scholarly journals Sward structure and short-term herbage intake in Arachis pintoi cv. Belmonte subjected to varying intensities of grazing

2017 ◽  
Vol 156 (1) ◽  
pp. 92-99 ◽  
Author(s):  
G. P. Silva ◽  
C. A. Fialho ◽  
L. R. Carvalho ◽  
L. Fonseca ◽  
P. C. F. Carvalho ◽  
...  
Keyword(s):  
Nutritive Value ◽  
Block Design ◽  
Intake Rate ◽  
Short Term ◽  
Tropical Pastures ◽  
Dairy Heifers ◽  
Bite Rate ◽  
Sward Height ◽  
Herbage Intake ◽  
Sward Structure

AbstractThe use of forage legumes has been proposed as a means of generating sustainable grazing environments. Their limited use, particularly in tropical pastures, is partially due to the limited knowledge regarding the efficiency of utilization by animals. The present study characterized the sward structure, nutritive value and ingestive behaviour of dairy heifers in pastures of peanut cv. Belmonte under continuous stocking management. Treatments corresponded to sward heights of 5, 10, 15 and 20 cm, according to a randomized complete block design, with four replications. The following response variables were evaluated: vertical distribution of the morphological components within the sward, forage mass, nutritive value (simulated grazing), bite rate (BR), bite mass (BM) and short-term herbage intake rate (STIR). The top half of the sward height was mainly composed of leaves and the bottom half mainly of stolon and dead material regardless of management height. Greater values of neutral detergent fibre and acid detergent fibre were recorded during autumn, while higher values of in-vitro dry matter (DM) digestibility (0·85) occurred during spring regardless of management height for the grazed stratum. In relation to treatments, greater values of crude protein were recorded on swards managed at 5 cm (0·27) and 10 cm (0·26). Bite rate, BM and STIR varied with sward height, but not with a season of the year. The STIR followed a broken line response to sward height, with increasing values up to 13·1 cm (106 g DM/kg body weight). Sward structure played an important role in determining the STIR. To maximize the STIR of dairy heifers under continuous stocking management, swards should be managed at heights of not <13·1 cm.

scholarly journals Sward structure and ingestive behavior of cows in tropical pastures managed under different forage allowances

2019 ◽  
Vol 71 (6) ◽  
pp. 2009-2016
Author(s):  
E.R. Janusckiewicz ◽  
D.R. Casagrande ◽  
E. Raposo ◽  
C. Bremm ◽  
R.A. Reis ◽  
...  
Keyword(s):  
Animal Behavior ◽  
Block Design ◽  
Ingestive Behavior ◽  
Displacement Rate ◽  
Brachiaria Brizantha ◽  
Tropical Pastures ◽  
Bite Rate ◽  
Sward Height ◽  
Randomized Block Design ◽  
Second Year

ABSTRACT This study evaluated how changing the structure of Brachiaria brizantha cv. Marandu pasture under different forage allowances (FA) of 4, 7, 10 and 13kg DM/100kg BW (body weight) affected animal behavior over a two-year evaluation period. The experiment was conducted as a randomized block design with three replications (paddock). Sward height, total forage, and stem mass were lower for pastures managed with lower FA. Lower leaf mass was observed for lower FA in the second year. In hand-plucked samples, leaf and stem percentages remained unchanged in the morning but leaf percentage increased while stems decreased in the afternoon. Permanence time decreased linearly with increasing FA. In turn, a quadratic effect was observed for displacement rate. The bite rate was similar among different FAs. The results demonstrate that FA varying between 7 and 10kg DM/100kg BW are more suitable to balance the amounts of leaves and stems in the sward. The studied FA levels do not limit forage availability. Permanence time decreases and displacement rate increases as FA increases.

Limitations in assessment of forage intake and diet composition of steers grazing tropical pastures with short-term intake rate and oesophageal fistulated steers

2006 ◽  
Vol 34 ◽  
pp. 41-47
Author(s):  
H. D. Hess ◽  
C.E. Lascano ◽  
M. Kreuzer
Keyword(s):  
Rainy Season ◽  
Daily Intake ◽  
Dry Season ◽  
Intake Rate ◽  
Short Term ◽  
Tropical Pastures ◽  
Arachis Pintoi ◽  
Herbage Intake ◽  
The Difference ◽  
The Relationship

SummaryTwo grazing trials were carried out to compare the grazing selectivity of oesophageal fistulated and intact steers, and to measure short term grazing behaviour and daily intake of steers in pastures (six pasture types) based on Brachiaria humidicola and Arachis pintoi. During the rainy season, the composition of the pasture affected the proportion of legume in the diet selected by the two groups of steers. The property of the pasture best related to legume selected by the intact steers was the legume mass in the forage available. The proportion selected by the fistulated steers was best related to the proportion of legumes in the pasture. The legume proportion selected by the two groups of steers was related to the bulk density of legumes in the forage, but the type of relationship varied between the groups. The relationship for the fistulated steers was linear, and that for the intact steers was exponential with an asymptote. During the dry season the relationships for the fistulated animals were similar to those observed during the rainy season, but the proportion of legume in the diet of the intact animals was not affected by attributes of the pasture. The pattern of intake in the short term was not affected by the height or amount of forage available during the rainy season, but during the dry season the weight per bite, and short-term intake was related to the height and amount of forage available. Daily herbage intake was not related to short-term intake.The results of the first experiment confirmed that the selection of legumes by grazing steers can vary considerably between intact and fistulated steers. Furthermore it was suggested that the difference resulted partially from the different reactions of the two groups of experimental animals to changes in the attributes of the pasture. The second experiment showed that the daily intake of forage is not necessarily related to intake behaviour in the short term.

scholarly journals Beef heifers grazing behavior and herbage intake in natural grassland under rotational grazing

2015 ◽  
Vol 45 (11) ◽  
pp. 2056-2062 ◽  
Author(s):  
Cezar Wankura Barbieri ◽  
Fernando Luiz Ferreira de Quadros ◽  
Felipe Jochims ◽  
Bruno Castro Kuinchtner ◽  
Thiago Henrique Nicola de Carvalho ◽  
...  
Keyword(s):  
Block Design ◽  
Beef Heifers ◽  
Rotational Grazing ◽  
Grazing Behavior ◽  
Bite Rate ◽  
Herbage Intake ◽  
Randomized Block Design ◽  
Thermal Sum ◽  
Natural Grassland ◽  
Rest Intervals

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

The effect of sward structure as influenced by ryegrass genotype on bite dimensions and short-term intake rate by dairy cows

2003 ◽  
Vol 58 (1) ◽  
pp. 2-11 ◽  
Author(s):  
P. D. Barrett ◽  
D. A. McGilloway ◽  
A. S. Laidlaw ◽  
C. S. Mayne
Keyword(s):  
Dairy Cows ◽  
Intake Rate ◽  
Short Term ◽  
Sward Structure

scholarly journals Forage intake processes by goats on a massai grass pasture with different sward heights

2016 ◽  
Vol 37 (6) ◽  
pp. 4339
Author(s):  
Marcônio Martins Rodrigues ◽  
Maria Elizabete Oliveira ◽  
Tânia Maria Leal ◽  
Raniel Lustosa Moura ◽  
Daniel Louçana da Costa Araújo ◽  
...  
Keyword(s):  
Crude Protein ◽  
Leaf Blade ◽  
Intake Rate ◽  
Crude Protein Content ◽  
Intake Process ◽  
Bite Rate ◽  
Sward Height ◽  
Morphological Composition ◽  
Reduced Crude Protein ◽  
Forage Intake

The objective of this study was to evaluate the forage-intake process of goats feeding on Massai grass pastures with different heights (40, 50, 60, and 70 cm). The experimental design was completely randomized, with treatments corresponding to four sward heights with two replicates over time and space. Collected data were related to the forage-intake process and the chemical and morphological composition of the pasture. Grazing trials (45 min) were performed with four Anglo-Nubian crossbred goats. Total forage mass intake, bite mass, and intake rate were expressed in relation to animal weight. Pasture density, forage mass, and leaf blade increased as forage height increased. The chemical composition of forage at the evaluated heights was similar, except for reduced crude protein content at 70-cm height. Bite rate, intake rate, and time per bite had a quadratic relationship with increasing sward height. The greatest intake rate was observed at 54.7 cm of height, with 0.136 g DM min-1 kg-1 LW. Bite rate exhibited a linear and positive correlation with increase in intake. At the 50-cm height, goats harvested a mass of 3.65 g DM bite-1 kg-1 LW, when they performed 34.5 bites per minute. Adult goats had a greater forage intake on 50-cm high Massai grass pastures because they could obtain a greater bite mass in a shorter time per bite.

scholarly journals Sward structure management for a maximum short-term intake rate in annual ryegrass

2012 ◽  
Vol 68 (2) ◽  
pp. 271-277 ◽  
Author(s):  
M. F. Amaral ◽  
J. C. Mezzalira ◽  
C. Bremm ◽  
J. K. Da Trindade ◽  
M. J. Gibb ◽  
...  
Keyword(s):  
Intake Rate ◽  
Annual Ryegrass ◽  
Short Term ◽  
Sward Structure

The determinants of herbage intake by grazing sheep: The interrelationship of factors influencing herbage intake and availability

1970 ◽  
Vol 21 (5) ◽  
pp. 755 ◽  
Author(s):  
WG Allden ◽  
IA McDWhittaker
Keyword(s):  
Plant Height ◽  
Spatial Relations ◽  
Initial Increase ◽  
Intake Rate ◽  
Short Term ◽  
Herbage Intake ◽  
Constant Rate ◽  
Herbage Yield ◽  
Grazing Sheep ◽  
Animal Size

The interrelationship of characters of the pasture (herbage yield, height of sward) and of the animal (size of animal, rate of intake, rate of biting, size of bite, and time spent grazing) which influence the consumption of herbage by the grazing sheep was examined in three short-term experiments. In one study the high correlation usually observed between herbage yield per unit of land area and plant height was disturbed by manipulating the spatial relations of the sward; it was observed that the rate of intake of pasture by grazing animals was closely associated with plant height (estimated from tiller length) there being little relation between herbage yield and intake. Size of bite increased almost linearly with changing tiller length, whereas after a small initial increase the rate of biting decreased. These differences produced a sevenfold change in the rate of herbage consumption between sheep grazing pastures of 3.7 cm tiller length (1.0 g dry matter/min) and 7.7 cm (7.1 g/min). At greater tiller lengths the size of bite and rate of biting varied inversely to maintain a constant rate of intake. When accessibility of herbage imposed limitations on the rate at which the animal was able to prehend its feed, it was shown that the sheep was able partially to compensate for the reduced amount of herbage present by an increase in grazing time (from 6 to 13 hr/day). However, as the animal extended its period of grazing the compensation became progressively more incomplete. Under sparse pasture conditions lambs were able to consume feed at a significantly greater rate than yearlings but as pasture availability increased the situation was reversed. The role of short-term grazing studies in relation to problems of grazing management is discussed.

Factors affecting diet selection by sheep. 2. Height and density of pasture

1984 ◽  
Vol 35 (4) ◽  
pp. 565 ◽  
Author(s):  
JL Black ◽  
PA Kenney
Keyword(s):  
Dry Matter ◽  
Intake Rate ◽  
Jaw Movements ◽  
Factors Affecting ◽  
Bite Rate ◽  
Sward Height ◽  
In Series ◽  
The One ◽  
Tiller Density ◽  
Ingestive Behaviour

Boards of artificial pasture were prepared by threading the top two leaves of tillers from either ryegrass or kikuyu grass, in their vegetative stage of growth, through 5-mm-diameter holes in pressed hardwood sheets. The holes were spaced in rows from 10 to 50 mm apart, and, with one, two or three tillers per hole, tiller density ranged from 346 to 25 980/m2. Sward height was varied by pulling tillers different distances through the holes before they were fastened to the underside of the boards, and the mass of herbage dry matter ranged from 0.04 to 7.61 t/ha. In series I experiments, the effects of sward characteristics on ingestive behaviour of two sheep were examined, whereas, in series I1 experiments, pastures that were consumed at different rates were offered in pairs and the preference of one sheep observed. The rate of pasture intake was related to sward height only when tiller density was constant and to herbage mass per unit volume (bulk density) only at similar sward heights. Intake rate was better described by herbage mass per unit area but, at herbage availabilities of less than 1 t/ha, intake rate was several-fold greater when sheep grazed tall, sparse pastures than short, dense pastures. The best predictor of pasture intake rate was herbage mass per area effectively covered by one bite. Intake per prehending bite declined with a reduction in both sward height and density, and was also best described by herbage mass per area effectively covered by one bite. Prehending bite rate doubled as intake per bite declined from 200 to 10 mg dry matter. The rate of jaw movements during grazing was virtually unaffected by sward characteristics; prehending bites accounted for 20% of jaw movements when intake per bite was 200 mg dry matter and 80% of jaw movements with short, widely spaced swards. When two pastures with different sward characteristics were offered together, sheep generally preferred the one they could eat faster.

scholarly journals Management targets for maximising the short-term herbage intake rate of cattle grazing in Sorghum bicolor

2012 ◽  
Vol 145 (1-3) ◽  
pp. 205-211 ◽  
Author(s):  
L. Fonseca ◽  
J.C. Mezzalira ◽  
C. Bremm ◽  
R.S.A. Filho ◽  
H.L. Gonda ◽  
...  
Keyword(s):  
Sorghum Bicolor ◽  
Cattle Grazing ◽  
Intake Rate ◽  
Short Term ◽  
Herbage Intake

scholarly journals Can animal performance be predicted from short-term grazing processes?

2015 ◽  
Vol 55 (3) ◽  
pp. 319 ◽  
Author(s):  
P. C. F. Carvalho ◽  
C. Bremm ◽  
J. C. Mezzalira ◽  
L. Fonseca ◽  
J. K. da Trindade ◽  
...  
Keyword(s):  
Conceptual Model ◽  
Abiotic Factors ◽  
Energy Costs ◽  
Intake Rate ◽  
Animal Performance ◽  
Short Term ◽  
Abiotic Conditions ◽  
Native Grasslands ◽  
Wide Range ◽  
Sward Structure

Despite all the biotic and abiotic factors affecting foraging by ruminants, there is a common and fundamental process, which is bite gathering. We hypothesised that because the mechanics of bite formation dominate the foraging process, changes in short-term bite mass are reflected in longer-term animal performance across a wide range of sward conditions. We focus at the meal level of foraging, using experiments in which the effect of abiotic factors and digestive constrains are minimised, making intake rate the main currency. We estimated bite mass across a wide range of structural challenges to large-herbivore foraging in a long-term experiment with heterogeneous native grasslands. A conceptual model was developed for average daily gain, where energy gain and energy costs were proximate causal variables. Energy gain was a function of diet quality and components of daily intake rate, where bite mass was the main component estimated. In turn, components of intake rate were determined by sward structure and bodyweight. Energy costs were a function of bodyweight and abiotic conditions. Finally, sward structure, bodyweight and abiotic conditions were determined by experimental treatments, seasons and years. Then, the conceptual model was translated into statistical models that included variables measured or estimated, and coefficients representing all links in the conceptual model. Weight gain was a function of bite mass, forage characteristics, and animal and abiotic conditions. Models were set up to test whether forage and stocking conditions affected monthly gain beyond the effects through bite mass, after correcting for abiotic factors. Forage mass, height and disappearance did help predict monthly gain after bite mass was included in the model, which supported our hypothesis. However, stocking treatments and season had significant effects not incorporated in bite mass. Although the model explained 77.9% of liveweight gain variation, only 35.2% was due to fixed effects, with 10.8% accounted by bite mass and its interactions. Concomitant experiments showed that sward structure (first with sward height and the second with tussock cover) does determine bite mass and short-term intake rate in the complex native grasslands we studied. Yet, other temporal varying components of monthly gain not correlated with bite mass, temperature or wind, added most of the observed variation in monthly animal performance. Part of the model failure to account for variation in performance may be related to a significant and temporally variable grazing of tussocks. We used a bite mass model that assumed no tussock grazing. In light of these results and a parallel experiment, we conclude that tussock grazing must be incorporated in future versions of the model.

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