Nutritional Evaluation of Three Local Barley Varieties and the Impact of Dietary Enzyme on their Apparent Metabolizable Energy
2006
George W. Barbour | Mohamad T. Farran | Nada N. Usayran | Ali H. Darwish | Hasan H. Machlab | Milan Hruby | Michel G. Uwayjan | Vahé M. Ashkarian
Two experiments were conducted to determine the true metabolizable energy corrected to zero nitrogen balance (TMEn) and true amino acid availability (TAAA) of three local barley varieties, two-row Litani (L2), two-row Pamir-35 (P2), and six-row Rihan-03 (R6) and to study the effect of enzyme supplementation on their apparent metabolizable energy corrected to zero nitrogen balance (AMEn). Forty grams of glucose, corn, or barley variety grains was precision intubated to eight individually caged Babcock B 380 roosters. The TMEn of L2, P2, and R6 (3224, 3419, and 3253kcal/kg, on dry matter basis (DM), respectively) was lower than that of corn (P<0.05). All the TAAA values in P2 and that of methionine, cystine, lysine, threonine, proline, and valine in L2 and R6 were comparable with that of corn. Again, compared to corn, all other TAAA values in L2 and R6 were significantly lower, except for serine, glutamic acid, and isoleucine in R6. In the AMEn experiment, a reference diet containing 55% glucose and diets containing 50% corn or L2, P2, and R6 at the expense of glucose, supplemented with either 0 or 0.1% enzyme, were each fed in 4 replicates (cages) to 4 birds/cage for 4 d, during which total excreta were collected at 48 and 96 h. Enzyme supplementation resulted in an AMEn improvement of 4.33, 11.5, and 17.2% for L2, P2, and R6, respectively with an average AMEn of 3243kcal/kg DM. In conclusion, TAAA in P2 was similar to corn whereas that of some amino acids such as arginine and leucine were lower in L2 and R6. Enzyme supplementation to barley diets resulted in an average AMEn improvement of 11%. The current findings can assist and encourage poultry producers in formulating least cost rations containing local barley varieties.
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