scholarly journals Botanical Composition of Diets of Cattle Grazing South Florida Rangeland

1984 ◽  
Vol 37 (4) ◽  
pp. 334 ◽  
Author(s):  
R. S. Kalmbacher ◽  
K. R. Long ◽  
M. K. Johnson ◽  
F. G. Martin
Keyword(s):  
Cattle Grazing ◽  
South Florida ◽  
Botanical Composition

Diet selection by cattle grazing Stylosanthes-grass pastures in the seasonally dry tropics: effect of year, season, stylo species and botanical composition

1996 ◽  
Vol 36 (7) ◽  
pp. 781 ◽  
Author(s):  
DB Coates
Keyword(s):  
Cattle Grazing ◽  
Diet Selection ◽  
Dry Season ◽  
Major Influence ◽  
Botanical Composition ◽  
Wet Season ◽  
Seasonally Dry ◽  
Dietary Preference ◽  
Dry Tropics ◽  
Opportunity For Selection

The dietary preference of cattle grazing Stylosanthes-based pastures in the seasonally dry tropics of North Queensland was studied using faecal carbon ratios (S13C) to determine grass-legume proportions. Estimates were made at monthly intervals for several years in 1 experiment to determine the effect of year, season and botanical composition on dietary stylo proportions. In another experiment, the effect of stylo cultivars (Verano and Seca) on dietary preference was monitored for 17 months. Where pastures provided ample opportunity for selection, cattle showed a strong preference for grass in the early wet season and in the late dry season. The proportion of stylo in the diet increased during the wet season and reached peak proportions (as high as 80%) in the late wet season or early dry season. Dietary stylo proportions decreased as pastures dried off and as the stylo shed leaf or became more stemmy. The length of the wet season and the amount and distribution of rainfall had a major influence on the seasonal pattern of diet selection. Stylo rarely fell below 20% in the diet. On an annual basis, stylo accounted for about 45% of the diet which was appreciably higher than the proportion of stylo in the pasture. Dietary stylo proportions were higher on Seca-based pasture than on Verano-based pasture. The avoidance of stylo in the early wet season was less pronounced with Seca compared with Verano. Later in the season Seca was the dominant dietary component for a much longer period than Verano. The effect of botanical composition on dietary grass-legume proportions varied between and within years. Correlations between grass-legume proportions in the pasture and in the diet were highest in the late dry season and early wet season when preference for grass was strongest. At the end of the wet season when cattle preferred stylo, dietary stylo was not related to pasture stylo content except in a drought year. Averaged over the full year, dietary stylo content was significantly correlated with pasture stylo content in all years and the correlation was highest in a drought year when there was a high level of utilisation and less opportunity for selection. A simple model relating dietary stylo to pasture stylo was developed and is discussed.

Estimation by calcium analysis of the proportion of grass in oesophageal fistula samples from cattle grazing grass-stylo pastures

1978 ◽  
Vol 18 (92) ◽  
pp. 329 ◽  
Author(s):  
MJ Playne ◽  
RG Megarrity ◽  
RP LeFeuvre
Keyword(s):  
Calcium Concentration ◽  
Cattle Grazing ◽  
Botanical Composition ◽  
Tropical Grasses ◽  
Plant Parts ◽  
Whole Plant ◽  
Plant Maturity ◽  
One Year

Variation in calcium (Ca) concentration in tropical grasses and Stylosanthes species growing in paddocks with and without superphosphate fertilizer was examined at six intervals over one year on whole plant tops and on hand-plucked samples. Variation in Ca concentration between plant parts was also measured on one sampling date. Extrusa samples obtained from cattle fitted with oesophageal fistulae in two grazing experiments were used to examine the relation between the Ca concentration and the botanical composition determined by the microscope-hit method. The concentration of Ca was 2.2 to 5.2 times greater in legumes than in grasses. While it decreased in legumes with increasing plant maturity, it remained relatively constant in the grasses, especially in those receiving fertilizer. Calcium concentration did not vary greatly between plant parts in the grasses, but the legume stems had lower (0.77 per cent Ca) concentrations than legume leaves (1.58 per cent Ca). The relationships found in the two grazing experiments did not differ, and the resulting combined equation describing it was : y = 128.4 - 82.0x (n = 40; r2 = 0.822; S y . x = 12.6) where y = per cent grass and x = per cent Ca.

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