The effect of season and of supplimentary feeding on the the rumen contents of African cattle grazing subtropical herbage:I Distribution of nitrogen and dry matter

Abstract

1. Africander and Mashona steers, fitted with rumen cannulae, were used to study levels of various nitrogenous fractions and of dry matter in the rumen of cattle grazing on natural subtropical herbage throughout the year. Some steers received various concentrate foods in addition to veldt grazing during winter. During the summer rainy season, four steers, two of each breed, were under trial, while in the winter drought period two extra steers of each breed were added to the experiment. The eight steers were divided into four groups for the winter, one group received a protein-rich concentrate, another group received a carbohydraterich concentrate, a third group was given a mixture of the two concentrates, while the fourth group received no additional food.

Nutritional Problems of Livestock Production From Semi‐arid Grasslands in the Tropics*

“…The third way is to measure the N content of the rumen contents. Elliott, Reed, Cmelik and Topps (11) found that, for cattle, maintenance of weight was associated with a level of 0-6 mg N/ml rumen liquor. The withdrawal of rumen fluid by stomach tube is not a difficult matter and the determination of its N content may give valuable information.…”

Seasonal Changes in Herbage and Cattle Diets on Sandhill Grassland

“…The samples used, however, were considered representative of their respective categories. It is quite evident that, during the growing season, steers selected a higher quality diet than was represented (Elliot et al, 1965;Topps, 1962). By December, differences in chemical composition between total herbage and cattle diets were minimal for most constituents.…”