Associations of Grazing and Rumination Behaviours with Performance Parameters in Spring-Calving Dairy Cows in a Pasture-Based Grazing System.

This study investigated the relationship of the length of time spent grazing and ruminating with the performance parameters of spring-calved grazing dairy cows (n = 162) over the lactation period for three lactation seasons (n = 54 per season). The cows were Holstein Friesian (HFR), Jersey (JE), and a crossbreed of Holstein Friesian/Jersey (KiwiCross), with 18 cows from each breed. The cows were either in their 1st, 2nd, 3rd, or 4th lactation year, and had different breeding worth (BW) index values (103 < BW > 151). The cows were managed through a rotational grazing scheme with once-a-day milking in the morning at 05:00 h. The cows were mainly fed on grazed pastures consisting of perennial ryegrass (Lolium perenne), red clover (Trifolium pretense), and white clover (Trifolium repens), and received additional feeds on various days in the summer and autumn seasons. This study used an automated AfiCollar device to continuously record the grazing time and rumination time (min/h) of the individual cows throughout the lactation period (~270 days) for three consecutive years (Year-1, Year-2, and Year-3). The milk yield, milk fat, milk protein, milk solids, liveweight, and body condition score data of the individual animals for the study years were provided by the farm. PROC CORR was used in SAS to determine the correlation coefficients (r) between the behaviour and production parameters. A general linear model fitted with breed × lactation year, individual cows, seasons, feed within the season, grazing time, rumination time, as well as their interactions, was assessed to test the differences in milk yield, milk fat, milk protein, milk solids, liveweight, and body condition score. The type I sum of squares values were used to quantify the magnitude of variance explained by each of the study factors and their interactions in the study variables. Grazing time exhibited positive associations with MY (r = 0.34), MF (r = 0.43), MP (r = 0.22), MS (r = 0.39), LW (r = -0.47), and BCS (r = -0.24) throughout the study years. Rumination time was associated with MY (r = 0.64), MF (r = 0.57), MP (r = 0.52), and MS (r = 0.57) in all study years, while there were no effects of rumination time on LW (r = 0.26) and BCS (r = -0.26). Grazing time explained up to 0.32%, 0.49%, 0.17%, 0.31%, 0.2%, and 0.02%, and rumination time explained up to 0.39%, 6.73%, 4.63%, 6.53%, 0.44%, and 0.17% of the variance in MY, MF, MP, MS, LW, and BCS, respectively.

Stall-Feeding of Sheep on Restricted Grazing: Effects on Performance and Serum Metabolites, Ruminal Fermentation, and Fecal Microbiota.

This study investigated the effects of three feeding systems, indoor feeding (CONT), indoor feeding with time-restricted grazing artificial pasture (4 h/day, G4H), and indoor feeding with an eight-hour daily grazing artificial pasture (G8H), on the growth performance, serum metabolites, ruminal fermentation, and fecal microbiota composition of lambs. Average daily gain showed a tendency (p = 0.081) to be higher for the G4H group compared with the CONT group. Moreover, feeding systems did not have a significant effect on most of the serum biochemical indicators in lambs. Concentrations of serum glutathione peroxidase and immunoglobulins (IgA, gG, and IgM) were significantly lower (p < 0.01) in the CONT group. Additionally, a tendency towards higher levels of volatile fatty acids, acetate, and butyrate was found in animals of the G4H group compared to the CONT group. Furthermore, fecal microbiota composition was altered in G4H and G8H groups, resulting in the increased relative abundance of Firmicutes and Ruminococcaceae UCG-005, as well as the decreased relative abundance of Ruminobacter compared with the CONT group. Overall, these results suggest that indoor feeding with restricted grazing time does not significantly affect fattening performance or rumen fermentation but enhances antioxidation and immune function activity and also alters fecal microbiota composition.

Effects of rotation grazing time on the characteristics of soil seed bank in desert steppe.

Exploring the characteristics of soil seed bank under seasonal grazing plays an important role in the reasonable use of desert steppe. We examined seed bank species composition, density, vertical distribution, diversity in the soil of 0-5, 5-10, 10-15 cm soil layers and the relationship with vegetation and soil environmental factors in Ningxia desert steppe. The treatments included enclosure (FY), traditional time rotation grazing (FG), delayed to start rotation grazing (YG), early to end rotation grazing (TG), delayed to start and early to end rotation grazing (YT) and free grazing (ZY). The results showed that there were nine families and 21 species in the soil seed bank in the study area. The species composition of soil seed bank in TG seed bank with 13 species was the largest, while FY and ZY soil seed banks had the least, with 8 species, respectively. The den-sity of ZY soil seed bank was significantly higher than that of FY, YG, TG and YT. The number of perennial species seeds in the soil seed bank of FY was the largest, reaching 32.0%, while that in the ZY was the least, only 12.4%, mainly with sexually reproduced annual weeds. Soil seed bank was mainly concentrated in the 0-5 cm surface layer. With increasing soil depth, the size of soil seed bank decreased. The dominance and diversity of soil seed bank were the highest in FY, while the dominance, diversity and uniformity were the lowest in ZY. The similarity between soil seed bank and aboveground vegetation was generally low. In contrast, the FG and ZY seed banks had higher similarity with vegetation, and the FY was the lowest. Soil moisture, organic matter, total nitrogen concentration, total phosphorus concentration, and soil bulk density were the main soil factors affecting soil seed bank. Compared with traditional whole year free grazing, seasonal four-zone rotation grazing could increase species richness and abundance of perennial plants in soil seed bank of desert steppe, as well as the total species richness, diversity and uniformity of the seed bank. Although the effect sof seasonal four-zone rotation grazing on seed bank was not as good as the long-term enclosure grassland, it was of great significance to the utilization and protection of desert steppe.

Ingestive Behavior of Young Lambs on Contrasting Tropical Grass Sward Heights.

The efficiency of grazing ruminant production systems is directly associated to the animals' ingestive behavior, and to structural characteristics of the pastures. The objective of this study was to evaluate the ingestive behavior of young lambs grazing three different heights of Capim Aruana (Panicum maximum). The experiment was carried out in two consecutive years, in which 30 tester lambs (4-5 months old) were equally divided into three paddocks (treatments) corresponding to different average sward heights of Aruana grass: (1) Tall-75 cm; (2) Medium-50 cm; and (3) Short-25 cm in a randomized block design. Ingestive behavior assessments were carried out every 28 days through 10-min observations of the main activities of the animals (grazing, ruminating, idling) and biting rate, from sunrise to sunset. In addition, the productive and qualitative characteristics of the pastures were assessed. Despite differences in pasture structure, grazing time (GT) and idling time were similar among treatments (P = 0.4266 and P = 0.2939, respectively). The shortest ruminating time (RT, P = 0.0181) was recorded in the treatment of lowest sward height. Lambs grazing on this treatment also showed 23% more bites per minute (P= < 0.0001) than animals in the Tall and Medium treatments. A Decision Tree analysis was performed for GT, identifying in a hierarchical order that the initial weight of the animals and sward height explained 62% (R 2 = 0.621) of the variation, representing the variables with the greatest influence on GT. Initial body weight explained 48% of the model. Thus, our research shows that the different sward heights of Capim Aruana mainly alter the lamb's RT and biting rate, and that the animals' initial body weight is a key factor influencing GT, given that this variable makes lambs more susceptible to changes in sward height.

Comportamento ingestivo de novilhas de corte em pastagem de sorgo forrageiro implantada com diferentes arranjos populacionais / Ingestive behavior of heifers in sorghum implanted with different population arrangements

O objetivo do presente estudo foi avaliar os efeitos da implantação de pastagem de sorgo forrageiro com diferentes arranjos populacionais no comportamento animal e na estrutura do pasto e de suas relações. Os tratamentos foram a combinação de dois espaçamentos entrelinhas e duas densidades de sementes ha-1, sendo 22 ou 44cm entrelinhas e 12 ou 24kg de sementes ha-1. Foram utilizadas 36 novilhas, com idade e peso corporal inicial de 15 meses e 262kg, respectivamente. Os tratamentos E44D24 e E22D12 apresentaram maior tempo de pastejo (469,33 e 467,78 minutos, respectivamente). Os animais do tratamento E44D24 apresentaram menor taxa de bocado (23,99 bocados minuto-1) em relação ao tratamento E22D24 (32,45 bocados minuto-1). Os animais do tratamento E44D12 apresentaram maior número de estações alimentares minuto-1 (9,21) e maior taxa de deslocamento (11,76 passos minuto-1). O espaçamento entrelinhas de plantio de 22cm aumenta o número de bocados estação-1. O aumento na densidade de sementes (24kg ha-1) e a utilização de maiores espaçamentos entrelinhas de plantio aumentam a densidade de folhas nos estratos inferior (0-30cm) e superior (acima de 60cm) do pasto. Os tratamentos E44D12 e E22D24 apresentaram maiores quantidades de colmos no estrato superior do pasto.(AU)

The objective of the study was to evaluate the effects of sorghum pasture implantation with different population arrangements in animal behavior and pasture structure and their relationships. The treatments were the combination of two row lines and two seeds per hectare densities, 22 or 44cm between rows and 12 or 24kg ha -1 of seed. 36 heifers at 15 months of age and 262kg body weight were used. The E44D24 and E22D12 treatments showed higher time of grazing (469.33 and 467.78 minutes, respectively). The animals in E44D24 treatment had lower bit rate (23.99 bites minute -1 ) compared to treatment with E22D24, a higher bit rate (32.45 bits min -1 ). The animals in E44D12 treatment presented the largest number of stations minute -1 (9.21) and higher displacement rate (11.76 steps min -1 ). The row spacing of 22cm increases the number of bits station -1 . The increase in seed density and the use of larger planting row spacing's increase the leaf density of the lower (0-30cm) and higher stratum (above 60cm) of pasture. The E44D12 and E22D24 treatment have higher amounts of stems in the upper stratum of the pasture.(AU)

Backgrounding steers on temperate grasses mixed with vetch and/or using energy supplementation.

OBJECTIVE: The aim was to evaluate backgrounding beef steers on oat + ryegrass pastures mixed with vetch and/or using energy supplementation. METHODS: A randomized block design with three treatments and three replications was used. The treatments were: grass + supplement (oat + ryegrass + supplementation), legume + supplement (oat + ryegrass + vetch + supplementation) and grass + legume (oat + ryegrass + vetch). A continuous grazing system with a variable stocking rate was used. Twenty-seven intact crossbred steers (1/4 Marchigiana, 1/4 Aberdeen Angus and 2/4 Nellore) aged 7 months old and average weight of 190 kg were used. Steers were supplemented at 1% of the body weight of ground corn. The experiment lasted 84 days, between May and August 2014. Behavioral assessments were performed two times per experimental period, for 24 hours. RESULTS: The forage mass was different between treatments, being greater for steers fed without legume. The accumulation rate, forage allowance, and stocking rate did not differ between treatments due to the adequate adjustment of forage allowance. The final weight of animals, as well as the dry matter intake (kg/d), did not differ between treatments. However, forage intake was higher for non-supplemented animals in relation to supplemented steers. Supplement intake did not alter the total digestible nutrient intake due to pasture quality. Animals fed grass + supplement had higher live weight gain per area than those fed grass + legume. Animals without supplementation spent more time in grazing. CONCLUSION: Feeding behavior was not altered by mixing with vetch or supplementation. Non-supplemented animals started the grazing peak earlier and spent more time in grazing than those supplemented; however, the average daily gain was similar between treatments. The live weight gain per hectare was 47% higher in pastures in which the animals received supplementation compared with those mixed with vetch, a consequence of the substitutive effect.

Evaluation of the RumiWatchSystem for measuring grazing behaviour of cows.

Feeding behaviour is an important parameter of animal performance, health and welfare, as well as reflecting levels and quality of feed available. Previously, sensors were only used for measuring animal feeding behaviour in indoor housing systems. However, sensors such as the RumiWatchSystem can also monitor such behaviour continuously in pasture-based environments. Therefore, the aim of this study was to validate the RumiWatchSystem to record cow activity and feeding behaviour in a pasture-based system. The RumiWatchSystem was evaluated against visual observation across two different experiments. The time duration per hour at grazing, rumination, walking, standing and lying recorded by the RumiWatchSystem was compared to the visual observation data in Experiment 1. Concordance Correlation Coefficient (CCC) values of CCC=0.96 for grazing, CCC=0.99 for rumination, CCC=1.00 for standing and lying and CCC=0.92 for walking were obtained. The number of grazing and rumination bouts within one hour were also analysed resulting in Cohen's Kappa (κ)=0.62 and κ=0.86 for grazing and rumination bouts, respectively. Experiment 2 focused on the validation of grazing bites and rumination chews. The accordance between visual observation and automated measurement by the RumiWatchSystem was high with CCC=0.78 and CCC=0.94 for grazing bites and rumination chews, respectively. These results indicate that the RumiWatchSystem is a reliable sensor technology for observing cow activity and feeding behaviour in a pasture based milk production system, and may be used for research purposes in a grazing environment.

Ingestive behavior of supplemented Nellore heifers grazing palisadegrass pastures managed with different sward heights.

Three sward heights (15, 25 and 35 cm) and three supplement types (energy, energy-protein, and a mineral mix supplement) were evaluated in a 3 × 3 factorial arrangement distributed in a completely randomized design to study changes in forage search patterns in Nellore heifers in a continuous grazing system. Pasture data were collected using two replicates (paddocks) per treatment over four periods during the rainy season. The behavior assessments were made in the first and fourth grazing seasons. It was hypothesized that supplements and pasture management would modify ingestive behavior, considering that animals would require less time grazing if they had energy requirements met through higher digestibility of better managed paddocks, or use of supplements high in energy. Total and green forage masses along with green : dead material ratio were greater in treatments managed with higher sward heights. Sward managed with 35 cm height resulted in lower leaf : stem ratio compared with 15 cm sward height treatments. The animals on the 15 cm pastures spent more time grazing overall and during each meal, but there were no differences observed in meal numbers in comparison to 35 cm treatments. Heifers fed protein and/or energy supplements spent less time grazing in the early afternoon, but overall grazing time was the same for all animals.

Canopy structure, ingestive behavior and displacement patterns of beef heifers grazing warm-season pastures / Estrutura do dossel, comportamento ingestivo e padrões de deslocamento de novilhas de corte em pastagens de estação quente

Analyses in a data set of six experiments (n=436) was performed with the aim of characterizing canopy structure and forage intake patterns of beef heifers grazing on Pearl millet (Pennisetum americanum), Alexandergrass (Urochloa plantaginea) and Coastcross (Cynodon dactylon). Forage and leaf lamina mass were similar among species, 3001.4 and 668.1kg of DM/ha, respectively, while leaf:stem ratio of canopy vertical strata was different. Intake rate (12g DM/minute), bite mass (0.343g DM/bite) and bite rate (36.6bites per minute) were similar in Pearl millet and Alexandergrass. In Pearl millet, neutral detergent fiber content (56.1%) in forage as grazed, grazing time (518.9 minutes/day) and displacement rate (8.8 steps/minute) were lower. Increased grazing time (639 minutes/day) represented the main compensatory mechanism for smaller bite masses (0.234g DM/bite) and reduced intake rates (8.8 grams of DM/minutes) in Coastcross. Bite rate variations happened as a response to constraints imposed by canopy structure. Surface utilization on Alexandergrass and Coastcross was increased by greater number of feeding stations visited and displacement rate. Ingestive behavior components of beef heifers are affected by differences in the canopy structure of Pearl millet, Alexandergrass and Coastcross.

Foi realizada a análise conjunta dos resultados de seis experimentos (n=436) com o objetivo de caracterizar a estrutura do dossel e os padrões de ingestão de forragem por novilhas de corte em pastagem de milheto (Pennisetum americanum), papuã (Urochloa plantaginea) e coastcross (Cynodon dactylon). As massas de forragem e de lâminas foliares foram similares entre as três espécies forrageiras, 3001,4 e 668,1kg/ha de MS, respectivamente, enquanto a relação lâmina:colmo do perfil vertical do dossel diferiu. A taxa de ingestão (12g MS/minuto), a massa de bocados (0,343g MS/bocado) e a taxa de bocados (36,6 bocados/minuto) foram similares no milheto e no papuã. O conteúdo de fibra em detergente neutro (56,1%) na forragem da simulação do pastejo, o tempo de pastejo (518,9 minutos/dia) e a taxa de deslocamento (8,8 passos/minuto) foram menores no milheto. O incremento no tempo de pastejo (639 minutos/dia) representou o mecanismo compensatório para a menor massa de bocados (0,234g MS/bocado) e para a reduzida taxa de ingestão (8,8 gramas MS/minuto) no coastcross. Variações na taxa de bocado ocorrem como resposta às limitações impostas pela estrutura do dossel. A exploração da área da pastagem de papuã e de coastcross foi aumentada pelo maior número de estações alimentares visitadas e pela maior taxa de deslocamento. Os componentes do comportamento ingestivo de novilhas de corte são afetados por diferentes estruturas no dossel de milheto, papuã e coastcross.

Effect of water-soluble carbohydrate content in orchardgrass pasture on grazing time and rumen fermentation in dairy cows.

Two experiments were conducted to clarify the effect of water-soluble carbohydrate (WSC) content in orchardgrass pasture on the diurnal distribution of grazing time. Six ruminally cannulated, non-lactating dairy cows were grazed on either of two pastures with different orchardgrass cultivars containing low WSC (LWSC; cultivar: 'Hokkai 28') or high WSC (HWSC; cultivar: 'Harunemidori'). The cows were grazed in morning and evening sessions in experiment 1, whereas the cows were grazed throughout the day in experiment 2. In experiment 1, grazing time of the cows on HWSC was longer than that of the cows on LWSC (P < 0.01). This difference was larger in the morning session than in the evening session (pasture × grazing session: P < 0.05). Effects on herbage intake were similar to those on grazing time. In experiment 2, daily total grazing time was longer for the cows on HWSC than for those on LWSC (P < 0.05). The cows on HWSC spent a longer time grazing than those on LWSC in the morning between 03.00 and 09.00 hours (P < 0.01). The results indicated that prolonged grazing time in the period between dawn and early morning could increase daily herbage intake in cows grazed on pastures of orchardgrass cultivars with high-WSC content.

Effect of time at pasture and herbage intake on profile of volatile organic compounds of dairy cow milk.

Volatile organic compounds (VOCs) in milk were investigated as quantitative markers of herbage intake (HI) at pasture. Eight Holstein cows were fed indoors with concentrate and conserved forages (grass silage, corn silage and hay) (NG), then were divided into three treatments according to the duration of access to pasture: 4 h (G4), 8 h (G8), and 20 h (G20) per day. The HIs were 4.3, 8.6, and 13.0 kg dry matter/day for the G4, G8 and G20 treatments, respectively. Milk from cows was sampled and analyzed VOCs by the steam distillation-extraction method and gas chromatography-mass spectrometry (GC-MS). From the intensity of the GC peak area, the levels of 1-phytene (3,7,11,15-tetramethyl-1-hexadecene) and 2-phytene (3,7,11,15-tetramethyl-2-hexadecene) were lowest in NG treatment and markedly increased with grazing time at pasture. With simple regression analysis on the HI to each diterpenoid, a strong correlation was found between the intensity of 1-phytene in the milk and the HI (r = 0.807, P < 0.001). 1-phytene content in milk could be useful as a quantitative marker of the HI of grazing cows.

Beef heifers grazing behavior and herbage intake in natural grassland under rotational grazing / Comportamento ingestivo e consumo de forragem de novilhas de corte em pastagem natural manejada com pastoreio rotativo

It was evaluated the effect of two rest intervals between grazing occupations in rotational grazing; 375 and 750 DD (degree-days); based on the cumulative thermal sum necessary for leaf expansion of native grasses of two functional groups over the grazing behavior variables from beef heifers with 12 months old. The experiment was conducted as a completely randomized block design, with two treatments, three replications and measures repeated over time. Grazing behavior was assessed in three occasions (Nov 2011, Jan and Mar 2012), with 24h each. The herbage intake was estimated using an external marker (Cr2O3). The leaf mass was similar among the rest intervals, with a mean of 1261kg DM ha-1. The average grazing time was 627.4min day-1 and bite rate was 37.1 bites min-1. The average number of daily meals was 5.9 with an average of 118.5 minutes. Number of feeding stations visited per minute was 6.1 and the feeding stations permanence time was of 12 seconds. There was a reduction only on grazing time and bite rate over the periods. The range of thermal sums evaluated to define the rest intervals in rotational grazing proved no effect on heifers' grazing behavior and herbage intake.

Foram testados os efeitos de dois intervalos de descanso entre pastoreios, 375 e 750 graus-dia, baseado na soma térmica para a expansão foliar de gramíneas nativas de dois grupos funcionais sobre o comportamento ingestivo de novilhas de corte. O delineamento foi em blocos ao acaso, com dois tratamentos, três repetições de área e medidas repetidas no tempo. Foram realizadas três avaliações (nov/11, jan e mar/12), com 24h cada, utilizando novilhas de corte com 12 meses. Estimou-se o consumo de forragem com marcador externo (Cr2O3). A massa de lâminas foliares foi semelhante entre os tratamentos, apresentando média de 1261kg MS ha-1. O tempo médio dispendido pelos animais em pastejo foi de 627,4 minutos e a taxa de bocados média foi de 37,1 bocados minuto-1. O número médio de refeições foi de 5,9 refeições dia-1, com uma média de 118,5 minutos por refeição. Os animais visitaram, em média, 6,1 estações alimentares por minuto e permaneceram nessas estações por 12 segundos. Houve diferença no tempo de pastejo e taxa de bocado nos períodos, com uma redução ao longo do tempo. Os intervalos de descanso testados provaram ter pouco efeito no comportamento ingestivo e no consumo de forragem das novilhas.

Comportamento ingestivo e desempenho produtivo de cordeiros mantidos em pastagem tropical e recebendo diferentes suplementações / Ingestive behavior and productive performance of lambs maintained in tropical pasture receiving different supplements

Avaliaram-se os efeitos dos tipos de suplementação sobre o desempenho produtivo e o comportamento ingestivo diurno de cordeiros mestiços Santa Inês mantidos em pastagem de capim-aruana (Panicum maximum cv. Aruana) sobressemeado com aveia branca (Avena sativa L.) e azevém (Lolium multiflorum Lam.), em um delineamento inteiramente ao acaso, com três tratamentos e três repetições. Os cordeiros foram distribuídos aleatoriamente em três sistemas alimentares, com seis animais cada, sendo: PAST - cordeiros mantidos exclusivamente a pasto; SIL - cordeiros mantidos em pastagem recebendo suplementação (1,0% do peso vivo) com silagem de milho; CONC - cordeiros mantidos em pastagem recebendo suplementação (1,0% do peso vivo) com concentrado. Os cordeiros suplementados com concentrado apresentaram ganho de peso médio diário 37,5% superior aos mantidos em pastagem, mas não diferiram da suplementação com silagem de milho. O tempo de pastejo foi superior para os animais não suplementados quando comparados aos animais suplementados. Cordeiros mantidos a pasto e suplementados com silagem de milho ou concentrado ganham mais peso do que os cordeiros não suplementados.

The aim of this work was to evaluate the types of supplementation on performance and the diurnal feeding behavior of crossbred Santa Inês lambs maintained in aruana (Panicum maximum cv. Aruana) pasture grass overseeding with oat (Avena sativaL.) and Italian ryegrass (Lolium multiflorum Lam.) pasture in a completely randomized design with three treatments and three replications. The lambs were randomly assigned to three food systems of six animals each, PAST - lambs fed only pasture; SIL - lambs fed pasture and supplemented (1% of live weight) with corn silage; CONC - lambs fed pasture and supplemented with concentrate. Animals supplemented with concentrate presented average daily gain 37,5% higher, but did not differ from supplementation with corn silage. Grazing time was higher for non-supplemented animals compared with supplemented animals. Lambs maintained in pasture and supplemented with corn silage or concentrate gain more weight than non-supplemented lambs.

Influence of Restricted Grazing Time Systems on Productive Performance and Fatty Acid Composition of Longissimus dorsi in Growing Lambs.

Fifty 3-month-old male Tan lambs (similar in body weight) were divided into 5 groups to investigate the effects of different restricted pasture grazing times and indoor supplementation on the productive performances and fatty acid composition of the intramuscular fat in growing lambs. The lambs grazed for different periods of time (12 h/d, 8 h/d, 4 h/d, 2 h/d, and 0 h) and received various amounts of supplementary feedings during the 120-day trial. Pasture dry matter intake (DMI), total DMI, average daily gains and the live body weights of the lambs were measured during the experiment. The animals were slaughtered at the end of the study, their carcass traits were measured, and their longissimus dorsi muscles were sampled to analyze the intramuscular fat (IMF) content and fatty acid profiles. The results indicated that the different durations of grazing and supplementary feedings affected the animal performances and the composition of fatty acids. Grazing for 8 h/d or 2 h/d with the corresponding supplementary concentrate resulted in lambs with higher body weights, carcass weights and IMF contents. Lambs with longer grazing times and less concentrate accumulated more healthy fatty acids such as conjugated linoleic acid and n-3 polyunsaturated fatty acid and had higher n-3/n-6 ratios. Overall, a grazing allowance of 8 h/d and the corresponding concentrate was recommended to maintain a high quantity and quality of lamb meat.

Comportamento ingestivo de vacas leiteiras em pastagem de azevém alimentadas com diferentes fontes proteicas / Ingestive behavior of dairy cows in annual ryegrass pasture, fed with different proteic sources

Estudou-se o efeito da substituição do farelo de soja da ração por pastejo controlado de trevo-branco (Trifolium repens L.) sobre o comportamento ingestivo de vacas da raça Holandesa em pastejo de azevém (Lolium multiflorum Lam.). Utilizaram-se dois grupos de animais, com média de 20 vacas agrupadas por produção, período de lactação e peso corporal, em delineamento experimental em blocos ao acaso. Um grupo recebeu, diariamente, 3kg de suplemento energético e teve acesso controlado à pastagem de trevo-branco por aproximadamente duas horas e meia (TB); o outro recebeu o mesmo suplemento, adicionado de quantidade de proteína equivalente ao consumo diário no tratamento anterior via trevo, na forma de farelo de soja (FS). Para a avaliação de comportamento, procedeu-se à observação e ao registro do ritmo de atividade dos animais, no período de pastejo em azevém durante dois dias consecutivos, quinzenalmente. Observou-se maior tempo de pastejo em minutos (min), 212,00 versus 194,24min dia-1, e frequência de bocados (bocado), 67,78 versus 64,09 bocado min-1, entre os animais do tratamento FS, em relação ao TB. Não houve diferença no consumo de azevém entre os tratamentos, com valores de 3,65 e 4,11kg vaca-1 dia-1 de matéria seca para TB e FS, respectivamente, o que sugere adequada adaptação dos animais às duas situações estudadas...

The effect of the replacement of soybean meal in the ration with controlled grazing of white clover (Trifolium repens L.) on the ingestive behavior of cows of the holstein breed grazing on annual ryegrass (Lolium multiflorum Lam.) was studied. Two groups of animals with an average of 20 cows grouped by production, lactation period and body weight were used in a randomized block experimental design. One group received 3kg from energy supplement daily and had controlled access to the white clover pasture for approximately 2.5 hours (TB); the other received the same supplement, added of a quantity of protein equivalent to daily intake in previous treatment via white clover, in the form of soybean meal (FS). For behavior assessment the observation and recording of the rhythm of activity of the animals, during the grazing period in ryegrass for two consecutive days, fortnightly was done. The longest grazing time in minutes (min), 212.00 versus 194.24min day-1, and bite frequency (bite), 67.78 versus 64.09 bite min-1, between the animals from treatment FS, when compared to TB was observed. There was no difference in the intake of ryegrass between the treatments, with values of 3.65 and 4.11kg cow-1 day-1 of dry matter for TB and FS, respectively, suggesting adequate adaptation of the animals in the two situations studied...

Effect of restricted grazing time on the foraging behavior and movement of tan sheep grazed on desert steppe.

To investigate the effect of restricted grazing time on behavior of Tan sheep on desert steppe, forty 4-months old male Tan sheep with an original body weight (BW) of 15.62±0.33 kg were randomly allocated to 4 grazing groups which corresponded to 4 different restricted grazing time treatments of 2 h/d (G2), 4 h/d (G4), 8 h/d (G8) and 12 h/d (G12) access to pasture. The restricted grazing times had a significant impact on intake time, resting time, ruminating time, bite rate and movement. As the grazing time decreased, the proportion of time spent on intake, bite rate and grazing velocity significantly (p<0.05) increased, but resting and ruminating time clearly (p<0.05) decreased. The grazing months mainly depicted effect on intake time and grazing velocity. In conclusion, by varying their foraging behavior, Tan sheep could improve grazing efficiency to adapt well to the time-limited grazing circumstance.

Comportamento ingestivo diurno de novilhas de corte recebendo níveis de suplemento / Diurnal ingestive behavior of beef heifers receiving levels of supplement

Este trabalho foi conduzido com o objetivo de avaliar a composição botânica da pastagem e o comportamento ingestivo diurno de bezerras de corte recebendo diferentes níveis de suplemento. Os animais foram mantidos em pastagem de aveia preta (Avena strigosa Schreb.) e azevém (Lolium multiflorum Lam.), recebendo ração comercial nos níveis de 0; 0,3; 0,6 e 0,9 por cento do peso vivo (PV). Em quatro datas, foram registradas as atividades diurnas de pastejo, ruminação, ócio, número de visitas e tempo de permanência no cocho e taxa de bocadas. Com aumento dos níveis de suplemento, houve redução no tempo de pastejo e aumento no tempo de ócio (P<0,05). A taxa de bocada e o peso de bocado foram afetados pelo suplemento e ciclo da pastagem (P<0,05). O tempo diurno de ruminação não foi afetado pelo fornecimento de suplemento (P>0,05). A composição botânica e estrutural da pastagem é influenciada pelos níveis de suplemento utilizados e o ciclo de produção das forrageiras.

The trial was conducted aiming to evaluate pasture botanical composition and diurnal ingestive behavior of beef heifers receiving different supplement levels. The animals were kept in black oats (Avena strigosa Schreb.) and Italian ryegrass (Lolium multiflorum Lam.) pasture, receiving 0; 0.3; 0.6 and 0.9 percent of live weight (LW) of supplement. The supplement utilized was a commercial ration. In four dates were registrated diurnal activities of grazing, ruminating, idle, number of visits and trough permanence time and bite rate. Increasing supplement levels reduced grazing time and increased idle time (P<0.05). Bite rate and bite weight were affected by the supplement and pasture cycle (P<0.05). Ruminating time was not affected by supplement levels (P>0.05). Botanical and structural composition of pasture were influenced by supplement levels and related with herbage production cycle (P>0.05).