Rotational Grazing System Research Articles

Effects of long-term cattle market conditions on continuous season-long and rotational grazing system revenues

In this study we evaluated the combination of long-term market conditions and the price slide in the cattle market on revenues associated with continuous and rotational grazing systems. A price slide is a market phenomenon in which lighter cattle sell at a higher price per unit of liveweight compared with their heavier counterparts. We used actual herd average starting and ending weights in this market analysis, and analysed the outcome using five years’ data from a continuous and rotational comparative grazing study. Despite consistently lower weight gains with rotational grazing, differences in gross revenues per steer between grazing treatments ranged from US$43.46 to minus $5.72 across the study years. We observed annual differences in the net returns across years between the two grazing systems; net returns were greater for steers in the continuous grazing treatment in three of the five years, one year with net returns that did not differ between systems, and one year in which net returns were lower with continuous grazing. These variable results showcase the complexity in having both differences in end of grazing season weight classes between the grazing systems and the differential effects of price slide among weight classes. Therefore, we argue that it may be a better management strategy for land managers to determine the optimal ending weights and the time of year to market livestock to meet the goals of an operation, rather than trying to determine which grazing system is ‘best’.

Supplementation of growing bulls grazing Panicum maximum cv. Coloniao increases average daily gain and does not impact subsequent performance in feedlot phase

ABSTRACT To evaluate the influence of supplementation strategies on the average daily gain (ADG) of cattle in a rotational grazing system of Guinea grass (Panicum maximum cv. Coloniao) pastures during the rainy season. It was further evaluated the residual effects in the feedlot finishing phase. Seventy-five 8 month-old crossbred bull calves averaging 200.1 ± 2.5 kg of body weight (BW) were stratified and grouped in three into 25 blocks according to BW, and then randomly assigned to one of three supplementation treatments: control (no supplement), energy supplement [65 g crude protein (CP)/kg dry matter (DM)] or protein supplement (200 g CP/kg DM) both fed as 6 g/kg BW. All animals composed a single herd and were separated daily according to treatment groups for supplementation. After the grazing phase, all animals were moved to a feedlot and received the same diet up until slaughter. Guinea grass was subjected to rotational stocking with pre- and post-grazing heights of 76 and 43 cm, respectively. Energy and protein supplements provided similar ADG (P > 0.05; 0.94 kg/day) which was greater than for non-supplemented animals during the grazing phase (P ≤ 0.05; 0.74 kg/day), but there was no difference in the subsequent feedlot phase (P > 0.05; 1.45 kg/day). The protein supplement had no incremental effects over the energy supplement on ADG and carcass traits of growing crossbreed bulls during the grazing phase, indicating that either source could be used, and that an energy supplement would lead to more efficient nutrient use coming from the grass.

Estimating natural grassland biomass by vegetation indices using Sentinel 2 remote sensing data

ABSTRACTEstimation of natural grassland biomass was carried out in a region located in the Brazilian Pampa, using field and remote sensing data and statistical models. The study was conducted in a grassland with a rotational grazing system, with grazing rest interval based on accumulated thermal sums 375 and 750 Degrees Day (DD). One image of the MSI (MultiSpectral Instrument) sensor aboard the Sentinel-2 satellite was evaluated and calibrated by 57 sampled biomass units collected in the field. Initially, the image was preprocessed, with extraction of the reflectance values of the Sentinel-2 bands, re-sampling of the pixels to 20 metres and calculation of vegetation indices. Data statistical analyses indicated significant correlations between field and remote sensing data. Multiple linear regression analyses were applied at each grazing rest interval using the remote sensing variables as predictors (independent) of the biomass (dependent). Among the variables, it is important to highlight the significant correlation of the red-edge bands with the biomass. The equations for estimating green biomass-presented coefficients of determination (R2) of R2 = 0.51 for the rest interval 375 DD and R2 = 0.65 for the rest interval 750 DD, while the senescent and total biomass generated adjustments with R2 ≤ 0.50 for the two rest intervals. Biomass estimates results were satisfactory, regardless of the interval evaluated. Sampling schemes at different seasons of the year and further spectral and field variables (spectral and biomass) are suggested to improve even more the accuracy of the estimates.

Forage management practices used in production of US grass-fed beef

ABSTRACT Objective Management of forage resources is critical to ensuring animals destined for the grass-fed beef (GFB) market have access to quality forage needed for growth and development for acceptable meat products. The objective of this study was to evaluate the forage management systems and species used by US GFB producers, adoption rates of rotational grazing systems, producers’ perceptions of the profitability associated with rotational grazing systems, and the economic effect of intensive grazing systems on GFB production costs and profitability. Materials and Methods A survey questionnaire was mailed to 1,052 US GFB producers to examine forage management systems used in US GFB production. A total of 384 completed questionnaires were received. An ordered probit model was used to determine the types of farms and demographics of producers more likely to be involved in an intensive rotational grazing system. Results and Discussion A total of 59 different forage species and types were listed in the study. In all US regions represented in the study, the average and median farm reported use of 3 to 4 forage species or types in their systems. More than half of the respondents indicated rotational grazing increased farm profit by greater than 20% relative to continuous grazing. Implications and Applications The level of rotational grazing differed by region with producers in the Pacific region rotating the least relative to others. Producer demographics and farm size also significantly affected the frequency of rotation.

Net neutral carbon responses to warming and grazing in alpine grassland ecosystems

In natural grasslands, effects of warming on net ecosystem CO2 exchange (NEE) may interact with grazing. Yet, the effects of these two main drivers of terrestrial carbon cycling are typically studied in isolation, limiting our understanding of how NEE would be affected under different global change scenarios. Here, we report results of a warming experiment using infrared heaters combined with summer and winter grazing for 7-years in a Tibetan alpine grassland. We found that regardless of warming summer grazing decreased soil carbon sink (i.e., increased annual mean net biome productivity (NBP) indicated by a negative value of NBP), and warming also reduced soil carbon sink under no-grazing only during 3-years of summer grazing. However, warming and grazing did not change soil carbon sink during 4-years of winter grazing. Interactive effects between warming and grazing on annual NBP varied with year and grazing season. Overall, both warming and grazing did not alter annual mean NBP under 7-years of the rotational grazing system in summer and winter grasslands because of offsetting effects on annual mean gross primary productivity and ecosystem respiration. Annual mean soil temperature explained 58% of the variation of annual mean NBP during summer grazing, whereas seasonal mean soil moisture explained 48 and 44% of its variation during winter grazing and the two season grazing system, respectively. Together, our results suggest that rotational grazing between summer and winter alpine grasslands would result in net neutral climate feedback based on the response of annual NBP under future warming. The two season grazing system not only supports animal production but also realizes balance in the soil carbon budget under future warming.

Supplementation strategies affect the feed intake and performance of grazing replacement heifers.

The literature lacks studies investigating the performance of supplemented replacement heifers grazing on intensively managed warm-season pasture. Our objective was to evaluate the effects of supplement composition (energetic or protein) on the performance, muscle development, thermogenisis, nutrient intake, and digestibility of replacement Holstein heifers grazing Mombaça grass. Eighteen Holstein heifers with an average age and initial body weight (BW) of 12.57 ± 2.54 mo and 218.76 ±47.6 kg, respectively, were submitted to a randomized block design, with six replicates on a rotational grazing system of Panicum maximum cv. Mombaça pasture. Treatments were: control (CON; mineral salt ad libitum); energy supplement (ENE; corn meal as supplement, 8% CP and 3.78 Mcal/kg DE); and protein supplement (PRO; corn and soybean meal, 25% CP and 3.66 Mcal/kg DE). Supplements were individually fed at 0.5% BW. The experiment lasted 120 days, subdivided into three periods. Titanium dioxide and indigestible neutral detergent fiber (iNDF) were used to estimate the intakes and digestibility of the nutrients. BW, wither height, thoracic circumference, body length, and ultrasound of ribeye fat thickness measurements were taken once per period. Body condition score (BCS) was assessed twice during the experiment. The MIXED procedure of SAS, including period as a repeated measure, was used and significance was declared at P ≤ 0.05. Dry matter intake (DMI), CP intake (CPI) and DE intake were greater in heifers fed PRO compared to CON and ENE. Heifers supplemented with ENE had the lowest DMI. Treatment affected pasture intake/BW; it was similar between PRO and CON heifers, and lower for the ENE treatment. A treatment × period interaction was observed for NDF intake (%BW), in which heifers fed PRO and CON had the greatest NDF intake and ENE had the lowest. The digestibility of DM was the greatest in PRO-supplemented heifers and the lowest in CON heifers. Heifers fed ENE had decreased CP digestibility compared to PRO and CON heifers. Average daily gain (ADG) and thoracic circumference gain were greatest in the PRO treatment. BCS was greater in PRO compared to CON and ENE heifers. Supplementing Holstein heifers at 0.5% BW using PRO supplementation resulted in better animal performance, primarily greater ADG, than feeding ENE or not supplementing (CON). In conclusion, our results indicate that dairy heifers should be fed a protein supplement when grazing intensively managed Mombaça grass pasture.

Cell grazing and Haemonchus contortus control in sheep: lessons from a two-year study in temperate Western Europe

Managing infections of sheep with anthelmintic resistant gastrointestinal nematodes (GIN) is a major challenge for sheep producers in Western Europe. New methods of grazing management have been poorly explored as a component of an integrated and sustainable control of these parasites. Therefore, the purpose of this study was to evaluate the effect of two different types of grazing systems of sheep (intensive cell grazing versus conventional rotational grazing) on GIN infections over two years in a farm located in a temperate environment of Western France. When considering the whole study, the type of grazing system did not influence significantly the intensity of egg excretions of adult ewes even if the proportion of ewes excreting high numbers of GIN eggs was higher in cell grazing system than in rotational grazing system. The most striking result of this survey was the effect of grazing system on the GIN species composition harbored by ewes and by their lambs: with time, the proportions of H. contortus infections were lower in cell grazing system than in rotational grazing system. In conclusion, the cell grazing system, as implemented in this study, could limit the importance of this highly pathogenic nematode species in sheep.

Grazing Management Plans improve pasture selection by cattle and forage quality in sub-alpine and alpine grasslands

Over the last decades, the reduction of manpower for herd management has led to an increase of continuous grazing systems (CGS) in the Italian Alps, which allow cattle to roam freely. Under CGS, due to high selectivity, livestock exploit grasslands unevenly, over- and under-using specific areas at the same time with negative effects on their conservation. To counteract these effects, a specific policy and management tool (i.e. Grazing Management Plan) has been implemented by Piedmont Region since 2010. The Grazing Management Plans are based on the implementation of rotational grazing systems (RGS), with animal stocking rate adjusted to balance it with grassland carrying capacity. A case study was conducted on alpine summer pastures to test the 5-year effects produced by the implementation of a Grazing Management Plan in grasslands formerly managed under several years of CGS on 1) the selection for different vegetation communities by cattle, 2) the abundance of oligo-, meso-, and eutrophic plant species (defined according to Landolt N indicator value), and 3) forage yield, quality, and palatability. A total of 193 vegetation surveys were carried out in 2011 and repeated in 2016. Cows were tracked yearly with Global Positioning System collars to assess their grazing selectivity, and forage Pastoral Value (PV) was computed to evaluate forage yield, quality, and palatability. Five years after RGS implementation, cow selectivity significantly decreased and the preference for the different vegetation communities was more balanced than under CGS. The abundance of meso- and eutrophic species increased, whereas oligotrophic ones decreased. Moreover, the abundance of moderately to highly palatable plant species increased, whereas non-palatable plant species decreased, with a consequent significant enhancement of the PV. Our findings indicate that the implementation of Grazing Management Plans can be considered a sustainable and effective management tool for improving pasture selection by cattle and forage quality in mountain pastures.

Social hierarchy and feed supplementation of heifers: Line or piles?

Cattle on pasture may have unequal access to grain supplement due to the effect of social dominance. Subordinate animals are known to have less access to resources when competition exists. This trial was designed to test if distributing feed supplement (corn meal) along and under the fence in individual piles would affect heifers feeding behaviour and grant better access to all animals compared to supplement offered in a continuous line. Four groups of nine heifers were used in a 2 × 2 cross-over design, and tested in two treatments: LINE (1 linear meter/animal) and PILE (one pile/heifer distant 1 m from each other). Each period had 3 days for habituation followed by 7 days for data collection. Animals were managed under Voisin’s rotational grazing system and observed for one hour from the moment they entered the new paddock (8:00 to 9:00). Individual behaviour of the heifers / grazing, eating grain supplement, competing or other) was registered at one-minute interval instantaneous scans. All agonistic interactions were recorded and a sociometric matrix was calculated for each group to define each heifer as dominant, intermediate or subordinate. Feeding behaviour as not affected by treatment, but it affected by social hierarchy status. High and intermediate ranking heifers spent more time eating supplement than low ranking ones (P ≤ 0.03). Subordinate heifers grazed longer than intermediate heifers, which in turn grazed longer than dominant heifers (P ≤ 0.01). Social rank did not affect competitive behaviour, but there was a trend for more competition events when concentrate was distributed in piles (P = 0.09). Dominance score was associated with initial body weight (r= 0.686; P ≤ 0.0001). In summary, distributing the grain supplement in individual piles did not benefit the subordinate heifers, as they had less access to the supplement than the dominant ones. When entering a new paddock with supplement offered, the subordinate heifers seemed to avoid competing for grain and spent more time grazing while the dominant heifers spent more time eating supplement.

Influence of intensive rearing, continuous and rotational grazing systems of management on parasitic load of lambs.

Aim:A trial was conducted to assess the influence of parasitic load on the lambs reared under the intensive system, continuous grazing, and rotational grazing systems of management.Materials and Methods:A total of thirty numbers of the undetermined breed of ewe lambs around 4-5 months of age were randomly selected and allotted to three treatment groups: T1 (intensive system – control), T2 (rotational grazing), and T3 (continuous grazing). The T1 group lambs were raised under a stall-fed system of management, the T2 group lambs were grazed under rotational grazing strategy in four paddocks of plot-A, while the T3 group lambs were continuously grazed in plot-B.Results:At the end of the study, there was a highly significant difference (p=0.01) in the fortnightly strongyle egg count per gram (EPG) of feces among the lambs pertaining to the three treatment groups; the lambs in T3 had a higher strongyle EPG compared to T2 lambs. With regard to the overall reduction in EPG from the initial count, lambs under rotational grazing showed the maximum decrease of 54.52% compared to lambs under T3 (continuous grazing). There was a strong positive correlation noticed between the mean temperature of the day at each fortnight and the subsequent EPG at each fortnight with R2=0.87. There was a strong positive correlation noticed between mean FAMACHA© scores and the EPG with R2=0.84, R2=0.83, and R2=0.83 for T1, T2, and T3, respectively.Conclusion:The grazing management with pasture rotation should be considered as a viable option for sustainable parasitic control in case of grazing-dependent livestock husbandry in India.

196 Performance of landrace hair sheep lambs in a forage-based, semi-continuous production system

Abstract Developing a system of year-round lamb production can address issues of continuous supply and product uniformity. In this project, Barbados Blackbelly (BB) and St. Croix (STX) Landrace hair sheep were used to produce cohorts of lambs in 4 mo intervals. Lambs were born on pasture, weaned at approximately 9 weeks, and returned to pasture after a period of post-weaning transition in pens. Ram lambs were rendered short-scrotum at weaning and grazed with ewe lambs as a single group in a rotational grazing system using cool season perennial grasses, warm and cool season annual forages, hay, and soy hull supplementation based on season and forage availability. Lambs were removed as they reached 35–40 kg or 12 mo of age. Data from two lamb cohorts born in April (n = 45) and August (n = 39), respectively, were analyzed for the effect of breed and sex on BW and ADG at different production stages. Birth weights of the April and August cohorts were similar (3.36 kg), but pre-weaning ADG and weaning weights were higher (P < 0.001) in the April (400 g/d and 15.6 kg) than August cohort (304 g/d and 12.1 kg). In contrast, pasture ADG (to 9 mo of age) was higher (P < 0.001) in the August (114 g/d) than April (73 g/d) cohort. Pasture ADG was higher (P < 0.05) in STX (100 g/d) than BB (88 g/d), and higher males (106 g/d) than females (81 g/d). During joint grazing of the two cohorts (December through March) ADG was initially higher (P < 0.001) in the older April (76 g/d) than August (16 g/d) lambs, but similar as they transitioned to annual forage (310 g/d). Pasture ADG fluctuated greatly in relation to forage quality, and to a lesser degree with breed and sex, and 79% of April and 84% of August cohort lambs reached target weights as yearlings.

Thermoregulatory, behavioral, and production traits of ½ and ¾ Holstein/Gir dairy cows

The aim of this study was to evaluate thermoregulatory, behavioral, and production traits of Holstein/Gir dairy cows of different genetic compositions. The experiment was carried out in the municipality of Turvânia - GO, Brazil, from July to December 2017. Twenty lactating cows of two genetic groups (½ and ¾ Holstein/Gir [HG]) were used in a completely randomized design where they were subjected to a rotational-grazing system in 24 irrigated Mombasa grass pastures with one day of occupation and 24 days of rest, and fed a 22% CP supplemental concentrate diet. During the experimental period, thermoregulatory, behavioral, and production data were collected on 12 occasions, at 15-day intervals. Environmental data such as ambient temperature, air relative humidity, and temperature-humidity index were recorded. Number of hairs, hair length and thickness, body surface temperature, rectal temperature, and respiratory frequency were analyzed as thermoregulatory traits. The behavioral assessment was undertaken by observing the feeding behavior, rumination, rest, and other activities. To determine production traits, milk yield and composition were analyzed. A higher respiratory frequency was observed in ¾ HG cows compared with ½ HG cows (p<0.05). Cows of the ½ HG group produced milk with higher protein contents (p<0.05). Rectal temperature, body temperature, number of hairs, hair length and thickness, feeding behavior, rumination, rest, and other activities were similar (p>0.05) between the two genetic groups, and the same was true for milk yield, fat and lactose contents, and somatic cell count.

Partial substitution of soybean meal with a yeast-derived protein in the diet of dairy cows under a rotational grazing system

This study's aim is to evaluate the substitution of soybean meal with a yeast-derived protein (YDP) in the diet of F1 Holstein (Bos Taurus) x Gyr (Bos indicus) dairy cows under rotational grazing (Guinea Grass, Panicum maximum cv. Mombaça) and to analyze the effects on milk yield, milk solids percentage, blood parameters, and feed efficiency (FE). Sixteen Holstein X Gyr (F1) multiparous cows with an average of 30 ± 1.8 kg/d (Mean ± SD) of milk, 489 ± 22 kg of body weight, and 62 ± 26 days in milk (DIM), at the beginning of the study, were assigned to four squares based on their DIM, milk yield, and parity. The experimental diets were based on the substitution of soybean meal with a YDP in equal proportions: treatment YDP0 (without a YDP), treatment YDP150 (substitution of 150 g of soybean meal with a YDP), treatment YDP300 (substitution of 300 g of soybean meal with a YDP), and treatment YDP450 (substitution of 450 g of soybean meal with a YDP). The substitution of soybean meal with a YDP in the diets of dairy cows under rotational grazing linearly decreased milk and solids production and affected the neutral detergent fiber (NDF) intake, without affecting the total feed intake. No difference was found in the microbial protein synthesis between treatments. FE tended to be lower at high inclusions of the YDP.

Climate Effects on Tallgrass Prairie Responses to Continuous and Rotational Grazing

Cattle grazing is an important economic activity in the tallgrass prairie systems in the Great Plains of the United States. Tallgrass prairie may respond differently to grazing management (e.g., high and low grazing intensity) under variable climate conditions. This study investigated the responses of two replicated (rep a and rep b) tallgrass prairie systems to continuous (C) and rotational (R) grazing under different climate conditions over a decade (2008–2017). The enhanced vegetation index (EVI) and gross primary productivity (GPP) were compared between grazing systems (C vs. R), while EVI was compared among paddocks under rotational grazing to show the impacts of time since grazing. The average EVI in rep a was usually higher than that in rep b which could be explained by different land characteristics (e.g., soil types) associated with different landscape positions. Similar to EVI, GPP was usually higher in rep a than rep b. The average growing season EVI and GPP were higher in rotational grazing than continuous grazing in rep b but not in rep a. The average EVI of paddocks in rotational grazing systems only converged in the growing season-long drought year (2011). In other years, EVI values varied from year to year and no paddock consistently outperformed others. The variations in EVI among rotational grazing paddocks in both reps were relatively small, indicating that rotational grazing generated an even grazing pressure on vegetation at annual scale. Overall, climate and inherent pasture conditions were the major drivers of plant productivity. However, the stocking rate in continuous grazing systems were reduced over years because of deteriorating pasture conditions. Thus, the results indirectly indicate that rotational grazing improved grassland productivity and had higher stocking capacity than continuous grazing systems under variable climate conditions. Adaptive grazing management (adjustment in stocking rates and season of use to adapt to changing climatic conditions) instead of a fixed management system might be better for farmers to cooperate with changing climatic conditions.

Influence of a feed additive containing vitamin B12 and yeast extract on milk production and body temperature of grazing dairy cows under high temperature-humidity index environment

A commercial feed additive, OmniGen-AF® (OMN; Phibro Animal Health, Teaneck, NJ), has shown positive impacts on thermoregulation and milk production in confined dairy cows. This study was carried out to evaluate whether OMN has similar effects on grazing dairy cows. For the latter purpose, feed intake, milk production, blood metabolites, and body temperature (including surface, rectal, and thermal imaging) were assessed. This study was performed in a commercial dairy farm at Mato Grosso do Sul State in Brazil and lasted for 84 d. Thirty-six multiparous Holstein cows (136 ± 52 days in milk, 23.8 ± 4.96 kg/d milk yield, and 518 ± 65 body weight, at the start of experiment) were enrolled to a completely randomized experiment and assigned either to control (0 g/d of OMN) or OMN (50 g/d). Cows were maintained under a rotational grazing system in pens uniformly covered with Panicum maximum (cv. Mombasa). After milking, cows were fed fixed amounts of corn silage with concentrate level adjusted according to average milk yield from the previous wk. OMN was top-dressed and hand mixed in the upper portion of corn silage and concentrate mixture. The average temperature-humidity index (THI) throughout experiment was 77.8 (29.8 °C air temperature and 52 ± 15.6% relative humidity), suggesting that heat stress (THI > 68) likely impacted cows. OMN increased pasture intake, milk and milk fat yields, and milk fat content. OMN decreased urea N concentration and somatic cell count in milk. Treatments neither influenced body weight nor body condition score. OMN increased blood glucose and ionized calcium concentrations, and decreased blood aspartate aminotransferase and alkaline phosphatase concentration. OMN reduced rectal temperature, body surface temperature, and respiration rate of cows. This study showed evidence that OMN improves performance and reduces signs of heat stress of grazing cows under an environment with high THI.

Rotational grazing and exclosure improves grassland condition of the halophytic steppe in Flooding Pampa (Argentina) compared with continuous grazing

The most common grazing management applied on rangelands is continuous grazing. However, it can cause negative changes in vegetation structure and ecosystem functioning, leading to rangeland degradation. In Flooding Pampa rangelands, scientific evidence in favour of rotational over continuous grazing was developed on the humid mesophytic meadow and the humid prairie communities, but not on the halophytic steppe community. We evaluated the changes in species composition, richness and diversity, vegetation and litter cover, functional group composition and forage quality during 8 years in halophytic steppe subjected to both continuous or rotational grazing, and exclusion from grazing. Grazing exclusion and a rotational grazing system caused significant changes in the vegetation structure compared with continuous grazing. These treatments increased vegetation and litter cover, the contribution of summer and annual and perennial winter grasses, all them of high forage value, and encouraged the appearance of several grasses adapted to fertile, well drained and non-saline soils. Because of these structural changes, species richness, diversity and pastoral value increased in the halophytic steppe of the Flooding Pampa, in a manner previously demonstrated in other grassland communities of this region.

Performance and digestive characteristics in dairy cattle maintained under grazing regime and supplemented with linseed

Linseed is characterized by the rich unsaturated fatty acids and slow release of oil in the rumen. The objective of the present study was to evaluate the intake, rumen degradability, and digestibility of dairy cattle maintained under grazing regime and supplemented with linseed. Twelve Girolando (¾ Holstein × ¼ Gir) cows with a mean age of 5.2 ± 1.9 years and body weight of 583.9 ± 67.6 kg were used. The cows were maintained in a rotational grazing system on the mombaça grass (Panicum maximum) and divided into 2 experimental groups. The CONTR (n = 6) group received only the base diet (pasture) and the LINS group (n = 6) received pasture plus linseed. Initially, a fifteen-day adaptation period was established to stabilize the desired consumption amount. After this period, the animals received 800 g of linseed for 126 d. The ruminal degradability was evaluated using 2 males with a cannula in the rumen, and they were provided the same experimental diet. The measured dry matter production of pasture did not show differences during the experimental period. The intake of crude protein and ethereal extract was higher, whereas neutral detergent fiber content was lower in the cows supplemented with linseed. However, this did not alter the weight gain and digestibility coefficients, except the digestibility coefficient of the ethereal extract. At the ruminal level, linseed showed low effective and potential degradability with negative effect on grass degradability.

Productive performance of Nellore steers on rotational grazing on Marandu grass and Convert HD 364 grass

The objective of this study was to evaluate the effect of Brachiaria spp. Cv. Mulato II (Convert) on performance, meat quality and carcass characteristics of castrated Nellore steers in the growing and finishing phases, in rotational grazing system, compared to Brachiaria brizantha cv. Marandu, under the same conditions. The experimental area was divided into two treatments: Marandu and Convert with 20 hectares each, splited in four replications per treatment, composed of five paddocks of one hectare each. Animals were managed based on the availability of leaf blade dry matter (6.19% body weight) in rotational grazing with 7 days of occupation and 28 days of rest. Ten animals were used in each replicate (testers), as well as regulatory animals whenever necessary. Animals were managed based on the availability of leaf blade dry matter (6.19% body weight) in rotational grazing with 7 days of occupation and 28 days of rest. Ten animals were used in each replicate (testers), as well as regulatory animals whenever necessary. For performance analysis, 10 animals of each replicate were used, while for carcass and meat analyses, only six of each replicate. Production and chemial characteristics of the two grasses were evaluated. The experimental design was completely randomized with two treatments and four replicates; data were tested by analysis of variance using the R software. Animals fed on Convert grass were superior than those fed on Marandu grass, with higher average daily gain (0.682 kg vs. 0.605 kg), slaughter weight (470.45 kg vs. 451.43 kg), hot carcass weight (239.93 kg vs. 232.36 kg). The study also showed the possibility of finishing castrated young steers (up to 30 months) and with subcutaneous fat thickness required by industry (3 mm) in both pastures.

A 5‐year rotational grazing changes the botanical composition of sub‐alpine and alpine grasslands

AbstractAimThe implementation of Grazing Management Plans (GMP), a specific policy and management tool, aimed at enhancing farm productivity while preserving plant diversity, soil and landscape. The GMP are based on rotational grazing systems (RGS) with animal stocking rate adjusted to balance grassland carrying capacity. The aim was to test the 5‐year effects produced by GMP implementation on botanical composition, plant diversity and soil nutrient content on sub‐alpine and alpine pastures.LocationVal Troncea Natural Park, western Italian Alps.MethodsA total of 199 vegetation transects was carried out in summer 2011 and repeated in summer 2016. The botanical composition was recorded and plant diversity indices, i.e. species richness and Shannon diversity (H′ index), were computed. Mean soil nutrient content was indirectly estimated through computation of Landolt N indicator value (N index) for each transect. Pair‐sample statistical tests and PERMANOVA were perfomed at different levels: on the whole vegetation dataset, on vegetation communities (i.e. vegetation types and ecological groups) and considering functional pools of species.ResultsConsidering the whole vegetation dataset, species richness, H′ index and N index significantly increased from 2011 to 2016. Moreover, species richness significantly increased in almost all vegetation ecological groups, with the highest increase within the mesotrophic group. The H′ index significantly increased in eutrophic, pre‐forest and thermic groups, while the N index increased in all vegetation groups, except in the eutrophic and snow‐bed groups. A significant difference in botanical composition was detected within oligotrophic, mesotrophic and thermic groups. The number and cover of N‐poor high‐elevation species increased in all groups and this result might be related to effects produced by livestock, which promoted seed transport and increased connectivity amongst different communities. The meso‐eutrophic species number and cover significantly increased within thermic, mesotrophic and pre‐forest groups, suggesting greater use of such areas by livestock under RGS than under continuous grazing.ConclusionsThe implementation of RGS with stocking rate adjustments proved to be an effective and a sustainable management tool to enhance botanical composition and plant diversity of sub‐alpine and alpine grasslands over a 5‐year span.

Pastoralists’ grazing systems and eco-related outcomes in Yewa Division of Ogun State, Nigeria

In Nigeria heavy dependence of cattle on natural pasture for grazing has resulted in the emergence of a range of grazing systems and ecosystem challenges. Consequently this study appraised the grazing systems in use and their eco-relational outcomes for sustainable cattle management in Yewa Division of Ogun State. A total of 143 pastoralists agreed to take part in the survey and provided data on the commonly practiced grazing systems and ecological effects through the use of an interview format, interactive discussions plus field observations. The study outcome showed continuous, unpatterned rotational and transverse grazing systems were commonly practiced. The study also revealed that the employed grazing systems were independent of size of the cattle herds. While cattle were healthy under the grazing systems employed, soil degradation occurred in some instances. While the grazing systems employed by the pastoralists were satisfactory from the animal perspective, studies are needed to minimize the extent of soil degradation in the area.