Evaluation of forage feeding strategie with or without methionine hydroxy analog on growing heifers performance [electronic resource].

Includes references.

TwentY-four Holstein heifers with an average of age 9.28 ± 0.36 mo. and weight 194 ± 9.84 kg, were fed restricted intakes formulated to allow for 700 g/d (NRC. 1989). Diets were formulated to contain either 50: 50 (moderate forage) or 75: 25 (high forage) forage: concentrate ratio diets dry maler basis. Forage comprised of corn silage (CS) and constant amounts of Berseem hay (1.5 and 2 kg/h/d for moderate and high forage. respectively). Heifers were fed with or without Methionine Hydroxy Analog supplemen:ation (MHA. 2.1 g / day/IOO kg BW). Live body weigbt (LBW) was taken biweekly, wbile some body measurements and blood samples were taken monthly. Digestibility trial was performed at 370 kg RW. during the digestibility trial heifers were fed individually in tie-stall, rumen sample collected at the end of digestibility triaL. We observed that. DM. OM. CP. and NFE digestibility were significantly (P<O.05) improved by reducing the forage portion of the diet. hoverer CF and EE digestibility had a significant (P<0.05) opposite direction. While, supplementation of MHA resulted in trends toward increased DM digestibility. Ruminal TVFA were significantly higher in moderate forage groups. however, ruminal PH was higher in high forage groups, while MHA trend to decreased TVFA only.

Summary in Arabic.

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