewes/ha. Implications These findings will contribute to guidelines for optimising ewe nutrition and resource allocation to improve lamb survival.