title: Composition of formaldehyde- and formic acid-treated alfalfa and orchardgrass silages harvested at two maturities and their effects on intake and growth by Holstein heifers.
abstract: Alfalfa and orchardgrass herbages were each harvested at two maturities (May 22 to 25 vs June 5 to 7) in primary growth and directly ensiled with 5 kg of a mixture of 30% formic acid and 25% formaldehyde per metric ton of fresh herbage in upright conventional silos. Alfalfa silage contained less NDF (71%) and more N (150%) and hot-water-insoluble N (117%) than orchardgrass silage did. Major differences between silages were that orchardgrass contained 20.4 percentage units more NDF and 1.10 percentage units less N than alfalfa. The NDF increased 104% and total N decreased to 86% with advancing maturity. Twenty-eight yearling Holstein heifers (223 kg BW) were given ad libitum access to the four silages with trace mineral salt, and growth rate was measured in a 119-d period. Daily DE intake was 297 kcal/kg.75 BW for heifers fed alfalfa silage compared with 202 kcal/kg.75 BW for heifers fed orchardgrass silage. Daily gain was 992 g for heifers fed alfalfa compared with 661 g for heifers fed orchardgrass. Gross efficiency, or gain per unit of DE, was similar for heifers fed orchardgrass and alfalfa. Rate of gain was primarily a function of ad libitum intake of DE. Heifers fed alfalfa had greater plasma essential amino acid concentrations (122%) than those fed orchardgrass did. Late alfalfa produced greater ADG than orchardgrass harvested 2 wk earlier.
authors.affiliation: Ruminant Nutr. Lab., Livest, U.S. Department of Agriculture, Beltsville, MD 20705.
authors.forename: H K
authors.initials: HK
authors.lastname: Goering
authors.forename: D R
authors.initials: DR
authors.lastname: Waldo
authors.forename: H F
authors.initials: HF
authors.lastname: Tyrrell
authors.forename: D J
authors.initials: DJ
authors.lastname: Thomson
mesh_terms: D000596:Amino Acids / Q000097:blood; D000818:Animals; D002417:Cattle / Q000254:growth & development* / Q000502:physiology; D004043:Dietary Fiber / Q000032:analysis; D004435:Eating; D004734:Energy Metabolism; D005260:Female; D005557:Formaldehyde / Q000494:pharmacology*; D005561:Formates / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D000455:Medicago sativa; D009584:Nitrogen / Q000032:analysis; D006109:Poaceae; D012820:Silage / Q000032:analysis*; D015430:Weight Gain
chemical_list: D000596:Amino Acids; D004043:Dietary Fiber; D005561:Formates; C030544:formic acid; D005557:Formaldehyde; D009584:Nitrogen