No abstract

Body measurements and weights of animals of varying ages were recorded in White Fulani (Bunaji), Sokoto Gudali and N'dama breeds of cattle. Chest girth accounted for 86-96% of the variation in body weight in the three breeds. The linear regression coefficient of weight on chest girth in the N'dama differed significantly from the other two breeds. Within each breed, the regression coefficient of young animals was lower than those of older groups. The variables that contributed most to improving the prediction of weights when added to chest girth were rump length and body length. Animals with low body condition scores had lower regression coefficients of weight on chest girth than those with high scores.

The mineral status of Flint Hills bluestem forage was assessed monthly between 1975 and 1976. Results Indicated that magnesium, potassium, and manganese were adequate for optimum performance of range cattle during spring and summer, but that magnesium and potassium were low in late fall and winter. Concentmtions of calcium, iron, and zinc, highest in spring, were higher throughout the year than established nutrient requirements. Burning significantly. decreased phosphorus and iron and increased magnesium. The low levels of phosphorus and potassium during fall and winter do not affect animal performance. Most of the many minerals essential for animal life normally are present and metabolically available in adequate amounts in pasture so only those likely to be deficient are important to range managers. Pasture, the main source of feed for ruminants, varies widely in mineral content because many factors influence minerals including seasons, soil, cultural or management practices, and stage of plant growth. Higher phosphorus (P) in winter and spring grasses than in summer and fall grasses have been reported (Melville and Sears 1953, Reith et al. 1964), while calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na) peak about September then decline to their lowest in winter (Walker et al. 1953, Hemingway 1962, Karn and Clanton 1976). Blincoe and Lambert (1972) reported that advancing season did not influence copper (Cu) or zinc (Zn) contents of crested wheatgrass from April to July in northern Nevada. Cu deficiency was reported in the Netherlands at the end of the grazing season (Hartmans 1969), while Fleming (1970) found Zn content of perennial ryegrass(Loliumperenne L.) increased until late September and then declined. Management practices, such as range burning, also greatly affect mineral status of forages. Range burning has been used to increase protein in forages (Campbell and Cassady I95 1, Smith and Young 1959) and apparent digestibility coefficients of dry matter and crude fiber (Smith et al. 1960, Grelen and Whitaker 1973). Burning also is believed to benefit plant growth by increasing organic matter, mineral elements, and nitrogen in the soil (Metz et al. 1961, Ahlgren and Ahlgren 1960). The widespread practice of burning in late winter increases protein and P in new growth, but the benefit lasts only until May when the young-leaf stage ends (Campbell and Cassady 1951, Duvall and Whitaker 1964). Glendening et al. (1952) reported mineral contents of prairie grass, mostly bluestem of Kansas. Their work, covering April, July, and winter months of 3 years, showed some minerals de& cient. A wide variety of plants grow under range conditions, and management, stage of maturity, precipitation, and location all affect the nutrient composition of range plants. It seemed to us that a monthly assessment of mineral composition of Flint Hills range

Eighteen growing cattle with a mean live weight of 180 kg were used to study the influence of restricted water on feed intake, nutrient utilization and nitrogen metabolism in Zebu cattle in the Sudano-Sahelian ecological zone of Nigeria.Feed intake and water consumption were negatively correlated (r = 0-63). As the amount of water intake was reduced from 15-8 to 11-9 I/day, the mean feed intake increased from 5-6 to 6-8 kg D.M./day; water to feed ratios decreased from 2-83 to 1 • 75 and average daily live-weight gain as well as apparent feed utilization efficiency improved significantly from free-choice water to 50 % of free-choice water treatments respectively.Apparent digestibility coefficients of almost all the nutrients from the 75 and 50% of free-choice water treatments indicated progressively higher (though not significant) values than those of the free-choice water treatment. Nitrogen metabolism did not indicate any difference in the nitrogen intake in any of the three treatments; however, nitrogen balance and nitrogen retained as a percentage of nitrogen intake were significantly (P < 0-05) higher on the 50% of free-choice water treatment.The survival ability of these Zebu breeds of cattle under water stress during the acute water scarcity of the protracted dry period of the Sudan-Sahelian zone of Nigeria could probably be attributed to increased recycling of nitrogen as well as a reduction in nitrogen loss during the period.

Eighteen bulls were used to investigate the influence of feeding frequency on feed consumption, nutrient utilization and nitrogen metabolism in growing zebu cattle.Results indicated higher feed intake, nutrient utilization and average daily live-weight gains for animals fed two or three times daily compared with those fed once daily. Feed efficiency and feed cost per kg gain as well as nitrogen metabolism also increased as the frequency of feeding increased from once to three times daily.More frequent feeding could evidently be of practical advantage in intensive beef cattle production where zebu cattle are raised on tropical hay diets.