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In New Zealand, intensively managed pasture-based dairy systems rely on binary pastures mostly comprised of Lolium perenne L. and Trifolium repens L.. More frequent and extreme climatic events have been negatively affecting the persistency and production of these pastures, which now present increased seasonality, with marked peaks and troughs of production throughout the year. Diversification of plant species offers a solution to deal with increased seasonality. However, little is known about animal behaviour and dietary preferences of dairy cows grazing diverse pastures. The present study aimed to assess the grazing preferences of dairy cows when unrestrictedly offered binary (L. perenne and T. repens ; Bi) and diverse pastures (L. perenne, Bromus valdivianus Phil. , Dactylis glomerata L. and T. repens ; Mix) subjected to three different leaf regrowth stage (LS) defoliation criteria. Secondarily, the study aimed to determine the main plant-related drivers for any potential animal preference. The treatments were MixLp (defoliated at L. perenne LS), BiLp (defoliated every time MixLp was defoliated), MixBv (defoliated at B. valdivianus LS) and BiBv (defoliated every time MixBv was defoliated), MixDg (defoliated at D. glomerata LS) and BiDg (defoliated every time MixDg was defoliated). Dairy cattle were evaluated over five agricultural seasons. The response variables were grazing time and location, bite rate, animal behavioural activity, pre-grazing herbage mass, undisturbed sward height, lamina:stem ratio, crude protein, metabolisable energy, organic matter digestibility, non-structural carbohydrates, neutral detergent fibre and lignin. Where significant differences were found, binary pastures presented lower sward height and higher non-structural carbohydrate content in comparison to the diverse pastures under the same LS defoliation criteria. However, no significant differences were found in the percentage of time that cows spent grazing both pastures. Season was the greatest contributor to the proportion variation found in all response variables, with values ranging from 47.55 % up to 88.77 %. In winter and spring, cows modulated their grazing behaviour (proportional time spent grazing, ruminating, or idling), investing more time actively grazing pastures under L. perenne LS interval of defoliation (2.5–3.0 LS), the criterion which resulted in shorter grazing rotations. This study allowed us to understand the suitability of diverse pastures from an animal perspective, and highlighted that independent of the pasture type, the positive productive and nutritional effects of defoliation management based on the LS may also extend themselves to positive outcomes in animal preference, interpreted as the percentage of time dairy cows spend grazing rather than ruminating or idling across and within seasons. • Lolium perenne, B. valdivianus, D. glomerata and T. repens comprise a diverse pasture. • No preference was found between binary and diverse pastures under the same leaf regrowth stage (LS) defoliation criteria. • Season was the greatest contributor to the proportion variation in all response variables. • Cows preferred pastures under LS defoliation criteria that resulted in shorter grazing rotations. [ABSTRACT FROM AUTHOR]

An understanding of the processes involved in grazing behaviour is a prerequisite for the design of efficient grassland management systems. The purpose of managing the grazing process is to identify sward structures that can maximize animal forage daily intake and optimize grazing time. Our aim was to evaluate the effect of different grazing management strategies on foraging behaviour and herbage intake by sheep grazing Italian ryegrass under rotational stocking. The experiment was carried out in 2015 in southern Brazil. The experimental design was a randomized complete block with two grazing management strategies and four replicates. The grazing management treatments were a traditional rotational stocking (RT), with pre- and post-grazing sward heights of 25 and 5 cm, respectively, and a 'Rotatinuous' stocking (RN) with pre- and post-grazing sward heights of 18 and 11 cm, respectively. Male sheep with an average live weight of 32 ± 2.3 kg were used. As intended, the pre- and post-grazing sward heights were according to the treatments. The pre-grazing leaf/stem ratio of the Italian ryegrass pasture did not differ between treatments (P > 0.05) (~2.87), but the post-grazing leaf/stem ratio was greater (P < 0.001) in the RN than in the RT treatment (1.59 and 0.76, respectively). The percentage of the non-grazed area was greater (P < 0.01) in post-grazing for RN compared with RT treatment, with an average of 29.7% and 3.49%, respectively. Herbage nutritive value was greater for the RN than for the RT treatment, with greater CP and lower ADF and NDF contents. The total time spent grazing, ruminating and resting did not differ between treatments (P > 0.05), with averages of 439, 167 and 85 min, respectively. The bite rate, feeding stations per min and steps per min by sheep were greater (P < 0.05) in the RN than in the RT treatment. The grazing time per hour and the bite rate were greater (P < 0.05) in the afternoon than in the morning in both treatments. The daily herbage intake by sheep grazing Italian ryegrass was greater (P < 0.05) in the RN than in the RT treatment (843.7 and 707.8 g organic matter/sheep, respectively). Our study supports the idea that even though the grazing time was not affected by the grazing management strategies when the animal behaviour responses drive management targets, such as in 'Rotatinuous' stocking, the sheep herbage intake is maximized, and the grazing time is optimized. [ABSTRACT FROM AUTHOR]

Gastrointestinal nematodes (GINs) are a concern for sheep production and are associated with significant economic losses globally, driving the need for effective management strategies. The aims of this research were first to determine the influence of GIN infections on sheep grazing behaviours, specifically grazing time (GT) and grazing event length (GL), and then to estimate the genetic and phenotypic correlation between faecal egg counts (FEC) and salivary specific IgA activity vs GT and GL. Data were collected from 146 Merino sheep on a commercial farm in Victoria, Australia. Faecal, saliva and body weight (BW) were collected at four time points (A: Oct 2019, B: early May 2020, C: late May 2020, and D: Jul 2020), while tri-axial accelerometer sensors recorded GT and GL for the length of 26 days between B and C. Univariate linear regression and Bayesian Generalised Linear Mixed Model, estimated using Markov Chain Monte Carlo, were used to assess the relationships between the behaviours and infection indicators. We found an increase in the logarithm of FEC was associated with a significant rise in grazing time (p < 0.05), suggesting compensatory behaviour in infected sheep. GT also accounted for 6% of the FEC variation. In contrast, the effect of IgA on GT was not significant (p > 0.05). There was a positive genetic and phenotypic correlation estimated between GT and FEC, however, the High Posterior Density interval for the genetic and phenotypic correlations between GT and FEC indicates some uncertainty in these estimates. These results imply that sheep may modify their grazing strategies as an adaptive response to parasitic infections to ease the impact on their nutritional intake. This study improves our understanding of how natural GIN infections affect sheep behaviour and highlights the potential to use animal behaviours as a precision livestock farming tool and in breeding for resilience against parasites. • Gastrointestinal nematode infection increases time spent grazing in sheep. • Grazing time accounts for 6% of FEC variability. • The genetic and phenotypic correlation between grazing time and FEC is positive. • Grazing time, the length of grazing event, IgA level and FEC were heritable. [ABSTRACT FROM AUTHOR]

Highlights • Genotype had no effect on any recorded grazing behaviour variables. • High genetic merit cows grazed for longer with more bites but had a lower grass dry matter intake. • No significant differences across genetic merit or genotype were observed for rumination measures. • Beef x dairy cows more efficiently convert herbage to milk production than beef. Abstract The objective of this study was to determine if differences in grazing behaviour exist between lactating suckler cows diverse in genetic merit for the national Irish Replacement index and of two contrasting genotypes. Data from 103 cows: 41 high and 62 low genetic merit, 43 beef and 60 beef x dairy (BDX) cows were available over a single grazing season in 2015. Milk yield, grass dry matter intake (GDMI), cow live weight (BW) and body condition score (BCS) were recorded during the experimental period, with subsequent measures of production efficiency extrapolated. Grazing behaviour data were recorded twice in conjunction with aforementioned measures, using Institute of Grassland and Environmental Research headset behaviour recorders. The effect of genotype and cow genetic merit during mid- and late-lactation on grazing behaviour phenotypes, milk yield, BW, BCS and GDMI were estimated using linear mixed models. Genetic merit had no significant effect on any production parameters investigated, with the exception that low genetic merit had a greater BCS than high genetic merit cows. Beef cows were heavier, had a greater BCS but produced less milk per day than BDX. The BDX cows produced more milk per 100 kg BW and per unit intake and had greater GDMI, intake per bite and rate of GDMI per 100 kg BW than beef cows. High genetic merit cows spent longer grazing and took more bites per day but had a lower rate of GDMI than low genetic merit cows, with the same trend found when expressed per unit of BW. High genetic merit cows spent longer grazing than low genetic merit cows when expressed on a per unit intake basis. Absolute rumination measures were similar across cow genotype and genetic merit. When expressed per unit BW, BDX cows spent longer ruminating per day compared to beef. However, on a per unit intake basis, beef cows ruminated longer and had more mastications than BDX. Intake per bite and rate of intake was positively correlated with GDMI per 100 kg BW. The current study implies that despite large differences in grazing behaviour between cows diverse in genetic merit, few differences were apparent in terms of production efficiency variables extrapolated. Conversely, differences in absolute grazing and ruminating behaviour measurements did not exist between beef cows of contrasting genotype. However, efficiency parameters investigated illustrate that BDX will subsequently convert herbage intake more efficiently to milk production. [ABSTRACT FROM AUTHOR]

Grazing is the most important activity that ruminant livestock undertake daily. A number of studies have used motion sensors to study the grazing behaviour of ruminant livestock. However, few have attempted to validate their approaches against various sward surface heights (SSH). The objectives of our study were to: (1) identify and compare the effects of different SSH on the grazing behaviour of sheep by analyzing data collected by a collar mounted Inertial Measurement Unit (IMU) sensor; (2) calculate the relative importance of the extracted features on grazing identification and compare the consistency of the selected features across various SSH; (3) validate the robustness by using classifiers trained from the dataset with specific SSH to distinguish the grazing activity on the datasets from different SSH; and (4) visualize the classification results of grazing versus non-grazing activities on various SSH. Linear Discriminant Analysis (LDA) was chosen as the classification method, while Probabilistic Principal Component Analysis (PPCA) was used to reduce dimensionality of the feature space for visualization of the results. Experimental results revealed that (1) our approach achieved high classification accuracy of grazing behaviour (over 95%) on all the epochs regardless of SSH; (2) Mean of accelerometer Z -axis, Entropy of accelerometer Y-axis, Entropy of accelerometer Z -axis, Mean of gyroscope X-axis and Mean of gyroscope Y-axis were the top 5 features that contributed most in classifying the grazing versus non-grazing activities and there were consistent trends in features across the three SSH; (3) there was enough robustness when the trained LDA classifier on a specific SSH was used to classify behaviour on different SSH; and (4) there existed a clear linear boundary between the data points representing grazing and those of non-grazing behaviour. Overall, our research confirmed that IMU sensors can be a very effective tool for identifying the grazing behaviour of sheep and there is enough robustness to use a trained LDA classifier on a specific pasture SSH to classify grazing behaviour at different SSH pastures. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the behaviour of White Fulani (WF) yearling calves grazing a Panicum maximum/Stylosanthes guianensis mixture under traditional management system in south western Nigeria. The effects of two biomass spatial distribution (dense and sparse) were evaluated in association with three pasture heights (10, 15 and 20 cm), with calves allowed access to the pasture for 2:00 h. The experiment was laid out in a split plot design with the two biomass spatial distribution assigned to the main plot and sward height assigned to the sub plot to give six treatments; this was replicated three times. The experiment took place from November to December, 2015. Grazing behaviour was recorded with the aid of a Chloride UK 8 channel, H.264 digital video recorder and Chloride UK IR waterproof camera fitted with 3.6 mm lens. Data on grazing time, walking time, idling/resting/rumination time and time spent by the animals exhibiting self-licking behavior were collected from the recorded CCTV video player. There was a significant difference in the time spent grazing by the calves with those grazing the pasture with dense biomass at 15 cm height recording more grazing time (87.33 min). Animals on the pasture with sparse biomass at 10 cm height recorded more (p < 0.05) idling/resting/rumination time (18.33 min). The time spent by the calves walking was similar for the pasture with dense biomass at 10 cm and 15 cm above the ground. Self-licking behaviour was generally exhibited by the calves across the treatments. However, calves grazing in the plot with sparse biomass at 20 cm height engaged in more self-licking behaviour than those in the dense biomass pasture. The differences observed in the behavioural parameters examined clearly indicated the capability of WF yearling calves to increase grazing time, reduce the time spent walking, idling/resting/rumination and self-licking time, thereby improving their efficiency of grazing. From management perspective, plots with dense pasture biomass cut to 15cm height is suggested for optimal production of grazing calves on sown Panicum / Stylosanthes mixture under the present production systems in south western Nigeria. [ABSTRACT FROM AUTHOR]

We assessed the effect of high instantaneous stocking rate, paddock shape and fence with electric shock on dairy cows' behaviour under rotational grazing system. Twelve Holstein Friesian lactating cows were used in two consecutive experiments. Experiment 1 used a 4×4 Latin square design with 4 two-day periods and 4 treatments: 2 paddock shapes (rectangular and square) and 2 instantaneous stocking rates (500 and 200 cows/ha). For Experiment 2, cows were divided in 4 groups of 3 cows and submitted to two treatments – smooth wire fence with electric shock (4000 V) and smooth wire fence without electric shock – in a cross-over experimental design with two replicates. Data were analysed in PROC GLIMMIX of SAS. The models included treatments as fixed effects and the group as the experimental unit. Cows in higher instantaneous stocking rate performed less grazing behaviour ( P ≤0.05). This finding was expected, as larger area per animal increase the herbage allowance for grazing, and thus grazing time. These same animals also performed more aggressions, but less idling behaviours ( P ≤0.05). Cows in paddocks without electric shock performed almost 15% more grazing behaviour than cows in paddocks with electric shock ( P ≤0.05), which indicates that they may have recognized the absence of shock, hence not avoiding being close to the fence. Paddock shape did not affect any of the behaviours analysed ( P >0.05). The results from this study reinforce the importance of paddock characteristics on dairy cows' behaviours. [ABSTRACT FROM AUTHOR]

• Adequate models to predict herbage intake of grazing dairy cows are needed. • None of the tested models predicted herbage intake of individual cows adequately. • No climate, management, or animal factor explained the remaining prediction bias. • Three models adequately predicted mean herbage intake of groups of cows. • Identified models can support decisions in farm management and extension services. The objective of the present on-farm study was to evaluate the adequacy of existing models in predicting the pasture herbage DM intake (PDMI) of lactating dairy cows grazing semi-natural grasslands. The prediction adequacy of 13 empirical and semi-mechanistic models, which were predominantly developed to represent stall-fed cows or cows grazing high-quality pastures, were evaluated using the mean bias, relative prediction error (RPE), and partitioning of mean square error of prediction, where models with an RPE ≤ 20% were considered adequate. The reference dataset comprised n = 233 individual animal observations from nine commercial farms in South Germany with a mean milk production, DM intake, and PDMI (arithmetic means ± one SD) of 24 kg/d, (±5.6), 21 kg/d (±3.2), and 12 kg/d (±5.1), respectively. Despite their adaptation to grazing conditions, the behaviour-based and semi-mechanistic grazing-based models had the lowest prediction adequacy among the evaluated models. Their underlying empirical equations likely did not fit the grazing and production conditions of low-input farms using semi-natural grasslands for grazing. The semi-mechanistic stall-based model Mertens II with slight modifications achieved the highest and a satisfactory modelling performance (RPE = 13.4%) when evaluated based on the mean observed PDMI, i.e., averaged across animals per farm and period (n = 28). It also allowed for the adequate prediction of PDMI on individual cows (RPE = 18.5%) that were fed < 4.8 kg DM of supplement feed per day. Nevertheless, when used to predict PDMI of individual animals receiving a high supplementation level, the model Mertens II also did not meet the threshold for an acceptable adequacy (RPE = 24.7%). It was concluded that this lack of prediction adequacy for animals receiving greater levels of supplementation was due to a lack of modelling precision, which mainly could be related to inter-animal and methodological limitations such as the lack of individually measured supplement feed intake for some cows. The latter limitation is a trade-off of the on-farm research approach of the present study, which was chosen to represent the range in feed intake of dairy cows across the diverse low-input farming systems using semi-natural grasslands for grazing. [ABSTRACT FROM AUTHOR]

Maternal undernutrition during gestation affects the behaviour, metabolism, and sensitivity to stressors of the offspring. Shearing is a stressor that triggers physiological and behavioural changes and augments the thermoregulatory demands in sheep. The aim of this study was to compare the thermoregulatory, metabolic, and behavioural responses to spring shearing of aged ewes born to mothers who grazed different pasture allowances during gestation. Nineteen non-gestating six-year-old Corriedale ewes born to mothers who grazed two pasture allowances from 23 days before conception until 122 days of gestation were used. The pasture allowance offered to the mothers was high [HPA group; n = 11; 10–12 kg of dry matter (DM)/100 kg of body weight (BW)/day] or low [LPA group: n = 8; 5–8 kg of DM/100 kg of BW/day]. The adult offspring of both experimental groups were sheared during spring (Day 0), and remained outdoors, grazing natural grassland, and the behaviour, the surface temperature and the rectal temperature were recorded. Blood concentrations of albumin, total protein, glucose, and insulin were also determined. Data were compared with a mixed model. The LPA ewes had lower ear and nose maximum and minimum surface temperatures before shearing (P < 0.05). On Day 15, the average surface temperature of the vulva was lower in LPA than in HPA ewes (P < 0.05). After shearing, rumination frequency was greater in HPA than in LPA ewes (P = 0.01), and LPA ewes were observed more time standing up than HPA ewes (P < 0.0001). Insulin concentration tended to be greater in LPA than HPA ewes (P = 0.06). Maternal undernutrition during gestation modified the thermoregulatory responses and the acute behavioural changes after shearing in aged female offspring, whilst the metabolism was affected to a lesser degree. The long-term effects noticed in this study highlight the importance of providing proper nutrition to pregnant ewes. • Undernutrition of pregnant ewes affected the thermoregulatory and the behavioural responses of aged female offspring to spring shearing. • Prenatal undernourishment reduces the vulva's surface temperature of aged ewes after shearing. • Aged ewes born to undernourished ewes ruminated less and spent more time standing up after shearing. • Aged ewes born to undernourished ewes tended to have a greater insulin concentration. [ABSTRACT FROM AUTHOR]

Nitrophilic thistles such as milk thistle ( Sylibum marianum ) and Syrian thistle ( Notobasis syriaca ) encroach rangeland areas where animals gather and defecate, in particular around watering and feeding points. High densities of milk and Syrian thistles (MST) diminish forage yields and detract from the amenity value of these areas. The aims of the present study were: (i) to test the safety of feeding MST to adult goats; (ii) to determine if preconditioning adult goats to MST, by feeding it indoors together with concentrate, enhances preference for MST when they graze MST-rich pastures; and (iii) to test for generational transfer by comparing the propensity to consume MST and the preference for MST over clover hay for weaned kids that previously suckled from does that were, or were not, preconditioned to consume MST fed as green fodder. We found that eating MST was not toxic to adult goats. Over six observation sessions of one hour, preconditioned goats devoted 50% more time to consuming MST than non-conditioned counterparts (30.3% versus 20.6%, respectively; P = 0.0005), and kids that experienced the preconditioning period together with their does tended (P = 0.08) to show a greater preference for MST over clover hay than their counterparts born to non-conditioned adults. Although the efficacy in depleting the seed bank has yet to be verified, from the point of view of the animal, goats may be used in targeted grazing of milk and Syrian thistles. [ABSTRACT FROM AUTHOR]

• We verified if salty, sweet, and bitter taste agents affect yak grazing behaviour. • Application of sweet and salty agents increased grazing intake. • Application of bitter agent had an inhibitory effect on grazing intake. • Taste agents may influence grazing behaviour by regulating feeding behaviour. • The results provide a method to promote grassland community stability. Feeding behaviour plays a significant role in promoting good animal health and welfare. It is also reflective of the quality and quantity of available feed. In fact, grazing livestock do not select their feed randomly, rather their behaviour is influenced by the texture, taste, and smell of each pasture species. Although taste agents are often used to modify feed intake for captive livestock, the effect on the feeding behaviour of grazing livestock has not yet been extensively evaluated in native grasslands. To address this gap in knowledge, herein, we sprayed three types of taste agents—salty (SA), sweet (SW), and bitter (BT)—on alpine meadows to investigate their effect on the grazing behaviour of yaks (Bos Grunniens) on the Qinghai-Tibetan Plateau (QTP). Behavioural observations showed that grazing was concentrated primarily in the morning and afternoon, while ruminating/resting peaked at noon; however, the diurnal behavioural patterns of grazing yaks were not affected by the taste agents. Application of the SA agent significantly increased the yaks' grazing time, bites per minute, bites per step, time per feeding station, and steps per feeding station, while significantly reducing walking time, steps per minute, and number of feeding stations per minute. Meanwhile, application of the SW agent significantly increased the yaks' time per feeding station, however, significantly reduced the steps per minute and number of feeding stations per minute. In contrast, the BT agent significantly increased the yaks' walking time, steps per minute, and number of feeding stations per minute, while significantly reducing grazing time, bites per minute, bites per step, and time per feeding station. Application of the SA agent also significantly increased the intake of favoured, edible, and inedible forage, while the SW agent improved inedible forage intake, however, had a more subtle effect on favoured and edible forage intake. Meanwhile, the BT agent had an inhibitory effect on grazing intake. Hence, the structural equation model suggested that taste agents may directly or indirectly influence grazing behaviour by regulating feeding behaviour. Our findings provide a theoretical basis for using taste agents in grasslands to control the grazing behaviour of livestock and provide a method to promote the stability of grassland communities, while mitigating the degradation of grasslands in the QTP. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of season and pasture species on variations in sward composition, pasture quantity (plant-height and biomass) and quality [crude protein (CP), neutral detergent fibre (NDF)and in vitro organic matter digestibility (IVOMD)]. Behavioural responses of a group of 10 pure Ankole and another of 10 crossbred (Ankole × Holstein) cows to the seasonal variations in pasture quantity and quality were also examined. Irrespective of season, the dominant pasture species was Brachiaria decumbens, with scanty presence of Hyparrhenia rufa, Themeda triandra, Sporobolus pyramidalis and Cymbopogonafronardus. The sward height, biomass, CP, NDF and IVOMD were dependent on both season and species(P < 0.001). Whereas the sward-height and biomass of B. decumbens, H. rufa, and T. triandra peaked during the rainy season, that of C. afronardus and S. pyramidalis peaked in the dry season. During the grazing cycle, a minimum plant-height of 31 cm and forage biomass of 118 g/m2, an equivalent of 1180 kg/ha, was recorded for most of the pasture species. The CP content of the pasture species were below 7%,irrespective of season, except for B. decumbens which had 8.7% CP in the rainy season. Minimum NDF content for all the pasture species was 67% and 50% during the dry and rainy seasons, respectively. Consequently, IVOMD ranged between 29-61% and 51-65% during the dry and rainy seasons, respectively. Ankole and the crossbred cows increased the number of feeding stations, bites and residence time in patches of species, which were scantly grazed in the rainy season. They also increased standing (P < 0.01)at the expense of walking (P < 0.001) and social activities (P < 0.001). Irrespective of season, more than40% of grazing occurred in B. decumbens patches and both genotypes grazed for ¾ of the time on pasture. However, the crossbred cows required extended grazing duration, resulting into less lying and rumination (P < 0.05) on pasture than the Ankole cows. Ankole and the crossbred cows grazed locales with high pasture groundcover and biomass. However, locales with high CP but low forage quantity were also grazed. This study revealed that at an appropriate stocking rate, sufficient forage supply was possible in both seasons. However, the low CP content and less preference for majority of the dominant species compelled the Ankole and the crossbred cows to graze for a long time. Thus, the crossbred cows were constrained by time in both the dry and rainy seasons. [ABSTRACT FROM AUTHOR]

Restricting time for grazing and concentrate supplementation affects feeding motivation, altering grazing behaviour, and performance of grazing ruminants. This study evaluated the combination of three lengths of restricting time at pasture and two levels of concentrate supplementation on behaviour, intake, and productive performance of dairy cows. Times out of pasture were 0, 4 (0800–1200 h) and 8.5 (0800–1630 h) hours. Levels of concentrate supplementation were 3 and 6 kg DM/cow/day. Measurements were: herbage dry matter intake and digestibility, grazing, ruminating and idling time, bite rate, milk yield and composition, as well as changes in live weight and body condition score. Restricting time at pasture increased ( P <0.01) grazing time and length of the initial grazing bout ( P <0.01) and reduced ( P <0.01) rumination and idling times. Restricting time at pasture did not affect herbage intake or milk yield; however, it reduced milk fat concentration ( P <0.01). Supplementation level reduced ( P <0.05) grazing time, but did not affect rumination and idling times. Bite rate was the greatest in cows that were not restricted and had the lowest level in R 8,5 S 6 groups ( P <0.01). Supplementation reduced herbage dry matter intake, and herbage and total organic matter digestibility ( P <0.01). Supplementation increased milk yield ( P <0.05) without effects on milk composition. Modulation of grazing behaviour in response to restricting time at pasture maintained herbage dry matter intake. Changes in grazing behaviour in response to restricting time at pasture plus concentrate supplementation counteract restrictions of restricted time at pasture and thereby help to maintain herbage and energy intake without negative effects on milk production. [ABSTRACT FROM AUTHOR]

The effect of sward type, grass only (GO) or grass white clover (GWc), on lactating dairy cow feeding behaviour, herbage depletion rate and rumen function was investigated in rotationally strip-grazed swards at a daily herbage allowance of 17 kg dry matter (DM)/cow/day, in two experiments. In 2011, eight rumen-cannulated cows were blocked into two groups and allocated to each sward type for a 14-day period in a change-over design (2 sward types×2 periods) on three occasions: late spring, summer, and autumn. Feeding behaviour, rumen pH and rumen volatile fatty acids and ammonia contents were measured. Following a continuous design, in 2012 feeding behaviour and herbage depletion rate measurements were undertaken at similar times to those in 2011 over 2–3 weeks in late spring, summer and autumn. Twenty-six (spring) and 36 (summer and autumn) cows were used. Grazing sward height (GSH) was measured five times/day. The percentage of grazed vegetative units, and the extended tiller height, free leaf lamina, tiller DM weight and tiller leaf DM weight of perennial ryegrass (ryegrass) tillers were estimated four times/day. During late spring, summer and autumn, sward white clover content (DM basis) was 7.5%, 8.8% and 30.9%, respectively, in 2011, and 18.0%, 29.7% and 30.6%, respectively, in 2012. In 2011 cows had similar grazing times on both sward types. Cows on GWc spent less time ruminating than cows on GO. Cows had similar total volatile fatty acids on both swards but the isoacids and d -lactic acid percentages, ammonia content and rumen pH were higher in autumn for cows grazing GWc. In 2012, cows on GWc grazed for longer in late spring, ruminated for less time in summer and for less time at night in autumn compared to cows grazing the GO sward. Both sward types had similar post-grazing sward heights and sward height depletion rates, except during morning grazing in autumn, when GWc had a greater sward height depletion rate. A similar percentage of grazed ryegrass tillers was observed between sward types, but the percentage of ryegrass grazed was greater than the percentage of white clover grazed in the GWc swards. The ryegrass tillers in the GWc swards were smaller than those in the GO swards but had similar depletion rates. The GWc swards influenced cow feeding behaviour and rumen characteristics with increased effect in autumn because of an increase in white clover content and a decrease in ryegrass quality. [ABSTRACT FROM AUTHOR]

Abstract: The relationship between herbage intake by herbivores and herbage available depends on the interaction between sward structure and animal behaviour. This relationship is a crucial component determining the stability, function and productivity of grazing systems. The present study aims at quantifying the mechanisms by which intake rate is determined in swards of contrasting structure and forage species, and it reveals the importance of animal choice in the interaction between animal and sward. We hypothesised that as sward height and herbage mass increased, bite mass and intake rate would increase. The relationship between intake rate and bite mass should exhibit a higher asymptote for the more succulent, less fibrous Avena than for Cynodon due to differences in chewing requirements per unit dry mass of intake. In four different experiments, Cynodon sp. cv. Tifton 85 and Avena strigosa cv. Iapar 61 swards of different heights were obtained by various durations of short time high-intensity grazing or by different growth periods. Bite mass and intake rate were estimated by the double-weighing technique with correction for insensible losses. Number and timing of jaw movements and bites were measured with behaviour recorders. Bite mass was the main variable determining intake rate. Contrary to expectations, bite mass first increased and then decreased with increasing sward height, a result that seems due to animal choice and not from restrictions imposed by the swards. As expected, Cynodon sp. swards required more chewing per unit DM intake due to their higher DM content (39.5 vs. 22.6, P <0.0001) and higher fibre (67.8 vs. 51.3, P <0.0001) content than A. strigosa. Harvesting and chewing jaw movements, the components of total jaw movements and time per bite, had different time costs, and values were remarkably similar to previously published values. On average, each harvesting jaw movement took 1s and a chewing jaw movement took 0.68s. The reduction in bite mass with increasing sward height in tall swards is discussed as a destabilising mechanism that generates spatial heterogeneity in sward height and mass. [Copyright &y& Elsevier]

Abstract: Automated systems for monitoring behaviour of cows within dairy production are increasing and developments in technology provide new opportunities in this area. This study aimed to validate the use of a 3D activity logger (HOBO® Pendant G Data Logger), that registers the cow's head positions during grazing, to distinguish grazing behaviour from non-grazing behaviour. 20 lactating dairy cows of the breed Swedish Red were included in the trial. All cows were observed for 30min each day either in the morning or afternoon. The behavioural observations were conducted by two trained observers during 5h a day for ten days, 2.5h in the morning (9:30–12:00am) and 2.5h in the evening (06:00–08:30pm). Each cow had a logger attached to the right bottom side of the halter and the logging interval was set to 5s, which means that the head inclination was measured every fifth second. Furthermore an IceTag3D™ logger was attached to the right hind leg of each cow in order to evaluate if this information together with the information from the 3D activity sensor could increase the precision of the prediction. The DISCRIM procedure in SAS 9.12 was used to find the optimal value of a linear discrimination between grazing and non-grazing registrations and the 3D activity sensor was validated with 5s, 5min and 10min logging intervals between observations points against the visual observation of grazing behaviour. The 5 and 10min logging point was taken from the 5s logging point occurring with 5 and 10min interval. The sensitivity (recognizing grazing behaviour as grazing) of the 3D activity sensor without or with the information from the IceTag logger with 10min interval was below 60% and thus not useful in determining grazing behaviour. However, the sensitivity of the 3D activity sensor alone was 83.6 and 85.5% for 5s and 5min respectively. The specificity (recognizing non-grazing behaviour as non-grazing) of the 3D activity sensor was 79.9 and 82.1% and the precision (proportion of calculated gracing behaviour that is real grazing behaviour) was 74.6 and 77.6% for 5s and 5min respectively. When the information from the IceTag3D™ was added to the data the sensitivity remained the same while the specificity increased to 90.2 and 90.5% and the precision was 85.8 and 86.8% for 5s and 5min respectively. It is concluded that a 3D activity logger is a useful tool for a continuous automatic registration of grazing behaviour in dairy cows. [Copyright &y& Elsevier]

Abstract: The majority of the European wild boar (Sus scrofa L.) that are farmed for their meat are produced using semi-extensive systems with access to pasture for grazing. Given that the pasture is an economic resource compared with supplemental diets, there is interest in determining strategies to increase pasture consumption. The objectives of this study were to assess the effect of the grazing system (continuous grazing vs. rotational grazing) on pasture consumption and grazing behaviour of European wild boar under semi-extensive production system conditions. Sixteen purebred nose-ringed European wild boar (initial average bodyweight of 18.3±0.45kg) were grouped into eight pairs. The pairs were assigned to eight paddocks of 35m2 with a Trifolium repens and Lolium perenne pasture, during summer. Animals grazed from 0830h to 1630h after which each pair entered a feeding station and had free access to a supplemental feed. Supplemental feed consumption was measured. In the “continuous grazing” treatment the animals entered the same pasture area (35m2) daily for five days. In the “rotational grazing” treatment the animals entered a new strip consisting of one-fifth of the surface of the continuous grazing area (7m2) daily, for five days (first grazing period). After these five days of grazing in the experimental area, the animals were moved to other areas of the paddock in which they grazed for 13 days. The animals then returned to the experimental area for another five days (second grazing period), with a change-over of treatments (cross-over design). The animals were individually weighed on the first and final day of every grazing period. Pre- and post-grazing pasture samples were taken to assess pasture consumption, botanical composition and nutritional composition. The behaviour of the animals during the grazing periods was evaluated during each evaluation day. Every 5min the activity of each animal was recorded by an observer as “grazing”, “lying down”, “walking”, “taking a bath”, “drinking water”, “playing” or “other activities”. The average pasture consumption was 242±18gDManimal−1 d−1 with no statistical difference between treatments. The animals spent 42.4% of their time “grazing”, being more active the first 3h (62% of their time grazing), and 45.4% “lying down” (especially from 1130h to 1530h), with no significant differences between treatments or periods. Pasture consumption and grazing behaviour of European wild boar does not differ between continuous and rotational grazing systems over a five-day period. [Copyright &y& Elsevier]

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

The benefits of using white clover in pastures have been widely recognised for many years. However, clover is perceived as being unreliable because of its typically low content, which is spatially and temporally variable, in mixed pastures. One proposed solution to increase the proportion of clover in the diet of grazing animals and composition in the pasture is to spatially separate clover from grass within the same field. In a field experiment ryegrass and white clover were grown in fine mixtures, and in pure alternating strips of ryegrass and clover of 1.5 m, 3 m or 18 m width within a field. Pastures were grazed for two grazing periods of 9 and 12 weeks, and measurements of sward surface height (SSH), herbage mass and composition and clover morphology were taken. Grazing behaviour was also observed. Results showed that spatial separation in the long term, when compared with a fine mixture, increased clover availability (18% to 30% v. 9%, based on standing dry matter) and was not grazed to extinction. Ewes maintained their preference for clover throughout the experiment (selection coefficient 2 to 5), which resulted in a reduction in the SSH of clover in monocultures to <3 cm and significant changes to the morphology of clover (smaller leaves, shorter petioles and thicker stolon), at the expense of maximising their intake. Spatial separation in the short term may therefore allow grazing animals to select their preferred diet; however, in the long term in continuously grazed pasture, their preference for clover depletes its availability. [ABSTRACT FROM PUBLISHER]

Abstract: The botanical composition of the diet and species preference of grazing goats in different physiological states were evaluated in the autumn and winter seasons. The study was performed in a desert rangeland in the northeast (NE) Mendoza region in Argentina. Food availability was estimated from forage species cover. Rectal grab faecal samples were collected from goats, and the botanical composition of the goat diet was determined using a microhistological technique. Goat preferences for each species consumed were calculated based on Ivlev''s index. Nutritional composition and secondary compounds of forage species were determined. Correlations between diet and availability; and between goat preference and nutritional composition of forage species were also estimated. The habitat consisted of a dominant woody stratum associated with an herb stratum primarily composed of grasses. Goats in different physiological states utilised a significantly higher proportion of woody vegetation compared to grass (p <0.01). When grass availability was high (autumn), the herb stratum was more utilised by pregnant and lactating goats than by dry goats (p <0.05). In the winter, the diet of lactating goats consisted of more Atriplex lampa compared to the diet of dry goats (p <0.05), probably due to the high crude protein content of the plant. Goats consumed forage species with highly variable total phenol and tannin contents, which did not negatively affect selection. Correlations between diet and availability were high in the winter for dry (r s =0.88, p <0.02), pregnant (r s =0.93, p <0.01) and lactating goats (r s =0.97, p <0.01) but were not significant in the autumn. A significant correlation between preference and crude protein was shown during the autumn season for pregnant and lactating goats (r s =0.6, p <0.05). Forage availability was the main factor influencing diet selection in this arid environment. When food availability was not a limiting factor, goats selected a diet that most closely matched their nutritional requirements. Physiological state modified nutrient requirements and affected diet selection in that pregnant and lactating goats selected forage species with high protein contents. [Copyright &y& Elsevier]

Abstract: The common military explosives 2-methyl-1,3,5-trinitrobenzene (TNT), 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) are distributed in many military training areas, and are thus encountered by grazing animals. The aim of this study was to examine small ruminant''s intake of forage contaminated with explosives. An indoor, experimental setup was used to determine if contamination of forage by these compounds affected intake by sheep. The results clearly demonstrate that contamination by any of the three explosives reduced forage intake in sheep; in order of increasing avoidance: RDX

Abstract: Grazing low-mass pastures is almost inevitable when extending the grazing season into late winter to reduce feed costs, cows'' performance being potentially affected. An experiment was carried out to estimate the performance, pasture intake (PI) and behavioural adaptation of dairy cows when grazing low-mass pastures at LOW, MEDIUM and HIGH pasture allowances (PA), corresponding to 19, 32 and 46kg OM/cow per day above ground level, respectively. The study took place in the late winter of 2008 on good quality perennial ryegrass/white clover pastures with a mean pasture mass and a pre-grazing platemeter height of 2.3t OM/ha above ground level and 5.8cm, respectively. Each cow was supplemented with 4.4kg OM of maize silage and 2.0kg OM of cereal concentrate. Daily time at pasture was restricted to 9h between the am and pm milkings. Eighteen midlactation Holstein cows (twelve multiparous and six primiparous) were used in a 3×3 orthogonal Latin square design with three consecutive periods of 13days. On average, the cows produced 25.3kg of milk and total OM intake was 14.4kg/d. Pasture OM intake averaged 7.9kg/d and linearly increased from LOW to HIGH (+0.04kg/kg PA). Similarly, milk production per cow (+0.09kg/kg PA) and milk protein concentration (+0.04g/kg per kg increase in PA) linearly increased with increasing PA. Milk fat concentration, on the other hand, decreased by 0.10g/kg per kg increase in PA. The daily grazing time (430min) and the proportion of time spent grazing (79%) were not affected by PA. On average, pasture intake rate was low (19g OM/min) and linearly increased from 16.9g OM/min in LOW to 20.7g OM/min in HIGH. In the present study, the PI was limited even at high PA because of the cumulative effect of the low-mass pasture (low intake rate) and the restricted access time (short grazing time). Consequently, the effect of PA on PI was low. However, the milk production response to variations in PI was high because of the low energy balance recorded in all treatments. [Copyright &y& Elsevier]

Abstract: A direct in situ observation method has been used, observing ingestive bites taken by continuously monitored Iberian pigs (10 uninterrupted hours, from 08:30 to 18:30) to calculate intake of acorns and grass and grazing activity during the fattening period in the dehesa (cleared Mediterranean forest like savannah) from November first to the end of December. The obtained results, together with measurements of weight gain, have been used to propose a new method for calculating stocking rate capacity. 60 grazing days have been studied corresponding to different randomly chosen Iberian pigs (110.2±1.3kg of average initial LW) during 2months. The results show a daily intake of 56.4±2.34MJ ME from grass and acorns, of which acorns accounted for 90.42% (2.92±0.13kg of kernel DM and 0.49±0.04kg of grass DM); to do so pigs walk 3.9±0.18km in 369.0±7.8min of activity which happens at an average temperature of 7.6±0.2°C. The daily expenditure of ingested energy is divided as follows: 13.8±0.18MJ for the resting metabolism (54.1%±0.44); 5.5±0.14MJ for thermoregulation (21.5%±0.29); 6.3±0.15MJ for grazing, divided in displacement (8.0%±0.32) and standing (16.4%±0.25) during the activity. The total energy cost is therefore 25.7±0.38MJ ME, which equals 51.2%±2.71 of the ingested ME. ME available for production was 30.7±2.33MJ per pig and day, equivalent to 0.8±0.06MJ/kg LW0.75 per day. The total heat losses were 31.8±0.59MJ per pig and day. The corresponding ratios are: 253.0±13.05g/kg DM for gain/feed, 15.3±0.79g/MJ for gain/ME intake and 1.4±0.06MJ/kg LW0.75. There are not significant differences between both sexes. With an average daily weight gain of 0.79±0.03kg, the conversion rate of the ME consumed as grass and acorns is 56.4±2.34MJ ME (corresponding to 4.0±0.29 Kg kernel DM and 0.7±0.08kg of grass DM). To ingest that amount of energy pigs have to use 10.5±0.75kg of entire acorns to shell these. Bearing in mind that the annual production of acorns of an average adult evergreen oak (Q. ilex rotundifolia) acorn production is very close to this amount, it could be established that pig feed conversion rate (FCR) for acorn equals the total acorn production from one adult tree. So stocking rate may be estimated by dividing the number of adult oaks of a dehesa by the expected weight gain; and it could be established that stocking rate should be <1pig/ha of dehesa to gain the minimum standard of 46kg only grazing natural resources. [Copyright &y& Elsevier]

Abstract: The foraging responses of ewes faced with a diversity of feed items and their effects on broom (Cytisus scoparius L.) consumption were examined. The experiment was conducted on a farm in the autumn with ewes (n =33) grazing three small paddocks (0.44ha on average, for at least 10 days each) located in broom shrubland. The effects of three different herbaceous covers on broom consumption were compared: 100% of paddock area previously grazed in summer; 50% of paddock area previously grazed in summer; and paddock area non-grazed during the year. The characteristics of herbaceous cover (availability and quality) and the ewes’ diet selection were encoded as bite categories. Flock activities were recorded through scan sampling. We used logistic regression to assess the relationship between feeding behaviour of sheep on herbaceous vegetation and on broom species, and calculated selectivity indices for this shrub. We showed that the presence of high-quality bite categories in the herbaceous cover affected the way ewes integrated broom into their diet. At the start of each paddock use period, ewes favoured high-quality larger and medium bites of the herbaceous cover. They gradually included larger bites of broom and reduced their bite size, but continued to seek out higher quality herbaceous plants, a pattern which suggested a stabilisation of their daily average digestibility and bite mass over time. A negative relation was observed between the percentage of ewes taking large and medium bites on highly digestible plant parts and the percentage of ewes browsing broom. A maximum of 26% of the flock browsing broom was observed on any given day. Hence, ewes have a threshold for this target shrubby species that they do not exceed during any paddock utilisation period. This finding was interpreted as a mechanism to deal with post-ingestive consequences and complementary interactions between nutrients and toxins. When comparing broom selection between paddocks in autumn, we found an earlier and thus longer broom selection in areas with herbaceous cover that had not been grazed during the year (possibly because of a lower palatability). Our results provide new insights into ways to manipulate diet selection in order to stimulate the use of broom by ewes. Bite categories are proposed as functional feed indicators that facilitate prediction of the herbaceous cover state preliminary to initial broom integration in the sheep''s diet. [Copyright &y& Elsevier]

Abstract: While herbage chemical composition varies diurnally, it is not known if this variation affects herbage biomechanical properties. The objective of this study was to evaluate changes in herbage toughness and particle size in relation to diurnal fluctuations of herbage chemical composition. Vegetative (i.e, tillers with three fully expanded leaves) micro-swards of Festuca pratensis Hud. were sampled at four times of the day being: 06:50 (sunrise), 11:10, 15:30 and 19:25h. Cut herbage was analysed for dry matter (DM), crude protein (CP), total non-structural carbohydrates (TNC), neutral and acid detergent fibre (aNDF, ADF), in vitro true digestibility (IVTD), toughness and particle size. The experiment was repeated on two consecutive days. Diurnal variation of temperature, relative humidity and photosynthetic radiation were recorded every 5min with an automated weather station. To characterize the relationship between dependent variables, Pearson correlations were performed. From 06:50 to 19:25h, DM, TNC and the proportion of small particles (<1mm) increased (P<0.05), CP, aNDF, ADF, toughness and proportion of large particles (>4.75mm) decreased (P<0.05) while IVTD remained constant (P>0.05). Toughness was negatively correlated (P<0.05) with DM and TNC concentrations, and positively correlated (P<0.05) with proportions of aNDF and ADF. The proportion of small particles was positively correlated (P<0.05) with DM and TNC concentrations, and negatively correlated (P<0.05) with proportions of aNDF, ADF and toughness. Results suggest an effect of time of day on herbage toughness and particle size as a function of increases in DM concentration, and reductions of aNDF and ADF concentrations, due to an increase in TNC. Diurnal fluctuations in chemical composition of herbage not only result in differential nutrient supply to grazing ruminants during the day, but also in temporal fluctuations in herbage biomechanical features. [Copyright &y& Elsevier]

Abstract: On rangelands, uneven or unmanaged livestock distribution can adversely affect plant community composition, riparian function, or displace wildlife. These issues have historic precedents and are still a challenge for those managing rangelands. A thorough understanding of the mechanisms governing livestock distribution can help land and livestock managers avoid or ameliorate many deleterious effects. To that end, this research tested hypotheses that grazing cattle seek nutritionally superior portions of rangeland pastures. Global positioning system (GPS) collars were used to track cattle movement and activity in three, 800+ha pastures where the spatial distribution of standing crop, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and forage digestibility (in situ dry matter disappearance (ISDMD)) were mapped in late spring. Four of five analyses implied grazing cattle spatially responded to forage quantity/quality attributes. Analyses indicated cattle favored higher than average CP (P =0.006) and ISDMD (P =0.078), and lower than average NDF (P =0.003) and standing crop (P =0.069) locales. No significant effect (P =0.954) occurred with ADF analyses. Correlations among those variables imply cattle may simultaneously respond to more than one nutritional attribute as they select foraging locales. Stepwise regression, however, relating grazing distribution to geophysical and forage quantity/quality characteristics were extremely poor predictors of where cattle grazed. Listed in order of entry, the model implied elevation above or below stock water, horizontal distance to stock water, forage CP content, and degree of slope were the site specific attributes most associated with cattle distribution. We speculate that cattle interactions with landscape level nutritional dynamics may at least partially explain seasonal changes in distribution and forage use by cattle across the landscape. These findings should help land and livestock managers understand, explain, and manipulate livestock distribution on their holdings. [Copyright &y& Elsevier]

Abstract: Two different herds of Iberian pigs have been studied in the montanera fattening period (from November first to end of December) in the dehesa agrosystem (clear forest of evergreen oaks, Quercus rotundifolia) during two different autumns and winters (2003 and 2004) without any supplementary feed. A direct in situ observation method has been used, with continuous observation of ingestive bites taken by continuously monitored pigs (10 uninterrupted hours, from 08:30 to 18:30) to calculate intake. 95 grazing days have been studied corresponding to different randomly chosen pigs. The obtained results show grass and acorns as the main resources with 56.5 and 43.3% of bites respectively. 14 other resources different from grass and acorns were registered, but only 9 resources (berries, bushes, inorganic rubbish, woods, roots, earth and sand, charcoal and ashes, carrion and straw) were consumed at a frequency ≥0.01%. The percentage distribution for daily bites showed no significant difference between years. However daily grazing times were significantly affected by year, and were associated with available drinking water from rain. Lack of water in second montanera forced pigs to return to shelters to drink and, in consequence, reduced daily mean grazing time (from 427±14 min in montanera 1 to 368±8 in montanera 2; P <0.001) and kernel acorn dry matter intake (from 3.6±0.3 kg in montanera 1 to 3.1±0.1 in montanera 2; P <0.05); however, it did not significantly influence either daily grass dry matter intake (0.38±0.04 kg in montanera 1 versus 0.49±0.04 kg in montanera 2) or total daily dry matter intake calculated from bite number (4.0±0.3 kg in montanera 1 versus 3.6±0.1 in montanera 2). [Copyright &y& Elsevier]

Abstract: The aim of this study was to assess the grazing, social and comfort behaviour of the indigenous purebred Ankole cattle breed and crossbred (Holstein×Ankole) animals under typical management conditions in south western Uganda. Twelve focal animals in each of four groups (two groups per genotype) were observed regarding their grazing, social and comfort behaviour on pasture. No significant differences in grazing behaviour patterns (eating, walking, standing) were found between the genotypes. Resting occurred only very rarely in both genotypes. Walking distances of Ankole and Ankole×Holstein crosses were also similar. There was no difference in the occurrence of agonistic interactions between the two genotypes. However, Ankole cattle engaged in more non-agonistic social interactions than their crossbred counterparts. Individual distances were lower in Ankole heifers and more herd mates were found within a radius of 5m around the Ankole animals. The most important comfort behaviour pattern in both genotypes was self-licking, which occurred to similar frequency in Ankole and crossbred heifer groups. Crossbred animals scratched themselves and rubbed on objects more often than Ankole heifers. Although Ankole cattle and their Holstein crosses did not differ in grazing, distances walked and agonistic behaviours, the significant differences between the two genotypes in herd cohesion and comfort behaviour may pose challenges on the management of crossbred animals under extensive open grazing conditions as present in south western Uganda. Thus, apart from (re)productive performance traits, behavioural traits of both genotypes may also be taken into account for breeding decisions and management under current production conditions. [Copyright &y& Elsevier]

Abstract: The objectives of this study were to determine the effects of breed, season and pasture moisture gradient on the extent and location of grazing and ruminating behaviour in cattle kept on heterogeneous semi-natural grasslands. Two groups of heifers, 12 of the traditional Swedish breed Väneko and 12 of the commercial Continental breed Charolais, were allocated into three enclosures per breed. Each enclosure consisted of heterogeneous semi-natural grasslands dominated by Deschampsia cespitosa (tufted hairgrass) and each contained dry, mesic and wet areas. In spring, summer and autumn, behaviour was recorded using automatic behaviour recorders, and positioning and activity were recorded using GPS receivers for 24h for every heifer. The Väneko heifers had a higher activity than the Charolais heifers (P =0.006), which supports the theories of resource allocation and contrafreeloading, but there were no differences between breeds in location of grazing, ruminating or idling. The heifers spent more time grazing in autumn (42.5% of the day) than in spring (38.5%; P =0.006) and summer (38.9%; P =0.014) and the efficiency of grazing (i.e. proportion of eating during grazing bouts) increased over the grazing period (P <0.001). The results indicate the heifers avoided grazing in darkness which is consistent with the theory that predation risk affects foraging. Herbage in wet areas had a lower concentration of crude protein (P =0.036) and a higher concentration of neutral detergent fibre (P =0.011) than herbage in dry areas. At the same time, on average over seasons, 28% of the herbage mass was found in the wet areas, whereas only 8% of the grazing occurred there. Furthermore, the proportion of eating during grazing bouts was lower (73.9%; P <0.001) in wet areas than in dry (80.1%) and mesic (79.6%) areas. The results indicate the heifers avoided grazing in wet areas where forage had a low nutritional value, supporting the theory of optimal foraging. In conclusion, both breed and season affects foraging behaviour of cattle on semi-natural grasslands, as the heifers of the traditional breed had a higher activity than the commercial breed and the grazing time was longer and more effective in late than in early grazing period. The cattle avoided foraging in wet areas, which may impact on the management of these areas. [Copyright &y& Elsevier]

Abstract: Inappetence is commonly associated with parasitism and has been observed in both housed and pastured ruminants. In seeking a functional explanation for these observations, it has been hypothesised that parasitized animals may feed more selectively in order to proportionally increase the protein content of their diet and thus partially compensate for their reduced feed intake. Support for this theory is found principally in studies in housed animals under carefully controlled experimental conditions. Grazing animals face a far more heterogeneous environment and a multiplicity of potentially confounding factors that could influence diet selection. Controlled grazing of adjacent monocultures of grass and clover can mitigate some of these variables and was used in the current study to examine the dietary preference of dairy heifers with sub-clinical parasitic gastroenteritis when compared to those receiving regular anthelmintic treatments. Grazing behaviour and herbage intake rates were determined through the use of jaw-movement recorders, direct observation and short-term liveweight change. Consistent with previous observations and despite evidence that nematode burdens were low in the untreated control heifers, a reduction in daily grazing time of 56min (P =0.054) was observed in the control animals. There was, however, no evidence that the control heifers showed greater preference for clover compared with ryegrass: partial preference for clover was 73.0% in the untreated controls and 75.5% in the treated heifers. Furthermore control heifers were observed grazing the clover swards significantly (P =0.032) less frequently than the treated heifers. This study provides additional evidence in grazing cattle for parasite-induced inappetence, manifest as a reduction in grazing time and in subtle changes in ingestive behaviour. The observed partial preference for clover in both treated and control cattle was not significantly affected by the level of parasitism. [Copyright &y& Elsevier]

Following the Chernobyl accident in 1986, restrictions were placed on the movement and slaughter of sheep within upland areas of the UK because radiocaesium activity concentrations in their meat exceeded 1000Bqkg−1 fresh weight. Some farms remain under restriction in 2007. From 1991 to 1993 detailed studies were conducted on three sheep farms within the restricted area of west Cumbria to systematically assess the various parameters which may contribute to the observed variability in radiocaesium activity concentrations within sheep flocks. This paper reports the spatial variation in soil and vegetation activity concentrations across the grazed areas at these farms and determines the influence of grazing behaviour on variability in 137Cs activity concentrations between individual sheep within the flocks. Together with previously reported results, these new data are used to draw conclusions on the factors determining variability within the three flocks. However, the factors are too site specific to be able to generalise the findings to other farms within the restricted areas of the UK. [Copyright &y& Elsevier]

Abstract: Thirty-six adult ewes rearing single male lambs were randomly allocated to three paddocks (n =12) grazing permanent Pyrenean pastures in spring (0.5 ha/lot). Treatments were rationed grazing (Rat-Gr) in which lambs remained indoors and ewes grazed during 8 h/day (08:00–16:00 h) and were supplemented 0.5 kg/day of barley meal; continuously grazing ewes rearing non-supplemented lambs (Gr) and continuously grazing ewes rearing supplemented lambs in creep feeders at pasture (Gr+S). Grazing behaviour was registered at weekly intervals by direct observation during the outdoor time in Rat-Gr and from dawn to dusk in Gr and Gr+S. Sward height of Rat-Gr became higher than the rest (P <0.05), resulting in a greater dry matter and a lower crude protein content of this pasture (P <0.05). Ewe live-weight, body condition score and lumbar fat thickness were similar across treatments (P >0.05), while milk yield was higher in Gr+S (P <0.05). Lambs from Rat-Gr and Gr+S presented a higher average daily gain than Gr treatment (P <0.05). Grazing behaviour records showed that all treatments spent grazing similar percentages of daylight time at pasture (average 52%; P >0.05). Ewes biting rate was greater in Gr (P <0.05) and it was higher after noon in all treatments (P <0.001). Gr and Gr+S showed an extended peak of grazing (min/h) in the evening. Lambs followed the grazing pattern of dams since 3 weeks old. It was concluded that in contrast with the traditional indoor system of managing production of light lambs both spring continuous grazing systems allowed producing Ternasco lambs (18–24 kg LW, younger than 90 days old). Lambs supplemented suckling their mothers and grazing until slaughter showed similar performance to those obtained in indoor system. Dietary supplementation of lambs at pasture did not impair ewes milk yield and grazing time but reduced their biting rate and the offspring grazing time. [Copyright &y& Elsevier]

Abstract: The aim of this study was to assess grazing behaviour, intake, rumen function, milk production and composition of dairy cows grazing perennial ryegrass varieties that were morphologically and chemically similar, but differed in their water-soluble carbohydrate (WSC) concentration. Eight multiparous rumen cannulated dairy cows were offered four varieties of perennial ryegrass under a 1-day strip-grazing system using a 4×4 Latin square design in two consecutive years. Two of the varieties were characterised by a high WSC content (HSV) and the other two varieties had a lower concentration of WSC (LSV). Grazing behaviour was recorded using a solid-state behaviour recorder. Daily intake was estimated using the n-alkane technique. Rumen function was measured using rumen evacuation. As expected the HSV had a higher WSC content (P <0.05) than the LSV with an average difference of approximately 32 g/kg dry matter. The other chemical constituents did not differ significantly between HSV and LSV. The sward surface height, herbage allowance and tensile strength were not significantly different between HSV and LSV. None of the grazing behaviour parameters (eating time, rumination time, bite rate, chewing rate and bite mass) were significantly different between HSV and LSV. Daily dry matter intake (DMI), fibre clearance rate, milk production and milk composition (fat, protein and lactose) were not different between cows grazing the HSV and LSV. At the level of difference in WSC content between the grass varieties reported in this study (32 g/kg), offering dairy cows a high sugar pasture did not influence grazing behaviour and rumen function and was not beneficial in improving DMI, milk yield or in altering the composition of milk. [Copyright &y& Elsevier]

Abstract: Grazing itineraries of herded and free grazing cattle (n =194), goats (n =148), and sheep (n =129) were monitored in a village territory over a 1-year cycle by direct observation of grazing and excretion behaviour and by parallel animal tracking using a Global Positioning System. During the study period, standing and litter biomass of spontaneous vegetation and crop residues was measured repeatedly on sample plots of fields (n =16), fallows (n =15) and rangeland (n =8). Based on a land use map, a Geographic Information System on forage availability was produced for the territory and overlaid with the livestock grazing itineraries. The animals’ behaviour at pasture was related to the forage mass encountered along their daily itineraries in order to analyse the spatial variation in behaviour as influenced by season, livestock species and herd management mode. Maximum daily itinerary lengths were 25km in cattle, 20km in goats and 21km in sheep; itinerary length varied significantly between species, herd management modes and season. Animals spent between 456 and 625min per day on pasture, the grazing day of cattle being longer than that of sheep and goats. Across seasons, all three species spent on average about 60% of the daily grazing time feeding, 20–26% walking and 12–20% resting. The forage mass encountered along the animals’ itineraries was higher than the average amount of forage available in the area. Particularly during the late dry and the rainy season, herding increased the amount of forage on offer to grazing livestock. Throughout the year, 39% of the observed excretions occurred on cropland, 31% on rangeland, 20% on fallows and 10% in and around settlements; the spatial repartition of excreta deposits differed between herded and free grazing animals, with free grazing animals depositing a higher share of excretions on barren land. The obtained information on the variation of grazing and excretion behaviour with respect to ruminant species, land use type, forage supply, season and herd management can be coupled with quantitative data on feed intake and excreta deposition, in order to compute livestock-mediated nutrient budgets for Sahelian agro-pastoral land use systems. [Copyright &y& Elsevier]

Abstract: On grasslands, herbivores make a trade-off between the quality and the quantity of their intake. They improve their searching efficiency by modulating their foraging velocity and/or their path sinuosity through the perception of their feeding environment. The aim of this study was to test the pertinence of fractal analyses of foraging paths in order to improve the understanding of spatial utilisation at grazing. By the analysis of grazing paths of herbivores grazing a continuously distributed and spatially limited resource, we aimed to identify the spatial scales at which the animals perceive heterogeneity of the sward, and to characterise how sheep modulate their foraging paths through resource abundance and heterogeneity. Two groups of five dry ewes, grazing two plots of contrasting areas from April to the end of September 2000, were studied. On the smaller plot (1500m2), the application of a high stocking rate (HSR) produced a resource of good quality but low quantity, and on the larger plot (3000m2) a low stocking rate (LSR) created a sward of low quality but good quantity. We show that on initially homogeneous swards, sheep exhibited correlated random walks, reducing movement quantities to achieve their intake. After a few weeks of grazing, vegetation structure become more complex and sheep modulated their foraging paths through resource abundance and/or sward structure. We identified a breakpoint at 5m for which fractal dimension is always low. At lower scales (below 5m), the modulation of sinuosity was not linked to sward abundance and structure, and sheep adapted grazing behaviour at bite and feeding station scales. At higher scales (above 5m), modulation of grazing activity was achieved through path sinuosity in relation to perception of the environment. Grazing paths were tortuous on tall swards in summer, and straighter on heterogeneous, well-structured swards showing visual cues in autumn. Fractal dimension of grazing paths proved to be a synthetic measurement, which allowed identification of a hierarchical threshold in the spatial adaptation of foraging behaviour in domestic herbivores at grazing. [Copyright &y& Elsevier]

Abstract: Wooded rangelands are a vast grazing land resource globally, including shrublands, savannas and forested ranges. They generally provide forage year-round for small ruminants and they are vitally important for livestock production, especially goats. While the productivity of wooded rangelands is low to moderate, their importance to small ruminant production is considerable. In this paper, we begin by discussing some anti-quality characteristics (mechanical and chemical defences) of woody vegetation that reduce their forage value, deter foraging, and reduce performance and productivity of small ruminants. We then present examples of grazing studies that illustrate how small ruminants select their diets on wooded rangelands. We conclude by discussing why small ruminants select the diets they do within the evolutionary processes of plant–herbivore interactions. Finally, we discuss how this knowledge can be integrated into approaches for sustainable management of wooded rangelands for small ruminant production. Plant defences are abundant in wooded rangelands but they are not a complete barrier to small ruminants as they often use woody plants as part of their diets. Indeed plants with such defences may represent a significant forage resource enabling small ruminants to survive on wooded rangelands with a prolonged dry period when more preferred defenceless species are absent. Future research in plant–herbivore interactions should include investigating how plant biochemical diversity influences herbivore preference for various plant communities, and integrating this information to develop recommendations for managing wooded rangelands. [Copyright &y& Elsevier]

Abstract: A small herd of donkeys was introduced in a coastal dune reserve ‘Houtsaegerduinen’ (ca. 80ha) in Belgium, in order to slow down expansion of dominant grass and shrub species. The Houtsaegerduinen is a nutrient poor scrub-dominated dune system with a spatially heterogeneous vegetation pattern. Different aspects of the grazing behaviour (grazing time, bite rate, habitat use, diet composition) of the free-ranging donkeys are described and analysed. Behavioural data (of maximum six adult mares) were collected through continuous focal animal observation in three consecutive years (1998–2001). Temporal variation in grazing time, habitat use and diet composition was determined. During daylight, donkeys spent most of their time on grazing (56%). In all 3 years, grazing time was significantly shorter in summer (45% of their time), longest grazing times were achieved in spring (64%). In spring, the donkeys also achieved the highest bite rate (21.5bites/min). The grassy habitat was preferred for foraging in all seasons, while the use of scrub and woodland was variable over time. Averaged over the four seasons, the general diet consisted for 80% of graminoids, 10% of forbs and 10% of woody plants. However, diet composition varied not only among seasons and years, but depended also on the foraged habitat type. We discuss the possible role of the donkeys in nature management. [Copyright &y& Elsevier]

Abstract: Foraging herbivores are often faced with spatial and temporal heterogeneity within the vegetation they have available to graze and therefore have to make decisions where and when to graze. The study reported in this paper investigated the influence of sward height on diet selection by horses grazing perennial rye-grass swards. The study comprised two experiments. In Experiment 1, perennial rye-grass paddocks were mown to four sward heights (heights: 3.5, 4.5, 7.5 and 15cm) to create a patchy environment. Within each paddock one horse grazed for a period of 1h during which residence time, number of bites and frequency of visits per patch were recorded. This was replicated with all seven horses used in the experiment. The same experiment was repeated in Experiment 2, but without mowing the field and allowing 1 week of re-growth for each paddock. During both experiments horses entered equally often but resided significantly longer on patches with long grass (15cm) than on those with short grass (below 4.5cm; P &#60; 0.05). Grazing time and number of bites on a patch were highly correlated. The number of bites on patches with the highest sward height was greater than that on short patches (P &#60; 0.05). Horses behaved as selective grazers, feeding mainly on grass taller than 7cm. In Experiment 2, re-growth of the sward reduced the difference in sward height between the patches. Time spent per patch and total numbers of bites taken were less affected by sward height than in Experiment 1. It is suggested that horses behaved as energy maximisers (residing longer periods on patches and increasing number of bites taken). These data complement previous findings that bite dimension and bite mass increase with increasing sward height. When grazing, a horse rarely resided on a preferred patch for a long duration of time (maximum 305s, median 79s), but moved on after a few minutes. They sampled their environment continuously, but almost exclusively returned to long patches for feeding. [Copyright &y& Elsevier]

Forty spring-calving cows and heifers (20 of each) were allowed to acquire infection with gastrointestinal (GI) nematodes naturally during grazing. The control group (10 cows and 10 heifers) were compared with 20 similar animals treated with eprinomectin in order to evaluate the effect of GI nematodes on grazing behaviour, milk production, body condition score and live weight. The animals were paired according to parity and milk yield during the week prior to treatment, then within replicate pair randomly allocated to a different treatment group. The grazing area was sub-divided into 20 replicated paddocks of equivalent size and topography. Grazing pairs of either control or treated animals were randomly assigned to each paddock over the duration of the study (one pair per paddock).Grazing behaviour was recorded for both groups over a 10-day period commencing 4 days after treatment with eprinomectin. Milk yield was recorded daily and milk quality was recorded weekly. Live weight and body condition score were recorded on the day of allocation, the day of initial treatment and thereafter at weekly intervals until the end of the 4-week trial.Faecal samples were collected from each animal prior to, and after, allocation and submitted for counts of nematode eggs. Additional faecal samples were taken at the end of the study for culture and nematode identification. Individual faecal samples were also analysed for residual digestibility. Pasture samples for nematode larval counts were taken at the same time as faecal sampling. The parasitological results showed low levels of faecal nematode egg output throughout the study, with the heifers having higher counts than the cows. Faecal culture yielded species of Ostertagia, Cooperia, and Trichostrongylus. Pasture larval levels were very low throughout with no value exceeding 68larvae/kg dry matter (DM) of herbage.There were significant (P < 0.05) effects of treatment on grazing time, eating time, total bites, total grazing jaw movements (TGJM), idling time and mean meal duration. Treated cows and heifers grazed for 47 and 50min longer per day, respectively, than controls (P = 0.016). Mean meal duration was extended as a result of anthelmintic treatment by 11 and 38min, in cows and heifers, respectively (P = 0.012). There were no significant (P > 0.05) treatment effects on ruminating time or residual faecal digestibility, but idling time was significantly reduced in both treated cows and heifers, by 50 and 110min, respectively (P = 0.010).In the treated cattle, there was an increase in solids-corrected milk yield compared with the control cattle, which was significant (P < 0.05) in weeks 2 and 3 after treatment. The response was particularly marked in heifers, where the difference in yield between treated and controls was up to 2.35kg/day. The differences in live weight gain and condition score over 28 days post-treatment were significant (P < 0.05) in both cows and heifers, in favour of the treated animals. [Copyright &y& Elsevier]

Pairs of ewes or heifers were allowed to graze for short periods from previously prepared ‘homogeneous’ areas of ryegrass, in order to study their bite dimensions and movement patterns and to investigate the role of different species in initiating spatial heterogeneity. Apparent bite area was calculated from number of bites and total bitten area when ewes or heifers took 10–15 bites from an 80 cm×80 cm area in a homogeneous Lolium perenne sward. Apparent bite depth was calculated from sward surface height (SSH) within and adjacent to bitten areas. Apparent bite mass was calculated from grazed stratum bulk density. Incisor arcade breadth was measured. Animals also grazed 20 m×40 m plots for 45 min. Position and activity were recorded and distance travelled calculated. Number of bites and steps, number and duration of grazing bouts, feeding station dimensions and horizontal head sweep were recorded. Bites per bout, per feeding station and per m forward movement, bite rate, inter-bout interval, and distance travelled, speed of movement, number of steps, step length and step rate within and between bouts were calculated. Distribution of grazing bout and inter-bout durations and the animals’ foraging paths were tested for randomness.Apparent bite area for heifers was 2.2 times that for ewes and incisor arcade breadth 1.8 times that for ewes. Apparent bite depths were similar at 0.35 of SSH. SSH distribution within bitten areas was non-normal and differed between animal species. Heifers’ bite mass was 2.1 times that for ewes. Heifers had longer grazing bouts, more feeding stations per bout, moved farther per bout but had similar movement speed while grazing. Distance between feeding stations was similar between species but heifers’ feeding station residence time was twice as long. Heifers’ biting rate was lower but they took more bites per bout, per feeding station and per metre of forward movement. Mean head sweep distance was greater for heifers. Both species moved a similar distance between grazing bouts but ewes moved more slowly with more, shorter steps. For both species, grazing bout and inter-bout durations were not randomly distributed. At a 1 m2 scale for both species and a 5 m2 scale for heifers, movement was non-random with a strong propensity to walk in a straight line but at a 5 m2 scale sheep movement was uniformly distributed on the circle. [Copyright &y& Elsevier]

Using heterogeneous vegetation through grazing is a necessary component of de-intensification of livestock systems and conservation of natural environments. Better understanding of the dynamics of animal feeding behaviour is therefore needed, in particular in response to feed diversity and variability. On the basis of three on-farm experiments with ewes and goats, we improved a direct observation method that links intake behavioural response with variations in plant structure. This method makes it possible to continuously and closely monitor an individual animal’s ingestive behaviour during the daily meals, by recording the mass and nutritive quality of its ingestive bites in situ and within its group. “Language” stemming from a coding grid for “bite categories” is proposed for real-time recording of all the bites taken from the full range of available plant parts. Bite categories are defined in order to be applicable to diverse and numerous plant species which allowed real-time recording in very diversified environments, while the impact of grazing alters the plant structure. The continuous presence of an observer does not appear to disturb the animals being monitored, since the variations of their total daily intake time and their diet quality are close to the ones of the groups. The dynamics of ingestive behaviour is explored at different time scales: daily intakes, meal kinetics and biting process. Daily intakes were similar for dry ewes grazing swards invaded by shrubs (77.9±10.2 and 75.1±16.9 g DM/kg LW0.75). They were much higher for lactating goats browsing within a shrub encroached oak coppice (125.8±7.5 g DM/kg LW0.75). Cumulative meal kinetics were quite regular and their slopes are of descending form. Our method allowed characterising the huge diversity of bite types that compose such a regular meal. Bite mass ranged between 0.01 and 1.72 g DM. Instantaneous DM intake rate and instantaneous quality of intake were highly variable (i.e. about 20% of variation in OM digestibility during a single meal). At the scale of biting, our method allows to explore the effect of plant structure alteration on the ingestive response and the resulting intake rate. We confirm that intake rate is more influenced by the mass than by the frequency of bites. The main advantage of this method lies in its capacity to characterise bite intake dynamics in very diversified vegetation, from the very short term, i.e. the meal components, to the long term, i.e. several days in a paddock. [Copyright &y& Elsevier]

In contrast to horses in pastures, it is thought that free-ranging horses do not perform latrine behaviour, i.e. a behavioural pattern whereby the animals graze and defecate in separate areas. However, few studies deal with this particular subject, reporting contrasting conclusions. We hypothesize that horses free-ranging in large heterogeneous areas do not perform latrine behaviour. Thus, we believe that grazing and elimination behaviour are spatially related: where horses graze, they will also defecate. Behavioural data were collected from Konik horses, Haflinger horses, Shetland ponies and donkeys, grazing in different nature reserves (54–80 ha). Data for the different equids were analyzed separately, as well as data for mares and stallions (Konik and donkey stallions only). We investigated the proportion of the number of defecations/urinations while grazing on the total number of defecations/urinations; furthermore, we searched for the sequence of behaviours representing latrine behaviour in the strict sense. Additionally, we analyzed the correlation between grazing behaviour and eliminative behaviour on both vegetation type level and patch level. All the female equids often continued grazing while defecating. During urination, grazing ceases in the majority of instances. Cases where a mare terminated grazing in a certain vegetation type and sward height to eliminate in another vegetation type or in another sward height within the same vegetation type were rarely observed. On the vegetation type level as well as on the patch level, there was a highly significant (P<0.001) positive correlation between grazing time and number of eliminations (or eliminating time). The high values of the correlation coefficients (in case of the defecation variables r ranges between 0.553 and 0.955; in case of the urination variables r ranges between 0.370 and 0.839) illustrate that the spatial distribution of the eliminative behaviour can be explained to a high degree by the spatial distribution of the grazing behaviour. Results in the case of the stallions are preliminary, but indicate the same pattern. Horses, free-ranging in large heterogeneous areas, do not perform latrine behaviour, but defecate where they graze. Possibly, animal density is of major importance to explain this behavioural difference with horses in pastures. We suggest that also spatial vegetation heterogeneity and plant productivity of the grazed area, as well as parasite status of the grazing animals could play a role. [Copyright &y& Elsevier]

The grazing process determines not only the nutrient intake of ruminants at pasture but also the intensity of their impact on vegetation. Grazing dynamics are the result of complex interactions between animal and sward characteristics. While sward is being depleted, a decline in intake rate is partly offset by longer grazing time. This behaviour may be controlled by nutritional feedback from digestion and nutrient absorption as the quality of the ingested herbage decreases. To simulate the dynamics of feeding behaviour and intake during sward exploitation, we developed a mechanistic model of intake rate that combines sward architecture and foraging decisions, and we linked this model with another focusing on control of intake. The sward was divided into horizons characterised by bulk density and nutritive value (NDF content and digestibility), enabling prediction of bite mass and potential intake rate for each grazed horizon. Animal decisions were simulated at two levels: (i) animal activity (eating, ruminating or resting) was self-regulated every minute by comparing a motivation-to-eat function with a satiation function based on a digestion and metabolic sub-model; (ii) while eating, the horizon to be grazed was decided through a choice function taking into account the relative availabilities and potential intake rates of the two upper horizons. The model simulates the animal–sward interactions from elementary parameters (bite mass, intake rate, etc.) to integrated outputs (sward height, daily intake, etc.). Hence, the interplay between characteristics of the vegetation and the internal state of the animal is dynamic taken from the level of a few bites to several successive days. Satisfactory validations were obtained on experimental data sets obtained in both rotational grazing with dry ewes and continuous grazing with lactating ewes. The sensitivity analysis highlights the balance between factors that control bite mass and intake rate and factors that control grazing time. Combining both series of factors in the same model represents significant progress in predicting intake at grazing in a mechanistic way. The model makes it possible to explore the balance between intake regulation by nutritional variables (animal needs and sward quality) and by the availability and structure of the sward. Finally, it is a promising tool to explore the sensitivity of the grazing process to characteristics of both sward (height, bulk density, nutritive value) and animals (weight, nutritional requirements, behavioural traits), and to management practices (stocking rate, rotational versus continuous grazing). [Copyright &y& Elsevier]

Studies of the grazing behaviour of ruminants show that there is a recurrent daily pattern of grazing behaviour. Various researchers have hypothesised that this pattern is controlled by daylight, but this theory is difficult to test with grazing animals under field conditions. The total solar eclipse that occurred across parts of Europe on the 11 August 1999 gave a rare opportunity to test this hypothesis.Twelve lactating Holstein–Freisian dairy cows were divided into four groups of three cows, and each group grazed a 0.96 ha grass paddock. The grazing and ruminating behaviour of all 12 cows was recorded automatically for two 24 h periods before and four 24 h periods after the total solar eclipse. The cows were milked twice daily, at approximately 07:00 and 16:30 h.The period of totality of the eclipse started at 10:11 GMT and lasted for 2′02″, during which time light intensity fell to less than 10 lx, i.e. similar to night-time levels. The total time spent grazing in the 24 h period after the eclipse was significantly lower than four of the five other 24 h periods. However, a downward trend in grazing time in the 24 h period before the eclipse makes it difficult to attribute this affect to the eclipse alone. The eclipse had little, if any, effect on ruminating behaviour.The total solar eclipse did not have a major affect on the grazing or ruminating behaviour of the cattle in this study. This suggests that light intensity alone does not play a major role in the control of circadian patterns of grazing behaviour. Other factors (e.g. the integration of light intensity over time, or the quality of light) cannot, however, be excluded. A total solar eclipse provides a useful tool for the investigation of the control of circadian grazing patterns, and further studies are encouraged. [Copyright &y& Elsevier]

Social grouping tendencies are known to influence the grazing behaviour of domestic herbivores. Here, we investigate how the strength of social bonds in a flock influences the choice of grazing location in sheep. Eight experimental ewes of INRA 401 breed grazed in plots in which a preferred feeding site, i.e. a patch of taller grass, was located 35 m away from a socially attractive site, i.e. five sheep confined in a pen, at one end of the plot. These penned sheep were either all familiar or all unfamiliar to the experimental ewes. Each experimental ewe was tested with one or four companions, which were either familiar or unfamiliar to her. The two group sizes, two degrees of familiarity with the penned sheep and two degrees of familiarity with the companions were incorporated into a Latin square design. In a series of 20 min tests, we recorded the behaviour of the experimental ewes by focal sampling and the location of each animal in the plots by scan sampling. As in a previous experiment, ewes in a larger group were more likely to move away from the penned sheep and to graze the preferred feeding site, and were also less vigilant. There was an additive effect of the degree of familiarity: the ewes with familiar companions grazed the preferred feeding site for longer, vocalised less and were less vigilant than those with unfamiliar companions. Inter-individual distances were also reduced when ewes grazed with familiar companions. Conversely, the degree of familiarity with the penned sheep had no effect on the ewes’ behaviour. Differences in the strength of social bonds within a flock are thus likely to affect the formation of subgroups and influence the way herbivores forage in patchy grasslands. [Copyright &y& Elsevier]

This experiment investigated how season-long, free-choice grazing affected weekly cattle grazing behavior and resource use. Our objectives were to determine if known forage preferences change through the season, if feedbacks from previous grazing intensity affect current use, and if resources such as water and salt in combination with a shorter forage base increase grazing time compared to previously rested pasture. Two replicate 24.4-ha grazing enclosures contained four forage types: smooth bromegrass (Bromus inermis), crested wheatgrass (Agropyron desertorum), western wheatgrass (Pascopyrum smithii) and native range. Each forage type was divided into three sub-areas containing either: a water source, a salt block, or forage deferred from use before the experiment (rested). Resource use was tracked with analysis of aerial photos of the pastures before and after the 3-year study and with weekly direct observation of animal use of each area of the pastures. As each season progressed, use of smooth bromegrass declined and use of crested wheatgrass and western wheatgrass increased. Use of native range remained relatively constant and low throughout the study. The previously rested sub-areas of the replicate pastures had significantly and substantially more grazing than those with salt or water. Significant auto-correlation in the data was well described by an auto-regressive parameter comprised of the sum of the previous 2 weeks grazing time, which showed gradual shifts in forage preference from 1 week to the next. Aerial photo analysis supported the findings of the behavioral data; preference between forage types changed over time, and grazing use within pastures was uneven and negatively correlated with salt and water sites. Cattle can rotate themselves among various pasture types if given free-choice; and season-long grazing may be an effective system if a variety of forage types are available. [Copyright &y& Elsevier]

Grazing by cattle on the scale of a single feeding station was studied to determine the patterns of defoliation and bite dimensions in short bite sequences. The sward was a continuous and homogeneous expanse of alfalfa without any imposed patchiness of structure. Treatments were bite sequences of 3, 6, 9 and 12 bites, with the forelegs of the observed animal stationary. Four 18-month-old heifers were used and the treatments were conducted over two grazing cycles. The bite scale defoliation imprints (non-contiguous grazed areas separated by undefoliated vegetation) were marked with white spray paint and photographed for shape and area measurements.The mean pre-grazing plant heights for all lengths of bite sequence were 24.8±0.6 cm (cycle 1) and 20.9±0.7 cm (cycle 2), and the mean grazed (residual) plant heights within the defoliation imprints were 14.4±0.6 cm (cycle 1) and 12.9±0.7 cm (cycle 2). One or more separate defoliation imprints was/were obtained for each length of bite sequence. Each imprint was created by one bite or a number of bites in touching or overlapping locations, and contained few undefoliated plant elements. The bite sequences created a variety of defoliation imprints with irregular, often lobed or fingered shapes, which were clearly related to the number of bites removed. The maximum dimension of the grazed imprint tended to be perpendicular to the orientation of the animal, and increased from 46 and 40 cm in cycles 1 and 2, respectively, after three bites to 76 and 85 cm in cycles 1 and 2, respectively, after 12 bites. The overall mean effective bite areas were 101±6.2 and 115±7.5 cm2 per bite in cycles 1 and 2, respectively. The mean effective bite area tended to decline with bite number in cycle 1 only, but the effect was not significant in the overall model. In the absence of a discrete, imposed feeding station structure, bite placement may result in depletion without depression. Care should be taken in applying patch depletion curves to continuous swards when these are derived from discrete-patch studies in which patch dimensions constrain bite placement. [Copyright &y& Elsevier]

[Display omitted] • Dairy cows divergent for MUNBV express different diurnal ingestive patterns. • Low MUNBV cows consistently have more mastications per bite than high MUNBV cows. • Low MUNBV cows have more chews per boli during different periods of the day. • MUNBV divergent cows grazing strategies differ at the same herbage allowance. The objective of this study was to describe the diurnal pattern of grazing behaviour of multi-parous dairy cows divergent for milk urea N breeding values (MUNBV) and the consistency of these differences across different sward compositions (perennial ryegrass [RG; Lolium perenne L.] or ryegrass with plantain [ Plantago lanceolata L.; RGPL]) and stages of lactation (early and late lactation). Jaw movement recorders were fitted to 24 animals in early lactation and 16 cows in late lactation, in early lactation 12 cows were assigned to the ryegrass diet and 12 cows assigned to the plantain diet, in late lactation 8 cows were assigned to ryegrass with the remaining 8 cows assigned to the plantain diet. For each diet half of the animals during both stages of lactation were classified as high for MUNBV and the other half as low for MUNBV. Low MUNBV animals had more mastications per bite over the day (P < 0.01) with a one-unit decrease in MUNBV resulting in 0.07 more bites per mastication during the first two grazing bouts, as well as differences in the temporal distribution of grazing bouts compared with high MUNBV cows. A one-unit decrease in MUNBV resulted in a 0.11 ± 0.02 increase in mastications per bite during the first grazing bout across both stages of lactation and sward composition. Ingestive behaviour has a large impact on the physical features of ingesta and thereby rumen function. The results of this study indicate that dairy cows divergent for MUNBV grazing the same forage apply different grazing strategies in terms of oral processing of ingesta and diurnal meal pattern. These results present potential explanatory variables for phenotypical differences observed in dairy cows divergent for MUNBV. [ABSTRACT FROM AUTHOR]