Browsing by Author "Tillman, A.D."
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Item Metabolism of Nitrogen in Boran and iIn Hereford-Boran Crossbred Steers(1972) Karue, C.N.; Evans, J.L.; Tillman, A.D.In trial 1, six 18-month-old boran steers were paired by weight to six 12-month-old;y,j: hereford, y,;: boran crossbre~ (hbc) steers and fed a low-protein hay iii a comparative digestibility trial over a ~ 8-day period. No supplementary energy or m.trogen (n) was provided, but adequate ml,nerals and vitamins were supplied. Voluntary mtake of dry matter (dmi) was 231)'0 higher (p< .01) for the boran than for the hbc. the coefficients of digestibility of dm, energy and n as well as the percent retained n in the t~o breeds were similar. The main differences in the protein metabolism between the bora? And the hbc were the higher (p<.os) urinary (un) and five times more (p<.oi) urinary urea n (uun) loss in the boran as compared to the hbc. The un of the boran and the hbc contained 47 and 12% uun, respectively, indicating an increase in the cycling of urea in the hbc on 7% protem hay.Item Utilization of Coffee Hulls in Cattle Fattening Rations(1972) Ledger, H.P.; Tillman, A.D.; E.A.A.F.R.O., MugugaIn East Africa the supplementary feeding of beef cattle to provide quality carcasses is currently receiving considerable attention. Whilst there is no difficulty in compounding suitable rations to provide the necessary nutrients for this purpose the narrow profit mar- gin for beef and the seasonal fluctuations in the price and availability of the most suitable feed components make it necessary to investigate the use of alternative feeds for economic production. Tillman et al. (1969) found that rice hulls, although only rating as a low-quality rough age, when included in a high-grain ration materially decreased the cost of a ration without reducing its productive efficiency. Rogerson (1955) found that coffee hulls, also a low-quality roughage were palatable to sheep. Because coffee hulls, a by-product of the coffee industry, are readily available in many parts of East Africa the value of their use in a cattle fattening ration similar to that in which rice hulls were used has been investigated.Item Voluntary Intake of Dry Matter by African Zebu Cattle(1973) Karue, C.N.; Evans, J.L.; Tillman, A.D.; East African Agriculture and Forestry Research Organization, Box 30148, Nairobi, KenyaA study on voluntary intake of dry matter (DMI) was conducted using 108 Zebu steers approximately 2.5 years of age as determined from their dentition. Their average weight was 271 kg with a range from 184 to 332 kilograms. The animals were fed poor quality hay (7% CP, 80% CWC) ad libitum supplemented with restricted amounts of nine concentrates providing cassava and molasses for energy and urea for nitrogen (N). The concentrate supplied energy in g/kg0.60 and urea N as a percent of total N requirement in a central-composite design as follows (N values in parentheses): 20 (70), 32 (42), 32 (98), 60 (30), 60 (70), 60 (110), 88 (42), 88 (98) and 100 (70), in diets one to nine, respectively. The DMI and body weight data were collected during an 84-day feeding period. Using six observations for each of 108 steers, the average reference base determined by regressing logarithm of DMI on the logarithm of body weight was kg0.79±0.03, which was not different (P>.05) from the reference bases of kg0.75 and kg0.73. The DMI was 80 g/kg0.79 and equivalent to 100 g/kg0.75, i.e. DMI=A (BW)b where DMI is in grams per kilogram metabolic mass, A equals a constant, and b equals a functional power of body weight.
