scholarly journals Selenium Fertilization in Tropical Pastures

Author(s):  
Letícia de Abreu Faria ◽  
Pedro Henrique de Cerqueira Luz ◽  
Adibe Luiz Abdalla





1975 ◽  
Vol 15 (73) ◽  
pp. 211 ◽  
Author(s):  
TH Stobbs

Yield and nutritive value of three summer annual forages, hybrid forage sorghum (Sorghum spp. hybrid cv. Zulu), bulrush millet (Pennisetum typhoides cv. Tamworth) and white panicum millet (Echinochloa crusgalli var. edulis) were determined in three experiments. Uninterrupted growth was measured every 2 weeks between 4 and 12 weeks after sowing, and leaf, stem and inflorescence components analysed for nitrogen, phosphorus, calcium, magnesium, sodium and potassium and dry matter digestibility by an in vitro technique. The value of 10-week-old herbage, from crops grown with 50 kg ha-1 N, was determined by grazing with 18 Jersey cows and by feeding chopped material to 12 cows indoors. White panicum was the lowest yielding forage (up to 6,360 kg ha-1 at 10 weeks) but contained the highest concentration of nitrogen, phosphorus, calcium and magnesium in both leaf and stem fractions at all stages of growth. After 10 weeks growth this feed contained a high proportion of seed and was eaten in arger quantities than zulu sorghum or bulrush millet. Cows grazing white panicum produced the highestr lmilk yields (6.5 and 7.1 kg cow-1 day-1 indoors and grazed) and milk from these cows contained a highe solids-not-fat and protein content than milk from cows fed bulrush millet or sorghum. Zulu sorghum was highest yielding (1 1,240 kg ha-1 at 12 weeks in experiment 1 and 81 50 kg ha-1 at 10 weeks in experiment 2). With advancing maturity stem content increased (>80 per cent from 8 weeks onwards) and the nitrogen content of both leaf and stem fractions rapidly declined to sub-optimum levels. Milk production of cows feeding on zulu sorghum was low, averaging 4.7 and 6.0 kg cow-1 day-1 for indoor and grazing experiments. Bulrush millet produced high forage yields with a higher leaf content than zulu sorghum and milk yields were higher. Butterfat content of milk from cows feeding on bulrush millet was lower than when cows were fed the other forages. It was concluded that these three forages are capable of providing a large bulk of feed but their feeding value at a semi-mature stage of growth is similar to perennial tropical pastures.



2010 ◽  
Vol 50 (4) ◽  
pp. 246 ◽  
Author(s):  
R. G. Chataway ◽  
R. G. Walker ◽  
M. N. Callow

Farmlets, each of 20 cows, were established to field test five milk production systems and provide a learning platform for farmers and researchers in a subtropical environment. The systems were developed through desktop modelling and industry consultation in response to the need for substantial increases in farm milk production following deregulation of the industry. Four of the systems were based on grazing and the continued use of existing farmland resource bases, whereas the fifth comprised a feedlot and associated forage base developed as a greenfield site. The field evaluation was conducted over 4 years under more adverse environmental conditions than anticipated with below average rainfall and restrictions on irrigation. For the grazed systems, mean annual milk yield per cow ranged from 6330 kg/year (1.9 cows/ha) for a herd based on rain-grown tropical pastures to 7617 kg/year (3.0 cows/ha) where animals were based on temperate and tropical irrigated forages. For the feedlot herd, production of 9460 kg/cow.year (4.3 cows/ha of forage base) was achieved. For all herds, the level of production achieved required annual inputs of concentrates of ~3 t DM/animal and purchased conserved fodder from 0.3 to 1.5 t DM/animal. This level of supplementary feeding made a major contribution to total farm nutrient inputs, contributing 50% or more of the nitrogen, phosphorus and potassium entering the farming system, and presents challenges to the management of manure and urine that results from the higher stocking rates enabled. Mean annual milk production for the five systems ranged from 88 to 105% of that predicted by the desktop modelling. This level of agreement for the grazed systems was achieved with minimal overall change in predicted feed inputs; however, the feedlot system required a substantial increase in inputs over those predicted. Reproductive performance for all systems was poorer than anticipated, particularly over the summer mating period. We conclude that the desktop model, developed as a rapid response to assist farmers modify their current farming systems, provided a reasonable prediction of inputs required and milk production. Further model development would need to consider more closely climate variability, the limitations summer temperatures place on reproductive success and the feed requirements of feedlot herds.



2014 ◽  
Vol 37 (3) ◽  
pp. 343-356 ◽  
Author(s):  
T. Casey Barickman ◽  
Dean A. Kopsell ◽  
Carl E. Sams


1993 ◽  
Vol 33 (7) ◽  
pp. 865 ◽  
Author(s):  
WJ Fulkerson ◽  
K Slack

The feasibility of estimating, with acceptable precision, temperate and tropical pasture mass in a subtropical environment was evaluated. For the tropical grasses kikuyu (Pennisetum clandestinum) and setaria (Setaria ancepts), 3 different pasture meters were calibrated against 1 of 3 dry matter (DM) estimates. Temperate pastures (predominantly Lolium perenne and Trifolium repens) were evaluated using the Ellinbank rising plate meter (RPMl) calibrated against DM to ground level. A single regression equation was developed for syegrass-white clover pasture from data pooled within season over first- and second-year swards. The s.e. of estimate (s.e.e.) for assessing tropical grass pasture mass using RPMl was similar to that for a heavier Ellinbank meter and substantially lower than that for the electronic pasture probe. Using RPMl, separate regression equations were required for early (November-February) and late (March-May) season determinations for both kikuyu and setaria. The regression equations were based on calibrations against shoot DM (>5 cm stubble height for kikuyu and 6 cm for setaria) and are only applicable to well-managed and highly utilised pastures. Calibrations of all pasture meters over all months to green DM (senescent leaf and stem removed) gave a lower s.e.e. than total DM (kikuyu 138 v. 177 kg DM/ha, n = 171; setaria 211 v. 224 kg DM/ha, n = 177) whilst shoot DM gave a more substantial reduction in s.e.e. (kikuyu 95 v. 147 kg DM/ha; setaria 140 v. 193 kg DM/ha).



2021 ◽  
Vol 53 (5) ◽  
Author(s):  
Antonio Leandro Chaves Gurgel ◽  
Gelson dos Santos Difante ◽  
João Virgínio Emerenciano Neto ◽  
Juliana Caroline Santos Santana ◽  
Patrick Bezerra Fernandes ◽  
...  


PANS ◽  
1976 ◽  
Vol 22 (1) ◽  
pp. 79-85 ◽  
Author(s):  
P. A. Chadhokar
Keyword(s):  


Author(s):  
Stephen Lapointe ◽  
Ronald Sonoda
Keyword(s):  


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