Search

According to the Optimal Foraging Theory, large herbivores, characterized as quantum feeders, should minimize the time for food search while foraging, in order to maximise food intake. As part of an on-going research project on beef cattle production in the forest, I studied the food search behaviour of cows during foraging bouts. I observed the behaviour of beef cattle on two common lands, Stange-Romedal Almenning (SRA) and Furnes-Vang Almenning (FVA) during summer 2016. The cattle ranges were situated in a heterogenous, forested landscape of the boreal forest zone, with the food distributed in patches on clear-cuts and along forest roads. I predicted that the frequency and time used for search depended on 1) season (spring June/July and fall August/September), 2) lactation status (dry cows and lactating cows), 3) available vegetation composition, measured as ground cover for different species groups, 4) time of day (morning 08:00-14:00 and evening 14:00-21:00), 5) livestock density (FVA high and SRA low density), and 6) breed size (intermediate and large). We monitored randomly selected, foraging cows continuously during sequences of 1 sec to over one hour and registered each change of behaviour with a timer. Search was defined as translocation with head down while not feeding, and did not include walking between grazing patches with head up. The cows used only 3.3% of the total observation time for search. They searched more frequently and longer in fall compared to spring. Lactating cows searched less than dry cows, and search frequency and time decreased with increasing ground cover of grass and herbs. Dry cows searched more in the evening than in the morning, while there was no time-of-day effect for lactating cows. In the high stocking density area FVA, search increased from spring to fall, while there was no relation between search and season in the low stocking area SRA. Search behaviour was not related to breed size in my study. My results combined with those of Dickel (2017) on feeding behaviour of cattle indicate that the heterogenous and patchy environment still allows the cows to feed in long bouts without long and frequent interruptions for food search, and that their behaviour is adapted to their nutritional needs. I følge den «optimale beiteteorien» skal store herbivore dyr bruke minst tid på å finne mat mens de beiter, siden de trenger et visst kvantum av mat. Som en del av et større forskningsprosjekt om kjøttfeproduksjon i skog studerte jeg kyrnes søk etter føde under beiting. Jeg observerte adferden til storfe som er nyttet til kjøttproduksjon i to studieområder, Furnes-Vang Allmenninger (FVA) og Stange-Romedal Allmenning (SRA) på utmarksbeite sommeren 2016. Utmarksbeitet er i et heterogent mellomboreal skogslandskap der maten finnes flekkvis på hogstflater og langs skogsbilveier. Jeg forventet at 1) sesong (vår er juni/juli og høsten er august/september), 2) laktasjon (ku med/uten kalv), 3) tilgjengelig vegetasjon målt som dekningsgrad av ulike plantegrupper, 4) tid på døgn (morgen 08:00-14:00 og kveld 14:01-21:00), 5) dyretetthet (FVA høy og SRA lav dyretetthet), og 6) rasestørrelse (mellomstore og store raser) vil påvirke både hyppigheten og tiden som kyrne bruker til å søke mat under beiting. Vi observerte tilfeldige, beitende dyrene kontinuerlig for sekvenser på 1 sekund til over 1 time, og registrerte alle atferdsendringene med stoppeklokke. Søk var definert som forflytning med hode ned uten spising, og ekskluderte forflytning med hode opp. Kyrne brukte bare 3.3% av den totale observasjonstiden til søk. De søkte oftere og lengre om høsten enn om våren, lakterende kyr søkte mindre enn gjeldkyr, søkehyppighet og –tid avtok med økende dekke av grass og urter, gjeldkyr søkte mer om morgen enn om kvelden, mens lakterende kyr hadde ingen forskjell på søk mellom morgen og kvelden, og i FVA (høy dyretetthet) økte søk om høsten mens i SRA (lav tetthet) ble det ikke noen forskjeller mellom sesongene. Størrelsen på rasen hadde ingen innvirkning på søk i dette studiet. Mine resultater sammen med resultatene til Dickel (2017) på beiteadferd til storfe i skogen indikerer at kyrne til tross for det heterogene habitatet klarer å beite på samme flekk uten lange og hyppige avbrudd, og at deres beiteatferd er tilpasset til deres energibehov.

Les Nématodes Gastro-Intestinaux (NGI) sont des parasites présents dans la totalité des élevages de petits ruminants au pâturage. Les symptômes dépendent des espèces de parasites et d’hôtes, mais peuvent aller de la simple perte de poids à la mort, dans un contexte d’élevage intensif. Outre le bien-être animal, les NGI impliquent des pertes économiques pour l’éleveur. Même si, globalement tous les animaux d’un troupeau sont exposés, le timing et le nombre de larves ingérées sont importants car cela déterminera le futur niveau de résistance et d'infestation de l’animal, et influencera en retour la dynamique de la population des stades infestants des parasites sur la parcelle. L’observation directe du nombre de larves ingérées par les animaux est un travail trop fastidieux et une approche de modélisation est nécessaire. Dans cette étude, nous avons voulu caractériser la répartition du risque d’infestation au sein d’un troupeau au pâturage tournant, consistant à laisser les animaux pâturer sur un ensemble de cinq parcelles, pour une durée d’une semaine par parcelle. Nous avons d’abord photographié deux troupeaux à l’aide d’un drone pour déterminer les positions GPS des individus. Ceci nous a permis de calculer des fréquences d’occupation des quadrats de la parcelle, et à l’aide d’une approche en simulation, nous avons pu estimer les cartes de répartition des larves sur la parcelle. Ces cartes nous ont enfin permis d’estimer le risque d’infestation des animaux réentrant sur la parcelle 5 semaines après. Nous avons montré que le risque d’infestation est réparti de manière à peu près uniforme pour la plupart des individus, mais qu’une faible proportion du troupeau ingérait un plus grand ou un plus petit nombre de larves. Nous avons également effectué une analyse de sensibilité pour discuter ces résultats. En termes de modélisation, ce travail pourrait entre autre permettre de mieux définir le nombre de larves ingérées par individus. Plus généralement cette approche pourrait permettre d’identifier des zones à fort risque au sein d’une parcelle, ainsi que des animaux potentiellement infestés.

Relative to temperate systems, there has been few reported detailed assessments of sward characteristics and associated grazing behavior from natural and established pastures in Nigeria. This study reviewed the important relationship between sward characteristics and grazing behaviour and discusses the implications of canopy characteristics for short-term intake. The review is divided into two sections with the first part highlighting the influence of sward characteristics (sward height, forage mass and sward maturity) as a means of manipulating grazing behaviour of ruminants. The second part brought to fore the process of grazing, bite feature and short-term grazing trials. The review showed that cattle prefer short dense leafy swards compared to senescent plant materials. This is based on research results suggesting that short dense sward possess high quantity of green materials which is relished by ruminants during grazing. The feasibility of intensifying grazing studies in the tropics, particularly in Nigeria, to examine the behaviour of ruminants in highly heterogeneous pastures has the potential to provide integrated (sward, animal, management) strategies for sustainable livestock production in Nigeria.Key Words: Sward characteristics; Grazing behaviour; Intake rate; Sward height; Forage mass; Ruminants.

Studies in grassland management and ecology have always been challenging because of the large amount and great variation of the entities representing and affecting the system. Despite that, we were able to progress significantly in range experimentation in the Campos, in Southern Brazil. Along past thirty years, a large amount of data and information was generated, from vegetation production to components of intake. In an attempt to integrate the information available, seeking for a deeper understanding of the functioning of native grasslands, we propose adapting a mechanistic vegetation model, aggregated of a spatialized grazing component to create PampaGraze. This model was developed for temperate perennial grasslands, and was adapted and tested for subtropical, C4-dominated grasslands of the Campos of Southern Brazil (Chapter III). Despite the limited capacity of field data for validating, the model was able to relatively well simulate the trends in vegetation production along the year and seasons, while overpredicting herbage production during peak growing season. The structure of the model as it is did not allow for an accurate simulation slow-growing, tussock-forming species. Further, we developed and integrated a grazing model, based on a hybrid approach of the classical mechanistic equations of the prey model (STEPHENS & KREBS, 1986), and experimental data on foraging behaviour measured on native grasslands (Chapter IV). The model was very successful on predicting the components of intake, and responded well to variation of components in relation to changes in vegetation and to selectivity pressures, compared to available literature. Regardless of the limitations on the vegetation model, we were able to further explore the relationships of components of intake, identifying possible major limitations for herbage consumption, thus animal performance, in native grasslands. A significant progress was achieved with this thesis, but still long ways to go with this project. A list of suggestions for further developments can be found in Chapter V. We identified the emergent needs for field studies on parameters and morphogenesis, for improving predictions of the vegetation model, as well as structural points of the model that could be addressed for better representation of natural phenomena. This thesis is the first step towards a more detailed and reliable tool for studying and predicting the behaviour of vegetation dynamics and animal production in sub-tropical grasslands. This can allow us to explore relationships and scenarios beyond our experimental capacity, and investigate the connectivity of the system, as well as each mechanism separately. The stage has been set, awaiting further developments.

The effect was evaluated of energy supplementation with ground maize grain on the performance and behaviour of Anglo-Nubian goats under a silvopastoral system of leucena and tropical grasses. The experiment was carried out in an area of Leucaena (Leucaena leucocephala (Lam.) De Wit.) intercropped with a herbaceous layer having a predominance of tropical grasses (Tifton 85, Andropogon and Guinea). A completely randomised design with four treatments and five replications was adopted. Growing goats were used; the control group being fed only on pasture, and the other groups supplemented with ground maize at 0.5, 0.9 and 1.3% of live weight. Supplementation reduced grazing time and increased rumination and idle time; although the goats spent approximately 85% of the time grazing on grasses, indicating a preference for this forage. Energy supplementation increased the weight gain per animal per unit area. Under a silvopastoral system of leucaena and tropical grasses, goats prefer the grasses, however, grazing on the legume results in a protein intake that justifies additional energy input. The supplementation of goats under a silvopastoral system of tropical grasses and leucaena, with maize as an energy source at a rate of up to 1.3% of live weight, influences feeding behaviour, having a favourable effect on animal performance. RESUMO Foi avaliado o efeito da suplementação energética com milho em grão moído no desempenho e comportamento de caprinos da raça Anglonubiana em sistema silvipastoril formado por leucena e gramíneas tropicais. O experimento foi realizado em área formada com Leucena (Leucaena leucocephala (Lam.) de Wit.) consorciada com estrato herbáceo com predominância de gramíneas tropicais (capim-Tifton 85, capim-andropógon e capim-colonião). Adotou-se o delineamento inteiramente casualizado com quatro tratamentos e cinco repetições. Foram utilizados caprinos em crescimento, sendo o grupo controle alimentado apenas com pastagem e os demais grupos suplementados com milho moído a 0,5; 0,9 e 1,3% do peso vivo. A suplementação reduziu o tempo de pastejo das gramíneas e aumentou os tempos de ruminação e ócio, embora os caprinos tenham despendido aproximadamente 85% do tempo pastejando gramíneas, indicando preferência por esta forragem. A suplementação energética aumentou o ganho de peso por animal e por unidade de área. Em sistema silvipastoril formado por leucena e gramíneas tropicais os caprinos preferem as gramíneas, no entanto, o pastejo da leguminosa proporciona consumo de proteína que justifica aporte energético suplementar. A suplementação de caprinos em sistema silvipastoril formado por gramíneas tropicais e leucena com milho como fonte energética na proporção de até 1,3% do peso vivo influencia o comportamento ingestivo, com efeito favorável sobre o desempenho dos animais.

The principles of domestic herbivore nutrition are well understood and have been developed through detailed physiological studies, although methods to accurately measure field-based intake still challenge herbivore nutrition research. Nutritional ecology considers an animal's interaction with the environment based on its nutritional demands. Although there are a number of theoretical frameworks that can be used to explore nutritional ecology, optimal foraging provides a suitable starting point. Optimal foraging models have progressed from deterministic techniques to spatially explicit agent-based simulation methods. The development of optimal foraging modelling points towards opportunities for field-based research to explore behavioural preferences within studies that have an array of nutritional choices that vary both spatially and temporally. A number of techniques including weighing animals, weighing herbage, using markers (both natural and artificial) and sampling forage, using oesophageal-fistulated animals, have been used to determine intake in the field. These intake measurement techniques are generally most suited to studies that occur over a few days and with relatively small (often less than 10) groups of animals. Over the last 10 years, there have been a number of advances in automated behavioural monitoring technology (e.g. global positioning systems) to track animal movement. A number of recent studies have integrated detailed spatial assessments of vegetation using on-ground sampling and satellite remote sensing; these data have been linked to behavioural preferences of herbivores. Although the recent studies still do not address nutritional interactions over months or years, they do point to methods that could be used to address landscape scale nutritional interactions. Emerging telemetry techniques used to monitor herbivore behavioural preferences and also to determine detailed landscape vegetation mapping provide the opportunity for future herbivore nutritional ecology studies.

As pastagens naturais e biodiversas que suportam a pecuária extensiva são caracterizadas por marcada variação da biomassa das espécies botânicas presentes, e do seu estado fenológico ao longo das estações do ano. Nestas circunstâncias, a utilização do alimento e a ocupação do espaço da pastagem podem ser muito heterogéneas devido, entre outras causas, ao comportamento de pastoreio dos ruminantes. Uma gestão eficiente do pastoreio exige conhecimento sobre o mecanismo de ajuste do comportamento de pastoreio à pastagem. Embora exista tecnologia GNSS que possibilita a monitorização do comportamento de pastoreio, o seu custo de aquisição é elevado, limitando a sua aplicação a ensaios científicos. O presente trabalho revê os princípios que permitem a aplicação desta tecnologia e tem por objectivo estudar a utilização de recetores GNSS comerciais de baixo custo ("commercial of the shelf – COTS”: CatTrackTM). Foram utilizados seis recetores, durante seis períodos de recolha de dados, ao longo de dois meses de pastoreio contínuo de uma pastagem natural tendo sido a exactidão dos recetores de 14m e de 40m em testes estáticos e dinâmicos, respectivamente, a precisão de 3m e a fiabilidade de 80%. O equipamento testado permitiu diferenciar as actividades dos animais (pastoreio, repouso e trânsito), determinar a localização de ovinos em pastoreio, e caracterizar padrões, percursos e zonas preferenciais. Conclui-se que o equipamento COTS apresenta uma elevada relação qualidade/preço, pelo que pode vir a ser uma ferramenta importante para suporte das decisões que são essenciais a um maneio mais preciso da pastagem., Revista de Ciências Agrárias, vol. 39 n.º 2 (2016)

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

Yonaguni horse which is a breed of the Japanese Native horse is grazed all the year round in the Zoysia tenuifolia Wild dominant grassland in Yonaguni island. The behavioral ecology of the Yonaguni horses under the extensive management is almost unknown. Understanding the grazing behaviour of the Yonaguni horse is important in order to raise them properly. This study was investigated from the viewpoint of grazing behaviour of the Yonaguni horse, especially maintenance behaviour. A mare in 1-year old age (150 kg body weight) and a stallion in 4-year old age (184 kg body weight) was grazed in the subtropical native pasture year-long. Observation of the Yonaguni horse was carried out continuously for 24 hours from six a.m. till six a.m. next day in June 28～30th, and October 26～28th on 2005. The observation mainly investigated grazing behaviour, rest behaviour, moving behaviour, grooming behaviour, eliminative behaviour yawing, snorting and gassing between mare and stallion were investigated. Grazing behaviour of 24 hours of Yonaguni mare and stallion were the longest time, and the value ranged from 830 minutes to 848 minutes. Secondly resting behaviour of mare and stallion were longer, the time was range from 415-490 minutes. Lying on side behaviour time of a stallion was longer than a mare. Grooming behaviour time was range from 50 minutes to 71 minutes. Although grazing behaviour of horses was often observed in early morning, daytime, late afternoon and midnight, it was measured markedly less at two o'clock afternoon. Resting behaviour of horses was well observed under the spesific tree in the grassland. Standing rest behaviour of mare and stallion were observed throughout a day, especially at two o'clock in the daytime. And lying on belly behaviour and lying on side behaviour were intensively observed during hours between nighttime and early morning. Grooming behaviour of mare and stallion were seen throughout a day, and defication behaviour of both horses were ranged from 7 times to 46 times., 与那国島に生息する与那国馬は日本在来馬の一種で，その多くが海岸沿いのコウライシバ優占草地で周年放牧されているが，その行動生態についてはあまり知られていない。与那国馬の放牧行動を把握することは適切な放牧管理を行うためにも重要である。そこで本研究では，野草地における与那国馬の放牧行動，特に維持行動に着目して調査した。与那国島と同様な粗放管理で与那国馬の雄1頭（４歳齢・体重184kg)，雌１頭（１歳齢・体重150kg）を亜熱帯野草地に放牧した。調査は，2005年６月28日～30日までの３日間，10月26日から28日までの３日間の計６日間行い，午前６時から翌日の午前６時までの連続24時間行動観察した。調査項目は，摂取行動(食草，飲水，舐塩）・休息行動・移動・身繕い行動・排泄行動，あくび，スノート，おなら等であった。与那国馬の１日の放牧行動において，食草行動は，もっとも長く，雌馬，雄馬ともに，830～848分の範囲であった。次に休息行動で415～490分の範囲であった。雄馬の横臥位休息は雌馬と比べ有意に長い時間であった。身繕い行動は50～71分の範囲であった。食草行動は，早朝・昼・夕方・深夜に多く観察され，14時には著しく少なかった。休息行動は特定の木の下でよく観察された。立位休息は雌雄ともに１日を通して見られたが特に14時に多く見られた。また伏臥位休息と横臥位休息は，夜から早朝にかけて集中して多く見られた。身繕い行動は，雌雄馬ともに１日を通して見られ，排糞は７～46回の範囲であった。, 紀要論文

Feeding site selection is a critical part of livestock foraging that can constrain and/or increase the choices available during diet selection. When livestock choose new feeding sites, vegetation and nutrient profiles can differ from other areas, especially in heterogeneous environments with rugged terrain. Correspondingly, livestock should remain longer in feeding sites in rugged heterogeneous pastures than in homogeneous pastures where animals may alternate among feeding sites to facilitate diet mixing and to prevent satiation. The objective of this study was evaluate how terrain and corresponding heterogeneity may affect the sequence and pattern of feeding site selection of free-roaming livestock. Grazing patterns of mature cows were evaluated on six ranches located in Arizona, Montana and New Mexico. In total, 11–19 cows were tracked for 1–3-month periods at each ranch by using global positioning system (GPS) collars. Positions were recorded at 10- or 15-min intervals and used to identify where cows grazed during the early morning (0500 hours to 1000 hours). Pastures (336–9740 ha) at each ranch were divided into seven to nine sections (48–1082 ha) as an indicator of feeding sites. Classification was based on cattle density and topographical and vegetation types. Sequences of daily section selection were evaluated using transition matrixes. For all ranches, the sequence of section selection differed from what would be expected by chance, indicating that the section selected on the following day depended on the section selected on the previous day. For ranches with relatively gentle terrain, cattle selected different feeding sites ~70% of the tracking period. In contrast, cows at the ranch with the largest pasture and enclosing both mountainous and gentle terrain stayed in the same feeding site for over 10 successive days for 42% of the tracking period. Smaller pastures with only mountainous terrain were intermediate. Cows grazing gentle topography and relatively homogeneous vegetation alternated among feeding sites (sections in the present study) more frequently than cows grazing pastures with more rugged topography and more heterogeneous vegetation. This pattern could help livestock mix forages and select a more diverse diet.

Dissertação de Mestrado em Engenharia Zootécnica/Produção Animal O comportamento dos equinos em pastagem integra uma série de escolhas que estão relacionadas com características da vegetação e com o próprio animal. No presente estudo foram avaliadas 15 éguas adultas e 9 poldras alfeiras, totalizando 24 animais, divididas em dois grupos de nível alimentar diferente: a parcela 1 com 7 éguas alimentadas ao nível de manutenção (G100) e 4 poldras em crescimento moderado (CM); a parcela 2 com 8 éguas alimentadas acima da manutenção (G130) e 5 poldras em crescimento óptimo (CO). Pretendeu-se avaliar o comportamento alimentar dos animais, a nível do tempo de busca e preensão de alimento e selecção do alimento. Verificou-se, num total de 13,15 horas de observação, que os animais passaram cerca de 11h horas em procura e ingestão de alimento (82%). Verificou-se que os animais da parcela 1 passaram mais horas em actividade de busca e preensão de alimento (11,44 horas) do que os animais da parcela 2 (11,03 horas). Em todos os animais avaliados se verificou que, as gramíneas, foram a família mais selecionada, no entanto, os animais da parcela 2 selecionaram mais gramíneas e leguminosas que os da parcela 1 (P

The use of corn silage to supplement grazing dairy cows can improve milk production and nutrient intake when the substitution rate is low. This enhancement occurs by increasing the total DM intake. The hypothesis tested in this study was that increasing corn silage supplementation level of dairy cows grazing annual ryegrass at medium pasture allowance could increase substitution rate and decrease milk production response. Three supplementation levels (0, 4 and 8 kg DM/day) were compared for dairy cows strip-grazing annual ryegrass (Lolium multiflorum cv. Common). The study was arranged as a 3 × 3 Latin square design, repeated three times using nine Holstein lactating cows. The supplement was a 7 : 1 mixture based on the DM of corn silage and soybean meal and was offered individually twice daily after the morning and afternoon milkings. Each treatment group of cows grazed separately at a common daily pasture allowance of 35 kg DM/cow to ground level. Each experimental period was 12 days, with an 8-day adaptation and a 4-day measurement period. The individual pasture intake was measured from Day 9 to Day 12 using the n-alkane technique. The daily pattern of grazing and ruminating times were measured by visual observations. The supplement DM intake was lower than expected, averaging 3.0 and 4.3 kg DM/day for cows receiving 4 and 8 kg DM/day, respectively. Pasture and supplement energy value were 7.0 and 6.3 MJ of NEL/kg DM, respectively. The substitution rate averaged 0.2 and was unaffected by the supplementation level. The pasture intake was similar for all treatments (14.0 kg of DM/day), and total DM intake and milk production (+0.5 kg of milk/kg DM of supplement) increased linearly with increasing supplementation level. The daily grazing time was shorter by 111 min/day for the supplemented cows than for the unsupplemented cows. Cows grazing the annual ryegrass at medium pasture allowance improved their total DM intake and individual performance when supplemented with corn silage.

Refereed/Peer-reviewed

Peer-reviewed article Food intake and feeding behaviour of Holstein-Friesian (HF) and Jersey × Holstein- Friesian (J × HF) dairy cows (14 primiparous cows of each genotype) were measured during a 54-day confinement period [cows offered a complete diet comprising conserved forage and concentrates; 66:34 dry matter (DM) basis], while herbage intakes and grazing behaviour were measured on three occasions during a 96-day grazing period. Throughout the experiment HF cows had a higher milk yield than J × HF cows (P < 0.05), while fat + protein yield was unaffected by genotype. During the confinement period HF cows had a higher food intake than the J × HF cows (P < 0.01), although DM intake/kg metabolic live weight (live weight0.75) was unaffected by genotype. With the exception of the number of ruminating bouts/day (P < 0.05), and idling time/day (P < 0.05), both of which were highest with the J × HF cows, genotype had no significant effect on any of the feeding behaviours examined during the confinement period. Herbage intake did not differ between genotypes during the grazing period, although when expressed on a kg live weight0.75 basis, intakes were highest with the J × HF cows (P < 0.05). While the smaller J × HF cows had fewer grazing bouts per day (P < 0.01), the mean duration of each grazing bout was longer (P < 0.001), resulting in a longer total grazing time (P < 0.05) and a greater number of grazing bites each day (P < 0.01). The smaller crossbred cows had to ‘work harder’ during the grazing period to achieve the same intakes as the larger HF cows. Department of Agriculture and Rural Development for Northern Ireland (DARD); Agri-Search

International audience

One of the main aims of pasture-based systems of dairy production is to increase the proportion of grazed grass in the diet. This is most easily achieved by increasing the number of grazing days. However, periods of inclement weather conditions can reduce the number of days at pasture. The two objectives of this experiment were: (i) to investigate the effect of restricting pasture access time on animal production, grazing behaviour and dry matter intake (DMI) of spring calving dairy cows in early lactation; and (ii) to establish whether silage supplementation is required when cows return indoors after short grazing periods. In all, 52 Holstein–Friesian spring calving dairy cows were assigned to a four-treatment study from 25 February to 26 March 2008. The four treatments were: full-time access to pasture (22H; control); 4.5-h- pasture access after both milkings (2 × 4.5H); 3-h pasture access after both milkings (2 × 3H); 3-h pasture access after both milkings with silage supplementation by night (2 × 3SH). All treatments were offered 14.4 kg DM/cow per day herbage from swards, with a mean pre-grazing yield of 1739 kg DM/ha above 4 cm, – and were supplemented with 3 kg DM/cow per day of concentrate. The 2 × 3SH treatment was offered an additional 4 kg DM/cow of grass silage by night. Restricting pasture access time (2 × 3H, 2 × 3SH and 2 × 4.5H) had no effect on milk (28.3 kg/cow per day) and solids-corrected milk (27.2 kg/cow per day) yield when compared with the treatment grazing full time. Supplementing animals with grass silage did not increase milk production when compared with all other treatments. Milk protein concentration tended to be lower (P = 0.08; 32.2 g/kg) for the 2 × 3SH animals when compared with the 22H animals (33.7 g/kg). The grass DMI of the 2 × 3SH treatment was significantly lower (−2.3 kg DM/cow per day) than all other treatments (11.9 kg DM/cow per day), yet the total DMI of these animals was highest (16.6 kg DM/cow per day). The 22H cows grazed for 481 min/cow per day, which is significantly longer than all other treatments. The 2 × 3H animals grazed for 98% of the time, whereas the 2 × 3SH grazed for 79% of their time at pasture. Restricting pasture access time did not affect end body weight or body condition score. The results of this study indicate that restricting pasture access time of dairy cows in early lactation does not affect milk production performance. Furthermore, supplementing cows with grass silage does not increase milk production but reduces grazing efficiency.

Many studies show that large herbivores can have an important impact on the composition of vegetation. With the establishment of a year round, low density grazing regime, plant ecologists and nature managers expect that through selective grazing, herbivores will create a mosaic of different vegetation communities varying in structure and plant species composition. It is believed that such a mosaic in the end will guarantee a high degree of biodiversity. Grazing will, therefore, seem to be a suitable means to maintain grass. Also important is the ability of herbivores affect vegetation through endozoochory. In this thesis I have tried to find out what species of diet horses prefer regarding to plant species and what plant species they can spread through out endozoochory. I have compared this knowledge with the composition of pasture and meadow vegetation at the researched locality in Malenice and Hoslovice. With the purpose of finding out the preferences I established spots where I registered data on vegetation before pasture and the time intervals during the pasture. Afterwards, I researched the amount of sprouts and the composition of seedlings in excrements that I let germinate. I had to create phytocenologic shots from the pastures and meadows to compare the species of composition of grazed and...

International audience; 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 (0.44 ha 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 mediumbites 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.

International audience

Neste estudo avaliou-se a influência da variação nas ofertas de fitomassa ao longo das diferentes estações de crescimento na dinâmica da pastagem e no rendimento animal. Os tratamentos consistiram de quatro ofertas fixas de fitomassa (4,0; 8,0; 12,0 e 16,0%, expresso em kg de MS/100 kg de PV por dia) ao longo da estação de crescimento e três ofertas variáveis (8,0% na primavera e 12,0% no restante da estação de crescimento; 12,0% na primavera e 8,0% no restante da estação de crescimento; e 16,0% na primavera e 12,0% no restante da estação de crescimento). O delineamento experimental foi o de blocos completamente casualizados com duas repetições. O método de pastejo foi o contínuo com lotação variável, utilizando-se a técnica de put-and-take. As produções primária e secundária e o comportamento de novilhos de sobreano foram medidos regularmente. Os resultados comprovaram que situações de oferta de forragem muito baixa, como no tratamento 4,0%, penalizam fortemente o desempenho dos animais. O tratamento de 8,0% na primavera e de 12,0% no restante da estação de crescimento promoveu bons ganhos de peso, sugerindo que esta prática pode ser interessante quando se pretende manipular a estrutura da pastagem. Os resultados do comportamento ingestivo dos animais indicaram que, diferentemente do que ocorre em pastagens cultivadas, a oferta de forragem e a massa de forragem não explicam suficientemente o tempo de pastejo dos animais. Em vegetações heterogêneas, deve-se considerar a diversidade estrutural na caracterização da pastagem visando sua associação ao comportamento em pastejo. This study tested the hypothesis that variation of herbage allowance during the growing season influences pasture dynamics and grazing behaviour. Treatments consisted of four fixed herbage allowances during the entire year (4.0, 8.0, 12.0, and 16.0%, expressed as kg DM/100 kg live weight/day) and three variable herbage allowances (8% in spring and 12% along the rest of the grazing season; 12% spring and 8% along the rest of the grazing season; 16% in spring and 12% along the rest of the grazing season). A randomized complete block design was used, with two replicates. It was used a variable continuous stocking method, using the "put-and-take" technique. Primary and secondary productions were measured, as well as steer grazing behaviour. Results showed that low herbage allowance, as in 4% treatment, jeopardize animal performance. Herbage allowance of 8% in spring and 12% along the rest of the grazing season promoted good animal performance, suggesting this management could be interesting when manipulating sward structure. Concerning grazing behaviour, results indicated that differently from what occurs in cultivated pastures, herbage allowance or herbage mass did not explain sufficiently the grazing time observed. It was concluded that in heterogeneous vegetation, it must be considered the structural diversity on pasture characterization in order to link that with grazing behaviour.

8 páginas, 4 figuras.-- Trabajo presentado a la XLVI Reunión Cientifica de la SEEP celebrada en Vitoria (España) del 4 al 8 de Junio de 2007., [EN]: Behaviour and spatial distribution of a 2800 sheep flock along its stay in a Pyrenean summer range has been studied. Sheep were conducted by shepherds during the first half of the grazing period and grazed freely the second half. The main activity and distribution of the flock was recorded in a daily basis. By means of a geographic information system, grazing distribution was superimposed to different layers related to vegetation and topographic variables. The selection by the flock of those variables has been analyzed taking into account two modes of grazing activity (“moving” and “still”) and two situations (“herded” and “unherded”). In free grazing sheep chosen higher elevations and steeper slopes, the explored surface was higher, and the ratio of “grazing in movement” increased. In the two periods and for the two modes of grazing, grasslands of Bromion, Nardion and Saponarion were selected. In the first period, while grazing in movement, sheep selected also grasslands under wood, and during the second period they selected grasslands of Elynion during “still grazing” and of Festuca eskia and F. scopariae during “grazing in movement”., [ES]: En este trabajo se ha estudiado el comportamiento y distribución espacial de un rebaño de 2800 ovejas durante su estancia en un puerto de verano del Pirineo occidental. La primera mitad del periodo de pastoreo se realizó con pastor y la segunda mitad en pastoreo libre. Se registró diariamente la distribución y la actividad principal del rebaño y por medio de un sistema de información geográfico se superpuso esta distribución a capas relacionadas con variables topográficas y de vegetación. Se ha estudiado la selección por dichas variables para dos actividades (pastoreo en movimiento y estacionario), y cuando el rebaño es guiado y en ausencia de pastor. En pastoreo libre las ovejas seleccionaron altitudes y pendientes más elevadas, la superficie explorada fue mayor y aumentó la proporción de pastoreo en movimiento. En los dos periodos y actividades, se seleccionan los pastos de Bromion, Nardion y Saponarion. En el primer periodo, durante el pastoreo en movimiento, las ovejas seleccionaron también el pasto bajo leñosas, y durante el segundo periodo, seleccionaron también los pastos de Elynion en el pastoreo estacionario, y los de Festucion eskiae y F. scopariae en el pastoreo en movimiento., Este trabajo se ha realizado con ayuda de los proyectos de investigación CGL2005-01131/BOS del Plan Nacional y RTA2005-00160-C02-00 del INIA.

International audience; The effect of the structure of a tropical pasture, based on Dichanthium spp., on the ingestive behaviour, in vivo digestibility of the diet and herbage intake by eight Creole tethered heifers was studied. Two levels of nitrogen fertilizer (0 and 50 kg ha-1) were applied to plots after each grazing cycle and there were 28 d between each of the three grazing cycles. Four heifers grazed indivi- dual subplots daily on each plot for 14 d in each of the successive grazing cycles. Simultaneous measurements of bite depth, bite mass, biting rate, short-term intake rate and daily grazing time were made in two 4-d periods at the end of each 14-d period. The in vivo organic matter digestibility (OMD) and daily herbage organic matter intake (OMI, expressed on a kg LW0·75 basis) were also measured at the same times. Relationships among pasture characteristics and ingestive behaviour were similar to those reported in other short-term studies: pasture height was highly correlated with bite depth, bite mass and biting rate (r = 0·91, r =0·79 and r = −0·68, respectively, P < 0·001). Pasture variables had lower correlations with grazing time and short-term intake rate than with bite depth, bite mass and biting rate. Pasture structure was more highly correlated with OMD than OMI: leaf mass and length and also the extended tiller length were highly correlated with OMD (r = 0·77, r = 0·76 and r = 0·72, respectively, P < 0·001) whereas the crude protein concentration of the herbage was correlated with OMI and digestible OMI (r = 0·50 and r = 0·69, respectively, P < 0·001). Ingestive behaviour variables, as well as OMD, were correlated more with pasture characteristics than was OMI.

Physiological and nutritional factors that influence the population dynamics of North Sea copepods were identified. Five digestive enzymes were measured in individual copepods. Short-term starvation elicited complex enzyme reactions. Protease isozyme patterns did not change. Seston C:N and POP:TPP correlated with reproductive success. Grazing behaviour and digestive system mediated the effect. Copepods took up N:P in ratios matching their body ratios. C:N and POP ingestion followed the seston pattern. Compensatory feeding was observed. Food quality and stable isotope signatures changed over time (Helgoland, 2004-2005) and between GLOBEC-stations (southern North Sea). Seston d15N and d13C revealed major composition shifts in spring and a strong heterotroph component in summer. A. clausi and T. longicornis utilised different carbon sources despite similar high trophic levels. A low seston d13C (spring) was favourable. Chitobiase activity indicated C assimilation, the other enzymes N assimilation. A low body d13C may denote high turnover rates. Combining methods explains zooplankton- phytoplankton interactions better than only one approach.

International audience

A small herd of donkeys was introduced in a coastal dune reserve ‘Houtsaegerduinen’ (ca. 80 ha) 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 (21.5 bites/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.

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 (1500m 2 ), the application of a high stocking rate (HSR) produced a resource of good quality but low quantity, and on the larger plot (3000m 2 ) 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.

Undesirable grazing distribution results in land degradation and inefficient forage utilization. Rewards like food supplements have been commonly provided at predictable times and locations in the less preferred areas in order to improve grazing distribution. The problem with this approach is the generation of search patterns that are concentrated at certain times and locations, causing either overgrazing of new areas or the rapid return of the animals to the most preferred areas. Our model of spatial–temporal schedule of reinforcement proposes that rewards that are unpredictable in space and time should promote search patterns that are extended in space and time. In order to test predictions from the model, we studied how the spatial–temporal arrangement of supplementation influenced selection of feeding sites by sheep on a grass-legume pasture. Each experimental plot had a fertilized and an unfertilized side (8 m × 16 m each) either adjacent (Trial 1) or separated by an alley (1 m × 32 m) (Trial 2). In both trials groups of three ewes were randomly assigned to each of four treatments resulting from the combination of two spatial and two temporal arrangements of supplementation in the unfertilized side of the pasture. All treatments received the same amount and type of supplement (500 g alfalfa/corn pellets per ewe per day). There were two repetitions per treatment. Animal positions were recorded every 2 min during 2 h daily grazing sessions for 12 (Trial 1) or eight (Trial 2) consecutive days. The response variable was the proportion of time spent on the unfertilized side of the pasture. In Trial 1 neither treatment effects nor the interaction treatment by day was significant (P > 0.05). In Trial 2, the random spatial and/or temporal arrangements of supplementation tended to increase the occupation of the unfertilized side of the pasture by sheep. The differences among treatments were larger at the beginning of the trial, when the availability of forage was relatively higher than towards the end of the trial, when the availability of forage was relatively lower. In both trials the proportion of time spent on the unfertilized side of the pasture decreased (P < 0.01) as the daily grazing session progressed from the first half hour to the second half hour to the last hour. Our results raise some interesting possibilities that warrant future tests of the model of spatial–temporal schedule of reinforcement to modify selection of feeding sites by free grazing animals. Fil: Distel, Roberto Alejandro. Universidad Nacional del Sur. Departamento de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina Fil: Soca, P. M.. Facultad de Agronomía ; Uruguay Fil: Demment, M. W.. University of California at Davis; Estados Unidos Fil: Laca, E. A.. University of California at Davis; Estados Unidos

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 (Pr 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.

This study was performed to gain more knowledge about the behaviour and habitat use of Haflinger mares, free-ranging in a low-productivity dune area. Detailed data on these animals' time budgets were collected over a full year, through the focal animal observation technique. On average the Haflinger horses spent 68% of the daytime grazing, 18% resting and 8% walking. Seasonal features influenced horses' behaviour, mainly through a change in grazing time. Shorter grazing time in summer allowed the animals to rest longer than during the other seasons. We suggest that especially the decreased forage quality and quantity of the grazed habitats in the non- growing season account for the increased grazing time in autumn and winter. In all four seasons the horses preferred grazing in the grassy habitat. However, habitat use showed seasonal variation. Grey dunes were grazed more intensively in winter and spring, compared to summer and autumn. The contribution of roughage, scrub and woodland to the habitat use was low over the entire year. For several response variables the observed variation could be partly explained by the differences between individual animals.

Foi estudado o comportamento em pastejo, o desempenho ponderal e o nível de infestação parasitária em ovelhas da raça Suffolk, no período de 1994 a 1995, em Nova Odessa, SP. Comparou-se dois sistemas de manejo: pastejo restrito, onde os animais foram soltos às 9:50h e presos às 17:30h e pastejo em período integral, no qual os animais não eram recolhidos, tendo a disposição abrigo para passarem a noite. Foram utilizadas 34 fêmeas adultas no verão (17 em pastejo livre e 17 em pastejo restrito) e 42 fêmeas adultas no inverno (21 em pastejo livre e 21 em pastejo restrito). Trabalhou-se ainda com 12 animais traçadores em cada estação do ano, sendo metade em cada sistema de manejo visando a contagem de nematódeos no trato digestivo dos animais. Durante 3 dias consecutivos nos meses de janeiro/fevereiro (verão) e julho/agosto (inverno) estudou-se, através da observação dos animais, a cada 30 minutos entre as 7:00 e 17:30h, o hábito de pastejo (pastando ou não; na sombra ou no sol). Acompanhou-se o nível de infestação parasitária dos animais em cada sistema, pela contagem do OPG do rebanho e dos traçadores e nematódeos recuperados nos traçadores. Concluiu-se que a restrição do horário de pastejo isoladamente não propiciou um controle efetivo da infestação parasitária nos animais mostrando. A restrição do tempo de pastejo é compensada pela maior atividade dos animais nas horas mais quentes do dia, todavia este comportamento afetou o desempenho, resultando em menor ganho de peso. A maior disponibilidade de forragem, em relação ao consumo estimado, pode explicar a similaridade entre os tempos de pastejo verificados nos dois sistemas de manejo, tanto no verão como no inverno. Grazing behaviour, ponderal growth and level of parasitic infestation were studied in Suffolk breed sheep, from 1994 to 1995, in Nova Odessa, São Paulo. Two management systems were compared: restricted grazing, where the animals were released to the pastures at 9:50 a.m. and confined at 5:30 p.m., and 24 hour grazing, where the animals were maintained all the time in the paddocks, but with access to shelters. Thirty-four adult ewes were used in the summer period (17 under restricted grazing and 17 full-time grazing), and 42 ewes in the winter period (21 with restricted grazing and 21 full-time grazing). Also, for both seasons, 12 tracer animals, six in each grazing system, were used to obtain worm counts from their digestive tracts. For three consecutive days, grazing behaviour, that is, whether grazing or not, was observed in January/February (summer) and July/August (winter) at 30 minute intervals from 7:00 a.m. to 5:30 p.m., also whether the animals stayed in the sun or shade, irrespective of whether they were grazing or not. The level of parasitic infestation was evaluated under each system by eggs per gram countings (EPG) of the herd and the tracer animals, as well as by larvae count. It was concluded that restriction of grazing time by itself does not provide any effective control of parasitic infestation in sheep, however a better control was obtained in the summer period. Restricted grazing time was compensated by the greater activity of the animals during the hotter hours of the day, however, this behaviour affected the animal performance, resulting in lower weight gains. Greater forage availability in relation to estimated consumption may explain the similarity between the grazing times observed in both management systems, either in the summer or in the winter.

Sward utilization by goats decreased as time spent on the same field decreased. The authors detected the variables affecting grazing behaviour by using anosmic goats.

Twenty-four female pluriparous crossbred Maltese goats were used to study the effect of supplementary feeding on goats grazing behaviour. The experiment was carried out between 11 May and 7 June 1992. The goats were allocated to three groups: group 1, receiving 2.4 kg of rehydrated chick-pea grain (300 g dry matter per goat per day); group 2, receiving 2.4 kg crushed whole barley grain (300 g dry matter per goat per day); group 3 (control group), without food supplementation. Within each group the goats were randomly and equally allocated to either treatment 1, with rumen fistula or treatment 2, with faecal rectal bag. The goats grazed during the day from 10:00 to 16:00 h, Italian Summer Time and were penned in the evening in large strawed pens. The grazing activity was recorded by a time sampling technique every ten minutes. Grazing activity significantly increased over the experimental period (P