Azzawi Dates (Phoenix dactylifera) as a Substitute for Corn as an Energy Source in Sheep Diet: In vitro Gas Production and Fermentation

In vitro gas production technique was used in the current study to evaluate Azzawi date (AD) as a substitute for corn grain (CG). The AD was used to replace corn grain at graded levels in the proportion: 0:100 (CG), 25:75 (AD25), 50:50 (AD50), 75:25 (AD75), and 100:0 (AD100). Gas production (GP) was continuously measured by incubating samples in buffered rumen fluid from cannulated sheep and it was recorded at 3, 6, 9, 12, 24, 48 and 72h of incubation. Cumulative GP, kinetics of GP (a, b and c), ammonia nitrogen (NH3-N) and volatile fatty acids (VFA) concentrations were determined, while metabolizable energy (ME), net energy (NE), organic matter digestibility (OMD), microbial protein (MP) were estimated. The gas volume was increased (P<0.05) at 12h with increasing the substitution levels of AD in the feed, the values ranged between 31.3 and 44.7 ml/200 mg DM. However, it was found to be decreased (P<0.05) at 48 and 72h with increasing substitution levels of AD. There were no differences in the gas production found at 24h. Data of VFA, NE, OMD and MP were similar (P>0.05) among the feeds. The energy (ME; MJ/kg DM) value of AD25 (10.4) and AD50 (10.3) were comparable to that of CG (10.5); however it was reduced (P<0.05) with AD75 and AD100. Data demonstrated that, Azzawi date at the level of 50 g/100g of substrate (i.e., AD50) may have similar energy contents as of corn grain, and it can be used as a source of energy in ruminant diets either alone or in combination with corn grain

Effects of urea supplementation on nutrient digestibility, nitrogen utilisation and rumen fermentation in sheep fed diets containing dates

Summary: The aim of the study was to determine the influence of increasing levels of urea (i.e., 0 (U0); 10 (U10); and 15 (U15) g kg–1 of concentrate) in sheep fed diets containing dates (local name: Azzawi), on nutrient intake and digestibility, N utilisation and ruminal fermentation. To maintain iso-nitrogenous and iso-metabolisable energy diets, the dates were added with increasing levels of urea. Sheep were fed a 400:600 (dry matter (DM) basis) concentrate:berseem hay (Trifolium alexandrinum) diet. Twelve Barki sheep (53.871.95 kg body weight) with three/diet were used in a randomised block design to determine digestibility and N balance, while four ruminally cannulated Barki sheep (56.672.15 kg body weight) were used in a 3 3 Latin square design to determine rumen function. Experimental periods were 22 days with the first 15 days for adaptation. The calculated metabolisable energy (MJ kg–1 DM) and actual crude protein (CP; g kg–1 DM) contents were 12.17 and 156.1, 12.69 and 158.2 and 12.60 and 154.8, for the U0, U10 and U15 diets, respectively. Increased urea feeding increased (Po0.05) digestibility of DM, organic matter (OM) and CP. Rumen ammonia N concentrations, allantoin in urine and the resultant microbial N supply increased linearly (Po0.05), as did the total ruminal volatile fatty acid concentrations. Results suggest that urea supplementation to sheep diets containing dates improved DM, OM and CP digestibility and substantially increased rumen microbial growth as well as ruminal fermentation function