PREDICTION THE NUTRITIVE VALUE OF PRICKLY PEAR PEELS AS A NATURAL UNCONVENTIONAL FEED RESOURCE FOR FEEDING RUMINANTS FROM CHEMICAL COMPOSITION AND IN VITRO DIGESTIBILITY USING DAISY II INCUBATOR

Prickly pear peels (PPPs) was evaluated for their chemical and nutritional composition as a natural feed resource for feeding ruminants in two experiments. Each experiment consisted of three rations.  Concentrate feed mixture (CFM), berseem hay (BH), rice straw (RS) and PPPs were used for formulating the experimental rations (60% concentrate + 40% roughage). In the first experiment 25% or 50% of RS were replaced by PPPs. In the second experiment, the inclusion rates of PPPs were instead of 25% or 50% BH. Chemical composition and in vitro digestibility using DAISY II incubator were used for nutritive value prediction. The results indicated that PPPs had lower contents of CP (5.67%) and CF (10.63%) while; it had higher values of NFE (69.59%) and NSC (66.56%) when compared with other ingredients used. Prickly pear peels had the lowest values of NDF (13.67%); ADF (10.20%), ADL (2.49%), hemicellulose (3.47%) and lignin (0.74%) when compared with other ingredients, but had higher NDF- cell soluble (86.33%). The highest values of apparent dry matter digestibility (ADMD) and true dry matter digestibility (TDMD) were recorded with PPPs (90.22% and 91.46%), respectively when compared with other ingredients. The natural detergent fiber digestibility (NDFD) was higher than that in RS and CFM while, it is lower than that in BH. The prediction parameters of nutritive values from chemical analysis for TDN% and NEL, ME, NEM, NEG, and DE (Mcal /Lb of DM) of PPPs were significantly (p<0.05) higher than those of other ingredients and followed by CFM. The lowest values were recorded with BH and RS. Ration (3) in which PPPs replaced 50% of RS recorded the best values of NFE and NCF, but lowest values of ash and CF when compared with control ration and ration 25% RS with PPPs. Ration 3 had the lowest values of NDF, ADF, cellulose, hemicellulose and lignin, followed by ration (2). The highest values were recorded with control ration. The highest increase value of NDF-cell soluble (17.45%) was recorded with ration (3) while, the increase in ration (2) reached 9.21% when compared with control ration. The effect of inclusion different levels of PPPs instead of the same levels of RS showed significant (<0.05) increase of ADMD% with ration (3) followed by ration (2) while TDMD% was not significantly influenced by inclusion of PPPs. In the contrarily, the NDFD% was decreased. Ration (3) had the highest values of TDN%, DDM%, DMI%, NEL, ME, NEM, NEG, DE (Mcal /Lb. of DM) and GE (MJ/Kg DM) while control ration recorded the lowest values. The highest feed cost and price of TDN unit were recorded for the control ration. The highest decreasing price of TDN unit (9.09%) was obtained by ration (3). Inclusion of PPPs instead of BH decreased CP%, EE%, CF% and fiber fraction % of rations 5 and 6, while NFE%, NSC% and NDF-cell soluble % were increased. Concerning, DM digestibility determination, the highest value of TDMD% was obtained with ration 6 followed by ration 5. The predicted energy values were higher with ration 6 while it recorded the lowest value of GE. This ration also recorded the highest feeding values. Replacing PPPs instead of BH up to 50% decreased the price of TDN unit by about 13.33%. Information provided by our work introduce a package of two types of rations containing different levels of PPPs which could be used successfully, economically and nutritionally as a good unconventional ration for feeding ruminants in different purpose of production and could reduce waste disposal problems, further investigation on PPPs and its utilization as a raw material in feeding ruminants is needed.