scholarly journals Sward structural characteristics and ingestive behaviour of beef heifers in a Pearl Millet pasture

2009 ◽  
Vol 38 (9) ◽  
pp. 1668-1674 ◽  
Author(s):  
Denise Baptaglin Montagner ◽  
Marta Gomes da Rocha ◽  
Teresa Cristina Moraes Genro ◽  
Fernando Luiz Ferreira de Quadros ◽  
Juliano Roman ◽  
...  
Keyword(s):  
Pearl Millet ◽  
Leaf Blade ◽  
Structural Characteristics ◽  
Experimental Period ◽  
Repeated Measure ◽  
Beef Heifers ◽  
Pasture Management ◽  
Bite Rate ◽  
Sward Height ◽  
Ingestive Behaviour

Ingestive behaviour of beef heifers and sward structural characteristics of Pearl Millet (Pennisetum americanum (L.) Leeke) were evaluated. The experiment was carried out in a randomized complete design following a repeated measure arrangement (three experimental periods) with three replications of two leaf blade masses (600 and 1,000 kg/ha DM), which were maintained using continuous grazing with variable stocking rate. The variables measured were sward height, herbage mass, leaf blade and stem bulk density in sward vertical strata (sward structural characteristics), grazing, idling, rumination time and bite rate of heifers (ingestive behaviour). Bite rate was modified by pasture management and was lower when the leaf blade mass was 1,000 kg/ha DM. The daily grazing, rumination and idling time of beef heifers were similar for both leaf blade masses. Structural variation of the sward, during the experimental period, altered the grazing, rumination and idling time of heifers, and affected the bite rate. In Southern Brazil, the beef heifers concentrate their grazing activities in the 12 p.m. to 6:00 p.m. period, decreasing the grazing between 12 a.m. and 6:00 a.m., even in the hottest season of the year.

scholarly journals Canopy structure, ingestive behavior and displacement patterns of beef heifers grazing warm-season pastures

2016 ◽  
Vol 68 (2) ◽  
pp. 457-465 ◽  
Author(s):  
C.L. Glienke ◽  
M.G. Rocha ◽  
L. Pötter ◽  
D. Roso ◽  
D.B. Montagner ◽  
...  
Keyword(s):  
Pearl Millet ◽  
Canopy Structure ◽  
Neutral Detergent Fiber ◽  
Ingestive Behavior ◽  
Displacement Rate ◽  
Compensatory Mechanism ◽  
Intake Rate ◽  
Beef Heifers ◽  
Data Set ◽  
Bite Rate

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.

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.

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 Leaf tissue flows and defoliation patterns of Alexandergrass grazed by heifers receiving energy supplement

2019 ◽  
Vol 41 (1) ◽  
pp. 44902
Author(s):  
Paula De Oliveira Severo ◽  
Luciana Pötter ◽  
Marta Gomes da Rocha ◽  
Mateus Negrini ◽  
Amanda Carneiro Martini ◽  
...  
Keyword(s):  
Body Weight ◽  
Experimental Design ◽  
Rice Bran ◽  
Leaf Blade ◽  
Leaf Tissue ◽  
Grazing Intensity ◽  
Repeated Measure ◽  
Feeding System ◽  
Stocking Rate ◽  
Beef Heifers

The study was carried out to evaluate defoliation patterns and to quantify leaf tissue flows in Alexandergrass (Urochloa plantaginea (Link.) Hitch) grazed by beef heifers receiving whole rice bran in three levels of supplementation (0, 0.5 and 1 % of body weight). A rotational stocking grazing method and two area replications were utilized. The experimental design was completely randomized following a repeated measure arrangement. The supply of rice bran to heifers grazing Alexandergrass increased the stocking rate by 13%. Regardless of the feeding system, the heifers grazed the expanding leaf blades in the top stratum of the canopy more frequently compared to other types of leaf. Leaf tissue flows, leaf blade intake and grazing intensity have not been changed by supplement fed.

scholarly journals Effect of grazing management strategies on the yield and nutritional value of Marandu grass in the semiarid of Brazil

2021 ◽  
Vol 42 (4) ◽  
pp. 2503-2522
Author(s):  
Maria Catiane Silva Veloso Araújo ◽  
◽  
Eleuza Clarete Junqueira de Sales ◽  
Flávio Pinto Monção ◽  
Vicente Ribeiro Rocha Júnior ◽  
...  
Keyword(s):  
Dry Matter ◽  
Nutritional Value ◽  
Accumulation Rate ◽  
Structural Characteristics ◽  
Block Design ◽  
Management Strategies ◽  
Grazing Management ◽  
Rotational Grazing ◽  
Pasture Management ◽  
Sward Height

The objective of this study was to evaluate the effects of two grazing management strategies on structural, productive and nutritional parameters of Marandu grass (Urochloa brizantha cv. Marandu). A completely randomized block design with two pasture management strategies and eight replications (blocks) was used. The grazing management strategies were: (1) low intensity rotational grazing (LI), with a pre-grazing sward height of 40 cm and a post-grazing sward height of 24 cm, i.e., a defoliation intensity of 50%; (2) High intensity rotational grazing (HI), with a pre-grazing sward height of 40 cm and a post-grazing sward height of 10 cm (±70% defoliation intensity). Pastures were sampled before and after grazing for estimation of forage mass, forage accumulation rate, structural characteristics, nutritional value and dry matter intake.The LI strategy resulted in higher dry matter production than HI before (18.33%) and after grazing (49.06%), increasing pre-grazing forage density by 13.21% (P < 0.05). The production of potentially digestible dry matter was highest (P < 0.05) in LI strategy (21.3% before and 39.6% after grazing, respectively). Higher post-grazing green forage mass (45%) increased the residual crude protein in LI. The LI management strategy increased forage mass production and can be used in Marandu grass pastures.

scholarly journals Ingestive behaviour of grazing ruminants: meta-analysis of the components linking bite mass to daily intake

2019 ◽  
Author(s):  
M. Boval ◽  
D. Sauvant
Keyword(s):  
Extreme Values ◽  
Meta Analysis ◽  
Daily Intake ◽  
Small Ruminants ◽  
Adaptive Responses ◽  
Livestock Farming ◽  
Pasture Management ◽  
Behavioural Adaptation ◽  
Sward Height ◽  
Ingestive Behaviour

AbstractThis meta-analysis shed light on the quantitative adaptive responses of feeding behaviour of Cattle (C) and Small Ruminants (SR), facing variations of sward characteristics, notably of sward height (SH, 18. 7 ± 13.9 cm) and herbage bulk density (HBD, 1.73 ± 1.30 kg DM / m3). All responses expressed a plateau stressing an adaptive limit with extreme values of SH and HBD. The minimum plateau of BR (46.9 ± 14.6 min-1) is around 40 min-1, while IR values (different for C and SR, respectively 69.1 ± 38.1 vs. 99.9 ± 45.7 g/min/kg BW) ranged between a minimum and maximum plateau around 50 and 100 g/min/kg BW. Two other pasture management factors affect IR, namely forage allowance (10.16 ± 6.0, DM % BW) and daily proportion of time spent grazing (0.30 ± 0.08). The results obtained confirm the specifically key role of BM (1.80 ± 127 mg DM/kg BW) on IR. The regressions are IR=145 (1-exp (-b BM), b being equal respectively for C and SR and C to 0.44 vs. 0.54. This literature review has also revealed fundamental differences in behaviour between C and SR although no study to date has attempted to compare them simultaneously. SR have to chew more (2.7 ± 1.2 vs. 1.6 ± 0.5 JM/bite) to ingest the same amount of DM per bite than C, expressed in relation to BW, which allow them to ingest slightly quickly.ImplicationsThis article, following the previous one of Boval and Sauvant (2019), proposes a quantitative appraisal of the ingestive behaviour of grazing ruminants, based on studies published over 40 years, as well as well robust average values and relationships, considering inter- and intra-study effects and animal species specificities. This knowledge should contribute to a better overall understanding of the behavioural adaptation of ruminants at pasture, to the identification of key threshold values and appropriate parameters of interest to be considered, and to improve the efficiency and sensitivity of automatic devices, which are booming in the context of precision livestock farming at pasture.

scholarly journals Tillering and forage accumulation in Marandu grass under different grazing intensities

Revista CERES ◽  
2011 ◽  
Vol 58 (6) ◽  
pp. 781-789 ◽  
Author(s):  
Maria Paula Cavuto Abrão Calvano ◽  
Valéria Pacheco Batista Euclides ◽  
Denise Baptaglin Montagner ◽  
Beatriz Lempp ◽  
Gelson dos Santos Difante ◽  
...  
Keyword(s):  
Block Design ◽  
Management Strategies ◽  
Experimental Period ◽  
Plant Responses ◽  
Pasture Management ◽  
Sward Height ◽  
Randomized Block Design ◽  
Grazing Intensities ◽  
Autumn And Winter ◽  
Sward Structure

Studies of plant responses to defoliation are important to develop pasture management strategies. The objective of this study was to evaluate the population density of basal, aerial and reproductive tillers, tiller appearance and mortality rates, forage accumulation and sward structure in Marandu grass pastures under different grazing intensities. The experimental period was from January to June 2006, divided in three seasons: summer, autumn and winter. The pastures were continuously grazed using variable stocking rates. The grazing intensities corresponded to 15, 30 and 45 cm of sward height. The experiment was arranged in a complete randomized block design with three treatments and two replicates. The sward heights were measured twice a week. The response variables were: forage accumulation, forage mass and its morphological components; and population densities of basal (TPDb), aerial (TPDa) and reproductive (TPDr) tillers. The highest TPDb (P > 0.05) was recorded for the shortest sward pasture, and the highest TPDr (P<0.05) for the tallest sward pasture. Swards showed a tiller size/density compensation mechanism and, consequently, the forage accumulation was similar (P > 0.05) among the grazing intensities. Pasture with a sward height of 35 cm had 94% of sun light interception. The highest variations in forage accumulation and sward structure were more influenced by seasonal differences than by grazing intensities. Pastures of Marandu grass showed large flexibility in grazing management, which allowed it to be maintained at sward heights between 15 and 35 cm.

scholarly journals Morphogenetic and structural characteristics of andropogon grass submitted to different cutting heights

2010 ◽  
Vol 39 (10) ◽  
pp. 2141-2147 ◽  
Author(s):  
Braulio Maia de Lana Sousa ◽  
Domicio do Nascimento Júnior ◽  
Sila Carneiro da Silva ◽  
Hélida Christhine de Freitas Monteiro ◽  
Carlindo Santos Rodrigues ◽  
...  
Keyword(s):  
Leaf Blade ◽  
Structural Characteristics ◽  
Stem Elongation ◽  
Block Design ◽  
Growth Conditions ◽  
Leaf Lifespan ◽  
Blade Length ◽  
Sward Height ◽  
Randomized Block Design ◽  
Andropogon Gayanus

This work was performed aiming to evaluate the morphogenetic and structural characteristics of Andropogon gayanus cv. Planaltina species submitted to three cutting heights (20, 27 and 34 cm). The three cutting heights were allocated in experimental units (12 m²) in a complete randomized block design with three replications. The cuts were done when the light interception by the sward reached 95%. At this moment, the sward height revealed itself constant with values close to 50 cm. The lowest cutting height (20 cm) influenced negatively the final leaf blade length, the number of live leaves, the leaf lifespan, the stem elongation rate and the tiller population density, and it influenced positively the phyllochron and the leaf senescence rate. Probably, cuts at 20 cm height caused a high decapitation and death of the tillers. The worst growth conditions in addition to the blossom of this specie occurred during fall resulted in higher stem elongation rates and number of live leaves, and lower phyllochron, final leaf blade length, and leaf lifespan. The sward height can be used as a practical and efficient criterion in the management of andropogon grass. Under intermittent management conditions, the regrowth of andropogon grass must be interrupted when the sward reaches 50 cm height, and the defoliation must be interrupted when the stubble height is close to 27 cm.

scholarly journals Effects of providing artificial shade to pregnant grazing beef heifers on vaginal temperature, growth, activity, and behavior

2021 ◽  
Author(s):  
Gleise M Silva ◽  
Lautaro R Cangiano ◽  
Thiago F. Fabris ◽  
Victoria R Merenda ◽  
Ricardo C Chebel ◽  
...  
Keyword(s):  
Growth Performance ◽  
Average Daily Gain ◽  
Experimental Period ◽  
Paspalum Notatum ◽  
Beef Heifers ◽  
Shade Treatment ◽  
Growth Activity ◽  
Gps Devices ◽  
And Behavior ◽  
Vaginal Temperature

Abstract This experiment evaluated the effects of providing artificial shade during summer on activity, behavior, and growth performance of pregnant grazing beef heifers. Thirty-six black-hided Angus and Angus crossbred pregnant heifers [418 ± 9 kg body weight (BW); approximately 90 d of gestation] were stratified by breed, blocked by BW, and allocated to 12 ‘Pensacola’ bahiagrass pastures (Paspalum notatum Flüggé; 1.3 ha, n = 3 heifers/pasture) with or without access to artificial shade (SHADE vs. NO SHADE; 6 pastures each) for 7 wk during summer. The shade structures were composed of shade cloth (11 × 7.3 m length, 2.4 m height: 26.8 m 2 of shade per heifer). Shrunk BW was recorded on enrollment (d 0) and wk 7 (d 47), whereas full BW was obtained on wk 2 (d 14), 4 (d 28), and 6 (d 42) to assess average daily gain (ADG). Vaginal temperature was recorded for five consecutive days during wk 1, 3, 5, and 7 using an intravaginal digital thermo-logger, and individual GPS devices were used to quantify the use of shade for an 8-h period. Activity was monitored using automated monitoring devices (HR-LDn tags SCR Engineers Ltd., Netanya, Israel) through the experimental period. Vaginal temperature was lower (P &lt; 0.01) for heifers in the SHADE compared with heifers in the NO SHADE treatment from 1200 to 1600 h and 1100 to 1900 h for wk 1 and 3, respectively. Heifers in the SHADE treatment spent 70% of the 8-h period evaluated under the shaded structure. Provision of shade increased (P &lt; 0.01) daily lying time (11.4 ± 0.2 vs. 10.3 ± 0.2 h/d) and standing bouts per day (P &lt; 0.01; 12.6 ± 0.4 vs. 10.8 ± 0.4 bouts/d), whereas it reduced (P &lt; 0.01) standing bout duration (61.6 ± 3.0 vs. 82.9 ± 3.0 min/bout) relative to heifers without access to shade. The interaction between treatment and hour affected (P &lt; 0.01) daily rumination time because heifers with access to SHADE had greater rumination between 1000 and 1200 h. Although ADG tended (P = 0.08) to be greater for the heifers in the SHADE treatment (0.20 vs. -0.02 kg, respectively), the access to shade did not (P = 0.79) affect the final BW. In conclusion, providing artificial shade during summer to pregnant grazing beef heifers was effective in reducing vaginal temperatures and exerted changes in heifer behaviors that translated into slight improvements in growth performance.

Response of beef heifers and non-suckling beef cows to different oestrous synchronization protocols

2002 ◽  
Vol 74 (3) ◽  
pp. 547-552 ◽  
Author(s):  
D. Cavestany ◽  
N. Negrin ◽  
R. Negrin ◽  
J. F. Groth
Keyword(s):  
Beef Cattle ◽  
Medroxyprogesterone Acetate ◽  
Artificial Insemination ◽  
Experimental Period ◽  
Fixed Time ◽  
Beef Cows ◽  
Pregnancy Rates ◽  
Gnrh Analogue ◽  
Beef Heifers

AbstractThe objective was to evaluate different oestrous synchronization schemes in beef cattle under range conditions. In experiment 1, 202 heifers averaging 26 months of age were assigned randomly to three treatments: (a) GnRH-PG. (no. = 44) day 0 (D0): injection of GnRH; D7: injection of PGF2α; D0 to D25 oestrous detection (OD) and artificial insemination (AI); (b) OD-PG. (no. = 45) D0 to D4; OD + AI; D5: injection of PGF2α; D5 to D25 OD + AI; and (c)Ovsynch. (no. = 113) D0: injection of GnRH; D7: injection of PGF2α; D9: injection of GnRH and 16 h later AI at fixed time. In experiment 2, 318 non-suckling cows were assigned randomly to three treatments: (a) GnRH-PG. (no. = 106) D0: injection of GnRH; D7: injection of PGF2α; D0 to D25 OD + AI; (b) GnRH-MAP-PG. (no. = 106) D0: injection of a GnRH analogue and insertion of an intravaginal sponge impregnated with 250 mg of medroxyprogesterone acetate; D7: injection of PGF2α and sponge withdrawal; D0 to D25 OD + AI; (c) controls. (no. = 106) OD and AI. The experimental period lasted 25 days and, with exception of the Ovsynch treatment, oestrous detection was carried out twice a day (a.m./p.m.) and inseminations performed 12 h later. The pregnancy rates assessed by ultrasonography 30 days after AI were: experiment 1: (a) 30·0%; (b) 28·6% and (c) 62·3% (P < 0·05); experiment 2: (a) 60·2%; (b) 57·8% and (c) 45·5% (P < 0·05). It is concluded that in heifers and non-suckling cows, oestrous synchronization treatments result in higher pregnancy rates. In non-suckling cows, the addition of a progestagen did not improve the response.

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