Studies on the Nutritive Values of Some Common Sudanese Fodder Crops Using Different Assessment Methods

Abstract

An evaluation of the nutritive value of four Sudanese green forages, two legumes (berseem and lubia) and two cereal forages (Abu 70 and maize) was carried out. The study was conducted in a series of experiments namely dry matter intake, digestibility and nitrogen retention, degradability, rumen study (pH, ammonia and TVFA) and gas production test from which microbial protein synthesis was estimated. Twelve entire males of the Sudan desert sheep, between 27-39 kg average body weights were used to study the dry matter intake and digestibility. The dry matter intake of legumes was higher (1.312 kg/d and 1.041 kg/d for lubia and berseem, respectively) and the lowest was of maize and Abu 70 (0.429 kg/d and 0.977 kg/d). Dry matter intake as a percentage of body weight was 2.5% - 3.6% for legumes and 1.5% for cereal forage and the difference between forages was significant (P<0.00l). In spite of the highly significance difference between feeds, there was no serious change in metabolic body weight or in mean live weight. There was a significant difference (P<0.001) between legumes and cereal forages in digestibility of dry matter, organic matter and nitrogen. There was a significant difference (P<0.001) in nitrogen balance intake. The highest value (2.13 g N/d) was for Abu 70 and the lowest value (-17.77 gN/d) was found for maize. A study was conducted in two fistulated calves to investigate the characteristics of forages. Legume forages showed higher degradation compared to the cereal forages. Maize forages showed lower degradation characteristics of both dry matter and nitrogen. Rumen study showed higher values of TFVA of legume forages than cereal forages and approximately the same pH values. The same was true for ammonia N level. Estimated microbial nitrogen yield (RDN) using the new factors calculated from gas production test and in situ degradability experiment showed higher values (62.56, 35.71, 2.36 and 0.33 g N/d) than the RDN estimated from ARC adopted factors (15.28, 11.26, 10.56 and 3.64 g/N /d) for lubia, berseem, Abu 70 and maize, respectively