title: Effects of forage ensiling and ration fermentation on total mixed ration pH, ruminal fermentation and performance of growing Holstein-Zebu cross steers.
abstract: Our objective was to determine the effect of forage ensiling and ration fermentation on total mixed ration pH, ruminal fermentation and animal performance. Thirty Holstein-Zebu cross steers were allotted to feeding treatments for 188 days in a randomized complete block design including: fresh grass-total mixed ration (GTMR; pH 4.7), grass silage-TMR (STMR; pH 4.0) and fermented-TMR (FTMR; pH 3.5). Average daily gain for STMR was greatest during the first 3 months period; however, that for FTMR tended to be greater than GTMR during the second 3 months period (P < 0.10). During the second period dry matter intake for STMR was the greatest (P < 0.01), but feed conversion ratio (P < 0.01) and cost per gain (P < 0.01) were the least for FTMR. Protein digestibility tended (P < 0.10) to be greater for FTMR than STMR and fat digestibility was greater (P < 0.05) for GTMR and FTMR than STMR. FTMR had less (P < 0.01) ruminal NH3-N content than STMR. Total volatile fatty acids post-feeding was greatest for GTMR (P < 0.01). Ruminal proportions of acetic and butyric acids were greater for FTMR than GTMR (P < 0.05); in contrast, propionic acid was greater for GTMR (P < 0.05). Utilizing silage or total ration fermentation did not negatively impact on ruminal pH. STMR and FTMRs can be used to maintain performance of growing crossbred Holstein steers.
authors.affiliation: Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Watcharawit
authors.initials: W
authors.lastname: Meenongyai
authors.affiliation: Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Virote
authors.initials: V
authors.lastname: Pattarajinda
authors.affiliation: Department of Animal and Dairy Sciences, University of Georgia, Athens, GA, USA.
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Stelzleni
authors.affiliation: Department of Animal Production Technology, Faculty of Agricultural Technology, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand.
authors.forename: Jutarat
authors.initials: J
authors.lastname: Sethakul
authors.affiliation: Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Monchai
authors.initials: M
authors.lastname: Duangjinda
mesh_terms: D019342:Acetic Acid / Q000378:metabolism; D000818:Animals; D020148:Butyric Acid / Q000378:metabolism; D002417:Cattle / Q000254:growth & development* / Q000378:metabolism*; D004032:Diet / Q000662:veterinary*; D004044:Dietary Proteins / Q000378:metabolism; D004063:Digestion / Q000502:physiology; D005285:Fermentation / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D008297:Male; D009584:Nitrogen / Q000378:metabolism; D006109:Poaceae; D012417:Rumen / Q000378:metabolism*; D012820:Silage; D013997:Time Factors; D015430:Weight Gain
chemical_list: D004044:Dietary Proteins; D020148:Butyric Acid; D009584:Nitrogen; D019342:Acetic Acid
keywords: VFA profiles; feed digestion; feedlot; fermented TMR