B. Fadlalla

Effect of strategic supplementary feeding on ewe productivity under range conditions in North Kordofan, Sudan

Strategic supplementary feeding practices were imposed on ewes prior to mating (flushing) and during late pregnancy (steaming-up) at two locations in North Kordofan, Sudan. The objective was to improve ewe reproductive performance and increase lamb birth weight. A completely randomized block design was used and the results analyzed from the economic point of view. Strategic supplementary feeding of ewes increased conception and lambing rates (P<0.01), reduced abortions (P<0.01), and resulted in higher lamb birth weights (P<0.05). The treatment also reduced ewe weight loss (P<0.05) and caused no ewe mortality. Respective lambing rates for the supplemented and control ewes were 91.7 and 41.7%. Strategic supplementary feeding was economically more advantageous and could accrue up to 382540 additional Sudanese pounds (US

Effects of particle size on digestion of hay by sheep

273.24) in returns. It was concluded that steaming-up and flushing are essential for improving ewe reproductive performance, increasing lamb birth weights, and minimizing pregnancy stress of ewes. Hence, the practice is recommended in similar ecological zones to improve productivity of desert sheep.

Digestion and retention time of stained food in sheep

The digestion and retention times of milled hay diets were first studied in three sheep fitted with rumen and abomasal cannulae. The hay was milled through 5, 20 or 40 mm screens. Solubility of dry matter (D.M.) in water and rate of loss of D.M. from hay in nylon bags suspended in the rumen increased with fineness of grinding. Apparent digestibility of D.M. within the gut tended to fall with fineness of grinding, as did mean retention time (MRT) of a particulate marker, [ 103 Ru]phenanthroline ([ 103 Ru]phen), within the gut and of [ 103 Ru]phen and a liquid marker, [ 51 Cr]EDTA, within the rumen. Dry-sieved abomasal particles were much smaller than particles of any of the hay preparations, most passing through a 0·6 mm screen. A second experiment was made on four other sheep, fitted with rumen cannulae and given a similar hay, chopped to 50 mm or milled through 2, 5 or 20 mm screens. Apparent digestibility of D.M. within the gut fell significantly with fineness of grinding, from 55% with the chopped hay to 46% with the 2 mm hay, as did MRT, from 45 to 40 h respectively. Rumen pH at 1 h after feeding decreased with fineness of grinding. In a third experiment, using the four sheep given chopped or 2 mm hay, retention times of particulate matter and of fluid in the reticulo-rumen and in the caecum-colon were measured. [ 103 Ru]phen and [ 51 Cr]EDTA were dosed together into either the rumen or the terminal ileum, and the rates of decline of marker concentration in rumen samples or faeces respectively were used to calculate the appropriate half times( t ½). In the rumen particulate and fluid markers showed significantly shorter t ½ values with the 2 mm hay (20·8 and 12·4 h, respectively) than with the chopped hay (25·9 and 15·6 h, respectively) without a significant difference in rumen outflow (0·437 and 0·492 l/h, respectively). In the caecum-colon the corresponding t ½ values were 6·4 and 6·3 h, and 7·1 and 6·6 h, there being no significant difference either between markers or between diets. Samples of chopped hay and of 20, 5 and 2 mm hays were suspended in bags in the rumen of sheep given either chopped or 2 mm hay to eat. The fine hays lost D.M. more rapidly than the coarse hays but D.M. loss was slower when the sheeps diet was 2 mm hay that when it was chopped hay. It is concluded that three factors accounted for the effect of milling on digestibility: retention time in the reticulo-rumen, D.M. degradation rate in the rumen, and the potential digestibility of the hay preparation (asymptotic D.M. loss as measured in the rumen bag studies). It appeared that fine grinding reduced the digestibility of the hay because the effects of shortened MRT in reducing duration of digestion and of lowered rumen pH in depressing cellulolysis outweighed the effects of grinding in accelerating digestion and increasing potential digestibility within the rumen.

Observation on cattle liveweight changes and fecal indices in Sudan.

SUMMARY The suitability of stained food and [ 103 Ru]phenanthroline-treated food as markers for measuring dietary retention time was examined in sheep. The digestibility of oat husk, assessed by incubation of samples contained in nylon bags in the rumen, was greatly depressed by staining with brilliant green, and slightly depressed by basic fuschsin. The latter effect appeared largely to be due to boiling rather than the stain itself. When milled hay treated with both basic fuschsin and [ 103 Ru]phenanthroline was introduced into the rumen, the mean retention time estimated with the stain was about 40% longer than that estimated with [ 103 Ru]phenanthroline.

Investment options for integrating water-livestock-crop production in sub-Saharan Africa

Changes in liveweight of sedentary and migratory herds of cattle in south Kordofan Province, Sudan, were determined monthly. Feces of these animals were analyzed for N and ADF during the same period. Both the sedentary and the migratory herds gained iiveweighbts during periods August to September and November to February and lost iiveweight during October and f’rom March to July. Changes in iiveweights were more highiy related to fecai ADF concentrations (r = -0.6O,p<O.O02) than to fecal N concentrations (I q -0.085, p<0305).