scholarly journals 87 Evaluation of two stocking rates for grazing heifers on mixed sward native warm-season grass pastures in the Black Belt Prairie region

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 27-27
Author(s):  
Jane A Parish ◽  
Kalisha C Yankey ◽  
Libby S Durst

Abstract Optimal use of native warm-season grasses in pasture systems involves stocking grazing livestock at suitable rates. The study objective was to evaluate forage nutritive value and heifer ADG at two stocking rates on mixed-sward pastures of big bluestem (Andropogon gerardi Vitman), little bluestem (Andropogon scoparius), and indiangrass (Sorghastrum nutans L.). Pastures (3 replications) were stocked for 56 d during June and July in 2 yr with crossbred (Bos taurus) heifers (n = 24 heifers/year) stratified by initial BW (288.3 ± 1.7 kg) to one of two continuous stocking rates: 1.9 heifers/ha (HIGH) and 1.2 heifers/ha (LOW). Mean forage nutritive values on a DM basis were not different between HIGH and LOW stocking rates, respectively, for CP (7.0 ± 0.2% vs 6.7 ± 0.2%; P = 0.27), ADF (41.0 ± 0.6 vs. 41.4 ± 0.6; P = 0.64), NDF (69.9 ± 0.5 vs. 68.7 ± 0.5; P = 0.09), or relative feed value (RFV) (76.0 ± 1.0 vs. 76.9 ± 1.0; P = 0.53). There was a year effect (P < 0.01) and stocking rate x day effect (P < 0.01) for TDN. At LOW, TDN decreased from day 0 to day 28 (P = 0.02) and day 28 to day 56 (P = 0.02). At HIGH, TDN decreased (P < 0.01) from day 0 to day 28 but remained steady until day 56 (P = 0.21). There was a stocking rate x day interaction (P < 0.01) with ADG: LOW day 28 to 56 (1.20 ± 0.08 kg/day), HIGH day 0 to 28 (0.89 ± 0.08 kg/day), HIGH day 28 to 56 (0.44 ± 0.08 kg/day), and LOW day 0 to 28 (0.30 ± 0.08 kg/day). Further assessment of cattle ADG using more divergent stocking rates and plant persistence measures is warranted to inform ideal native grass stocking rate recommendations.

1999 ◽  
Vol 50 (4) ◽  
pp. 537 ◽  
Author(s):  
G. R. Saul ◽  
G. A. Kearney ◽  
P. C. Flinn ◽  
C. L. Lescun

The effect of superphosphate fertiliser on digestible dry matter (DDM) and crude protein (CP) percentages of perennial ryegrass and subterranean clover was assessed on a long-term, grazed experiment in western Victoria. CP of both species increased significantly (3–6 units) where long-term average phosphorus (P) applications were 33 kg/ha.year compared with 1 kg/ha.year. CP of herbage was also greater on paddocks grazed at higher (9–23 ewes/ha) than lower (5–13 ewes/ha) stocking rates (1–3 units). DDM of subterranean clover significantly increased (8–10 units) with higher superphosphate applications but there was little effect on the DDM of perennial ryegrass. Long-term applications of superphosphate were associated with larger increases in both DDM and CP than if the same rate was applied in autumn of the year of measurement. For subterranean clover, 30 kg/ha of P applied to infertile soils (Olsen P 5 mg/kg) in autumn increased the DDM of herbage collected in September by only 4–6 units. The nutritive value of most volunteer pasture species also increased with higher superphosphate applications but the DDM of these species was usually inferior to perennial ryegrass. The results highlight the importance of monitoring nutritive value, pasture composition, and herbage production to quantify fully the likely effect of fertiliser applications on animal production.


1997 ◽  
Vol 77 (1) ◽  
pp. 111-118 ◽  
Author(s):  
J. D. Popp ◽  
W. P. McCaughey ◽  
R. D. H. Cohen

A 3-yr field experiment was conducted (1991–1993) near Brandon, MB to determine the effects of continuous and rotational stocking, both at heavy (2.2 steers ha−1) and light (1.1 steers ha−1) stocking rates, and of season of use on nutritive value and sward characteristics of an alfalfa-grass pasture [approximately 70% alfalfa (Medicago sativa L.), 25% meadow bromegrass (Bromus biebersteinii Roem & Schult.) and 5% Russian wildrye (Psathyrostachys juncea (Fisch.) Nevski)]. Grazed herbage quality and herbage mass were determined concurrently on continuous and rotational stocking treatments several times each year, as animals entered and exited the 5th of 10 rotationally stocked paddocks. Grazing system and stocking rate did not affect (P > 0.05) dietary CP and IVDOM, except once (P < 0.05) for IVDOM in 1993. Both ADF and NDF were sometimes greater (P < 0.05) on heavy compared to light stocking rate treatments, but did not differ (P > 0.05) between grazing systems. As the 1991 season advanced, there was a decline (P < 0.05) in CP, but IVDOM, ADF and NDF remained unchanged (P > 0.05). In 1992, seasonal declines (P < 0.05) in CP and IVDOM and increases (P < 0.05) ADF and NDF were observed for all treatments. In 1993, in vitro digestible organic matter and CP decreased (P < 0.05) on most treatments, while ADF and NDF increased (P < 0.05). Herbage mass tended (P < 0.10) to be lower when heavy stocking rates were used in all years, but was not affected (P > 0.05) by grazing system. Significant relationships (P < 0.001) among IVDOM, ADF and NDF were found. Neither grazing system nor stocking rate appeared to affect the quality of herbage ingested by cattle grazing alfalfa-grass pastures. Key words: Alfalfa, pasture, grazing system, stocking rate


1973 ◽  
Vol 81 (2) ◽  
pp. 205-209 ◽  
Author(s):  
J. P. Langlands ◽  
I. L. Bennett

SummaryEstimates were made at monthly intervals between January and December 1965 of the intake and nutritive value of the diet of unmated Merino ewes grazed continuously at stocking rates ranging from 2·5 to 37·1 sheep/ha. Oesophageally fistulated sheep were used to estimate intake and nutritive value.Drought conditions existed during the experiment. Digestibility declined linearly with increasing stocking rate. The intercepts of the relationship between digestibility and stocking rate differed between months, being at a maximum in spring. Nitrogen content was also greatest in spring but did not change consistently with increasing stocking rate. Organic-matter intake declined linearly with stocking rate and increased asymptotically with total herbage available, the asymptotic relationship being the more precise. Neither relationship differed significantly between months. Organicmatter intake/ha increased continuously with increasing stocking rate and the maximum intake was predicted to occur at a stocking rate greater than that at which the sheep survived.


2019 ◽  
Vol 11 (3) ◽  
pp. 1 ◽  
Author(s):  
Guillermo Scaglia

The development of breeding heifers is a critical point in the beef cattle enterprise. The effect of stocking rate and supplementation strategy at high stocking rate were evaluated on Brahman influenced heifers (BW = 250&plusmn;3.6 kg) continuously stocked on annual ryegrass (Lolium multiflorum Lam. cv. &lsquo;Nelson&rsquo;) with the following treatments in a completely randomized design with 3 replicates: 1) LOW stocking rate (2.5 heifers/ha); 2) MED stocking rate (5.0 heifers/ha); 3) HIGH stocking rate (7.5 heifers/ha); 4) High stocking rate + 1% BW of ground corn (HIGH+C); and 5) High stocking rate + 1% BW of soybean hulls (HIGH+SBH). Dry matter intake was greater (P = 0.03) for heifers in LOW and MED, while those in HIGH, regardless receiving supplement or not, were the lowest. Heifers grazing LOW and MED did not differ (P = 0.06) in ADG. Supplemented heifers and those in MED produced the most beef per unit of land; however MED and HIGH were not significantly different. Grazing days was greater for LOW and supplemented heifers. There was a year effect for ADG, beef production, and grazing days which were smaller in year 1; however years 2 and 3 were not different (P &gt; 0.05) between them except in production per hectare. Lower stocking rates allowed for appropriate BW gains. Level of supplementation affected DMI from ryegrass, replacing it and affecting animal performance. Weather conditions had an impact on forage production, hence affecting animal performance. Supplementation programs must consider level and type of energy supplement used.


2020 ◽  
Vol 98 (2) ◽  
Author(s):  
Reinaldo F Cooke ◽  
Courtney L Daigle ◽  
Philipe Moriel ◽  
Stephen B Smith ◽  
Luis O Tedeschi ◽  
...  

Abstract Beef production needs to increase from 60 million to 130 million tons by 2050 to feed a growing world population, and 70% of this production increase is expected from beef industries located in subtropical and tropical regions of the world. Bos indicus-influenced cattle predominate in these regions but are often managed using practices developed for Bos taurus breeds reared in temperate climates. Hence, a fundamental step to meet the increasing global demand for beef is to develop specific management for B. indicus-influenced cattle in tropical or subtropical environments. Bos taurus and B. indicus are different subspecies, and diverge in social and biological functions due to selection pressure caused by complex evolutionary and domestication processes. Bos indicus cattle display different social responses compared with B. taurus counterparts, which must be taken into account by management planning as these traits directly impact cattle performance and welfare. In tropical and subtropical regions, warm-season perennial C4 grasses are the dominant forages, and their availability has a significant influence on the productivity of beef cattle systems. The resilience of C4 grasses under adverse conditions is one of their most important characteristics, even though these forages have reduced nutritive value compared with forages from temperate climates. Accordingly, nutritional planning in tropical and subtropical conditions must include management to optimize the quantity and quality of C4 forages. Nutritional requirements of cattle raised within these conditions also require special attention, including inherent metabolic compromises to cope with environmental constraints and altered energy requirements due to body composition and heat tolerance. Nutritional interventions to enhance beef production need to be specifically tailored and validated in B. indicus-influenced cattle. As an example, supplementation programs during gestation or early life to elicit fetal programming or metabolic imprinting effects, respectively, yield discrepant outcomes between subspecies. Bos indicus-influenced cattle produce carcasses with less marbling than B. taurus cattle, despite recent genetic and management advances. This outcome is mostly related to reduced intramuscular adipocyte volume in B. indicus breeds, suggesting a lesser need for energy stored intramuscularly as a mechanism to improve thermotolerance in tropical and subtropical climates.


2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 28-28
Author(s):  
Jane A Parish ◽  
Kalisha C Yankey ◽  
Libby S Durst

Abstract Native grasses are touted for use in drought mitigation strategies for grazing cattle. It is important to determine how these forages compare in specific production environments to more widely used improved grasses such as bermudagrass [Cynodon dactylon (L.) Pers.] that they may replace as pasture. Native warm-season grasses including big bluestem (Andropogon gerardi Vitman), little bluestem (Andropogon scoparius), and indiangrass (Sorghastrum nutans L.) were evaluated against bermudagrass pastures in the Black Belt Prairie region of Mississippi for stocker cattle grazing. Objectives were to compare bermudagrass (BG), indiangrass (IG) and mixed-sward native warm-season grass (mix of big bluestem, little bluestem, and indiangrass) (NGMIX) pasture for forage nutritive value and steer ADG. Crossbred (Bos taurus) steers (n = 36 steers/year) were stratified by initial BW (339.7 ± 4.3 kg) to 2.02-ha pastures (3 replications) during 56-d grazing periods in June and July for 2 yr. Mean forage nutritive values on a DM basis were: BG [8.8% CP, 43.4% ADF, 67.3% NDF, 58.7% TDN, and 77 relative feed value (RFV)], IG (6.7% CP, 39.6% ADF, 68.3% NDF, 58.2% TDN, and 79 RFV) and MIXNG (7.3% CP, 40.5% ADF, 69.5% NDF, 58.1% TDN, and 77 RFV). A forage treatment x day x year effect existed (P &lt; 0.01) for each these nutritive values. There was no effect (P = 0.47) of forage treatment on steer ADG (BG: 0.4 ± 0.1 kg/d; IG: 0.5 ± 0.1 kg/d; NGMIX: 0.5 ± 0.1 kg/d). Thus, no net advantage or disadvantage in steer growth rates was observed due to forage species. Other factors such as forage establishment cost and animal stocking rates supported may be relevant to consider in decisions to replace bermudagrass with warm-season native grasses.


Author(s):  
J. Hodgson

Recent assessments of the relative importance of stocking rate. stocking policy and grazing management on the output from pastoral systems are used as a starting point to argue the need for objective pasture assessments to aid control of livestock enterprises to meet production targets. Variations in stocking rates, stocking policy and other management practices all provide alternative means of control of pasture conditions which are the major determinants of pasture and animal performance. Understanding of the influence of pasture conditions on systems performance should provide a better basis for management control and for Communication between farmers, extension officers and researchers. Keywords: Stocking rate, pasture condition, pasture cover


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 450e-451
Author(s):  
Virginia A. Gaynor ◽  
Mary Hockenberry Meyer

There is great interest in prairie gardens and prairie restorations in the central United States. Small prairie gardens are often established with plugs, but most restorationists and landscape contractors use seed for large plantings. If initial establishment is poor, restorations are often interseeded the second or third season. However, to evaluate early establishment and determine if interseeding is necessary, contractors must be able to identify native grasses in the seedling and juvenile stages. In this study we investigated vegetative characteristics of native prairie grass seedlings. Seven species of native prairie grass were grown in the greenhouse: Andropogon gerardii (big bluestem), Sorghastrum nutans (Indian grass), Panicum virgatum (switch grass), Schizachyrium scoparium (little bluestem), Bouteloua curtipendula (sideoats grama), Elymus canadensis (Canada wildrye), and Bromus kalmii (Kalmís brome). Every 2 to 3 weeks after germination, seedlings were photographed, pressed, and mounted. Additional photographs were taken through the dissecting scope at key stages of development. Ligules and auricles were found to be useful in distinguishing species, and our close-up photographs highlight these structures. Hairiness and color were variable within a species and could not be used reliably in identification. A seedling identification key will be presented for the species studied.


2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 26-27
Author(s):  
Caroline Chappell ◽  
Landon Marks ◽  
Katie Mason ◽  
Mary K Mullenix ◽  
Sandra L Dillard ◽  
...  

Abstract A 2-yr study was conducted at Black Belt Research and Extension Center in Marion Junction, AL, to evaluate the effect of nitrogen (N) fertilizer application rate on forage production characteristics, nutritive value, and animal performance of beef heifers grazing a mixture of native warm-season grasses (NWSG) including big bluestem, little bluestem, and indiangrass. Six, two-hectare plots were randomly assigned to one of two treatments (0 or 67 kg N ha-1 applied in early April; n = 3 replications per treatment). Paddocks were continuously stocked with four weaned Angus × Simmental beef heifers (initial BW 288 ± 7 kg) from late May/early June through mid-to-late August during 2018 (73 grazing d) and 2019 (70 grazing d), respectively. Put-and-take cattle were used to manage forage to a target of 38 cm. Forage mass and canopy heights were collected every two weeks during the trial. Visual ground cover ratings, canopy light interception, and botanical composition were measured at the beginning and end of the trial in each year. Hand-plucked samples were collected every two weeks during the grazing trial to determine forage nutritional value. Data were analyzed using the PROC MIXED procedure in SAS 9.4, and differences were declared significant when P ≤ 0.05. Nitrogen fertilized NWSG had greater crude protein (P &lt; 0.0001), sward heights (P = 0.0003), and canopy light interception at the beginning of the season (P = 0.0049) compared to non-fertilized paddocks. However, there were no differences (P ≥ 0.05) among N-fertility treatments for mean forage mass, heifer ADG, or BCS across the 2-yr study. Botanical composition data indicated that indiangrass decreased from 64% to 61% (P = 0.0022) and weed pressure increased from 11% to 15% (P = 0.0064) across the summer grazing season. Canopy light interception decreased by 51% from early June to August in fertilized NWSG and 26% in unfertilized paddocks, respectively. These data illustrate that NWSG systems may provide a viable grazing system in the summer months under reduced N inputs.


1977 ◽  
Vol 28 (1) ◽  
pp. 133 ◽  
Author(s):  
JP Langlands

Grass and milk consumption and liveweight changes of lambs grazed at stocking rates ranging from 9 to 35 sheep/ha were measured during a 105 day lactation. Grass consumption and wool production of their mothers and of similar ewes without lambs were also determined. The forage and total organic matter intakes of the lamb increased with time while milk consumption declined; all three variables were negatively correlated with stocking rate. The intake of the ewe and its liveweight gain were not sensitive to increasing stocking rate, but wool production declined at higher stocking rates. The maintenance requirement of the ewes was estimated to be 218 kJ metabolizable energy/kg liveweight, and the efficiency with which metabolizable energy was utilized for milk production was 66%. Lactation increased the intake of the ewe but reduced its wool production.


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